bluuebunny/crossref_metadata_2025 huggingface dataset:
Longitudinal Development of Executive Functioning and Spoken Language Skills in Preschool-Aged Children With Cochlear Implants
Authors: Kronenberger William G. , Xu Huiping , Pisoni David B.
Published: March 2020

Purpose

Auditory deprivation has downstream effects on the development of language and executive functioning (EF) in prelingually deaf children with cochlear implants (CIs), but little is known about the very early development of EF during preschool ages in children with CIs. This study investigated the longitudinal development of EF and spoken language skills in samples of children with normal hearing (NH;
N
= 40) or CIs (
N
= 41) during preschool ages.

Method

Participants were enrolled in the study between ages 3 and 6 years and evaluated annually up to the age of 7 years. Mixed-effects models were used to evaluate and predict growth of spoken language and EF skills over time.

Results

Children with CIs scored lower than NH peers on language measures but improved significantly over time. On performance-based neurocognitive measures of controlled attention, inhibition, and working memory, children with CIs scored more poorly than the sample of NH peers but comparable to norms, whereas on a parent report behavior checklist, children with CIs scored more poorly than both NH peers and norms on inhibition and working memory. Children with CIs had poorer EF than the sample of NH peers in most domains even after accounting for language effects, and language predicted only the verbal working memory domain of EF. In contrast, EF skills consistently predicted language skills at subsequent visits.

Conclusions

Findings demonstrate that, despite significant improvement over time, some domains of EF (particularly parent-reported EF) and language skills in children with CIs lag behind those of children with NH during preschool ages. Language delays do not fully explain differences in EF development between children with CIs and NH peers during preschool ages, but EF skills predict subsequent language development in children with CIs.
Siliceous foam material and its application in post-combustion carbon capture for NGCC plants: effects of aging conditions
Authors: Yang Meng , Yuxin Yan , Peng Jiang , Xinyun Wu , Cheng-gong Sun , Tao Wu , Cheng Heng Pang
Published: March 2020

In an effort to reduce the overall energy penalty and capital expenditure associated with carbon capture technologies, a variety of porous solid adsorbents have been developed. The limitations of solid sorbent in large-scale process are related to its CO2 uptake, physicochemical stability, lifecycle, regenerability and operation condition. In this paper, siliceous foam materials were synthesized via a modified microemulsion templating method and functionalized with branched polyethylenimine (PEI). The physical characteristics of synthesized silica adsorbents under different aging conditions were analysed via N2 sorption analysis and Scanned Electron Microscopy (SEM) morphological analysis. CO2 uptake was evaluated by thermogravimetric analyser (TGA). The results show that CO2 uptake is desirable even under low CO2 partial pressure and is predictable with multiple linear regression (MLR) model in the range of examined materials.
A fuzzy function model for remote evaluation of chlorophyll-a concentration in the Northern of South China Sea-Hong Kong
Authors: Xu Zhao , Qian Xu , Shan Baoguo , Duan Jinhui , Sun Xiangdong
Published: March 2020

Chlorophyll-a (Chla) concentration is an important indicator to monitor eutrophication, which is a persistent problem that affects the ecological health of coastal water or shallow lakes. We have applied a Gaussian-like fuzzy function model for the estimation of Chla concentration in Hong Kong Coastal Waters, based on the spectral signature using the HJ-1A /1B CCD images and measured data. The method of this paper is as follows. Firstly, reflectance peak and fluorescence band were used to figure out the bands or bands combination which impact the Chla concentration significantly; and then calculated the value of all the pixels without measured data according to their similarity degree with the measured points; finally, the full Chla concentration maps in the study area were produced by GIS spatial interpolation. It is concluded in this paper that the method can retrieve the Chla concentration accurately and the result of changes detected coincides with the observed result extremely, what’s more, the maps generated are continuous and smooth which are quite different from traditional RS maps that can only accurate to pixel size.
The peculiarities of bronchopulmonary system under the influence of adverse ecological factors
Authors: Abdrassulova Zhanna , Tuleukhanov Sultan , Issayev Gani , Amankeldiyeva Aidana , Turmetova Gulmira
Published: March 2020

This research gives an insight into the problem of atmospheric pollution composition and morbidity that affects the overall well-being and health state of children of Ust-Kamenogorsk. The work shows that age specific features of the respiratory system are characterized by increase in lung volume and bronchial patency trees. The specific methodology assisted to determine the increase in the patency of large and medium bronchi occurs more dynamic in boys than in girls. The bronchial obstruction was assessed by the methods of pneumotachometry with the help of “PneuMedics” (USA) device. The environmental factors of Ust-Kamenogorsk affect the state of the cardiorespiratory system of children, so level of contamination place of residence highly affects the general health state of the children at different age categories and anthropometric measurements. One of the important results was that children with growth and weight coefficient who have higher than the average value are characterized by a decrease of functional reserves of the bronchopulmonary system, and children with the coefficient lower than average, on the contrary, are characterized by decrease in the cardiovascular system.
Ability to Use Flexible Project Management in the Hotel Business
Authors: Turginbayeva Ardak , Nurseitova Gulmira , Zhakupbekova Guldana , Doszhanov Kairat , Konysbay Aidar
Published: March 2020

