bluuebunny/crossref_metadata_2025 huggingface dataset:
Smart Community in Public Toilet Management in Demaan Slum Settlement, Jepara Regency
Authors: Sunarti S , Helmi M , Widjajanti R , Purwanto A A
Published: December 2019

One program in sanitation improvement is the construction of public toilets in coastal slums located in Demaan, Jepara Regency. The public toilets construction is a substitute for the helicopter latrines above the sea. However, most of public toilets still cannot be beneficial to the community, because there are many obstacles in its management. The purpose of this study is to examine the form of public toilet management in coastal slums with smart community approach in Demaan. The research approach uses qualitative methods. Data collection techniques are done by observation and in-depth interviews. Sampling technique using snowball method. The informants are the community who is user of public toilets, public toilet management institutions and government agencies related to the construction of public toilets. Data analysis using qualitative descriptive method and Engagement-Participation-Empowerment method. Based on the analysis result, community empowerment include establishing public toilet management institutions along with regulations and financial management, as well as developing economic values and the benefits of public toilets by adding other potential functions/activities accompanied by the use of information technology in the form of the internet. Smart communities for the development and management of public toilets can be achived if smart people have succeeded according to their ability, openness, thinking, flexibility and creativity in utilizing proper toilets.
Interactive Eco-Cell Parametric Shading Structure Simulation (Hexagonal Shell of Light) by using Parametric Environmental Tool
Authors: El Gendy Marwa Abdelkader
Published: December 2019

Software and methods (such as Parametric modeling) could be effective for architects and engineers to improve the design and reparametrize modeling. These methods will help develop the best solutions for improving the sustainable design. A challenge for designers is to integrate daylight and shade study with optimization into the design process. For achieve accurate results, most of the building environmental performance simulation tools need a large amount of time and repetition. Furthermore, the combination of daylight and energy performances has always been an issue, as different software packages are needed to present detailed calculation. This paper describes the control of codes and calculations that modern designers can use to produce new structures as opposed to specifically design them. The paper reviews paradigm shifts in architecture, and gives a description for parametric design and parametric design types, Also, The Paper introduces Eco-cell simulation study using Rhino and Grasshopper as a new tool of parametric design. An Eco-cell is an interactive hexagonal cell that achieves environmental concepts. The paper explores this environmental study by using Ladybug plug-in to study sunlight analysis and radiation analysis. EPW file is used to draw the sun path and finally the simulation study to control the whole cell structure. The Paper used the evolutionary solver Galapagos to attain the most effective result in daylight quality by controlling interactive hexagonal cell structure.
Simulation-based energy efficiency retrofit of listed building ensembles: An alternative solution with a climate envelope
Authors: Karasu A , Hantouch Y , Steffan C
Published: December 2019

This article draws an innovative architectural solution for enhanced energy efficiency by retrofitting ensembles of listed buildings. A combination of various simulation tools and a self-developed feasibility tool has been used at the preliminary design stage to develop a measure at an urban scale within the campus of TU Berlin.

First, a potential analysis for 48 buildings within the campus has been run using multi-zone simulations with Modelica. Afterward, with the feasibility analysis tool based on Python, called HCBC-Tool, all possible measures have been ranked at the pre-stage of this project. As a conclusion, by buildings where standard measures are not feasible, alternative solutions have been developed using DesignBuilder, where not only energy-related issues both also architectural ones were considered. Additionally, energy substitution measures have been simulated with SunnyDesign to complete the concept. Here, a “climate envelope (CE)”, which is an additional transparent envelope covering the buildings partially, has been developed for a building ensemble built between 1883-1975. Enhancing the energy efficiency of all five buildings within the ensemble with standard measures up to the new building level according to the German energy efficiency regulations would reduce their energy consumption app. 32%. Nevertheless, this regulation is not mandatory by listed buildings. Besides, 12,152 m2 external envelope surface should be retrofitted. By comparison, a CE could lead to enhanced energy efficiency and it alone could reduce the energy demand of the building ensemble up to 33% and combining it with standard measures could increase the savings up to 60%.
The impact of climate change on Building Energy Simulation (BES) uncertainty - Case study from a LEED building in Egypt
Authors: Elrawy Omar O. , Attia Shady
Published: December 2019

