bluuebunny/crossref_metadata_2025 huggingface dataset:
The Speech “Bamana”: Using the Syllable Repetition Task to Identify Underlying Phonological Deficits in Children With Speech and Language Impairments
Authors: Roepke Elizabeth , Bower Kathryn E. , Miller Catherine A. , Brosseau-Lapré Françoise
Published: July 2020

Purpose

This study compared performance on the Syllable Repetition Task (SRT) by preschoolers with diverse speech and language abilities to identify underlying impairments in speech processes.

Method

Three groups of 13 children ages 4 and 5 years with (a) typically developing (TD) speech and language, (b) speech sound disorder (SSD), and (c) comorbid developmental language disorder and speech sound disorder (DLD + SSD) completed the SRT. We calculated competence, memory, encoding, and transcoding scores, as well as word-initial stress pattern and vowel accuracy.

Results

A 3 × 3 (Group × Syllable length) factorial multivariate analysis of covariance revealed group differences for all measures and syllable length differences for memory, transcoding, and competence. There were no interactions between group and syllable length. TD children obtained the highest scores on each measure, though children with DLD + SSD performed similarly to TD children on encoding when vocabulary was included as a covariate. Children with SSD only outperformed children with DLD + SSD on competence and transcoding, and these two groups performed similarly on memory. A separate exploratory analysis using a 3 × 3 multivariate analysis of covariance revealed that children with DLD + SSD were more likely than children in the other groups to produce weak word-initial stress and vowel errors during syllable repetition.

Conclusion

Children with SSD and DLD + SSD exhibit underlying phonological deficits on the SRT compared to TD children. Results support the claim that memory and encoding are deficits in SSD. In addition, transcoding deficits were identified among children with no known oromotor impairment. Therefore, more research is required to identify the relationship between SRT performance and explicit measures of phonological processing.
Assessment practice of geomechanical risks for slopes and retaining walls
Authors: Polovov Boris , Valiev Niyaz , Volkov Maksim , Lebzin Maksim
Published: July 2020

The methods of geomechanical analysis are considered, which together allow to correct and propose new proactive approaches to ensure the geomechanical safety of slopes and retaining walls of mining structures. A very promising solution to this problem is the addition of a traditional deterministic measure for assessing the condition of slopes and retaining walls, i.e. safety margin factors, with simulation quantitative assessments of risk levels that objectively reflect the instability of the environment. In such a complex, the deterministic block performs insurance functions and determines that the results of the analysis do not contradict the requirements of regulatory documents; simulation (according to the Monte Carlo method) provides an unambiguous solution on the factors of economic and social security, eliminates or significantly reduces the likelihood of making unnecessary costs.
Separation of minerals in a centrifugal field using circulating concentration
Authors: Penkov Pavel , Morozov Yuri
Published: July 2020

Due to the high speed of rotation of the centrifugal separator cone, it is possible to separate particles of small sizes. In its turn, the high speed of rotation of the centrifugal separator cone leads to clogging of the grooves of the separator cone with solid particles. The increased pressure of the turbulizing agent contributes to the loosening of solid particles in the grooves of the centrifugal separator cone, but can wash out particles with increased density from the grooves. Also, the loss of a valuable component is associated with the fact that particles of a valuable component located on the surface of the near-wall layer do not have time to get into the grooves in one cycle and are washed out of the separator cone together with the light fraction. In this regard, there is a need to study the increase in centrifugal separation using it in the circulating concentration scheme. Experiments were carried out in laboratory conditions on an artificial mixture of tungsten and quartz. The results of the experiments show an increase in enrichment rates.
Procedure of computation and automatic marking of drill hole spacing at excavation of horizontal workings
Authors: Kononenko Maxim , Ganiev Ruslan , Kuzminykh Roman
Published: July 2020

Contemporary approaches and techniques impacting subsurface penetration performance and penetration rate are studied and analyzed. Two main dimensions are identified, and the works performed during operation were compared. A solution based on implementation of modular architecture of the system with optional connection of modules, performing computations according to various techniques, enabling comparison of calculation results and selection of the most effective option, is proposed. A computational experiment based on real-objects data was conducted. The factors effecting drilling-and-blasting operations were identified during its course. A model designing the optical projections over targeted drill holes is also obtained. The proposed approach is more effective and accurate than manual application of drill hole spacing by paint; in addition, is saves a lot of time required for setting-up. Another highlighted advantage of the developed approach is high quality and accuracy at marking of the drill hole spacing for blasting pattern in accordance with geometrical features of the surfaces, vs. approaches and techniques used at preparation to drilling earlier. Aside from that, a clear trend of consistent improvement and perfection by means of application of intelligent algorithm is observed in this scope.
Aerodynamic adaptivity criterion in the production methodology of the energy-efficient mine turbomachines
Authors: Makarov Vladimir , Makarov Nikolai , Lifanov Alexandr , Materov Artem , Kosarev Nikolay
Published: July 2020

