bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling the single-mode thermally guiding very-large-mode-area Yb-doped fiber amplifier
Authors: Cao Jian-Qiu  , Liu Wen-Bo  , Chen Jin-Bao  , Lu Qi-Sheng  ,   College of Optoelectric Science and Engineering, National University of Defense Technology, Changsha 410073, China
Published: December 2020

The very-large-mode-area (VLMA) fiber is of great importance for suppressing the nonlinear effects which are considered as main limitations to the power scaling-up of high-power fiber lasers and amplifiers. The thermally guiding (TG) VLMA fiber is a novel VLMA fiber, the waveguide of which is formed by the thermal lens effect. Then, a low numerical aperture can be realized, which is promising to achieve the expanding of mode area with a high-quality beam. In order to study the performance of TG VLMA fiber in a fiber amplifier, we present a rate-equation model of the single-mode ytterbium-doped TG VLMA fiber amplifier, which consists of the steady-state rate equations and thermal transferring equations. With this model, the forward-pumped single-mode TG VLMA fiber amplifier is numerically studied. It is found that the diameter of fundamental mode field rises with the increase of the signal power, which shows the superiority of the TG VLMA fiber in suppressing the nonlinear effect in the fiber amplifier. The optimum fiber length and pertinent physical mechanism are also investigated. It is revealed the optimum fiber length is related to the input pump power, and it decreases with the increase of input pump power. However, when the input pump power is large enough, such a variation of optimum fiber length will become weakened. The numerical results also illuminate that the thermal load at the optimum length of TG VLMA fiber should not change too much with the input pump power. Moreover, the mode of output optical field is also discussed. It is found that the thermal load at the optimum length may not be large enough to realize a core-confined mode. In order to ensure that the core-confined mode can be output, the thermal load at the end of the fiber amplifier should be larger. It requires that the fiber length used in the amplifier should be shorter than the optimum fiber length, which will induce the decrease of the output signal power to some extent. In spite of that, the numerical results reveal that the decrease of output signal power should not be much, and the pertinent slope efficiency is not obviously lowered, either. Thus, it is verified that the core-confined mode with a VLMA can be obtained from the TG VLMA fiber amplifier with high slope efficiency. The pertinent results have significant guidance in the design of TG VLMA fiber amplifier.
Calculation of the equivalent resistance and impedance of the cylindrical network based on recursion-transform method
Authors: Tan Zhi-Zhong  , Zhang Qing-Hua  ,   Department of Physics, Nantong University, Nantong 226019, China;,   Department of Mathematics, Nantong University, Nantong 226019, China
Published: December 2020

A classic problem in circuit theory first studied by German physicist Kirchhoff more than 170 years ago is the computation of resistances in resistor networks. Nowadays, resistor network has been an important model in the fields of natural science and engineering technology, but it is very difficult to calculate the equivalent resistance between two arbitrary nodes in an arbitrary resistor network. In 2004, Wu F Y formulated a Laplacian matrix method and derived expressions for the two-point resistance in arbitrary finite and infinite lattices in terms of the eigenvalues and eigenvectors of the Laplacian matrix, and the resistance results obtained by Laplacian matrix method is composed of double sums. The weakness of the Laplacian matrix approach is that it depends on the two matrices along two orthogonal directions. In 2011, Tan Z Z created the recursion-transform (RT) method, which can resolve the resistor network with arbitrary boundary. Using the RT method to compute the equivalent resistance relies on just one matrix along one direction, and the resistance is expressed by single summation.
In the present paper, we investigate the equivalent resistance and complex impedance of an arbitrary mn cylindrical network by the RT method. Firstly, based on the network analysis, a recursion relation between the current distributions on three successive vertical lines is established through a matrix equation. In order to obtain the eigenvalues and eigenvectors of the matrix, and the general solution of the matrix equation, we then perform a diagonalizing transformation on the driving matrix.Secondly, we derive a recursion relation between the current distributions on the boundary, and construct some particular solutions of the matrix equation. Finally by using the matrix equation of inverse transformation, we obtain the analytical solution of the branch current, and gain the equivalent resistance formula along the axis of the arbitrary mn cylindrical network, which consists of the characteristic root and expressed by only single summation. As applications, several new formulae of equivalent resistances in the semi-infinite and infinite cases are given. These formulae are compared with those in other literature, meanwhile an interesting new identity of trigonometric function is discovered. At the end of the article, the equivalent impedance of the mn cylindrical RLC network is also treated, where the equivalent impedance formula is also given.
The mechanism and suppression methods of optical background noise in phase-sensitive optical time domain reflectometry
Authors: Zhang Xu-Ping  , Zhang Yi-Xin  , Wang Feng  , Shan Yuan-Yuan  , Sun Zhen-Hong  , Hu Yan-Zhu  ,   Institute of Optical Communication Engineering, Nanjing University, Nanjing 210093, China;,   Key Laboratory of Modern Acoustics, Nanjing University, Nanjing 210093, China;,   Automation School, Beijing University of Posts and Telecommunications, Beijing 100876, China
Published: December 2020