Climate change and global warming are two major concerns over the globe today, and the rapid change in climate became more sensible as it impacts diverse industries and disciplines. Buildings share of the global energy use exceeds 40%, and buildings’ Green House Gas (GHG) emissions resembles one-third of global GHG emissions; hence, Building Energy Simulation (BES) process became an essential step during building design, to study and minimize whole buildings’ energy use, and consequently minimize buildings’ carbon footprint. A significant and underestimated input to the BES process is the weather data; BES process normally uses historical weather data in the form of a weather file to simulate the building’s outdoor conditions, those outdoor conditions impacts the amount of thermal load on the building, therefore they significantly impact building’s estimated thermal comfort and annual energy use. With the rapid change in the outdoor weather conditions year after year, using those historical weather data files must be questioned, as they impact the estimated energy use, and consequently put what’s deemed as the “optimum energy use” in question. Using those historical weather data is hence expected to increase BES degree of uncertainty. This paper studies and quantifies the impact of weather data accuracy on building’s annual energy performance. The paper follows an empirical research approach by simulating an office building located in Cairo, Egypt. The study relies on using a typical weather data file and real weather files to run and compare two simulations for the same case study. Finally, the paper quantifies the impact of weather data’s accuracy on the total annual energy use by comparing both simulation results.
Economic Evaluation of Renewable Energy Systems, Case Study: an Eco-House Powered by Nano-Crystal PV in New Aswan, Egypt
Authors: Mohamed Abdelaziz F.
Published: December 2019

Based on the tendency of depending on the renewable energy resources in Egypt of the last decades, it is necessary to confirm that the use of solar energy in all applications is an effective energy source. This is driven by advanced technologies such as the use of better and cheaper material, more efficient production processes, increasing efficiencies as well as other conventional systems. Many researches are presented to develop the photovoltaic panels through their power efficiency and reasonable price to fulfil the buildings’ energy requirements. Nanotechnology is used to enhance the properties of the PVs in order to produce more power and increase their useful life. This research presents a design of a Nano-crystal PV system for providing the electrical loads in an eco-house according to its energy requirement. It is found that providing electricity to the eco-house in New Aswan city in the Egyptian south valley using Nano-crystal photovoltaic system is very beneficial and competitive with the other types of conventional energy sources. In addition to the decreasing prices of these systems and their increasing efficiencies, it is maintaining a clean environment for people. The proposed Nano-Crystal PV panels are applied in the eco-house which is designed to be eco-friendly with its context and the life cycle cost of the alternatives energy proposals are compared. The main results prove that the NCPV is economical than others.
Simulation-Based Optimization of Building Orientation for Optimum Electricity Consumption of Indian Residential Buildings
Authors: Biju Ann M , Ayyathurai Vignesh
Published: December 2019

The demand for electrical energy had grown tremendously over the last few decades. The 2019 annual report by electricity sector of India shows that India is the third largest consumer of electricity in the world. Studies revealed that buildings are major consumers of electricity, in which residential buildings consumes the most. Tremendous increase in electricity demand are anticipated in Indian residential sector in the coming years due to development plans such as Power for all policy. Studies depicted that residential buildings have an energy saving potential of about 30-50% and most of the previous researchers had focused only to replace the electrical appliances in the constructed facility and had ignored the design features of the building to minimize electricity consumption. The present study therefore focused on reducing the energy use in residential sector of India by simulation-based optimization of buildings at its design stage. Design Builder software version 6.1.0.006 with Energy Plus simulation engine 8.9 was used for the study. A two storied residential building in Kochi, Kerala was considered for the study. The building model was validated using previous electricity bills and was then retrofitted using Energy Conservation Building Code (ECBC). The model was simulated for eight different orientations for different cases in five different climatic zones in India. East orientation was found to be the best orientation for all cases except cold climatic zone. The percentage saving in annual electricity consumption and cost of electricity bills that could be saved by opting the best orientation were also found.
The influence of different courtyard ratios in university buildings on their thermal performance during the hot period: (Faculties of Agriculture and Education, New Sohag University, Egypt as a case study).
Authors: Abdallah Amr Sayed Hassan , Mohammad Dina Ahmed , Ali Abdel-Monteleb Mohammad
Published: December 2019