The article discusses the possibilities of implementing flexible project management methods to ensure the effectiveness of projects in the hospitality industry. The Project Leader should encourage each participant to abandon his or her approved behavior model in order to promptly resolve any issues that may arise during the implementation of the project and to respond to internal objections. As the hotel business is customer-centric, providing end-to-end services is not possible through standard management of individual customer requirements. Therefore, this study aims to determine the feasibility of using the methodology by identifying several criteria for project management (APM) in the hotel business.
Risk management in the financing of ICO projects: prospects for the use of modern technologies in Kazakhstan
Authors: Doszhan Raigul , Alimbekova Gaukhar , Kalymbekova Zhanna , Talasbek Meruyert
Published: March 2020

The article discusses the potential risks when investing in projects and ICO. The initial coin offering (ICO) is a new way for startups to raise funds and for blockchain startups, perhaps the predominant way. This new method of fundraising has only been around for a couple of years and has already enabled entrepreneurs and innovators to raise billions of dollars from global investors. The relevance of the article is to determine the advantages in the financing of ICO projects and to determine their elimination by determining the main risks arising from the financing. Analyzing the financing on foreign experience, to determine the prospects of ICO projects implemented in Kazakhstan. The purpose of this article is to determine the factors affecting the development of the economy in the financing of ICO projects. The need to study the nature of risk management in the financing of ICO-projects will allow to understand in more detail the prospects for the use of modern technologies in Kazakhstan.
Sustainable business models for innovation and success: bibliometric analysis
Authors: Bilan Yuriy , Pimonenko Tetyana , Starchenko Lyudmila
Published: March 2020

In the ongoing world trends focusing on the ecological issue, corporate social responsibilities, sustainable development goals, the current business could not be competitive without the implementation of the innovations. Besides, the application of changes contributes to the relevant transformation of the business model, considering the worldwide trends. The paper deals with the analysis of the leading scientific trends in analysing of the sustainable business models and innovations. In the paper, the authors used the bibliometric analysis of the scientific papers from Web of Science and Scopus. The main limitation to select scientific papers were as follows: published for 2000-2019 years; the language of the paper – English; papers which contain keywords – sustainable, business model and innovations. For the analysis, the VOSviewer, Scopus and Web of Science tools were used by the authors. Tools from the scientific databases allowed to identify the main parameters of the scientific publications: quantity, dynamic, country, the most cited papers, etc. VOSviewer allowed visualising the main scientific clusters which analysed the sustainable business model. Considering the findings, the rapid increase of articles on the sustainable business model was in 2000. The authors identified 13 clusters; three of them had strong linking. The most significant cluster contained focused on innovations, the second – on corporate social responsibilities and environmental management, the third cluster – on cleaner production as a core element of a sustainable business model. The tendency of scientific investigation allowed concluding that sustainable business model could not be without a complex system of innovations, corporate social responsibilities and cleaner production.
The formation of ecosystems of employment for persons with disabilities
Authors: Sokira Tatyana , Dzhulaeva Almazhan , Myshbayeva Zemfira , Bolatkyzy Saltanat , Otepbergen Kenzhakhan
Published: March 2020

The problem of employment of persons with disabilities is in the attention of all international organizations, is one of the seventeen sustainable development goals set by the UN, which defined decent work as an opportunity and prospects for personal development of any person, including those with disabilities. The urgency of this problem is becoming more acute in the modern world due to the fact that the number of disabled people is growing. This is due to the aging of the population – older people are at increased risk of disability, – and also because of the global increase in chronic diseases among the population. The article presents a comparative analysis of foreign and domestic experience in forming a social partnership ecosystem in solving the problems of persons with disabilities, analyzes the level of employment of persons with disabilities, and suggests practical steps for all stakeholders, including governments, civil society structures, and organizations of persons with disabilities, to create a favorable environmental ecosystem, develop rehabilitation and support services, and provide appropriate social support, developing inclusive policies and programs, and ensuring the application of new and existing standards and legislation for the benefit of persons with disabilities and the General public, based on a comparative analysis of the ecosystems of leading European States.
Study of the social impact of investment activities of foreign companies on the development of society: a review and analysis
Authors: Rakhmatullayeva Dinara , Khajiyeva Aiman , Kakizhanova Tolkyn , Boluspayev Shalkar
Published: March 2020

In this study, based on an analysis of foreign experience, the authors systematized the main tools for assessing the social impact of investments, including foreign direct investment (FDI), on the development of the economy and society. The authors made an attempt to generalize and explore the essence and content of each approach and recommend them for use in Kazakhstan’s practice. This is important not only for improving the investment policy in the field of attracting and regulating the activities of direct investors in Kazakhstan, but also for increasing their social responsibility to the country’s society.
The university-industry cooperation: The role of employers in quality assurance of Education
Authors: Manarbek Gulden , Zhakupova Gulnaziya , Kaliyeva Assem , Hezi Huang
Published: March 2020