Competitive growth of enterprises in the mining and oil and gas industries of the Russian economy, combined with industrial safety requirements, updates the task of developing the design and production methodology for the aerodynamically adaptive turbomachines with a nature-like dominance. Such machines adequately and economically soundly establish the necessary parameters of the air environment in the technological space that implement the concept of optimal subsurface management ecotechnology. This article proposes a production methodology for the energy-efficient turbomachines using the aerodynamic adaptability criterion that determines the relations between the velocity circulation and flow acceleration around the vane cascade profiles as the nature-like dominance of the process for converting the mechanical rotational energy of impeller into the internal energy of the air flow. The Karman theory of bound and free vortices, the Chaplygin-Joukowski-Kutta hypothesis, the conformal mapping method, and curve irregularities are used for development of a mathematical model for controlling the aerodynamic adaptability. It is proved that the control dominant is the intensity of the sources distributed over the turbomachine impeller vane profile that determine the flow diffusivity and as a result the acceleration circulation around the profile. It has been experimentally confirmed that the use of profiles obtained using the proposed technique increases the aerodynamic adaptability coefficient of the turbomachine by 51%, while increasing the area of its cost-effective performance by at least 2 times.
Simulation of stresses and contact surfaces of disk rolling cutters with the rock when sinking in mixed soils
Authors: Gubanov Sergey , Petsyk Alexander , Komissarov Anatoly
Published: July 2020

In this paper, we consider the crack propagation in the rocks during sinking depending on the distance between the cutters. Under the same conditions, the hard and soft rocks form various fracture networks that leads to uneven sinking and decrease in the efficiency of the tunneling machine. In order to study this issue, four ranges of distance between the contact surfaces and various incidence angles of the contact surface were selected. The study includes a system that is a mountain mass layout with a disk cutter the only parameter of which is the tip width or the contact width of the disk cutter with the end-type rock. Simulation of research conditions and finding a solution to the problem were performed using the Autodesk Inventor Nastran 3D simulation software.
Studies of factors affecting stability and efficiency of anion exchanger
Authors: Mukhtarova Nigora , Aliev Bakhodir , Turabdzhanov Sadritdin , Rakhimova Latofat
Published: July 2020

Various industries such as mining and the chemical industry are one of the most used ion exchange processes for water and wastewater treatment. The first section of this work presents the mechanism of the polycondensation reaction to obtain the polymer matrix of anion exchanger. Elemental analytical data conformed that anion exchanger holds 34,99% of nitrogen atoms and 44,47% oxygen atoms in the structure. In addition to the synthesis of the anion exchanger, physicochemical factors have a significant effect. The temperature of reactions for a certain time using a Lewis catalyst, the choice of the optimal solvent for improving swelling capacity of the starting monomers, due to their advantages as effective materials at a low price, are described in the second section. The information in the last section of the paper is devoted to the sorption properties and the ion-exchange processes in where the obtained anion exchanger was studied and used.
Environment protection during mining in the Russian Arctic: modern trends and perspectives
Authors: Gassiy Violetta , Stoikov Vasiliy
Published: July 2020

The paper is devoted to the fundamental issues of the environment protection and mining in the Arctic territory. The author considers the main trends of the industrial development and its impact on the specific ecosystem of the Arctic. The newest laws adopted in the Russian Federation on Arctic development and state policy is researched. In the paper the analysis of the data on the investment to the environment protection in Russia is also performed. It allows developing recommendations for the improvement of environment protection including organizational, legal and scientific measures. The author also researches the industrial development impact on human living conditions and health decreased by the worsening environment of the Arctic. In the paper the necessity of the partnership and cooperation between subsoil user, government and local communities (including indigenous peoples) is justified. The recommendations given in the conclusions include the community councils’ formation for the monitoring the quality of the environment on the local level. It could help to prevent conflicts in the Arctic during mining. Other recommendations consider possible ways for the improvement of state policy in the Arctic as well as the mechanisms of the environment economics.
The study of the main soil types and their composition in the Tarnier deposit
Authors: Parfenova Larisa , Ekimova Olga
Published: July 2020

In this paper, soil types found on the territory of the Tarnier deposit of copper pyrite ores are considered. The contents of rock-forming components in the main soil types are determined. The analysis of excesses of permissible concentrations in soils was performed.
Analysis and Feasibility of Measures to Minimize the Impact of Acid Mine Waters Discharged by Abandoned Copper-Sulphide Mines on Hydrosphere of the Tagil River
Authors: Ribnikova Liudmila , Navolokina Vera
Published: July 2020