Due to the importance of courtyards in educational buildings, their role in improving climate and their impact on students’ performance and learning. This paper aims to comparing the thermal performance of courtyards with different dimensions and ratios, with their impact on overlooking space in university buildings, as well as their impact on the thermal comfort of the students in such courtyards in “the Faculties of Agriculture and Education, New Sohag University” during the hot period of the academic year (March, April, May). It’s worth noting that in order to achieve this aim, the research adopted the analytical and the applied methods; which included field measurements and questionnaire Furthermore, Parameters (such as indoor/outdoor temperatures, relative humidity, and airspeed) of the courtyards and spaces overlooking them were measured. In addition to 900 questionnaires forms that were distributed in the courtyards of the faculties of Agriculture and Education during the hot period which represent measurement months (March, April and May). Meanwhile, the findings indicated that the temperatures of “the Faculty of Agriculture courtyard” with a height/width ratio of (0.7) was higher than the temperature of “the Faculty of Education courtyard” with a height/width ratio of (1.2). The findings also revealed that the “Faculty of Education courtyards” with a H/W ratio of (1.2) achieved a sense of the thermal performance of overlooking spaces and Acceptable thermal comfort for students better than “the Faculty of Agriculture courtyards” with a H/W ratio of (0.7) during the hot period.
Modelling of filtration of liquid binder in the composite textile structures under RTM processes
Authors: Dimitrienko Yu I , Bogdanov I O
Published: December 2019

The paper deals with three-scale modelling of the filtration of a weakly compressible liquid binder in the tissue material of the filler in the production of composite materials based on the RTM method. The technique is based on the application of the asymptotic homogenization method for the Navier-Stokes system of equations. Local filtration problems for the threads level and for the monofilaments level are obtained.
On modeling of three-layered thin bodies
Authors: Nikabadze Mikhail , Ulukhanyan Armine , Khizhenkov Andrey
Published: December 2019

Some questions about the new parameterization of three-dimensional thin body with one small size are considered. The vector parametric equations of the multilayered thin body are given. The geometric characteristics are considered. The representations of several differential operators, the equations of motion, the boundary conditions and the constitutive relations (CR) of classic and micropolar theories of elasticity are given. Some interlayer contact conditions are obtained. The definition of the k-order moment of any quantity with respect to the system of Legendre polynomials is given. The problems of the classic and micropolar theories of one-, two- and three-layered prismatic elastic thin bodies in moments of displacement and rotation vectors with respect to the system of Legendre polynomials are formulated. The problem of one-layered two-dimensional rectangular plate with two pinched edges under the distributed load are solved.
Reduction of heat loss of pump-compressor pipes for oil production due to optimal thermal insulation based on basalt and glass fibers
Authors: Komkov M A , Badanina Y V , Garashchenko A H
Published: December 2019

The results of investigations of high-temperature and low-density heat insulation of pump-compressor pipes made of short basalt fibers and alumina bundles are presented. It is shown that in order to achieve a significant reduction in the thermal conductivity of the material from the initial staple fibers, it is necessary to grind them and clean them from impurities by liquid method. It is shown that the heat-insulating coating has restrictions on the thickness of the insulation wall and the size of the running mass of the pipe.
The information-physical mechanism of diagnostic of the functional coatings erosive wear by water jet
Authors: Barzov A A , Galinovsky A L , Provatorov A S
Published: December 2019

This paper discusses process of the functional coatings erosive wear by water jet with the purpose of coatings quality characteristics diagnosing. The probabilistic model of this process is considered. The main model feature is the surface and volume damages analysis after water jet influence. The experiments show the directly dependence between these coatings damages types. This fact highlights the water jet diagnostic efficiency.
Modern approaches to the manufacture of ceramic-matrix composite materials for long-term operation at temperatures above 1000°C. Review of world experience and capabilities of JSC “Kompozit”
Authors: Timofeev P A , Timofeev I A , Bogachev E A , Timofeev A N
Published: December 2019