The purpose of the study is to discuss the role of employers’ engagement in the educational process of universities in assuring the quality of educational services and preparing quality graduates. Realization of the principle of integrating education, science and industry in modern conditions ensures a balance between the content of educational programmes, results of R&D and industry. Thus, the paper discusses the current launched mechanisms of Kazakh National University in Kazakhstan aimed at promoting an establishment of mutual trust between the university and the employer community to ensure the quality of provided educational services. The results of the paper could serve as a guide to the most necessary aspects of cooperation practices between universities and employers for potential academy managers and practitioners in quality management processes.
Digitalization as a New Direction in Education Sphere
Authors: Dinis Sousa Rui , Karimova Beybitkul , Gorlov Sergey
Published: March 2020

Digitalization in education sphere is the new paradigm of high technologies development. The article proves that digital technologies are relevant and widely used in various areas of society: management, economic relations, science and education. However, digitalization of the educational process is of particular importance, because the several factors such an advance of the quality and relevant experience in this sphere. Today, important transformation processes are taking place in the field of education: electronic textbooks, Internet portals, databases of information needs are spreading, systems of online courses and distance learning are actively developing.
Locality of interatomic forces in tight binding models for insulators
Authors: Ortner Christoph , Thomas Jack , Chen Huajie
Published: March 2020

The tight binding model is a minimalistic electronic structure model for predicting properties of materials and molecules. For insulators at zero Fermi-temperature we show that the potential energy surface of this model can be decomposed into exponentially localised site energy contributions, thus providing qualitatively sharp estimates on the interatomic interaction range which justifies a range of multi-scale models. For insulators at finite Fermi-temperature we obtain locality estimates that are uniform in the zero-temperature limit. A particular feature of all our results is that they depend only weakly on the point spectrum. Numerical tests confirm our analytical results. This work extends Chen and Ortner [Multiscale Model. Simul. 14 (2016) 232–264] and Chen et al. [Arch. Ration. Mech. Anal. 230 (2018) 701–733] to the case of zero Fermi-temperature as well as strengthening the results proved therein.
Is the gait profile score a good marker of gait dysfunction in individuals with late effects of poliomyelitis?
Authors: Supiot Anthony , Genêt François , Cattagni Thomas , Salga Marjorie , Roche Nicolas , Pradon Didier
Published: March 2020

Late effects of poliomyelitis (LEoP) are characterized by new gait abnormalities that occur many years after the initial poliomyelitis illness. Currently, there is no consensus on the most appropriate evaluation to detect gait disorders following LEoP. This study aimed to assess and compare the effectivenes of the gait profile score with that of the symmetry index (SI) to charaterize gait abnormalities resulting from the LEOP. The SI for stance, swing, double-support duration and the step length, and gait profile score were computed from gait analysis of 12 poliomyelitis subjects and 12 healthy participants. Receiver operating characteristic analysis was used to measure the sensitivity and specificity of the SI and the gait profile score to discriminate patients with the LEoP and healthy participants. The area under the receiver operating characteristic curve was calculated for both gait the profile score and SI. With AUC values all above 0.83 (good discrimination), SI and GPS significantly discriminated the participants with the LEoP from the healthy participants (allp-values < 0.001). The results of this study show that both the gait profile score and SI may be used with a similar sensitivity by clinicians to identify potential gait abnormalities in patients with the LEoP.
Peroral endoscopic myotomy (POEM): a comparative study between Chagasic and idiopathic achalasia
Authors: Farias Galileu F.A. , de Moura Diogo T.H. , de Moura Eduardo T.H. , de Rezende Daniel T. , Hathorn Kelly E. , Nasi Ary , Queiroz Natália S.F. , de Moura Eduardo G.H.
Published: March 2020

Background and study aims Achalasia can be classified as either primary (idiopathic) achalasia or secondary achalasia, which is a consequence of another systemic disease. Peroral endoscopic myotomy (POEM) is an effective and safe treatment for achalasia. We evaluated the efficacy and safety of POEM in patients with Chagasic achalasia compared to idiopathic achalasia.

Patients and methods We evaluated POEM procedures performed at a single institution from November 2016 to January 2018. Demographic data, Eckardt score, lower esophageal sphincter (LES) pressure, body mass index, post-operative erosive esophagitis, adverse events, length of hospital stay, and procedure-related parameters were analyzed.

Results Fifty-one patients underwent POEM as a treatment for achalasia in this period (20 patients with Chagasic and 31 with Idiopathic etiology). The overall clinical success rate was 92.1 %, with no statistical difference between groups (90 % in the Chagasic group vs. 93.5 % in the Idiopathic group, P = 0.640). Both groups had significant reduction in Eckardt score and in LES pressure, and increase in bodey mass index (BMI) at 1-year follow-up. There was no statistical difference between groups regarding Eckardt score (P = 0.439), LES pressure (p = 0.507), BMI (P = 0.254), post erosive esophagitis (35 % vs. 38.7 %, P = 0.789), adverse events (30 % vs. 12 %, P = 0.163,) length of hospital stay (3.75 days vs. 3.58 days, P = 0.622), and operative time (101.3 min vs. 99.1 min, P = 0.840).