Mass closure of copper-sulphide mining sites both in the Sverdlovsk Region and worldwide resulted in the emergence of environmental challenges. One of such challenges is generation and discharge of acid mine waters. Manmade and natural factors have their impact on chemical composition of mine waters due to activation of sulphides oxidation processes taking place in disturbed rock mass and mines. Concentrations of components in treated mine waters are much higher than MAC (dozens and hundreds of times for iron, copper and zinc). That results in pollution of hydrosphere which goes on for decades and spreads over large distances along rivers. Quite a few reasons cause environmental degradation of hydrosphere in old industrial districts. These are baseline amounts of metals in the hydrosphere, low rates of self-rehabilitation of dead pits, high amounts of acid waters, high amounts of contaminants in mine waters, imperfection of treatment systems. Given the demand of mine waters treatment over decades, improvement of existing treatment systems and implementation of new technologies are required.
Regulating ecosystem service ‘Regulation of greenhouse gas flows’: Current status and regulatory Promotion in Russia
Authors: Akhmedova Irina , Pinigina Elena , Prituzhalova Olga , Sulkarnaeva Liliia , Zherebyateva Natalia
Published: July 2020

Ecosystem services are an integral part of a country's natural capital, and they require economic valuation. However, in Russia, there is no legislative methodological basis for the economic assessment of many ecosystem services in Russia, particularly the regulation of greenhouse gas flows. The Global climate change, the urgent need in transition to a low-carbon economy, the fall in global oil demand and the dissimilation of the alternative energy sources, the need to reduce the carbon footprint emphasize the strong demand for the creation of the system of payment for ecosystem services and considering service "regulation of greenhouse gas flows" as a category of marketable goods. "Low carbon" is a significant competitive advantage in the markets. The article considers the Russian experience of the ecosystem services of terrestrial ecosystems assessment snd provides an overview of crucial Russian regulations in the field of regulating greenhouse gas emissions. We established that the rhetoric of the key legislation items in the field of greenhouse gas regulation goes along with the world agenda. The main problem today is the need to launch an economic mechanism for regulating greenhouse gas emissions.
Small mining and exploration enterprises in the Urals
Authors: Boltyrov Vladimir , Storozhenko Lyubov , Degtyarev Sergey , Bobina Tatyana
Published: July 2020

The article describes small mining and exploration enterprises in the Urals, some considerations are put forward to improve procedures of commercialization of natural and man-made facilities to be used by the small enterprises.
On improving the historic manufacture territories in the mining cities of the Middle Urals
Authors: Kolchina Margarita , Konovalov Vladimir , Kolchina Natalya
Published: July 2020

The article is devoted to the analysis of spatial organization of the mining cities historical sites located in the Middle Urals with a special focus on the old mining territories. The article overviews the Demidov family contribution in the mining development of the Ural Region; the presented research also suggests a mining cities classification in terms of their age; the given study analyses the land management and construction development of the historic sites and its residential areas, and the condition of the architectural objects which form these sites and areas; the authors of article propose a classification of historical sites. The research singles out the ecological, social and economic problems resulting from the still existing out-dated mining sites. The authors recommend a concept of revitalizing the historic mining territories. The article also determines the trends for further research.
Assessment of occupational risks of employees engaged in open-pit mining
Authors: Timofeeva S.S. , Drozdova I.V. , Boboev A.A.
Published: July 2020

Currently, Uzbekistan is in the process of legislation modernization, primarily in matters of labor protection and industrial safety. Modernization consists in the transition from a previously existing ineffective system focused on compensation payments to a modern system based on preventive approaches, which imply continuous improvement of work conditions. The aim of this work is to analyze the legislation in the field of labor protection management, obliging employers to proceed to occupational risks assessment and their management, as well as the assessment of occupational risks for miners, working under the influence of harmful and dangerous production factors during gold mining in the quarry, and the development of measures to reduce them.

The possible reasons for the discrepancy with the stated requirements of the physical factors of the miners working environment when performing work in gold mining quarries are analyzed. It has been established that professional risks for personnel are classified as high and medium and it is necessary to carry out organizational and technical measures to minimize them.
Social and technical differentiation in smart meter rollout: embedded scalar biases in automating Norwegian and Portuguese energy infrastructure
Authors: Sareen Siddharth
Published: July 2020

Within the energy geographies debate on the uneven scalar effects of energy transitions, this article addresses the under-examined, increasing intersection of automation and energy transitions. Using a comparative case of national smart meter rollouts—the deployment of distributed energy monitors whose diffusion constitutes the foundation for layering and automating energy infrastructure—it draws on two contrasting studies. One features an urban living lab during Norway’s rapidly completed smart meter rollout to 2.9 million consumers; the other targets the national scale in Portugal during its recently accelerated two-fifths completed smart meter rollout across six million consumers. The article identifies twin scalar biases: (i) social aspects of automation are controlled at higher scales while users are responsibilised for them at the household scale, and (ii) both control over and responsibility for technical aspects are restricted to higher scales. It empirically specifies how these scalar biases modulate socio-technical infrastructural interventions, such as smart meters. On this basis, it argues that embedding social and technical differentiation due to such scalar biases risks dehumanising technical aspects while detechnicising social aspects in this early intersection of energy transitions and automation.
Sol–gel synthesis of doped Cu2V2O7 fine particles showing giant negative thermal expansion
Authors: Sato M. , Warne-Lang V. , Kadowaki Y. , Katayama N. , Okamoto Y. , Takenaka K.
Published: July 2020