Phase-sensitive optical time domain reflectometry (-OTDR) has the advantages of fast response and high sensitivity. Therefore, it can realize fully distributed monitoring of weak vibrations along an optical fiber, which is of great value in many applications such as perimeter security and structural health monitoring. However, the optical background noise in the -OTDR will disturb the extraction of effective signals and limit the performance of this system. The optical background noise mainly includes the laser center frequency drift, the polarization-relevance noise and the distortion measurement due to the nonlinear relationship between optical fiber strain and interference intensity. In this paper, the generating mechanism of these optical background noise was analyzed and the corresponding noise suppression methods were proposed. The experiment results showed that the proposed methods could suppress the optical background noise effectively and improve the sensing performance significantly.
Ultrahigh resolution fiber optic strain sensing system for crustal deformation observation
Authors: He Zu-Yuan  , Liu Qing-Wen  , Chen Jia-Geng  ,   State Key Laboratory of Advanced Optical Communication Systems and Networks, Shanghai Jiao Tong University, Shanghai 200240, China
Published: December 2020

Due to the advantages of high resolution, low cost, small size, easy deployment and capability of multiplexed sensing, the recent developed optical fiber grating sensors provide powerful tools for crustal deformation monitoring. This paper reviews the development of several types of fiber-optic sensors with ultrahigh resolution in quasi-static domain. The fiber Bragg grating based Fabry-Perot interferometers and the -phase-shifted fiber Bragg gratings which are used as sensing components in the high resolution sensors are introduced. Some novel techniques such as interrogating the sensing components with intensity modulation sideband, dual feedback-loop structure for high bandwidth/large measurement range sensing, and the time-domain multiplexing of the high resolution quasi-static strain sensor are discussed in detail. Each sensing scheme with both operation process and achieved performances are given. The implementation of fiber grating sensors for in-situ measurement of crustal deformation and the results are also introduced. Compared with the traditional methods used in crustal deformation observation, the high-performance fiber optic strain sensors mentioned in the paper shows great potentials in providing wider measurement approaches in geophysical researches.
Influence of the external condition on the damage process of the GaAs pseudomorphic high electron mobility transistor induced by the electromagnetic pulse
Authors: Xi Xiao-Wen  , Chai Chang-Chun  , Liu Yang  , Yang Yin-Tang  , Fan Qing-Yang  ,   Ministry of Education Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices, Xidian University, Xi'an 710071, China
Published: December 2020

Electronic system and device are vulnerable under intensive electromagnetic pulse (EMP) environment, where low noise amplifer (LNA) is a typical sensitive instance for electromagnetic energy. This work focuses on the EMP-induced damage effect of GaAs pseudomorphic high electron mobility transistor (PHEMT), which is the core part of LNA. Using the simulation softeware Sentaurus TCAD, an EMP-induced damage model of the GaAs PHEMT is established in this paper, and verified through the experimental result. It is shown that the damage position of the device under the injection EMP exists in the center area under gate terminal. Based on this model and aiming at EMP parameters and external resistances, the influence of the external conditions on the damage effect of the device is investigated. The results indicate that the damage time is related to EMP parameters obviously:1) the damage time is inversely proportional to EMP amplitude since higher power density is absorbed under a stronger EMP; 2) the damage time is in direct proportion to signal rising time since the breakdown time is postponed under EMP with a slower rising edge. Furthermore, it is found that a load resistor is able to weaken current channel which is effective in delaying the damage process, and this effect is more obvious, with load resistor connected with source terminal. It should be noted that the results are beneficial to and valuable in hardening method against EMP of semiconductor devices. It is feasible to design external circuit protection units, aiming at attenuating signal amplitude and increasing the rising time of injected pulse. Another effectual approach is to enlarge the source series resistance under the premise of the performance meeting the requirements.
Anti-plane fracture problem of four nano-cracks emanating from a regular 4n-polygon nano-hole in magnetoelectroelastic materials
Authors: Yang Dong-Sheng , Liu Guan-Ting ,   College of Mathematics Science, Inner Mongolia Normal University, Hohhot 010022, China
Published: December 2020

According to the conformal mapping from the exterior region of the regular n-polygon hole to the exterior region of a unit circle and from the exterior region of four cracks emanating from a circle to the interior region of a unit circle, a new conformal mapping is constructed to map the exterior region of four cracks emanating from a regular 4n-polygon hole to the interior of a unit circle. Then, based on the Gurtin-Murdoch surface/interface model and complex method, the anti-plane fracture of four nano-cracks emanating from a regular 4n-polygon nano-hole in magnetoelectroelastic material is studied. The exact solutions of stress intensity factor, electric displacement intensity factor, magnetic induction intensity factor, and energy release rate are obtained under the boundary condition of magnetoelectrically impermeable with considering the surface effect. Without considering the effect of the surface effect, the exact solution of four cracks emanating from a regular 4n-polygon hole in a magnetoelectroelastic material can be obtained. The numerical results show the influences of surface effect and the size of defect on the stress intensity factor, electric displacement intensity factor, magnetic induction intensity factor and energy release rate under the magnetoelectrically impermeable boundary condition. It can be seen that the stress intensity factor, electric displacement intensity factor, and magnetic induction intensity factor are significantly size-dependent when considering the surface effects of the nanoscale defects. And when the size of defect increases to a certain extent, the influence of surface effect begins to decrease and finally tends to follow the classical elasticity theory. When the distance between the center and the vertex of the regular 4n-polygon nano-hole is constant, the dimensionless field intensity factor decreases gradually with the increase of the number of edges, and approaches to the conclusion of a circular hole with four cracks. With the increase of the relative size of the crack, the dimensionless field intensity factor increases gradually. The dimensionless energy release rate of the nanoscale cracked hole has a significant size effect. The increase of mechanical load will increase the normalized energy release rate. The normalized energy release rate first decreases and then increases with electrical load increasing. The normalized energy release rate decreases with magnetic load increasing.
Bi2O2Se photoconductive detector with low power consumption and high sensitivity
Authors: Li Dan-Yang , Han Xu , Xu Guang-Yuan , Liu Xiao , Zhao Xiao-Jun , Li Geng-Wei , Hao Hui-Ying , Dong Jing-Jing , Liu Hao , Xing Jie ,   School of Science, China University of Geosciences, Beijing 100083, China
Published: December 2020

