Improvement of Step Tracking Algorithm Used for Mobile Receiver System via Satellite

In the mobile communication via satellite, received systems are mounted on the mobile device such as ship, train, car or airplane. In order to receive continuous signals, received antenna system must be steered in both the azimuthal and elevation angle to track a satellite. This paper proposes the improved step-tracking algorithm using for mobile receiver system via satellite Vinasat I. This paper also presents the results of study, design and manufacture of the discrete-time controller system for the fast tracking of a satellite by applying an improved step tracking algorithm with fuzzy proportional integral derivative proportional integral derivative controller. Simulated and experimental results indicate that the system performances obtain from applying the improved step tracking algorithm and the fuzzy controller was better than traditional control systems

Magnetophonon Resonance in Quantum Wells with Parabolic Potential

The linear dc magnetoconductivity in the$(x,y)$ plane of a parabolic quantum well, with a magnetic field$\vec B = B\vec e_z$ applied, is evaluated for electron - opticalphonon interaction. For nonpolar optical and polar optical phonons,the magneto-conductivity oscillates as a function of the magneticfield with resonances occurring when $P\omega_c=\omega_0$, where$\omega_c$ and $\omega_0$ are cyclotron frequency and optical phononfrequency, respectively, and where $P$ is an integer. The analyticresults are numerically evaluated to show explicitly the dependenceof magneto-conductivity on the magnetic field, the confinementfrequency in $z$ direction, and the temperature of the system

Evaluation of genetic diversity and DNA fingerprinting of 19 standard reference rice varieties using SSR markers

Molecular markers are advanced-tools for identifying new varieties at DNA levels. According to the International Union for the Protection of New Varieties ofPlants,  new breeded varieties need to be tested for the Distinctness, Uniformity and Stability (DUS), before being recognized as the new ones. Traditional DUS criteria based on 62 - 65 morphological and biochemical characteristics, which evaluated on comparison of new varieties with 19 standard reference varieties for traits of interest.  Study on the genotypic polymorphism of 19 standard reference rice varieties provides genotypic information of these varieties for the evaluation of new rice varieties based on genotyping analysis.  The reference marker set (30 markers) was used to evaluate the genetic diversity and DNA fingerprinting of 19 standard reference rice varieties. The results showed the similarity coefficient of 19 varieties varied from 0.04 to 0.548. At the genetic similarity coefficient of 0.1, the 19 rice varieties divided into two main groups. Group one included 3 varieties: DH1, DH5, DH13. Group 2 included the remaining 16 varieties. Inside group two, phylogenetic tree divided into two main branches at the genetic similarity coefficient of 0.3. Branch 1 includes 5 varieties including DH2, DH6, DH10, DH11 and DH7. The 11 remaining varieties were in the branch 2. The most closely varieties were DH6 and DH10 with the genetic similarity coefficient of 0.548. This study shows that, the standard reference varieties have high uniformity and high genotypic polymorphism, could used for testing new varieties based on genotyping by DNA fingerprinting combining with phenotype

Identification and sequence analysis of a dreb subfamily transcription factor involved in drought stress tolerance from rice

DRE (dehydration responsive element)/CRT (C-repeat) is a cis-acting element that involves in gene expression responsive to abiotic stress in higher plants. To date, all well known DREBP transcription factors in Arabidopsis, rice, maize and other plants regulate gene expression in response to drought, high-salt and cold stresses by binding specifically to DRE/CRT. Using a target sequence of 50 nucleotides on Glutamate dehydrogenase-like protein (JRC2606) promoter containing the core sequence of DRE cis-acting element (A/GCCGAC) for yeast one-hybrid screening, we have identified two transcription factors:  a completely homology of OsRAP2.4A gene and another is a new sequence. The new sequence contained an ORF (Open Reading Frame) of 1017-bp and 5’ non-coding area of 35-bp and 3’ non-coding area of 341-bp. The deduced amino acid sequence contains an AP2 domain and belongs to  the subgroup  A6  of DREB subfamily, temporarily named OsRAP2.4B. Sequence alignment showed that OsRap2.4B had homology with ZmDBF, a maize transcription factor involved in drought stress tolerance

Design of a Front-End for Satellite Receiver

This paper focuses on the design and implementation of a front-end for a Vinasat satellite receiver with auto-searching mechanism and auto-tracking satellite. The front-end consists of a C-band low-noise block down-converter and a L-band receiver. The receiver is designed to meet the requirements about wide-band, high sensitivity, large dynamic range, low noise figure. To reduce noise figure and increase bandwidth, the C-band low-noise amplifier is designed using T-type of matching network with negative feedback and the L-band LNA is designed using cascoded techniques. The local oscillator uses a voltage controlled oscillator combine phase locked loop to reduce the phase noise and select channels. The front-end has successfully been designed and fabricated with parameters: Input frequency is C-band; sensitivity is greater than -130 dBm for C-band receiver and is greater than -110dBm for L-band receiver; output signals are AM/FM demodulation, I/Q demodulation, baseband signals

Composición de los aceites esenciales de Euodia lepta (Spreng.) Merr y Euodia calophylla Guill., crecidas en Vietnam