We report the sol–gel synthesis of Cu2V2O7 fine particles, in which some of the constituent Cu is replaced with other elements. The sintered body of Zn substituted β-Cu1.8Zn0.2V2O7 shows a large negative thermal expansion (NTE) over a wide temperature range due to microstructural effects peculiar to a ceramic body. Using the sol–gel method, we successfully produced β-Cu1.8Zn0.2V2O7 ceramic fine particles that retain the same level of thermal expansion suppression capabilities as the bulk with a size of about 1 μm. We also succeeded in performing rare earth metal (Ce, Sm, Yb) substitutions, which might be a clue for improving NTE performance. These achievements provide particulate filler for thermal expansion control of a micrometer region, which has been earnestly sought in many fields of technology.
Analysis of the different sources of stress acting in fully rough turbulent flows over geometrical roughness elements
Authors: Toussaint D. , Chedevergne F. , Léon O.
Published: July 2020

The discrete element roughness method is considered in this article for the prediction of turbulent flows over rough walls. This approach is derived by ensemble- and volume-averaging the Navier–Stokes equations, providing double-averaged Navier–Stokes equations, and yielding three unknown terms in the momentum equation: the Reynolds stress and dispersive stress tensors and the average drag force acting on the roughness elements. This work aims at analyzing these different terms, quantifying their respective contributions to the near-wall momentum budget, and providing guidance for their modeling. For this purpose, relevant data of turbulent flows are required. Roughness-resolved Reynolds-averaged Navier–Stokes simulations of transitionally and fully rough channel flows over academic roughness configurations are performed at high friction Reynolds numbers ranging from 3500 to 8000. Comparisons with existing and new velocity measurements performed in rough-wall turbulent boundary layers provide support to the simulation results, a particular emphasis being given on the validity of the numerical results in the wake of the roughness elements. These numerical results highlight the influence of roughness elements geometry and density on the roughness drag coefficient and the dispersive stress. It is particularly suggested that the standard roughness drag closure model should be revisited for double-averaged flows. Furthermore, the dispersive stress is shown to mainly originate from the wake of the roughness elements, an observation that could be leveraged for its modeling. However, since this stress contributes only marginally to the global stress and to the skin friction coefficient, such a modeling may not be critical at first order.
Understanding the interplay of stability and efficiency in A-site engineered lead halide perovskites
Authors: Ünlü Feray , Jung Eunhwan , Haddad Jinane , Kulkarni Ashish , Öz Senol , Choi Heechae , Fischer Thomas , Chakraborty Sudip , Kirchartz Thomas , Mathur Sanjay
Published: July 2020

Organic–inorganic hybrid lead halide perovskites have gained significant attention as light-harvesting materials in thin-film photovoltaics due to their exceptional optoelectronic properties and simple fabrication process. The power conversion efficiency of perovskite solar cells (PSCs) has surged beyond 25% in a short time span. Their transition to commercial market is a “work in progress” due to limited long-term operational stability and the persisting environmental concern due to the presence of lead. Comprehensive investigations on the interplay of material composition and interfacial effects on the device performance of PSCs based on methylammonium lead iodide have shown the crucial role of an A-site cation in incipient deterioration of the material through external stimuli (moisture, light, oxygen, or heat). Consequently, a partial or complete replacement of A-site cations by up to four isoelectronic substituents has resulted in many new perovskite compositions. The correlations between the chemical composition and the optoelectronic properties are, however, not always easy to determine. A-site cation management is governed by stability and charge neutrality of the lattice, and the choices include Cs+-cations and organic cations such as CH3NH3+ or CH(NH2)2+ and combinations thereof. Since the size of the cations is an important structural parameter, an adequate compositional engineering of the A-site could effectively optimize the stability by reducing non-radiative defect sites and enhancing carrier lifetimes. This Perspective reflects on the experimental strategies for A-site cation management and their direct impact on the stability and device performance. It also highlights the opportunities and challenges for further research and industrial commercialization of PSCs.
Corpus-based contrastive studies
Authors: Hasselgård Hilde
Published: July 2020

This article outlines the beginnings of corpus-based contrastive studies with special reference to the development of parallel corpora that took place in Scandinavia in the early 1990s under the direction of Stig Johansson. It then discusses multilingual corpus types and methodological issues of their exploration, including thetertium comparationisfor contrastive studies based on different types of corpora. Some glimpses are offered of recent developments and current trends in the field, including the widening scope of corpus-based contrastive analysis, concerning language pairs as well as the kinds of topics studied and the methods used. The paper ends by identifying and discussing some challenges for the field and indicating prospects and directions for its future.
Questions in English and Swedish fiction texts
Authors: Axelsson Karin
Published: July 2020