With the advent of graphene, atomically thin two-dimensional materials receive great attention in both science and technology. However, the characterization of zero-band gap of graphene hinders its applications in semiconductor logic and memory devices. To make up for the imperfection of graphene, one has made efforts to search for other two-dimensional layered materials. The Bi2O2Se is an emerging material with very high electron mobility, modest bandgap, and excellent thermal and chemical stability. In this work, high-quality Bi2O2Se thin films are synthesized through chemical vapor deposition. The effect of temperature on the morphology and size distribution of Bi2O2Se thin film are discussed in detail experimentally. Under an optimized experimental condition, the Bi2O2Se thin films with a lateral size of 100 μm are achieved. Interestingly, Bi2O2Se nanowires are obtained at a lower growth temperature (620–640 ℃). The photoelectric performances of Bi2O2Se on mica and silicon oxide substrate are examined based on a photoconductive mode. At a small bias of 0.5 V, the responsivity and specific detectivity of the rectangular Bi2O2Se thin film on the mica substrate reach 45800 A/W and 2.65 × 1012 Jones, respectively, and the corresponding photoelectric gain is greater than 105. The photoelectric performance of our device is comparable to the best results achieved by other research groups, which may be related to the higher quality and appropriate absorption thickness. The Bi2O2Se nanowire and Bi2O2Se thin film transferred to Si/SiO2 by a polystyrene-assisted method also exhibit a good photoresponse under the illumination of a 532 nm laser with a high optical power density (127.4 mW/cm2). The experimental results demonstrate that the Bi2O2Se has great potential applications in the optoelectronic devices with low power consumption and high sensitivity.
Inverse design method of microscatterer array for realizing scattering field intensity shaping
Authors: Wang Zhi-Peng , Wang Bing-Zhong , Liu Jin-Pin , Wang Ren ,   Institute of Applied Physics, University of Electronic Science and Technology of China, Chengdu 610054, China
Published: December 2020

It is a novel and interesting idea to inversely design the scattering structure with the desired scattering field intensity distribution in a given target area as the known information. The inverse design method proposed in this paper does not need to be optimized, and the spatial distribution and dielectric constant distribution of the micro-scatterer array can be quickly analytically calculated according to the desired scattering field intensity in the target area. First, based on the spatial Fourier transform and angular spectrum transformation, the plane wave sources required in all directions are inversely obtained from the electric field intensity distribution required in the target area. Then, based on the theory of induced source, a method of irradiating the array of all-dielectric micro-scatterers with incident electromagnetic field to generate the required plane wave source is proposed. The scattering fields generated by these micro-scatterers will be superimposed on the target area to achieve the desired scattering field strength intensity. Finally, according to the proposed inverse design theory model, a specific three-dimensional (3D) design is carried out. In the 3D example, we study the scattering field intensity distribution of the point-focused shape of the square surface target area, and show an all-dielectric micro-sphere distribution design. Its spatial distribution and permittivity distribution are both obtained through the rapid analytical calculation of the desired scattered field intensity shape in the target area. Finally, based on the principle of linear superposition, we quickly and easily generate the complex shapes of “I”, “T”, and “X” in the target area. The satisfactory results of full-wave simulation show that the proposed inverse design method is effective and feasible.
The connectome of the adult Drosophila mushroom body provides insights into function
Authors: Li Feng , Lindsey Jack W , Marin Elizabeth C , Otto Nils , Dreher Marisa , Dempsey Georgia , Stark Ildiko , Bates Alexander S , Pleijzier Markus William , Schlegel Philipp , Nern Aljoscha , Takemura Shin-ya , Eckstein Nils , Yang Tansy , Francis Audrey , Braun Amalia , Parekh Ruchi , Costa Marta , Scheffer Louis K , Aso Yoshinori , Jefferis Gregory SXE , Abbott Larry F , Litwin-Kumar Ashok , Waddell Scott , Rubin Gerald M
Published: December 2020