Conclusion POEM is an effective and safe treatment for patients with achalasia. There is no difference in POEM outcomes for those patients with Chagasic or Idiopathic achalasia.
Successful repair of wide traumatic rectal perforation using over-the-scope clip
Authors: Manno Mauro , Deiana Simona , Gabbani Tommaso , Vavassori Sara , Ottaviani Laura , Soriani Paola
Published: March 2020

Background and study aims We report on a case of a traumatic rectal perforation that occurred in a 16-year-old girl, which was successfully treated using an over-the-scope clip, avoiding major surgery and stoma.
Applied solidarity in times of crisis: exploring the contexts of civil society activities in Greece and Germany
Authors: Durán Mogollón Lía , Eisele Olga , Paschou Maria
Published: March 2020

The European ‘crisis decade’ triggered discussions about solidarity and it´s limits; at the policy level, the debates were mostly about determining thedeservingnessof solidarity of each vulnerable group, and at the street level, actors involved saw the demand for concrete service provision grow while their resources stayed the same or retrenched. This paper is interested in the limits of solidarity precisely at the street level; hence we investigate what combinations of operational conditions (budget, status, volunteers) lead the civil society organizations to engage in more solidarity activities (service provision and advocacy). Civil Society Organizations (CSOs) are, beside the state and the family, a vital provider of solidarity services and a significant actor in advocacy for vulnerable groups. As any organization, CSOs are rationalised structures that pursue a concrete goal and for this purpose, rely on different resources and strategies. The paper, therefore, investigates configurations of operational conditions that account for higher levels of solidarity activities by CSOs in Germany and Greece. These countries have both experienced an increase in the demand of social services while they present different civil society traditions, different welfare systems and have been differently affected by crises. While Germany was less dramatically affected by the financial crisis and voluntarily took in almost a million refugees in 2016, Greece was severely hit by the financial crisis and, located at the EU borderland, has had a different experience with the inflow of migrants and refugees. The analysis builds on a series of semi-structured interviews conducted with CSO representatives of the social sector in the framework of the TransSOL project (www.transsol.eu) in 2017. We employ a fuzzy set qualitative comparative analysis (QCA) to understand the necessary and sufficient conditions under which CSOs are more active, looking at their organizational traits and preconditions, their capacities to mobilise volunteers, their status in the community and their cross-sectional coverage of social issues.
Particle assisted structuring on metallic substrate: Anomaly when particle size exceeds irradiation wavelength
Authors: Sugathan Bijoy , Nilaya J. Padma , Pillai V. P. Mahadevan , Biswas Dhruba J.
Published: March 2020

We present here results of our study on particle assisted micro-structuring on a metallic surface. For this, dielectric polystyrene spherical particulates were deposited on an optical grade stainless steel (SS) surface, and the fundamental emission from a Nd:YAG laser and its second harmonic, to which the particulates are transparent, were used as the coherent sources for these experiments. The diameters of the particulates were chosen so as to encompass all the possibilities, viz., particulate size ≈ wavelength, particulate size < wavelength, and particulate size > wavelength. While the experimentally measured fluence values for the onset of pitting are in agreement with the analytically estimated field enhancement factors in the former two cases, there is a strong departure noted in the latter case. Percentile absorption of the incident radiation by the SS substrates as measured by an integrating sphere bore testimony to this anomalous behavior. Toward gaining a deeper insight into this phenomenon, atomic force microscopy based topographic analysis of the laser exposed surface was undertaken. This study clearly reveals the formation of double pits underneath the particulate when its size exceeds the wavelength of exposure, thus pointing to the fact that the incident energy is being redistributed, giving rise to the observed anomaly.
Potential effects of bycatch from the squat lobster fisheries in central Chile on the benthic ecosystem: a survey data approach
Authors: Montero José T. , Flores Andres , Queirolo Dante , Farias Ariel , Wiff Rodrigo , Lima Mauricio , Rivera-Rebella Carla , Ahumada Mauricio
Published: March 2020

In Chile, bottom trawling for squat lobsters is one of the most important crustacean fisheries. The fishery has been monitored for the past 15 years to assess the resource status, spatial distribution and effects on benthic species. Understanding the interactions of fishing and non-fishing activities with the benthic communities is of critical importance to estimate the potential bycatch of important economic species from fishing operations and to determine adequate spatial and temporal fishing bans. In this study we characterised the community of the main non-target species caught during historical squat lobster biomass surveys from 2000 to 2015 and interpreted the species included as potential bycatch of the fishery. Four ecological assemblages were found that differed in abundance but not in species richness, which suggests that the community structures did not differ among the areas, but rather in the relative abundances of the species. In addition, we created habitat suitability maps for the groups identified and discuss the effects of the environment and the survey method on the distribution of the groups. Managers can use this information to detect regions with high bycatch risk for demersal trawl fisheries and understand the potential interaction of fishing operations with the environment.
Noise temperature distribution of superconducting hot electron bolometer mixers*
Authors: Zhou Kang-Min , Miao Wei , Geng Yue , Delorme Yan , Zhang Wen , Ren Yuan , Zhang Kun , Shi Sheng-Cai
Published: March 2020