The aim of this article is to shed new light on the use and translation of English and Swedish questions in fiction by using a combination of parallel and comparable corpus data extracted from the bidirectional English-Swedish Parallel Corpus. In particular, the study examines questions containing a question mark (QMquestions) categorised intowh-interrogatives, polar interrogatives, alternative questions, tag questions (including those with invariant tags), declarative questions,wh-fragments and non-wh-fragments. The parallel analysis shows that most QMquestion types are more often translated congruently into English than into Swedish. The focus is on types with low mutual correspondence scores: fragments, tag questions and declarative questions. The comparable analyses concern both bilingual contrasts between the original texts and monolingual contrasts between the translation and original subcorpora in both languages. The bilingual analysis aligns with several preliminary findings in the parallel analysis, e.g. the favouring of tag questions and some types ofwh-fragments in English. The monolingual analysis reveals both over- and underuse in translations and points to a strong effect of source-language influence.
Placement patterns of English and French conjunctive adjuncts of contrast
Authors: Dupont Maïté
Published: July 2020

In many languages, conjunctive adjuncts (e.g.however, therefore) are syntactically mobile. Several corpus-based contrastive studies have shown that languages differ in the positions that they tend to prefer for conjunctive adjuncts. However, the studies available have formulated general cross-linguistic differences in placement for languages as wholes, without considering the possibility that such contrasts may be influenced by register. The objective of this paper is to investigate and compare the placement patterns of English and French conjunctive adjuncts of contrast in two written registers (viz. editorials and research articles) in order to measure the impact of register variation on the differences between these two languages. The results suggest that, although register variation plays a significant role on placement within each language system, language is a better predictor of placement than register, since cross-linguistic differences in placement between English and French are stable across communicative situations. In a second stage, the results obtained in the comparable corpus study are complemented with the analysis of translation data, with a view to assessing the translators’ degree of awareness of the inherent word order preferences of the target language. The study is grounded in the framework of Systemic Functional Linguistics and relies on the notions of Theme and Rheme to describe conjunctive adjunct placement.
Dialogue vs. narrative in fiction
Authors: Oksefjell Ebeling Signe , Ebeling Jarle
Published: July 2020

This paper explores both comparable and translation data from the fiction part of the English-Norwegian Parallel Corpus (ENPC) in a new way. Rather than studying fiction as a unified register, we investigate to what extent fiction can be seen to contain (at least) two distinct registers – dialogue and narrative – and to what extent this may have implications for contrastive studies based on a corpus such as the ENPC. Token counts show that, although the texts are predominantly narrative in nature, the Norwegian texts are even more so than the English ones. On the basis of word lists, two items proportionally more frequent in dialogue and that had previously been studied on the basis of the fiction texts in the ENPC were identified and chosen for further scrutiny:thereandsee. Results from these two case studies uncover some differences in the use ofthereandseein dialogue vs. narrative, most conspicuously forseewhere its preferred use in dialogue is the cognition sense and in narrative the perception sense. Forthere, a noticeable difference is the choice of verb in the Norwegian translations of existentialthere-clauses in dialogue and narrative. In narrative, verbs other than verbs of existence are sometimes chosen, while this is never the case in dialogue.
Combination of diethyldithiocarbamate with 12-O-tetradecanoyl phorbol-13-acetate inhibits the growth of human myeloid leukemia HL-60 cells in vitro and in xenograft model
Authors: Ma Yuran , Chen Shaohua , Chen Min , Ren Xiang , Patel Nandini , Liu Wenfeng , Huang Huarong , Zhou Renping , Zhang Kun , Goodin Susan , Li Dongli , Zheng Xi
Published: July 2020

12-O-tetradecanoylphorbol-13-acetate (TPA), is a major active constituent of the seed oil of Croton tiglium L., has pharmacological activity for the treatment of acute myeloid leukemia patients. Diethyldithiocarbamate (DTC) is a potent inhibitor of NF-κB show activity of anticancer. In this study, we determined the effect of DTC and TPA in combination on HL-60 cells cultured in vitro and in vivo. In this study, we have shown that DTC and TPA synergistically inhibited the growth of HL-60 cells and strongly induced apoptosis in the cells. Mechanistic studies showed that the combined effects of DTC and TPA were associated with a decrease in Bcl-2. The animal experiment showed that the combination of DTC and TPA more potently inhibited the growth of HL-60 tumors than either agent alone. Our results indicate that the administration of TPA and DTC in combination may be an effective strategy for inhibiting the growth of acute myeloid leukemia cells.
Relax-and-split method for nonconvex inverse problems
Authors: Zheng Peng , Aravkin Aleksandr
Published: July 2020

We develop and analyze a new ‘relax-and-split’ (RS) approach for inverse problems modeled using nonsmooth nonconvex optimization formulations. RS uses a relaxation technique together with partial minimization, and brings classic techniques including direct factorization, matrix decompositions, and fast iterative methods to bear on nonsmooth nonconvex problems. We also extend the approach to robustify any such inverse problem through trimming, a mechanism that robustifies inverse problems to measurement outliers. We then show practical performance of RS and trimmed RS (TRS) on a diverse set of problems, including: (1) phase retrieval, (2) semi-supervised classification, (3) stochastic shortest path problems, and (4) nonconvex clustering. RS/TRS are easy to implement, competitive with existing methods, and show promising results on difficult inverse problems with nonsmooth and nonconvex features.
Simple equipment for teaching internal photoelectric
effect
Authors: Schirripa Spagnolo Giuseppe , Postiglione Adriana , De Angelis Ilaria
Published: July 2020