Making inferences about the computations performed by neuronal circuits from synapse-level connectivity maps is an emerging opportunity in neuroscience. The mushroom body (MB) is well positioned for developing and testing such an approach due to its conserved neuronal architecture, recently completed dense connectome, and extensive prior experimental studies of its roles in learning, memory, and activity regulation. Here, we identify new components of the MB circuit inDrosophila, including extensive visual input and MB output neurons (MBONs) with direct connections to descending neurons. We find unexpected structure in sensory inputs, in the transfer of information about different sensory modalities to MBONs, and in the modulation of that transfer by dopaminergic neurons (DANs). We provide insights into the circuitry used to integrate MB outputs, connectivity between the MB and the central complex and inputs to DANs, including feedback from MBONs. Our results provide a foundation for further theoretical and experimental work.
Bulgarian Men’s Travels to Mount Athos in the Context of the Ritual Year
Authors:   Institute of Ethnology and Folklore Studies with Ethnographic Museum, Bulgarian Academy of Sciences, Bulgaria, Matanova Tanya
Published: December 2020

As several monasteries and shrines of the monastic republic Mount Athos are connected with the Bulgarian history, in some cases they function not only as places of religious worship by Bulgarian men but also as sites of national memory. Therefore, placed in the context of the ritual year of pilgrimage, as an object of research are chosen Bulgarian men’s 21st century group travels to Mount Athos. More exactly, the focus lies on the places, holidays and celebrations instigating Bulgarian men to visit different destinations at the monastic peninsula, following different routes and motives. Further attention is paid to the performed religious and commemorative practices at the various locations of the Athonite peninsula.
Data augmentation-based conditional Wasserstein generative adversarial network-gradient penalty for XSS attack detection system
Authors: Mokbal Fawaz Mahiuob Mohammed , Wang Dan , Wang Xiaoxi , Fu Lihua
Published: December 2020

The rapid growth of the worldwide web and accompanied opportunities of web applications in various aspects of life have attracted the attention of organizations, governments, and individuals. Consequently, web applications have increasingly become the target of cyberattacks. Notably, cross-site scripting (XSS) attacks on web applications are increasing and have become the critical focus of information security experts’ reports. Machine learning (ML) technique has significantly advanced and shown impressive results in the area of cybersecurity. However, XSS training datasets are often limited and significantly unbalanced, which does not meet well-developed ML algorithms’ requirements and potentially limits the detection system efficiency. Furthermore, XSS attacks have multiple payload vectors that execute in different ways, resulting in many real threats passing through the detection system undetected. In this study, we propose a conditional Wasserstein generative adversarial network with a gradient penalty to enhance the XSS detection system in a low-resource data environment. The proposed method integrates a conditional generative adversarial network and Wasserstein generative adversarial network with a gradient penalty to obtain necessary data from directivity, which improves the strength of the security system over unbalance data. The proposed method generates synthetic samples of minority class that have identical distribution as real XSS attack scenarios. The augmented data were used to train a new boosting model and subsequently evaluated the model using a real test dataset. Experiments on two unbalanced XSS attack datasets demonstrate that the proposed model generates valid and reliable samples. Furthermore, the samples were indistinguishable from real XSS data and significantly enhanced the detection of XSS attacks compared with state-of-the-art methods.
Sonhos interrompidos
Authors: Mayer Verônica Feder , Coelho Mariana de Freitas
Published: December 2020

Este trabalho tem o objetivo de compreender as experiências de turistas que viajaram durante a propagação da Covid-19, explorando as emoções e memórias em um contexto cronológico da viagem. A abordagem metodológica é qualitativa, com base em 21 entrevistas em profundidade a turistas brasileiros que relataram suas viagens entre janeiro e março de 2020, contemplando experiências em todos os continentes do mundo. A análise dos dados se deu pela teoria fundamentada, como base na codificação aberta, axial e seletiva. Os resultados demonstram as particularidades vivenciadas em experiências de viagem durante a pandemia, com emoções que permeiam a felicidade, medo, frustração, tensão e alívio. Ainda, discute-se como os turistas se envolveram com o planejamento de viagem, foram pressionados socialmente e fizeram avaliações de risco antes de viajarem. Durante a viagem, experiências inesperadas geraram a transfiguração da viagem outrora planejada, o atendimento precário e o desamparo, bem como comportamento de autoproteção (ou não) foram elencados. Por fim, os turistas refletiram sobre a viagem e suas consequências. As contribuições envolvem a classificação dos estudos sobre turismo e Covid-19, e a proposição de um framework teórico que representa as emoções e memórias de viajantes antes, durante e após a experiência de viagem.
Viva ou deixe morrer
Authors: Bouças da Silva David Leonardo , Miranda Anderson Lourenço , Hoffmann Valmir Emil
Published: December 2020

