bluuebunny/crossref_metadata_2025_split huggingface dataset:
{Demonstrate the Double Negative Behavior of Metamaterial Using the Effective Medium Theory
Authors: Tung Nguyen Thanh , Hoai Pham Van , Binh Nguyen Trung , Hong Le Van , Lam Vu Dinh , Lee Y. P. 
Published: September 2014

We fabricated the electric and magnetic metamaterial, and measured their transmission spectra. The electromagnetic response of the combined structure, which consists of cut-wire pair and continuous wire, are experimentally and numerically studied in the microwave frequency regime. The simulations are performed in a qualitative agreement with experiment utilizing the transfer-matrix method. The double negative behavior of combined structure is observed and demonstrated using the effective medium theory.
Monte-Carlo Determination of Dose Rates In Spherical Pressurized Water Reactor Shield
Authors: Ngoc Le Van , Ha Trinh Dang 
Published: September 2014

The nuclear reactor emits various kinds of nuclear radiations during operation. However, the main contributions to the radiation field in the reactor are given by neutrons and gamma rays. These radiation components are the principal concern of reactor shielding. In our study the neutron and gamma radiation dose rates at different depths in concrete bio-shield of the PWR were calculated based on spherical model for M-C simulation with using MCNP4C2. The simulation results were compared with the results obtained from calculations based on S$_{8}$P$_{3}$ spherical approximation with using the ANISN code.
Inhomogeneous Cosmological Models in Bimetric Theory of Gravitation
Authors: Tripathy S. K. , Behera D. , Sahoo P. K. 
Published: September 2014

Plane symmetric inhomogeneous cosmological models for perfect fluid distribution are investigated in the frame work of Rosen's bimetric theory of gravitation. A negative pressure corresponding to false vacuum state is considered. Some of the physical and kinematical properties of the models are discussed.
An Aquaculture Water Checker--design and Manufacture
Authors: Anh Nguyen Tuan , Cu Dang Xuan , Bao Phung Quoc , Phi Vu Anh , Duong Bach Gia 
Published: September 2014

A real-time, mobile aquaculture water checker is presented. The configuration of double integrating spheres is developed for simultaneously measuring backward scattering $R_d$, forward scattering $T_d$ and transmitted light $T_c $. Based on Kubelka-Munk model, a set of optical parameters including absorption coefficient $\mu _a $, scattering coefficient $\mu_s$ and anisotropy $g$ are calculated. The obtained results for diluted milk standard samples with different milk concentrations and aquaculture water samples with different densities of Psexdo-Nitzschia-delicatissium algae are also reported.
Intensity Distribution of the 3<SUP>1</SUP>P¬1<SUP>1</SUP>S<SUP>+</SUP> Band System of NaLi
Authors: Sau Vu Ngoc , Khoa Dinh Xuan , Bang Nguyen Huy 
Published: September 2014

In the framework of adiabatic approximation we perform numerical calculations of intensity distribution for the 31P¬11S+ band system of NaLi based on the Franck-Condon (FC) principle. In addition, the internuclear distances at which the most favorable transitions occurred are predicted. Comparing the calculated FC factors and the corresponding spectral lines observed recently reveals a good agreement, particularly, at node of envelop of the FC factors. Some local deviations in spectral intensity between the calculated results and experimental data indicate local perturbations in the 31P state. This result requires further investigations in details.
Mobility Enhancement in Square Quantum Wells: Symmetric Modulation of the Envelop Wave Function
Authors: Quang Doan Nhat , Tung Nguyen Huyen , Hong Nguyen Trung , Hai Tran Thi 
Published: September 2014

We present a theoretical study of the effects from symmetric modulation of the envelop wave function on quantum transport in square quantum wells (QWs). Within the variational approach we obtain analytic expressions for the carrier distribution and their scattering in symmetric two-side doped square QWs. Roughness-induced scattering are found significantly weaker than those in the asymmetric one-side doped counterpart. Thus, we propose symmetric modulation of the wave function as an efficient method for enhancement of the roughness-limited QW mobility. Our theory is able to well reproduce the recent experimental data about low-temperature transport of electrons and holes in two-side doped square QWs, e.g., the mobility dependence on the channel width, which have not been explained so far.
Search for High Energy Skimming Neutrinos at a Surface Detector Array
Authors: Thuan Vo Van , Khanh Hoang Van , Diep Pham Ngoc 
Published: September 2014