In this paper, an educational tool is proposed to show the internal photoelectric
effect in a simple and clear way for Undergraduate Physics courses or High
Schools. Experimental evidence of the photoelectric effect is particularly
important in the didactic experience. This effect is fundamental to introduce
students to the world of quantum mechanics, and to the concept of quantized
energy. However, it often requires uneconomical and not easy to use equipment.
For this reason, here we describe the realization of a simple and low-cost
system based on the LED to LED structure; LEDs can in fact act as light sources,
but also as photodetectors, being sensitive to wavelengths equal to or shorter
than the predominant wavelength they emit. Through the lightning of LEDs of
different colors, we thus show that the verification of the photoelectric effect
becomes easy.
Impact of heterogeneous gate dielectric on DC, RF and circuit-level performance of source-pocket engineered Ge/Si heterojunction vertical TFET
Authors: Tripathy Manas Ranjan , Singh Ashish Kumar , Samad A , Singh Prince Kumar , Baral Kamalaksha , Jit Satyabrata
Published: July 2020

This paper reports the DC, RF and circuit-level performance analysis of short-channel Ge/Si based source-pocket engineered (SPE) vertical heterojunction tunnel field effect transistors (Ge/Si SPE-V-HTFETs) with and without a heterogeneous gate dielectric (HGD) structure for the first time. The DC performance parameters in terms of ION/IOFF and subthreshold swing (SS) are investigated for the proposed V-HTFETs. The average SS for the proposed V-HTFET with an HGD is found to be as low as 20 mV dec−1 compared to V-HTFET without any HGD (26 mV dec−1) at VDS = 0.5 V. The proposed Ge/Si SPE-V-HTFET with an HGD possesses higher cut-off frequency of 502 GHz and maximum frequency of oscillation of 2.33 THz at VDS = 0.5 V over the Ge/Si SPE-V-HTFET without any HGD which possesses cut-off frequency of 273 GHz and maximum frequency of oscillation of 1.47 THz. The proposed Ge/Si SPE-V-HTFET with and without an HGD have then been used for designing a basic current mirror circuit. Device-level study has been carried out using SILVACO ATLASTM TCAD simulator while the circuit-level investigation has been performed using the look up table based Verilog-A models in the CADENCE Virtuoso tool. The performances of the Ge/Si SPE-V-HTFET with HGD based current mirror circuit is observed to be better than the corresponding current mirror circuit designed by Ge/Si SPE-V-HTFET without any HGD.
Quantum phases for bosons in a magnetic lattice with a harmonic trap
Authors: Song Ya-Fei , Yang Shi-Jie
Published: July 2020

The phase diagram of ultracold bosons in a 2D optical lattice subjected to a uniform magnetic flux is studied by the inhomogeneous Gutzwiller variational method. With a harmonic external potential, the density profile exhibits wedding-cake shape and the Mott phase forms a series of circular platforms with integer fillings. There are annular rings of superfluid between these platforms. We identify a lot of phases, including the unicirculation phase, the Meissner phase, the vortex phase, the reversed current phase and the vortex superfluid phase, by examining the super-currents. The circular chiral currents of the reversed current phase are opposite to other phases in annular superfluid and we analyzed the transitions between different phases.
Evaluation of geomorphologic similarity between the sub-catchments of Cauvery river basin
Authors: Gowri R , Mujumdar P P
Published: July 2020

Estimation of morphometric indices can be useful in defining similarity relationships between catchments over a wide range of scales and it facilitates the effective understanding of hydrogeologic processes. This study aims at evaluating morphometric parameters to investigate geomorphologic similarity between the sub-catchments of the Cauvery river basin which is a major river basin in Peninsular India. The Digital Elevation Model (DEM) obtained from Shuttle Radar Topographic Mission (SRTM) at 30 m spatial resolution is used for assessing the linear, areal and relief aspects of morphometric analysis. The stream network analysis of sub-catchments reveals that the basin is dominated by streams of lower order and the Cauvery basin can be characterized as a seventh order basin. Linear parameters indicate that the basin is subjected to less structural disturbances. Assessment of areal parameters shows that most of the sub-catchments have elongated shape, low drainage density and course drainage texture. Evaluation of relief parameters suggests that the sub-catchments have mild slopes with moderate ruggedness and resistant soil surface. The sub-catchments are found to be geomorphologically similar in behaviour and this analysis can throw insight on development of scaling relationships as well as hydrological predictions in ungauged areas of the drainage basin.
Adsorption of copper ions from waste water using PPy/Al2O3-Fe2O3 nanocomposite
Authors: Mary Lissy P N , Madhu G , Thomas Roy M
Published: July 2020