Este trabalho objetivou identificar as estratégias desenvolvidas por micro e pequenas empresas (MPE) do turismo ludovicense para enfrentar a crise provocada pela COVID-19. Adicionalmente, detectou-se impactos da pandemia sobre os negócios. Metodologicamente, desenvolveu-se uma pesquisa qualitativa, transversal, descritiva e exploratória com MPE de hospedagem, transporte, agenciamento, A&B, consultoria, cerimonial e eventos. Os dados foram coletados, por meio de roteiro semiestruturado contendo as categorias: impactos e gerenciamento de crise. Utilizou-se a técnica de análise de conteúdo. Os resultados apontam impactos negativos, como “dificuldades financeiras”, e positivos, a exemplo das “oportunidades de qualificação profissional”. Empresas de A&B obtiveram “melhorias no faturamento” graças ao delivery. As estratégias para enfrentamento versam sobre gestão de marketing, finanças, operacional e pessoas, e variam conforme segmentos e stakeholders envolvidos. No geral, as empresas não fazem planos contingenciais e agem de forma responsiva às crises. Destacou-se a atuação de instituições públicas e privadas no “apoio técnico e financeiro” aos negócios, embora a “lentidão no acesso aos subsídios financeiros” venha comprometendo o futuro das MPE. Para o pós-crise, os empreendimentos almejam estratégias que estejam em consonância ao “novo normal” e fortaleçam a percepção de segurança nos consumidores.
Factors Contributing for Vulnerability on Livelihood of Fishers of Ratnagiri, Maharashtra State, India
Authors: Yadav B. M. , Wasave S. M. , Mandavkar S. S. , Patil S. V. , Shirdhankar M. M. , Chaudhari K. J.
Published: December 2020

Aims: The present study was carried out to investigate the impact of vulnerability on livelihood of fishers of Ratnagiri, Maharashtra state of India.

Study Design: For this study interview schedule was used to collect the fisher information.

Place and Duration of Study: In present study, the data were collected from the fishers of the three fishing villages of Ratnagiri district of Maharashtra during the year 2019-2020.

Methodology: The data were randomly collected from 64 fisher by using questionnaire in the Google form and interview schedule. The vulnerability variables considered in this study are categorised as natural shocks like cyclones, heavy rain, environmental changes; personal factors like illness, sea accidents, sudden death, social conflicts and seasonality includes decline in fish catches, unpredictable price fall and non-availability of markets. The opinions of respondents with respect to vulnerability factors were recorded on the basis of three categories i.e. high impact, medium impact and low impact. The descriptive statistics i.e. percentage and frequency analysis was used to represent the results.

Results: The overall results of vulnerability indicated that the natural shocks factors like cyclones, heavy rain, environmental changes and personal factors like illness, sea accidents, sudden death, social conflicts have high impact on more than 90% respondents; while seasonality factors like decline in fish catches, unpredictable price fall and non-availability of markets have high impact on livelihood of about 70% fishers respondents.

Conclusion: The respondents reported that the various factors of vulnerability have direct impact on livelihood of fishers and ultimately socioeconomic conditions of the fishers.
Constraints Encountered by Beneficiary Farmers in Adopting National Food Security Mission (NFSM) Interventions in Selected Districts of Karnataka State, India
Authors: Chaitra G. , Gowda N. S. Shivalinge , Shivalingaiah Y. N.
Published: December 2020

India is facing the problem of food insecurity since independence. The Government has taken several measures to overcome this, still there was no maximum change that has taken place in the status of country’s food security. For the growing population the country has to produce more and more year after year. To make this possible the government announced National Food Security Mission Scheme to enhance the productivity of crops and income of the farmers through various crop based interventions. The present study on constraints faced by beneficiary farmers of NFSM in adopting NFSM interventions was undertaken in Belagavi and Haveri districts of Karnataka State with sample size of 180 beneficiaries from different components of NFSM viz., NFSM – Rice, NFSM – Pulse and NFSM – Coarse Cereals. Expost - facto research design of social research was used in the present investigation. The major constraints faced by the beneficiary farmers in adopting NFSM interventions among the beneficiary farmers of Belagavi district were, lesser amount of subsidy (in Rs), limited number of demonstrations and subsidy paid after purchase while an initial payment remains the highest problem. Whereas in case of Haveri district, the major constraints encountered by beneficiary farmers were, poor quality materials/machinery are supplied, non availability of particular seed varieties or hybrids and redtapism.
Preliminary Evaluation of Olive (Olea europaea L.) Cultivars in Northwest and Central of Mexico
Authors: Grijalva-Contreras Raúl Leonel , Macías-Duarte Rubén , López-Carvajal Arturo , Robles-Contreras Fabián , Valenzuela-Ruiz Manuel de Jesús
Published: December 2020

A strategy to improve productivity in olive orchards is the evaluation of cultivars that respond better to the environmental growing conditions The objective of this experiment was to evaluate the yield potential and oil quality of five olive cultivars (Arbequina, Coratina, Manzanilla, Arbosana and Mission) in two regions of Mexico. The experiment was carried out during two consecutive years 2018 and 2019. At Northwest Region the five olive cultivars were planted in 2013 at a spacing of 10 x 5 m (having 200 trees ha-1) and Central Region olive cultivars were planted in 2013 at spacing of 6 x 6 m (278 trees ha-1) and both locations under drip irrigation systems. The variables evaluated were:  yield, fruit weight, oil content and oil quality (acidity, peroxide value and absorbance K232 and K270). The experiment was analyzed using a randomized complete block design with four replications. 