The article describes modern approaches to the creation of ceramic-matrix composite materials for long-term operation in oxidizing environments. It provides information on advanced technologies for the formation of ceramic matrices and their recipes. The current problems and prospects for the production of such filaments in Russia are discussed.
Silicon nitride-based ceramic composite materials for corrosion-resistant rolling bearings
Authors: Pakhomova S A , Povalyayev A I
Published: December 2019

The technological process of obtaining material and manufacturing ceramic rolling elements of the bearing is considered. The composition of a silicon nitride-based ceramic composite material was investigated. The chemical inertness of ceramic materials determines the low adhesive wear in the mating parts of the supporting elements and makes it possible to use the rolling elements of the bearings in conditions of poor lubrication. Bearings with ceramic rolling elements show excellent running performance in emergency conditions and do not lead to sudden failures. The excellent corrosion resistance of ceramic materials allows them to be used in aggressive environments. The combination of such properties is accompanied by a decrease in temperature in the working area and allows the use of higher rotational speeds. The feasibility of using ceramics for the production of balls for bearings and the main advantages of using a ceramic material compared to metal products are shown. The process mode of hot pressing of blanks of ceramic rolling elements has been developed.
Comparative analysis of averaging methods for obtaining composite material elastic characteristics
Authors: Zarubin V S , Sergeeva E S , Magnitsky I V
Published: December 2019

Composites are widely used as engineering structural materials in different technical areas, given their higher mechanical properties combined with their smaller weight as compared with the “pure” materials. An important characteristic of a composite is a set of its elastic properties. To determine these properties, both experimental methods and mathematical simulation are used. Due to large material costs and time expenditures inherent in each experiment (fabrication of the material and the test sample, performance of the experiment and processing of the results), on the material design stage, as well as when determining the material application area, preference is given to the simulation methods.This paper is focused on the comparative analysis of the available mathematical simulation methods in terms of performance study of the unidirectional fiber-reinforced composite in the plane normal to the fiber orientation. For illustrative purposes, composites with two different kinds of matrix, polymeric and metal, are considered.
Metallurgy of thixotropic materials: the experience of organizing the processing of structural materials in engineering Thixo and MIM methods
Authors: Semenov A B , Kutsbakh A A , Muranov A N , Semenov B I
Published: December 2019

A brief review of the modem development of thixotropic metallurgy as a new direction in the field of science and technology of metal processing is offered.
Design and process for production of spacecraft structures using radial braiding and transfer molding
Authors: Khaliulin V I , Batrakov V V , Savitskiy V V
Published: December 2019

The paper presents the results of research dedicated to design and development of spacecraft structures using radial braiding and transfer molding. Experience in development, optimization and manufacturing of structures with closed section and biaxial and triaxial reinforcement is described for bearing rod, X-fitting, support platform, transformable lattice structure and ‘capillary’ tube.
Sol-gel synthesis of oxide protective coatings of carbon fibers to increase heat resistance in aggressive oxidizing environments
Authors: Tselovalnikova A A , Trubin D A , Karandashev A N
Published: December 2019

Ceramic coatings of the Al2O3/SiO2 composition by the sol-gel method on carbon fibers were obtained in order to prevent oxidation and destruction of the fiber at temperatures above 450°C. Various combinations and ratios of aluminum and silicon oxides were used. The results of scanning electron microscopy and X-ray diffraction showed a change in the topographic properties of carbon fiber during the deposition of coatings thereon. Thermal analysis showed that oxidative stability improved significantly due to coverage, increased to 1100°C.
Optimization of curing mode of epoxy resin based composites
Authors: Chen Yangyang , Malysheva G
Published: December 2019