We report on the investigation of optimal bias region of a wide-band superconducting hot electron bolometer (HEB) mixer in terms of noise temperature performance for multi-pixel heterodyne receiver application in the 5-meter Dome A Terahertz Explorer (DATE5) telescope. By evaluating the double sideband (DSB) receiver noise temperature (T
rec) across a wide frequency range from 0.2 THz to 1.34 THz and with a large number of bias points, a broad optimal bias region has been observed, illustrating a good bias applicability for multipixel application since the performance of the HEB mixer is uniquely determined by each bias point. The noise temperature of the HEB mixer has been analyzed by calibrating the noise contribution of all RF components, whose transmissions have been measured by a time-domain spectroscopy. The corrected noise temperature distribution shows a frequency independence relation. The dependence of the optimal bias region on the bath temperature of the HEB mixer has also been investigated, the bath temperature has limited effect on the lowest receiver noise temperature until 7 K, however the optimal bias region deteriorates obviously with increasing bath temperature.
Simulation of helium supersonic molecular beam injection in tokamak plasma*
Authors: Wu Xue-Ke , Wang Zhan-Hui , Li Hui-Dong , Shi Li-Ming , Wan Di , Fan Qun-Chao , Xu Min
Published: March 2020

To study helium (He) supersonic molecular beam injection (SMBI) into H-mode tokamak plasma, a simplified multicomponent-plasma model under the assumption of quasi-neutral condition is developed and implemented in the frame of BOUT ++. The simulation results show that He species propagate inwards after He SMBI, and are deposited at the bottom of the pedestal due to intensive ionization and weak spreading speed. It is found that almost all injected helium particles strip off all the bounded electrons. He species interact intensively with background plasma along the injection path during He SMBI, making deuterium ion density profile drop at the He-deposited location and resulting in a large electron temperature decreasing, but deuterium ion temperature decreasing a little at the top of the pedestal.
Topology and ferroelectricity in group-V monolayers*
Authors: Rehman Mutee Ur , Hua Chenqiang , Lu Yunhao
Published: March 2020

The group-V monolayers (MLs) have been studied intensively after the experimental fabrication of two-dimensional (2D) graphene and black phosphorus. The observation of novel quantum phenomena, such as quantum spin Hall effect and ferroelectricity in group-V elemental layers, has attracted tremendous attention because of the novel physics and promising applications for nanoelectronics in the 2D limit. In this review, we comprehensively review recent research progress in engineering of topology and ferroelectricity, and several effective methods to control the quantum phase transition are discussed. We then introduce the coupling between topological orders and ferroelectric orders. The research directions and outlooks are discussed at the end of the perspective. It is expected that the comprehensive overview of topology and ferroelectricity in 2D group-V materials can provide guidelines for researchers in the area and inspire further explorations of interplay between multiple quantum phenomena in low-dimensional systems.
Prediction of structured void-containing 1T-PtTe2 monolayer with potential catalytic activity for hydrogen evolution reaction*
Authors: Lei Bao , Zhang Yu-Yang , Du Shi-Xuan
Published: March 2020

Two-dimensional (2D) transition metal dichalcogenides (TMDs) have attracted considerable attention because of their unique properties and great potential in nano-technology applications. Great efforts have been devoted to fabrication of novel structured TMD monolayers by modifying their pristine structures at the atomic level. Here we propose an intriguing structured 1T-PtTe2 monolayer as hydrogen evolution reaction (HER) catalyst, namely, Pt4Te7, using first-principles calculations. It is found that Pt4Te7 is a stable monolayer material verified by the calculation of formation energy, phonon dispersion, and ab initio molecular dynamics simulations. Remarkably, the novel structured void-containing monolayer exhibits superior catalytic activity toward HER compared with the pristine one, with a Gibbs free energy very close to zero (less than 0.07 eV). These features indicate that Pt4Te7 monolayer is a high-performance HER catalyst with a high platinum utilization. These findings open new perspectives for the functionalization of 2D TMD materials at an atomic level and its application in HER catalysis.
Ab initio studies on ammonium iodine under high pressure*
Authors: Lu Mengya , Huang Yanping , Tian Fubo , Li Da , Duan Defang , Zhou Qiang , Cui Tian
Published: March 2020