Our results showed high differences between locations, Arbequina was the cultivar with the highest yield at the fifth and sixth years of planting with an average of 48.8 kg tree-1 at Northwest Region and only 15.5 kg tree-1 at Central Region. The cultivar with the highest oil content in the Northwest Region was Manzanilla with an average of 12.3% and the lowest for Arbequina with only 9.3%, while at Central Region the cultivar with the highest oil content was Coratina with 20.2% and the lowest in Manzanilla with 16.1%. Extra virgin olive oil was obtained in all the cultivars in both locations according to chemical analysis. Finally, it is necessary to continue with the evaluation of other varieties with resistance to high temperatures at Northwest Region and resistance to frost at Central Region.
Phenotypic and Genotypic Identification and Antifungal Susceptibility of Some Fungi Isolated from Tympanotonus fuscatus var. radula
Authors: Kelly Asemota Uwem , Obuneme Obiekezie Smart , Danladi Makut Makwin , Owuna Jubril Egwu
Published: December 2020

Aim: This study aimed to identify fungi isolated from Tympanotonus fuscatus var. radula and evaluate its level of susceptibility to known antifungal compounds.

Place and Duration of Study: Biotechnology Advanced Research Centre, Sheda Science and Technology Complex, Abuja between September and December 2019.

Methods: Tympanotonus fuscatus var. radula samples were purchased from the Keffi, Masaka, and Orange markets in Nasarawa State, Nigeria. Fungal isolation was achieved using Sabouraud dextrose agar supplemented with chloramphenicol and incubated at 28ᵒC for 5 days. ITS-1 and ITS-4 primers were used at 94°C for 2 min, 52°C for 1 min, and 72°C for 2 min for the polymerase chain reaction before sequencing at Inqaba Biotech South Africa. Disk diffusion technique was employed for antifungal susceptibility testing.

Results: Data obtained revealed that the suspected fungal species exhibited a generally higher level of resistance (19-40 mm) to 1 µg voriconazole in addition to a 20-35.5 mm zone of inhibition against 10 µg ketoconazole. Blast sequence analysis of the isolated samples revealed a 99.65% sequence homology to Meyerozyma guilliermondii, 99.38% to Fusarium oxysporium isolate E-225 1 and 96.23% to Aspergillus terreus isolate A2S4.  

Conclusion: Food safety involves isolating and accurately identifying disease causing pathogens such as fungi in food. Based on the fungal load obtained from this study, proper cooking and handling of sea-food which would otherwise cause disease, is highly recommended.
How to Develop Cultural and Creative Tourism at a Demonstrated Village in Yi Nationality Region of Liangshan Prefecture
Authors: Liu Yu-Xiang , Xiong Jian-Lin , Chen Yi , Yen Tsai-Fa(TF)
Published: December 2020

Liangshan Prefecture, located in Sichuan Province in Southwest China, is the largest inhabited area of the Yi ethnic group and is also known as a contiguous impoverished area in the country. Therefore, poverty needs to be addressed through rural revitalization. The purpose of this study is to explore the strategic objectives and achievements of rural revitalization in Liangshan Yi Area through the construction of demonstration villages, to explore the current situation and problems of cultural and creative tourism development, and to provide Suggestions for improvement through literature collection and empirical investigation. The research finds that the problems of cultural and creative tourism development in the case model village include the strengthening of infrastructure construction, the adjustment and upgrading of industrial structure, the lack of downward publicity and external publicity, and the low cognition and acceptance of cultural and creative tourism. Finally, this study suggests that to develop cultural and creative tourism in the model village, the government must make relevant improvements, such as strengthening policy support, actively promoting and guiding the development of cultural and creative tourism in the model village, and increase the link with colleges and universities. For the demonstration villages, this study suggests that the professional quality of cultural and creative tourism of village leaders, the establishment of cultural and tourism seed teachers, and the establishment of village organization and manpower training should be improved.
Population Dynamics and Management of Invasive Blue Tilapia (Oreochromis aureus) in Garmat Ali River, Basrah, Iraq
Authors: Mohamed Abdul-Razak M. , Salman Ayat N.
Published: December 2020

The blue tilapia, Oreochromis aureus is an invasive species that has successfully established itself in most of the Iraqi waters. However, there is little information on the population dynamics of the species in these waters. Hence, the growth parameters, mortality rates, probability of capture, recruitment pattern and yield per recruit of blue tilapia in Garmat Ali River, Iraq was assessed using FiSAT II software. A total of 1664 blue tilapia fish were collected by different fishing gears from October 2019 to September 2020 for recording the relevant data. The length-weight relationship obtained was W=0.0147*L3.0748 for fish ranging from 7.5 to 26.3 cm total length suggesting that the species shows positive allometric growth. The asymptotic length (L∞), growth constant (K), theoretical age at zero-length (t0), growth performance index (Ø') and longevity (tmax) were 29.9 cm, 0.205, -1.293, 2.345 and 10.7 years, respectively. The total mortality (Z), natural (M), fishing (F) and exploitation (E) were 1.09, 0.61, 0.48 and 0.43, respectively. Length at first capture (L50) was found to be 13.92 cm. The main recruitment pulse was from March to July with a peak in April, which account for 18.4% of the total recruitment in the year. The relative yield per recruit analysis revealed that the present exploitation rate (Epresent) for blue tilapia was below than the biological target reference points (E0.1 and Emax), which denotes that this stock was not over-exploited. For management purposes, higher yields can be achieved by reducing the mesh sizes of the nets during fishing.
Variation in Community Perception on Mosquito-Borne Diseases between Urban and Rural Communities in Gombe State, Nigeria
Authors: Abba Ezra , Paul Tabitha , Yoriyo Kennedy Poloma , Emmanuel Blessing Chinwendu
Published: December 2020

Aims: This work is aimed at knowing the variation in community perception on mosquito-borne diseases between urban (Gombe) and rural (Filiya) of Gombe State.