In the present study we propose a new method for detectionof high energy cosmological muon neutrinos by transition radiations at amedium interface. The emerging electro-magnetic radiations induced by earth-skimming heavy charged leptons are able to trigger a few of aligned neighboringlocal water Cherenkov stations at a surface detector array similar tothe Pierre Auger Observatory. The estimation applied tothe model of Gamma Ray Burst induced neutrino fluxes and the spherical earth surface shows a competitive rate of muonneutrino events in the energy range below the GZK cut-off.
Preliminary results on prompt \(\Xi^+/\Xi^-\) production ratio in pp collisions at\(\sqrt{s} = 7\) TeV
Authors: Chung Nguyen Mau , Dung Nguyen Thi , Tam Tran Minh 
Published: September 2014

The ratio of prompt \(\Xi^+/\Xi^-\) production has been investigated from a limitedsample of data registered by the LHCb experiment at the CERN Large Hadron Colliderin 2010. This ratio has been determined in the rapidity region \(1.9 \leq y \leq 4.9\) covered bythe LHCb detector. The determination of anti-hyperons to hyperons production ratio willallow to study the transport of baryon number from \(pp\) collisions to final state hadrons andto constrain and tune Monte Carlo models.
Determination of GT-transition Strengths in \(A=34\) Isobars Using Charge Exchange \((^3\text{He},t)\) Reaction
Authors: Khai Nguyen Tuan , Linh Bui Duy , Thiep Tran Duc , Fujita Y. , Adachi T , Fujita H. , Tamii A. 
Published: September 2014

Under the assumption that isospin \(T\) is a good quantum number, mirror transitions \(T_{z }= +1 \to 0\) and \(T_{z }= -1 \to 0\) were studied in \(A = 34\) isobars, where \(T_{z}\) is \(z\) component of iospin \(T\) and is defined by \(T_{z} = (N-Z)/2\). With a high energy resolution of 35 keV in \(^{34}\)S\((^{3}He,t)^{34}\)Cl reaction measurement at \(0^{\circ}\) scattering angle and at an incident energy of 140 MeV/nucleon, strengths of Fermi and Gamow-Teller (GT) transitions from the \(J^{\pi } = 0^{ + }\), \(T_{z }= +1\) ground state of \(^{34}\)S to the \(J^{\pi } = 1^{+ }\), \(T_{z }= 0\) excited states in \(^{34}\)Cl were determined up to excitation energy \((E_{x})\) of \(7.08\) MeV. The corresponding isospin-symmetric transitions connecting \(T_{z }= -1\) and \(T_{z }= 0\) states can be studied in the \(^{34}\)Ar \(\beta ^{ + }\) decay. The strengths of the \((GT)_{\pm }\) transitions were compared up to the excitation energy of 3.1 MeV. A good agreement was observed for two strong transitions to \(2.580\) MeV and \(3.129\) MeV states, while a disagreement about \(45\text{%}\) was observed for a weaker transition to \(0.666\) MeV low-lying state.
A Feasibility Study in Application of a Gamma Scattering Technique for Inspecting Density Variation by Monte Carlo Method
Authors: Khiem Le Hong , Trong Tran Dinh , Thao Nguyen Van 
Published: September 2014

Back-scattering gamma-rays have been extensively used for years as a nondestructive tool for inspecting the materials in different fields of the economy. The intensities of Compton scattering gamma-rays from the scattering medium strongly depend on its electron density and therefore in its mass density. This feature is very useful for using it as a viable tool for inspecting material. This work aims to investigate the feasibility of application of gamma scattering technique for inspecting density variation in some construction objects by Monte-Carlo simulation method. The gamma-ray sources of different energies and strengths have been used to extract the information of density variation for interior of sample by recording the backscattering gamma-rays with a gamma-ray detector. The results of our simulations confirm that the resolution for density variation in the inspected objects is quite good. The results should also prove useful in the optimum design of the nondestructive density gauges.
Synthesis and Photoluminescent Property of \(\text{MgO:Cr}^{3+}\) Powders
Authors: Loan Trinh Thi , Long Nguyen Ngoc , Cuong Le Hung 
Published: September 2014