The performance of Alumina-Iron Oxide nanocomposite as an adsorbent in the removal of Copper has been investigated. The experimental studies reveal that the removal of heavy metal from waste water can be increased within shorter duration when the nanocomposite is coated with a suitable polymer. The adsorptive properties of prepared nanocomposite with and without polymer were evaluated for the removal of copper ions using batch mode adsorption system. Characterization of the prepared nanocomposite using SEM, TEM and XRD analysis was done to check the removal efficiency before and after adsorption. This paper deals with the removal of copper from synthetic waste water using alumina/iron oxide nano composite and the increase in removal efficiency within a short period of time when it is treated with polymer coated alumina Iron/Oxide nanocomposite. The effects of pH, adsorbent dosage and time were investigated for optimum adsorption on the uptake of copper ions and observed 98 % removal. An ideal experimental response design has been carried out using Box Behnken design to evaluate the effect of different parameters in the batch mode study.
Comparative study of experimental and numerical analysis of fluid parameter around tall buildings
Authors: Nair Sreelakshmi K , Thowsif Mohammed
Published: July 2020

The rapid growth of the urban population and the consequent pressure of limited space have influenced city residential developments, which ultimately resulted in the sudden sprouting of tall and vertical structures. The structural system of present day has become less stiff and lighter than earlier, hence are usually more sensitive to the effect of lateral loads acting on it, especially wind loads. Inorder to ensure serviceability of the structure, the analysis and design must be carried out efficiently. From being termed a simple static drag force, wind force gained new dimension taking into consideration the dynamic aspects, thus demanding more attention in structural analysis and design. This paper deals with the comparative study of fluid parameters around tall structures when subjected to the traditional experimental analysis by Wind Tunnel test and the most modern approach of numerical simulation using Computational Fluid Dynamics (CFD). The comparison of result obtained via both of the above-mentioned approach and the further extend of possibilities in adopting CFD is also discussed.
Analysis on the Four Areas and Three Lines Planning on Chemical Industry Park Periphery
Authors: Xiaoming Chen
Published: July 2020

Chemical industry park and its peripheral areas are important parts of urban construction land. By analyzing the potential safety risks of the park, planning the hierarchical structure of the peripheral space, exploring the way of harmonious coexistence between the park and city, useful guidance can be provided for the planning and construction of the chemical park.
Study on adsorption of phenol by modified montmorillonite
Authors: Zong J P , Qu Y F
Published: July 2020

Organic montmorillonite was prepared from montmorillonite and cetyltrimethylammonium bromide. The absorption of phenol under different condition of time, temperature and initial concentration of phenol was measured with montmorillonite, organic montmorillonite and bentonite as raw materials. Experimental results indicated that organic montmorillonite was the best adsorbent for phenol among the three raw materials, followed by montmorillonite. And the adsorption effect of bentonite was the worst. The results also showed that the optimal conditions for adsorption were 25 °C and two hours. And montmorillonite was suitable for the absorption of high concentrations of phenol. Compared with the infrared spectra of organic montmorillonite before and after adsorption, no new chemical bonds were formed in organic montmorillonite. The organic montmorillonite only absorbed phenol in the form of physical adsorption.
Ventilation Pipeline Safety Early Warning System Based on Pipe Wall Vibration and Sound Wave
Authors: Zhang Yingchun , Shi Jian
Published: July 2020

Due to the limitation of working conditions and working environment, the ventilation pipeline safety monitoring system in an underground laboratory is facing the technical difficulties of high wind speed and high background noise. In order to effectively guarantee the safe operation of fresh air system, an abnormal early warning method for pipeline operation based on pipe wall vibration and acoustic wave is proposed, which can realize the monitoring and location of pipeline resonance and other safety incidents.
Research on Marine Radar Image Processing Method in Sea Ice Information Extraction Process
Authors: Li Ying , Gao Pengju , Chen Duo
Published: July 2020

Firstly, the effectiveness of sea ice information extraction research with navigation radar is proposed. Different methods of image pre-processing are used for different sea ice information elements, and then the functions and characteristics of various processing methods are respectively summarized. The above processing methods, while taking advantage of the convenience of obtaining image data by shipborne navigation radar, can successfully process the radar image through MATLAB and provide a basis for the next extraction of sea ice information and further expansion of research on sea ice monitoring by marine radar.
Improving Land Vehicle Gravimetry Using a New SINS/GNSS/VEL Method
Authors: Yu Ruihang , Qiu Xiaotian , Cao Juliang , Cai Shaokun , Lu Shuhai , Xu Xiao , Wang Lin
Published: July 2020