Study Design: Each of the two communities was sectioned into longitudinal zones and 150 houses were then randomly selected from the zones in each of the communities for the administration of questionnaires. The data were analyzed using descriptive statistics

Place and Duration of Study: The study was conducted between April and June 2018 in Gombe and Filiya communities of Gombe state.

Methodology: Quantitative data were collected utilizing open-ended questionnaire covering 300 respondents.

Results: In Gombe (urban community) 98% of respondents had knowledge about mosquitos’ existence unlike Filiya (rural community) with 74%. Concerning mosquito-borne diseases, up to 92% of urban dwellers are aware of one or more mosquito-borne diseases compared to the rural respondent with 46% awareness. 68% of the urban respondents agreed that the frequent breeding places for mosquitoes are drains and polluted waters. On the other hand, 28% of the respondents from the rural community shared this view about the frequent breeding sites of the mosquitoes with the urban dwellers. More so, up to 34% of the rural respondent does not know mosquito breeding sites. Majority of the respondent in the urban areas relied on Nets for protection against mosquito bites while the rural respondent majorly uses coils. Only 36% of respondents in urban community source their treatment from Government health facility against 12% in the rural community. Half of the respondent in the rural community sought treatment from one source or the other.

Conclusion: The popular Mosquito-Borne disease is malaria. Most people have a fair knowledge about malaria prevention and control and see malaria as a threat to their lives and community but the majority had poor practices towards malaria prevention and control. The government should intensify the campaign against malaria.
Carbides and Carbon Control in MC – Reinforced Superalloys
Authors: Berthod Patrice
Published: December 2020

Polycrystalline alloys based on cobalt and elaborated by classical foundry are known since the middle of the last century. They are currently still used, notably for geometrically complex components working at high temperature. Beyond the oldest ones reinforced by chromium carbides, new principles of carbides–strengthened cobalt–based alloys have recently appeared. MC–type refractory mono–carbides allow maintaining the melting start temperature at a high level when they are present as single carbide phase. Their high temperature stabilities and script–like morphologies also favor high mechanical properties at elevated temperatures. Optimized MC–carbides fractions can be obtained with carbon contents, close to 0.4 wt.%C, for achieving significant strengthening without threat for the low and high temperature toughness. Controlling the carbon content is thus of prior importance. Unfortunately the most common metallographic apparatus used for measuring the chemical composition of alloys – the Energy Dispersion Spectrometers (EDS) attached to Scanning Electrons Microscopes (SEM) – are not able to analyze, with sufficient accuracy, carbon with so low contents. A simple indirect method using both EDS and SEM is proposed here to get some information about the carbon content in several MC–reinforced Co–based superalloys.
Electrolyte Concentrations and Liver Enzymes in Car Spray Painters Exposed to Car Spray Paints within Port Harcourt Metropolis, Rivers State, Nigeria
Authors: Kalio Ibiene Sarah , Donatus O. Onwuli , Ndubuisi Abel Callum , Godgift Obisie-eke
Published: December 2020

Aim: To determine the effect of car spray paint on electrolyte concentrations (sodium, potassium, bicarbonate and chloride), Anion gap, Total Protein, Albumin, liver enzymes (Alanine amino transferase and Aspartate amino transferase) of car spray painters.

Place of Study:  The study was conducted within Port Harcourt metropolis, Rivers State Nigeria.

Methodology: Twenty (20) male car spray painters age range between 25 and 61 years with 7- 28 years work experience in car spray painting (test subjects) and twenty (20) apparently healthy male individuals aged between 25 and 61 years who work within an office setting far away from car spray painting garage (non-exposed individuals) were used as control for the study. Plasma electrolyte concentrations were estimated using Ion selective electrode method while Liver Enzymes Alanine amino transferase and Aspartate amino transferase were estimated using spectrophotometric method. Results obtained from the experiment were expressed as Mean ± Standard Deviation. P < .05 were considered statistically significant.

Results: Sodium, Potassium, Bicarbonate and Chloride concentrations in plasma of car spray painters when compared to non-car spray painters did not showed any significant difference (P> .05). However, Anion gap was significantly increased (P<.05) in plasma of car spray painters when compared to non-car spray painters. Alanine amino transferase activity were significantly higher in plasma of Car spray painters (P < .05) when compared to non-car spray painters while Aspartate amino transferase activity, Total protein and Albumin concentrations remained relatively unchanged when compared between the studied groups. However, Aspartate amino transferase and Alanine amino transferase activities were affected by years of exposure to car paints.