MgO:Cr3+ powders with different dopant contents have been synthesized by sol-gel method using the following precursors: magnesium nitrate (Mg(NO3)2), chrome nitrate (Cr(NO\(_3\))\(_3\)), and citric acid. The effect of the Cr\(^{3+}\) concentration and heat-treating temperature on structural and optical properties of the synthesized samples has been studied. For the samples with the low Cr3+-dopant concentrations or low heat-treating temperature, the photoluminescent (PL) spectra consist of sharp lines assigned to the \(^2\)E \(\to\) \(^4\)A\(_2\) transition of ions Cr3+ in perfect octahedral symmetry sites. But for the samples with the high Cr\(^{3+}\)-dopant concentrations and undergone high heat-treating temperature, the PL spectra appear a broad emission bands, which is assigned to the \(^4\)T\(_1\to ^4\)A\(_2\) transitions within the Cr\(^{3+}\) ions in the MgO orthorhombic symmetry crystal field.
Density Functional Based Tight Binding Study on Wurzite ZnS Nanowires
Authors: Lien Le Thi Hong , Tuoc Vu Ngoc , Thuong Nguyen Thi 
Published: September 2014

We present a semi-abinitio - Density Functional Based Tight Binding (DFTB) study on the atomic and electronic structure of ZnS Nanowire (NW) and examine the dependence of surface stress on nanowire lateral size and shape. The ZnS wurtzite wire size ranges from 10 to 45Å and of various possible shapes - triangular, hexagonal and circular-like. We investigate the role of unsaturated dangling bond state in the region of band gap varying the wire's diameter. We have calculated the surface formation energy and find that it decreases with increasing the wire diameter and a greater stability (lower surface formation energy) comes with hexagonal and circular-like depending on wire's diameter. Other electronics and mechanical properties e.g. density of states (DOS), Young modulus... also are found to depend on the wire's size and shape. Futher the wire passivation by hydrogen has also investigated.
Influence of Reaction Temperature on Optical Property of Mn-Doped ZnS Nanoparticles
Authors: Van Bui Hong , Ben Pham Van , Nhat Hoang Nam 
Published: September 2014

The reaction temperature has essential effect on quality of the product synthesized by hydrothermal method. We report here the variation of the optical characteristics of Mn-doped ZnS nanocrystallites prepared by mean of the stated method from Zn(CH$_{3}$COO)$_{2}$.2H$_{2}$O, Mn(CH$_{3}$COO)$_{2}$.4H$_{2}$O and Na$_{2}$S$_{2}$O$_{3}$.5H$_{2}$O as the precursors. The reaction temperature was set to vary from 120\r{}C to 240\r{}C at a constant reaction time of 15 hours. The XRD patterns showed that, for the reaction temperature range from 120 to 160\r{}C, the obtained products possessed a cubic $T_d^2 - F\overline 4 3m$ and a wurtzite $C_{6v}^4 - P6_3 mc$structure, in which the cubic phase was dominant. At the temperature range from 180 to 240\r{}C, the structures exhibited a cubic phase with the lattice constant increased from 5.41 to 5.43 {\AA}. The photoluminescence spectra showed that with the increase of reaction temperature from 120 to 240\r{}C the intensity of a blue band around 425 - 500 nm (attributed to both Zn, S vacancies) gradually decreased while the intensity of a yellow-orange band at 585 nm (attributed to the $^{4}$T$_{1}(^{4}$G) - $^{6}$A$_{1}(^{6}$S) transition of Mn$^{2 + }$ ions) was enhanced and reached maximum at 220\r{}C. The excitation spectra of the 585 nm band recorded at 160\r{}C showed a band at 335 nm which should be assigned to the near band-edge absorption. With increasing temperature to 200-240\r{}C the new bands appeared at 390, 430, 467, 494 nm. The intensity of these bands increased with temperature and achieved the maxima at 220\r{}C. They should be attributed to the absorption transitions of electrons from ground state $^{6}$A$_{1}(^{6}$S) to excited states$^{ 4}$E($^{4}$D); $^{4}$T$_{2}(^{4}$D); $^{4}$A$_{1}(^{4}$G) - $^{4}$E($^{4}$G); $^{4}$T$_{2}(^{4}$G) of Mn$^{2 + }$(3d$^{5})$ ions, respectively. The bands at 467, 494 nm only exposed clearly in the absorption spectra at 220\r{}C and 240\r{}C.
Ward-Takahashi Identity for Vertex Functions of \(\text{sQED}\)
Authors: Hung Ha Thanh , Hue Le Tho , Long Hoang Ngoc 
Published: September 2014