Ammonium iodine (NH4I) as an important member of hydrogen-rich compounds has attracted a great deal of attention owing to its interesting structural changes triggered by the relative orientations of adjacent ammonium ions. Previous studies of ammonium iodide have remained in the low pressure range experimentally, which we first extended to so high pressure (250 GPa). We have investigated the structures of ammonium iodine under high pressure through ab initio evolutionary algorithm and total energy calculations based on density functional theory. The static enthalpy calculations show that phase V is stable until 85 GPa where a new phase Ibam is identified. Calculations of phonon spectra show that the Ibam phase is stable between 85 GPa and 101 GPa and the Cm phase is stable up to 130 GPa. In addition, ammonium iodine dissociates into NH3, H2, and I2 at 74 GPa. Subsequently, we analyzed phonon spectra and electronic band structures, finding that phonon softening is not the reason of dissociation and NH4I is always a semiconductor within the pressure range.
Optical modulation of repaired damage site on fused silica produced by CO2 laser rapid ablation mitigation*
Authors: Tan Chao , Zhao Lin-Jie , Chen Ming-Jun , Cheng Jian , Yin Zhao-Yang , Liu Qi , Yang Hao , Liao Wei
Published: March 2020

CO2 laser rapid ablation mitigation (RAM) of fused silica has been used in high-power laser systems owing to its advantages of high efficiency, and ease of implementing batch and automated repairing. In order to study the effect of repaired morphology of RAM on laser modulation and to improve laser damage threshold of optics, an finite element method (FEM) mathematical model of 351 nm laser irradiating fused silica optics is developed based on Maxwell electromagnetic field equations, to explore the 3D near-field light intensity distribution inside optics with repaired site on its surface. The influences of the cone angle and the size of the repaired site on incident laser modulation are studied as well. The results have shown that for the repaired site with a cone angle of 73.3°, the light intensity distribution has obvious three-dimensional characteristics. The relative light intensity on z-section has a circularly distribution, and the radius of the annular intensification zone increases with the decrease of z. While the distribution of maximum relative light intensity on y-section is parabolical with the increase of y. As the cone angle of the repaired site decreases, the effect of the repaired surface on light modulation becomes stronger, leading to a weak resistance to laser damage. Moreover, the large size repaired site would also reduce the laser damage threshold. Therefore, a repaired site with a larger cone angle and smaller size is preferred in practical CO2 laser repairing of surface damage. This work will provide theoretical guidance for the design of repaired surface topography, as well as the improvement of RAM process.
Effect of chemical ordering annealing on superelasticity of Ni–Mn–Ga–Fe ferromagnetic shape memory alloy microwires*
Authors: Liu Yanfen , Zhang Xuexi , Shen Hongxian , Sun Jianfei , Li Qinan , Liu Xiaohua , Li Jianjun , Cheng Weidong
Published: March 2020

Ni50Mn25Ga20Fe5 ferromagnetic shape memory alloy microwires with diameters of ∼ 30–50 μm and grain sizes of ∼ 2–5 μm were prepared by melt-extraction technique. A step-wise chemical ordering annealing was carried out to improve the superelasticity strain and recovery ratio which were hampered by the internal stress, compositional inhomogeneity, and high-density defects in the as-extracted Ni50Mn25Ga20Fe5 microwires. The annealed microwires exhibited enhanced atomic ordering degree, narrow thermal hysteresis, and high saturation magnetization under a low magnetic field. As a result, the annealed microwire showed decreased superelastic critical stress, improved reversibility, and a high superelastic strain (1.9%) with a large recovery ratio (> 96%). This kind of filamentous material with superior superelastic effects may be promising materials for minor-devices.
High gain fiber-solid hybrid double-passing end-pumped Nd:YVO4 picosecond amplifier with high beam quality*
Authors: Dong Xueyan , Li Pingxue , Li Shun , Wang Dongsheng
Published: March 2020

We propose a fiber-solid hybrid system which consists of a semiconductor saturable absorber mirror (SESAM) mode-locked fiber seed with a pulse width of 10.2 ps and a repetition rate of 18.9 MHz, a two-level fiber pre-amplifier and a double-passing end-pumped Nd:YVO4 amplifier. In the solid-state amplifier, to enhance the gain and the extraction efficiency, a specially designed structure in which the seed light passes through the gain medium four times and makes full use of population inversion is used as the double-passing amplifier. Besides, the beam filling factor (the ratio of the seed light diameter to the pump light diameter) and the thermal lens effect of the double-passing amplifier are considered and its optical-to-optical conversion efficiency is further improved. To preserve the beam quality of the double-passing amplifier, a new method of spherical-aberration self-compensation based on the principles of geometrical optics is used and discussed. Our system achieves a maximum average power of 9.5 W at the pump power of 28 W, corresponding to an optical-to-optical efficiency of 27%. And the beam quality factor M
2 reaches 1.3 at the maximum output power.
Microstructure and ferromagnetism of heavily Mn doped SiGe thin flims*
Authors: Wang Huanming , Sun Sen , Xu Jiayin , Lv Xiaowei , Wang Yuan , Peng Yong , Zhang Xi , Xiang Gang
Published: March 2020