Conclusions: This study suggest that car spray paint affects Anion gap and Alanine amino transferase activity in car spray painters hence safety apparatus should be worn while working. However further test on other liver enzymes should be done to validate the effect of spray paint on the liver.
Effect of Tillage Practices and Cultivation Year on Natural Mycorrhization and Mineral Uptake of Durum Wheat during Tillering Stage under Rainfed Conditions
Authors: Chaieb Nadia , Labidi Sonia , Ayed Sourour , Mdellel Lassaad , Chiab Abdelkarim , Jeddi Faysal Ben , Hammouda Moncef Ben-
Published: December 2020

Conservation agriculture has been proposed as an alternative to conventional agriculture to mitigate the climate change impact and ensure food security. This study examined the effect of conventional tillage (CT) and no tillage (NT) on mycorrhization and mineral elements uptake of durum wheat for three cultivation years during the tillering stage. The experiment was conducted in a referential farm (Krib, Siliana, North West Tunisia). The results showed that tillage practices (T) had significant effect on mycorrhization rate (MR) for the first cultivation year and the highest mycorrhization rate was noted for NT with 24%. Moreover, tillage (T) had no significant effect on plant mineral composition in tillering stage for the three cultivation years. The cultivation year (Y) had showed significant effects on P and K amounts for both tillage practices when it had no effect on Ca and Na amounts. The interaction T x Y had no significant effect on mineral elements concentration. Mycorrhization rate (MR) showed significant negative correlation with K. For partial correlation based on Tillage practices, MR showed significant negative correlations with P and K.  Considering the partial correlation based on cultivation year, MR had no significant correlations with the studied parameters (P, K, Ca and Na concentrations). This work expands our knowledge on durum wheat natural mycorrhization and mineral elements uptake as influenced by tillage practices helping decision makers in upscaling the adoption of no tillage in Tunisia under rainfed conditions
Evaluation of Mathematics Teachers’ Knowledge at UNRWA Schools in Gaza Strip about the Action Research Concepts and Process
Authors: Abuabdou Heba A. M. , Abuabdou Salahaldin M. A.
Published: December 2020

In this study, the availability of action research knowledge was measured among teachers of mathematics in schools belongs to Relief and Works Agency for Palestine Refugees (UNRWA) in Gaza Strip. The study sample consisted of 241 male and female teachers, where the study sample contained (25%) of the total study population, which consists of (972) active teacher during the current study time (second semester- 2019/2020). It was found that the sample has a strong knowledge about the action research concepts. Moreover, it was confirmed that there are no significant differences attributed to the variables of gender, training programs, and educational qualification. Meanwhile, the results showed that there is a significant effect by the teacher’s age and cumulative experience on the teachers’ knowledge of action research. Based on the findings, the challenges and obstacles that prevent teachers or limit their ability to perform action research must be studied and thus an attempt should be made to overcome those obstacles in order to push the teacher to perform the action research.
Market Arrivals and Prices of Paddy in Major Markets of Telangana State
Authors: Paul K. Solomon Raju , Sunandini G. P. , Irugu Shakuntala Devi
Published: December 2020

The study was conducted to investigate the price behaviour of paddy and the relationship between market arrivals and prices in Suryapeta and Tirumalagiri markets of Telangana. In view of this the present study was undertaken by collecting monthly wholesale prices and arrivals of paddy in both the markets of Telangana for a period of 5 years (2015 to 2019). The seasonal price index provides a measure of the month to month variation in paddy prices. The price indices were lowest in the month of November in suryapeta markets where as Tirumalagiri market in price indices were lowest in the month of December. The study concluded that there was an inverse relationship between market arrivals and the prices.
Effect of Placement and Foliar Application of Urea, KCl & Zn (Supplementary Nourishment) on Growth and Yield of Cowpea (Vigna unguiculata L.) under Guava (Psidium guajava L.) based Agri-horti System
Authors: Dey Sonu , Prasad Sant , Chichaghare A. R.
Published: December 2020

Aims: To investigate the effect of the placement and foliar application of Urea, KCl & Zinc on growth and yield of cowpea under guava based agri-horti system in Vindhyan region, India.

Study Design:  RBD with nine treatments and three replications.

Place and Duration of Study: Agricultural Research Farm, Barkachha, Mirzapur (UP), India during kharif season (June-Oct) of 2017.

Methodology: This experiment consisted nine different treatments viz; Control (T1), 2% Urea spray (T2),  30 kg KCl ha-1 (T3), 2% KCl spray (T4), 2% Urea spray + 2% KCl spray (T5),  5 kg Zn ha-1 (T6), 2% Urea spray + 5 kg Zn ha-1 (T7), 30 kg KCl ha-1+ 5 kg Zn ha-1 (T8),  2% Urea spray + 2% KCl spray + 1.5% Zn spray (T9). Various growth parameter, yield attributes, N, P, K and nutrients contents were recorded and compared.

Results: Significantly higher growth parameters like  plant height-1, no of branches plant-1, fresh weight-1 and dry weight-1, yield attributes like number of seeds pod-1, pod length, pod yield plant-1, green pod yield were recorded in 2% Urea spray + 2% KCl spray + 1.5% Zn spray (T9). Maximum N, K and protein content in straw and seed also observed in T9.

Conclusion: foliar spray of 2% Urea + 2% KCl spray + 1.5% Zn spray was best method for supplementary nourishment of cowpea under guava based Agri-horti system. The experiment should be reported for one to two seasons more in order to reach final conclusion.