In this article the techniques for determining the thermos-physical properties of epoxy binders depending on their different state of aggregation are presented. The epoxy composition based on epoxy resin and modified aliphatic polyamine was used as an object of research. Experimental studies were carried out to determine heat capacity and thermal conductivity of epoxy binders, depending on their degree of conversion. Mathematical modeling of the curing process of epoxy binder at different heating rates by the finite element method was carried out. When using the results of mathematical modeling, the kinetics of the curing process was optimized depending on different heating rates by the ideal point method. Moreover, a study was conducted on the effect of limit condition on optimization results.
Hybrid composites in reusable space vehicles wing structures
Authors: Ashikhmina E R , Ageyeva T G , Prosuntsov P V
Published: December 2019

The study is dedicated to the solution of a complex problem – development of an optimal thermal design of the tourist class reusable space vehicle (RSV TC) wing structure. The complexity of the problem resides in the necessity to consider critical factors of the suborbital flight and in a number of nesting tasks,that need to be solved. The authors implemented a multiscale modeling approach covering design of hybrid composite material thermal properties (i.e. mesoscale level), determination of thermal loads and thermal state analysis of a composite wing (i.e. macroscale and structural scale levels). Analysis of thermal fields demonstrated the necessity of thermal protection (TP) application for the wing structure. Consequently, optimal from the weight efficiency point of view TP thicknesses were determined. Summing up, the results of a RSV TC wing structure development are presented in the current paper.
Development of branched aromatic maleimides as components of self-healing binders for polymer composites
Authors: Karelina N.V. , Solodilov V I , Polezhaev A.V.
Published: December 2019

Various modifications of epoxy resins with maleimides and polyimide fragments results in the formation of heat-resistant materials with excellent mechanical and electrical properties together with high chemical, corrosion, and radiation resistance. Such materials can be used in the aerospace industry, electronics, instrument making, and other industries. The ability of some epoxy-maleimide resins to react with furanic groups through thermo-reversible Diels-Alder reaction open a new area in composite material science - self-healing binders. Selfhealing materials can restore their structure and mechanical properties after a damage that results in an increase of the service life several times and, therefore, reduce their cost. In this paper, maleimides were modified by diglycidyl ethers to obtain not previously described polyethers, capable of self-healing of mechanical properties after damage. All compounds were characterized by 1H NMR.
Related problems of designing heat-loaded structures from ceramic matrix
Authors: Ezhov A D , Bykov L V , Artemchuk N V
Published: December 2019

The paper presents a method of mathematical modeling of the mechanical and thermal state of the contact pairs on the example of contact between two composites. The algorithm of the study including the preparation of profilograms roughness of the contacting surfaces of the samples (identification roughness parameters), construction of a three-dimensional model of the surface roughness, mechanical interaction analysis microroughness contacting surfaces, determining the thermal contact resistance and the calculation of thermal fields in the contact zone. The technique was tested on a contact pair of ceramic-matrix composites for various values of mechanical and thermal loading. The obtained calculated data are verified according to the experimental study.
Development of carbon/epoxy composite bracket for housing sensitive element of spacecraft
Authors: Komarov V A , Pavlov A A , Pavlova S A
Published: December 2019

The article considers the challenge of using layered carbon/epoxy composite materials in a high-loaded airframe structures. It is demonstrated by a redesign of the bracket for housing a sensitive element of the spacecraft. The new design approach considering simultaneously structural and technological features of composite constructions. It can also be applied to other design tasks to develop a structure of minimum weight.
In situ supported VOx on carbon nanotubes for the low-temperature selective catalytic reduction of NO with NH3
Authors: Jin W , Jiao B Q , Chen W , Li M Y , Zhao J , Zhang X W
Published: December 2019