Heavily Mn-doped SiGe thin films were grown by radio frequency magnetron sputtering and then treated by post-growth thermal annealing. Structural characterizations reveal the coexistence of Mn-diluted SiGe crystals and Mn-rich nanoclusters in the annealed films. Magnetic measurements indicate the ferromagnetic ordering of the annealed samples above room temperature . The data suggest that the ferromagnetism is probably mainly contributed by the Ge-rich nanoclusters and partially contributed by the tensile-strained Mn-diluted SiGe crystals. The results may be useful for room temperature spintronic applications based on group IV semiconductors.
STM study of selenium adsorption on Au(111) surface*
Authors: Liu Bin , Zhuang Yuan , Que Yande , Xu Chaoqiang , Xiao Xudong
Published: March 2020

Adsorption of chalcogen atoms on metal surfaces has attracted increasing interest for both the fundamental research and industrial applications. Here, we report a systematic study of selenium (Se) adsorption on Au(111) at varies substrate temperatures by scanning tunneling microscopy. At room temperature, small Se clusters are randomly dispersed on the surface. Increasing the temperature up to 200 °C, a well-ordered lattice of Se molecules consisting of 8 Se atoms in ring-like structure is formed. Further increasing the temperature to 250 °C gives rise to the formation of Se monolayer with Au(111)-

3

×

3

lattices superimposed with a quasi-hexagonal lattice. Desorption of Se atoms rather than the reaction between the Se atoms and the Au substrate occurs if further increasing the temperature. The ordered structures of selenium monolayers could serve as templates for self-assemblies and our findings in this work might provide insightful guild for the epitaxial growth of the two-dimensional transition metal dichalcogenides.
High performance InAlN/GaN high electron mobility transistors for low voltage applications*
Authors: Mi Minhan , Zhang Meng , Wu Sheng , Yang Ling , Hou Bin , Zhou Yuwei , Guo Lixin , Ma Xiaohua , Hao Yue
Published: March 2020

A high performance InAlN/GaN high electron mobility transistor (HEMT) at low voltage operation (6–10 V drain voltage) has been fabricated. An 8 nm InAlN barrier layer is adopted to generate large 2DEG density thus to reduce sheet resistance. Highly scaled lateral dimension (1.2 μm source–drain spacing) is to reduce access resistance. Both low sheet resistance of the InAlN/GaN structure and scaled lateral dimension contribute to an high extrinsic transconductance of 550 mS/mm and a large drain current of 2.3 A/mm with low on-resistance (R
on) of 0.9 Ω⋅mm. Small signal measurement shows an f
T/f
max of 131 GHz/196 GHz. Large signal measurement shows that the InAlN/GaN HEMT can yield 64.7%–52.7% (V
ds = 6–10 V) power added efficiency (PAE) associated with 1.6–2.4 W/mm output power density at 8 GHz. These results demonstrate that GaN-based HEMTs not only have advantages in the existing high voltage power and high frequency rf field, but also are attractive for low voltage mobile compatible rf applications.
A Framework for Requirements Prioritization Process in Agile Software Development
Authors: AbdElazim Khaled , Moawad Ramadan , Elfakharany Essam
Published: March 2020

Requirements engineering is a crucial phase of software engineering, and requirements prioritization is an essential stage of requirements engineering particularly in agile software development. Requirements prioritization goals at eliciting which requirements of software need to be covered in a particular release. The key point is which requirement will be selected in the next iteration and which one will be delayed to other iterations for minimizing risk during development and meeting stakeholders’ needs. There are many existing techniques for requirement prioritization, but most of these techniques do not cover continuous growth and change of requirements or cover requirements dependencies. So, most of these prioritization techniques need to be more continuous, scalable, implemented merely and integrated with software development life cycle and not work separately. This paper introduces a framework to prioritize requirements in agile software development. This framework tries to find solutions for the challenges facing this prioritization process such as how to make this prioritization continuous and scalable and how to deal with rapidly requirement changes and its dependencies.
Mapping the potential pollution of fisheries industry wastewater in the Southern Coast of Jember Regency: Preliminary study on wastewater management planning
Authors: Ariyunita S , Listyawati R N
Published: March 2020

Fisheries industries produce wastewater as by-product. Based on preliminary surveys, there is no integrated wastewater management in the Southern Coast of Jember Regency where the centre fisheries industry was taken place. This study aims to find areas that are potentially polluted by fisheries industries wastewater and offer the information for planning integrated wastewater management in the coastal area of Jember Regency. We collected primary and secondary data about fish processing production and the impact of wastewater for environment. The results were analysed descriptively and potentially polluted areas were mapped with Arc-Gis software. The study area involves two sub-districts, Puger and Ambulu sub-district. Surveys conducted to 16 fisheries industries showed that 81.25% of them discharged the untreated wastewater into the stream directly. Wastewater disposal into the stream not only cause pollution in water bodies but also cause pollution in the Indian Ocean.
Process simulation of power screw failure on fatigue load using autodesk inventor
Authors: Mustika V , Triono A , Wibowo R K K
Published: March 2020