Ward-Takahashi identity is an useful tool for calculatingamplitude of scattering processes. In the high-order perturbative theory of sQED, propagator and vertex functions contain many high-order corrections. By using Ward-Takahashi identity, each vertex function is separated into two parts: ``longitudinal'' and ``transverse'' part. The longitudinal part can be directly calculated from Ward-Takahashi identity. The transverse part depends on the expanding of specific orders of the theory. In this report, we present one method based on the Ward-Takahashi identity, to calculate this part of vertex functions at the one-loop order in arbitrary gauge and dimensions in sQED.
Phenomenology of the Reduced Minimal 3-3-1 Model
Authors: Lam Tran Thanh , Thao Nguyen Chi , Tinh Ho Hoang , Xinh Nguyen Thi , Xuyen Nguyen Van , Long Hoang Ngoc 
Published: September 2014

The detailed analysis of the gauge model based on \(\mathrm{SU}(3)_C\otimes \mathrm{SU}(3)_L \otimes \mathrm{U}(1)_X\) group with minimal content of lepton and Higgs is presented. It is shown that with just two Higgs triplets, all fermions and gauge bosons can get correct masses. The advantage of the model under consideration is that a huge number of free parameters is reduced, and the model's predictiveness is much improved.
Uncorrelated electron-hole transition Energy in GaN│InGaN│GaN Spherical QDQW Nanoparticles
Authors: El Ghazi Haddou , Jorio Anouar , Zorkani Izeddine 
Published: September 2014

The electron (hole) energy and uncorrelated \(1S_e - 1S_{h}\) electron-hole transition in Core(GaN)| well(In\(_x\)Ga\(_{1 - x}\)N)| shell(GaN) spherical QDQW nanoparticles is investigated as a function of the inner and the outer radii. The calculations are performed within the framework of the effective-mass approximation and the finite parabolic potential confinement barrier in which two confined parameters are taking account. The Indium composition effect is also investigated. A critical value of the outer and the inner ratio is obtained which constitutes the turning point of two indium composition behaviors.
Fabrication and Magnetic Properties of \(\text{Nd}_2\text{Fe}_{14}\text{B/Fe}_{65}\text{Co}_{35}\) Hard Magnetic Ribbons
Authors: Truong Nguyen Xuan , Khanh Nguyen Van 
Published: September 2014

Nd\(_2\)Fe\(_{14}\)B/Fe\(_{65}\)Co\(_{35}\) hard magnetic ribbons were fabricated by melt-spinning technique using Nd\(_{16}\)Fe\(_{76}\)B\(_{8 }\) and Fe\(_{65}\)Co\(_{35}\) pre-alloys as starting materials. The results showed that the formation of the interactive hard/soft nanocomposite with the homogeneous distribution of the Fe-Co phase throughout the Nd\(_{2}\)Fe\(_{14}\)B matrix provided the Curie temperature (\(T_{c})\) as high as 747 K, the magnetic remanence (B\(_{r}\)) of 8.88 kG and the maximum energy product, (BH)\(_{\max}\), of 16.75 MG.Oe for the fabricated Nd\(_{2}\)Fe\(_{14}\)B/Fe\(_{65}\)Co\(_{35}\) ribbons at the optimal speed of 25 m/s. In addition, the intrinsic coercivity (\(_{i}\)H\(_{c}\)) of 9.27 kOe and remanence coercivity (\(_{b}\)H\(_{c}\)) of 6.94 kOe were found for these ribbons. The roles of the soft Fe\(_{65}\)Co\(_{35}\) phase in the increasing of \(T_{c}\), \(B_{r}\) as well as in the (00l) preferred crystallographic orientation of hard magnetic grains on the free surface side of the fabricated ribbons were also discussed.
On Yukawa Couplings in the Zee-Babu Model
Authors: Long Hoang Ngoc , Vien Vo Van 
Published: September 2014

The exact solution for neutrino mass matrix of the Zee-Babu modelis derived. The tribimaximal mixing imposes the conditions on the Yukawa couplings, from which the normal mass hierarchy ispreferred. The derived conditions give a possibility of maximal \(CP\) violation in the neutrino sector.
Folding of proteins in presculpted free energy landscape
Authors: Hung Nguyen Ba , Hoang Trinh Xuan 
Published: September 2014