GNSS plays a key role in land vehicle gravimetry. However, GNSS is unstable due to the influence of the observation environment, which adversely affects the gravimetry accuracy. The velometer can get rid of the restrictions on the use of GNSS by land vehicle gravimetry. In this paper, a SINS/GNSS/VEL method is proposed. This method uses both centralized filtering and federated filtering methods to process the gravity data. Based on the SGA-WZ02 strapdown gravimeter developed by the National University of Defense Technology (NUDT), the vehicle gravimetry test was carried out on a road of approximately 37 kilometers in east Changsha. The test consists of 4 lines in the south-north direction with an average speed of 40 km/h. Compared with traditional SINS/GNSS method, the accuracy of repeated lines using the centralized filtering method improves from 1.58mGal to 1.37mGal, and the external accuracy improves from 2.31mGal to 2.19mGal with a resolution of 2 km. Using federal filtering method, the internal accuracy is 1.36mGal and the external accuracy is 2.22mGal. It indicates that these two methods proposed could both improve the accuracy of gravimetry compared with the traditional SINS/GNSS method. Meanwhile, with adding the external sensor observation, these methods can improve the stability of gravimetry especially for practical survey operations that will save cost and improve efficiency. Finally, several discussions are proposed on the applicability and further improvement of the method.
Research of Extreme Precipitation Variation in Shanxi Based on R / S Analysis
Authors: shaoxiong Xu , jingbo Zhao , Duzhuoqun
Published: July 2020

In this paper, the daily precipitation observation data collected from 21 meteorological stations in Shanxi Province from 1958 to 2018 by China meteorological data network were used. The R/S analysis method and MATLAB analysiz were adopted to calculate and analyze the future trend of extreme precipitation in Shanxi Province in the past 60 years. According to the study, R/S prediction analysis show that in the last 6 decades, the indexes of changes of continuous dry period and heavy rainfall show a downward trend, the indexes of the changes of annual precipitation and heavy rain days shows an upward trend, and the indexes of the future change trend of continuous wet period, extreme heavy rainfall, rainfall intensity, daily maximum precipitation and 5-day maximum precipitation remain uncertain.
Application of MBR Technology in Schoolyard Domestic Sewage Treatment
Authors: Diao Liyue
Published: July 2020

This paper discusses the special features of campus sewage, and chooses more suitable sewage treatment for campus sewage. At the same time, it expounds the advantages and disadvantages of it. Compared with city sewage from industry and agriculture, campus sewage has much more characteristic content of pollutants with higher COD, SS and tiny toxic pollutants[5]. Therefore rather than using the traditional activated sludge process, MBR is more appropriate for schoolyard domestic sewage treatment for small area, stable effluent quality, good removal efficiency and little residual sludge production. Additionally, new campuses of universities are always built far away from the city centre, and the water transportation cost can be saved with a sewage treatment system in the campus. The treated water has the quality to be used as gray water for campus watering, cleaning and so on, which can also help the universities to save money. Undeniably, it also has the disadvantages of high energy consumption and cost, for it needs to update the active membrane regularly. If it is used in cities, it will be a huge financial burden for governments. But when it is used in campuses, less sewage will need less membranes, and the polluted membranes can also be used for students’ research.
Discussion on the development of ecotourism education in China’s national parks
Authors: Yang Shuhui , Duan Xiaoyu
Published: July 2020

Ecotourism education is the foundation for the healthy development of national park ecotourism. It guides visitors to standardize their behavior, cultivate tourists’ awareness of environmental protection, and develop the local economy. At the same time, ecotourism education also contributes to regional ecological and economic sustainability. On the basis of summarizing the existing problems of eco-tourism education in China’s national parks at this stage, this paper discusses the ways and methods to solve the problems and provides references for the development of eco-tourism education in China.
Effects of Polyacrylamide on Runoff and Sediment Characteristics of Slope in Northeast Black Soil Area
Authors: Liu Hongtao , Li Qilong , Li Qiqi , Han Yu , Cai Die
Published: July 2020

Soil erosion caused by hydraulic erosion has become the main driving force to destroy the ecosystem and has become a worldwide environmental problem. The effect of polyacrylamide (PAM) on slope erosion characteristics in black soil area was studied under different conditions. The method of artificial simulation of rainfall was adopted. At 4 slopes and 5 PAM concentrations, the rainfall lasted 60min and the rainfall intensity was 80mm/h. The results show that when the rainfall intensity and underlying surface conditions are the same, the slope increases from 10° to 25°, the average runoff on the slope increases first and then decreases, and the sediment yield increases with the increase of the slope. The sediment yield on the 25° slope is 1.64 times that of the 10° slope. With the same rainfall intensity and slope compared with bare land, the concentration of Polyacrylamide in 2g / m2 increased to 5g / m2, and the average yield decreased by 10.6% to 20%. The average sediment yield decreased with the increase of the concentration, which was 20.4%∼52.5% lower than that of the bare land. The variation law of PAM and bare slope sediment yield can be described by power function. Compared with the total sediment yield of PAM and bare slope, PAM is obviously decreased. The bare slope surface is mainly characterized by splash erosion and surface erosion. The application of PAM can reduce the erosion area of slope compared with bare slope, which plays an important role in corrosion prevention.