La composición químicas de los aceites esenciales obtenidos por hidrodestilación de las hojas, tallos y flores de Euodia lepta y Euodia callophylla cultivadas en Vietnam, fueron analizados por cromatografía de gases-detector de ionización de llama (GC-FID) y la cromatografía de gases/espectrometría de masas (GC-MS). Los principales compuestos del aceite de hojas de E. lepta fueron (E) -β-ocimeno (24,4%), α-pineno (9,8%), (Z)-β- ocimeno (6,3%) y δ-cadineno (5.2%), mientras que los tallos de aceite estaban compuestos de spatulenol (26,0%), (E) -β-ocimeno (9,9%) y (Z) -9- octadecenamida (7,7%). Sin embargo, cis-carano (19,2%), α-cadinol (10,8%), α-pineno (10,5%) y (E) -β-ocimeno (9,0%) estaban presentes en el aceite de flores de E. lepta. Por otro lado, α-pineno (8,3%), trans-α-bergamoteno (7,5%), (E) - β-ocimeno (7,0%) y (E) -nerolidol (6,6%) fueron los principales constituyentes del aceite de las hojas de E. calophylla. Los compuestos cuantitativamente significativos del aceite de los tallos fueron (E, E)-farneseno -α (11,9%), α-terpinoleno (11,3%) y α-pineno (8,2%), mientras que α-pineno (21,6%), limoneno (19,0%) y sabineno (15,5%) se obtuvieron del aceite de las flore

Credit composition and income inequality in Vietnam: an empirical analysis

Purpose This paper examines credit composition and income inequality reduction in Vietnam. In particular, the authors focus on the distinction between policy and commercial credits and investigate whether these two types of credit adversely affect on income inequality. The authors also examine whether the educational level and institutional quality condition the impact of policy credit on income inequality. Design/methodology/approach The authors use the primary data set, which contains a panel of 60 provinces collected from the General Statistics Office of Vietnam from 2002 to 2016. The authors employ the generalized method of moments to solve the endogenous problem. Findings The authors show that while commercial credit increases income inequality, policy credit reduces income inequality in Vietnam. In addition, we provide evidence that the institutional quality and educational level condition the impact of policy credit on income inequality. Based on the findings, the paper implies that it was not the size of the private credit but its composition that mattered in reducing income inequality due to the asymmetric effects of different types of credit. Practical implication The government should focus on credit for the poor by helping them to exit poverty through investing in human capital, health and micro enterprises activities. Originality/value This is the first study that examines the links between the two components of credit and income inequality as well as the constraints of the links. The authors argue that analyzing the separate effects of commercial and policy credits is more important for explaining the role of credit in income inequality than the size of total credit

CAMELLIA HOABINHENSIS (THEACEAE: SECT. CHRYSANTHA), A NEW YELLOW-FLOWERED SPECIES FROM NORTHERN VIETNAM

A new species, Camellia hoabinhensis (section Chrysantha, Theaceae), is described and illustrated based on specimens collected from a lowland forest on limestone hills in Hoa Binh Province, northern Vietnam. The species is characterized by its small habit to 4.5 m tall, large flowers 9.0–9.5 cm in diameter with 18–19 light yellow petals, and hairy filaments, ovaries, and styles. A comparison of the new species with similar species, C. euphlebia, C. impressinervis, C. phanii, and C. velutina, is provided. The IUCN conservation status of the proposed species is Data Deficient (DD)

ZnO/CdS Bilayer used for Electrode in Photovoltaic Device

In this article we present the fabrication and characterization of the nanoporous ZnO and/or ZnO/CdS thin films onto indium doped-tin oxide (ITO) substrates, based on the thermal evaporation technique followed by thermal treatment. The preparation method was relatively simple and low-cost for large scale uniform coating to produce clean, dense and strong adhesion to substrate thin films. The nanostructured ZnO and ZnO/CdS thin films were characterized by X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM). The nanostructured ZnO/CdS bilayer film was used in a photo-electrochemical (PEC) cell as a working electrode and a Pt net as a counter electrode. The results show that the photovoltaic cell with nanostructured ZnO/CdS bilayer film electrode has significantly improved photoelectric capability in comparison with that of ZnO electrode

RECOVERY OF POLY(3-HYDROXYBUTYRATE) FROM Yangia sp. ND199 BY SIMPLE DIGESTION WITH SODIUM HYPOCHLORITE

Polyhydroxyalkanoate (PHA) is a biodegradable polymer synthesized intracellularly by many microorganisms. After extraction from the cells, they possess the common features of non-toxic, biocompatible, biodegradable and recyclable. These features render them highly competitive with polypropylene or other petroleum-derived plastics, especially in medicine. The isolation and purification of PHA from bacterial cells are the key step of PHA production process. There are several methods have been used for OHA purification, these include solvent extraction, enzymatic hydrolysis, and chemical digestion. In this study we used chemical digestion method for purification of PHB from Yangia sp. ND199. Among various chemical tested (NaOH, HCl, KOH, NaOCl, and SDS), NaOCl was found as an efficient chemical for PHB recovery and PHB purity from Yangia sp. ND199. The optimal purity and recovery conditions were a ratio of 1:1 (v/v, solution containing 100 g/l bacterial cells and solution containing 6% NaOCl), a 30 oC temperature and a 1 h treatment time. Under such conditions, a purity of 99% and a recovery of 94% were obtained. This method is sumple and can be developed and used for industrial scale