The paper presents the study on the use of simulation software in manufacturing industry. It is perceived as a tool for visualization of an on-going process in fatigue load. The design of this study is to simulate the stress distribution due to the loading of the power screw (or lead screw) fatigue using Autodesk Inventor software simulation version 2018. Power screw used is steel material with a round bar shape. It is called medium carbon steel (S 45 C) with specifications of tensile strength at 48 kg/mm2, creep limit at 29 kg/mm2, hardness range (Hs) of 137 to 197 kg/mm2, chemical elements in a percentage of 0.27 to 0.33, Si of 0.15 to 0.35, Mn of 0.60 to 0.90, P of 0.030 and, S of 0.035. The modeling used in this study is by finite element method analysis, which consist of several steps. The steps involve 3D geometry design based on the existing dimension, importing the CAD (Computer Aided Drawing) of 3D geometry design to finite element software, engineering the data by entering the mechanical properties, meshing which indicate the limit of the geometry of the model into numbers of elements in the properties, determining the fixed position of the central points of the static load and fatigue load given to power screw components application, and determining the coordinate system for the solution. The results shows the mechanical properties of S45C carbon steel power screw. It has a maximum von mises stress of 4.546 MPa with the first principal stress of 4.518 MPa. The third principal stress of the material is 0.538 MPa, the displacement is 0.001602 mm, and safety factor is 15 ul.
Diversity of freshwater crab (decapoda) in meru betiri national park
Authors: Susilo V E , Suratno  , Wowor D , Abror M N
Published: March 2020

The abundance of flora and fauna in tropical forests throughout Indonesia is very high. Indonesian fauna shows its diversity in terms of ecology found in various ecosystem types. One of them is freshwater ecosystem. Freshwater crabs have a wide habitat distribution so they can be found in various forms of freshwater. This study aimed to determine the level of diversity and determine the abiotic conditions of freshwater crab habitat. The location determination of sampling was done purposively along with road sampling. The tools used to catch freshwater crabs were bubu and tray net. The results obtained in the Meru Betiri National Park, especially in Andongrejo and Bandealit resorts, revealed that five species of freshwater crabs consist of three families. The diversity index of freshwater crabs in both resorts is relatively low. That is because most freshwater crab species belongs to endemic animals because of their limited spreading ability, relatively low fecundity, and stenotopic habits. Meru Betiri National Park has abiotic conditions that are ideal for supporting freshwater crab life.
Super edge local antimagic total labeling of some graph operation
Authors: Karimah M , Dafik  , Slamin  , Kurniawati E Y , Agustin I H
Published: March 2020

Let G be a simple connected, and undirected graph. Graph G has a set of vertex denoted by V(G) and a set of edge denoted by E(G). d(v) is the degree of vertex v ∈ V(G) and Δ(G) is the maximum degree of G. A total labeling of graph G(V, E) is said to be local edge antimagic total labeling if a bijection f : V(G) ∪ E(G) → {1, 2, 3, …, |V(G)| + |E(G)|} such that for any two adjacent edges e
1 and e
2, wt
(e
1) ≠ wt
(e
2), where for e = uv ∈ G, wt
(e) = f(u) + f(uv) + f(v). The local edge antimagic total labeling induces a proper edge coloring of G if each edge e is assigned the color wt
(e). The edge local antimagic chromatic number of G denoted by γelat
(G), is the minimum number of distinct color induced by edge weights over all local antimagic total labeling of G. In this paper, we determined the edge local antimagic chromatic number of Diamond Ladder graph, Pn
⊙ Pm
Three Circular ladder graphht, and shack(F
2, v, n).
On total H-irregularity strength of graphs
Authors: Hidayatul M , Dafik  , Agustin I H , Nisviasari R , Kurniawati E Y
Published: March 2020

Let G be a graph with vertex set V and edge set E. Total labeling f : V(G) ∪ E(G) → {1, 2, 3, …, l} called a total l-labeling of a graph G. The total l-labeling is a total H-irregular l-labeling of graph G if for H ⊆ G, the total H-weights wtf
(H) = ∑
v∈V(H)
f(v) + ∑
e∈E(H)
f(e) are distinct. The irregularity strength s(G) of a graph G is known as the minimum k for which G has an irregular assignment using labels at most k. The total H–irregular a–labeling from the minimum where the graph G is called the total H–irregularity strength of G, is denoted by tHs(G). In this paper, we have obtained tHs from linegrid, buttrefly, hexagonal and diamond graphs. To obtain the tHs, we begin to study the total irregularity strength of graph G with subgraph H.
Modeling the relationship between public transportation and traffic conditions in urban areas : a system dynamics approach
Authors: Sardjono W , Selviyanti E , Perdana W G
Published: March 2020

The goals of the paper were to describe were and find the relations between numbers of available public transportation and traffic congestion and other variables that can reduce traffic congestion in Jakarta. The data that used in the simulation were provided by DKI Jakarta Provincial Statistics Agency from view years ago. To analyze the problem, System Dynamics are used to simulate the condition in the future using the models created based on relations between several variables. The results of the analysis shows that numbers of available public transportation cannot reduce traffic congestion if the numbers of private transportation weren’t decreased. It can be concluded that government must force their citizen to reduce the number of private transportation by increasing the inflation supported by increasing numbers of available public transportation to accommodate deficit in transportation while building new roads to accommodate transportation growth in the future.