Recent studies of the tube model of protein have indicated that the free energy landscape of proteins is presculpted by symmetry of the protein backbone and geometrical constraints played by the hydrogen bonds. In this study, we investigate the role of amino acid sequences in the folding of proteins. We consider two models that are differed by sequence specificity: the tube HP model with hydrophobic (H) and polar (P) sequences, and the tube Go model with native-centric contact potentials. Monte Carlo simulations are carried out for two sequences of length of 48 amino acids, whose ground states are a three-helix bundle and a GB1-like structure. The results show that folding inthe Go model is more cooperative than in the HP model. In the HP model the collapse transition and the folding transition are separated, whereas in the Go model the two transitions coincide.
Methane Emissions From Natural-Gas Systems: A Comparative Assessment for Select Industry Segments
Authors: Ritter K.. , Shires T.M.. M. , Lev-On M.. 
Published: September 2014

Summary
The recent rapid expansion of natural-gas developments and usage worldwide are bringing into focus the need to improve understanding and characterization of greenhouse-gas (GHG) emission sources, including methane (CH4), associated with petroleum and natural-gas systems. New production technologies and practices, including those involving hydraulic fracturing, necessitate a thorough review of existing quantification methods for fugitive CH4 emissions from venting, flaring, and equipment leaks associated with petroleum and natural-gas systems and operations.
In the past few years, widely divergent estimates have emerged regarding CH4 emissions from the US natural-gas-industry sector. Some discrepancies noted by industry surveys have led to a thorough review of newly available information and are leading to the improvement of estimation methods and emission factors associated with activities that comprise natural-gas systems. This has manifested itself in the engineering estimations that are used for compiling the national GHG Emissions Inventory and in the methods used by companies for reporting under the mandatory national GHG Reporting Program. Both the inventory and the reporting program are programs of the US Environmental Protection Agency (EPA).
This paper presents results of a comparative analysis of GHG-emissions data, including CH4, for key industry segments such as on-shore natural-gas production and natural-gas processing and their contribution to the Petroleum and Natural Gas Systems sector. The data analyzed will contrast the “top-down” assessments used in developing the GHG Emissions Inventory with the “bottom-up” estimation of actual emissions as reported under Subpart W of the GHG Reporting Program. The analysis will provide a comparison of the estimation methods and evaluation of the contribution of key sources with overall CH4 emissions.
The ultimate goal of this effort is to incorporate the new information that is becoming available into consistent methods that can be used both for national GHG inventory development and for corporate reporting. Harmonization of these methods is expected to contribute to informing the public debate on natural-gas use and its role in mitigating overall GHG emissions.
Characterization and outcome following excision of masses in the nictitating membranes of horses: 50 cases (1998–2012)
Authors: Scherrer Nicole M. , Lassaline-Utter Mary , McKenna Brianna C. 
Published: September 2014

Abstract
Objective—To determine the histologic findings associated with masses in the nictitating membranes (third eyelids) of horses and to identify prognostic factors associated with recurrence and the outcome.
Design—Retrospective case series.
Animals—50 horses with masses in a third eyelid.
Procedures—Medical records of horses with partial or complete excision of a third eyelid and submission for histologic evaluation between September 1998 and November 2012 were reviewed. Horses were included if follow-up information for at least 1 year after surgery was available. Information regarding signalment and treatment was obtained from the medical records. Histopathology reports were examined to determine surgical margins and vascular invasion. Data were analyzed by means of a χ2 test to determine the association between recurrence and type of excision (partial or complete), surgical margins, vascular invasion, and use of chemotherapy as well as the association between partial excision of a third eyelid prior to referral and outcome.
Results—Squamous cell carcinoma was the predominant tumor type of the third eyelid. There was recurrence in 10 of 50 (20%) horses; recurrence was at a mean of 2.25 years and median of 1.5 years after excision. Partial excision prior to referral was associated with outcome.
Conclusions and Clinical Relevance—In horses with masses in a third eyelid, recurrence and mortality rates were high, which suggested that long-term monitoring is important for all patients in which partial or complete third eyelid excision is performed.
Kalman Filter Realization for Orientation and Position Estimation on Dedicated Processor
Authors: Romaniuk Sławomir , Gosiewski Zdzisław 
Published: September 2014

Abstract
This paper presents Kalman filter design which has been programmed and evaluated in dedicated STM32 platform. The main aim of the work performed was to achieve proper estimation of attitude and position signals which could be further used in unmanned aeri-al vehicle autopilots. Inertial measurement unit and GPS receiver have been used as measurement devices in order to achieve needed raw sensor data. Results of Kalman filter estimation were recorded for signals measurements and compared with raw data. Position actualization frequency was increased from 1 Hz which is characteristic to GPS receivers, to values close to 50 Hz. Furthermore it is shown how Kalman filter deals with GPS accuracy decreases and magnetometer measurement noise.