The vanadium oxide/carbon nanotube (VOx/CNTs) composite catalyst was prepared by in-situ growth of VOx nanoparticles on CNTs with a cetylpyridinium chloride (CPC) assisted reflux route. The in-situ prepared catalysts exhibit better NH3-SCR activity in a broader temperature window at low temperature than those prepared by impregnation or a mechanically mixed method. The structural characterizations show that vanadium oxide nanoparticles have a good dispersion on the CNTs surface, with much lower valence vanadium species and chemisorbed oxygen species. The physics-chemistry properties indicate that there is a strong interaction between the VOx and CNTs, and the catalysts present a larger amount of stronger acid. The abovementioned reasons have eventually led to the enhancement of NH3-SCR activity.
Tailoring quasi-two-dimensional high conductivity and superconductivity areas at the interfaces of ferroelectric/dielectric heterostructures
Authors: Mamin R F , Pavlov D P , Piyanzina I I , Lysogorskiy Yu V , Mukhortov V M , Adachi T , Kawamata T , Koike Y , Balbashev A M , Tayurskii D A , Kabanov V V
Published: December 2019

The results of the investigations of high conducting and superconducting areas at the interfaces between ferroelectric oxide and insulating oxide are presented. The numerical simulations of BaTiO3/LaMnO3 and BaTiO3/La2CuO4 heterostructures have been performed. It is found that in the samples of the Ba0.8Sr0.2TiO3/LaMnO3 heterostructure the electrical resistance decreases significantly and exhibits metallic behaviour at low temperatures for the case when the c axis of ferroelectric film is directed along the normal to the surface of the single crystal. The superconducting behaviour with transition temperature Tc about 30K has been found at the interface of the Ba0.8Sr0.2TiO3/La2CuO4 heterostructure. The proposed concept promises the ferroelectrically controlled interface conductivity and superconductivity.
Thromboresistant properties of nanostructured tantalum coatings on the stainless steel surfaces
Authors: Melnikova G B , Kuznetsova T A , Petrovskaya A S , Tolstaya T N , Lapitskaya V A , Chizhik S A , Zykova A , Safonov V
Published: December 2019

The nanostructured coatings of tantalum and its compounds on the stainless steel surfaces were investigated by atomic force microscopy. Their hydrophilic properties were studied by sessile drop and atomic force spectroscopy methods. The thromboresistant properties of samples were analysed in vitro by incubation of the samples in the rich platelets plasma of patients with acute coronary syndrome. The effect of surface properties on the thromboresistant properties was analysed.
Shapes change of PbO nanoparticles produced by laser ablation in liquid
Authors: Pryakhina V I , Gunina E V , Lisjikh B I , Osipova M A , Greshnyakov E D , Shishkina E V , Shur V Ya
Published: December 2019

Production of non-spherical crystalline nanoparticles by laser ablation in liquid has been demonstrated recently. Here we studied the shape variety of PbO nanoparticles prepared by laser ablation in deionized water and IPA. The key role of water in the formation of PbO non-spherical nanostructures was demonstrated. Only spherical nanoparticles have been obtained in isopropyl alcohol (IPA). PbO non-spherical nanostructures have been formed only in presence of water, which supports the growth mechanism by oxidation. Using mixture of IPA and water in various proportions and revealing the time and temperature dependences of non-spherical nanostructure morphology can be used for controlled growth of PbO non-spherical nanostructures.
Features of combining scanning probe microscope with optical and scanning electron microscopes
Authors: Sapozhnikov I D , Gorbenko O M , Felshtyn M L , Zhukov M V , Golubok A O
Published: December 2019

The designs of combining a scanning probe microscope (SPM) with an optical microscope (OM) or scanning electron microscope (SEM) have been presented. To reduce the size of the SPM units the self-sensing probes and a piezo-inertial displacement system are proposed to use. The peculiarities of working of such SPM units are discussed. The examples of visualization of different nature objects in combined systems SPM-OM and SPM-SEM have been presented.
Studying surface Fermi level pinning in GaP nanowires with gradient Kelvin probe microscopy
Authors: Sharov V A , Alekseev P A , Fedorov V V , Bolshakov A D , Mukhin I S
Published: December 2019

In this work, we use scanning Kelvin probe gradient force microscopy to study surface Fermi level pinning in horizontal undoped nanowires with axial GaP/GaPAs heterojunction. The nanowires were separated from the growth substrate and dispersed on smooth surface of Ni/Si substrate. Then longitudinal and transverse surface potential profiles of several nanowires were captured. The study revealed a distinction between the work function of GaP and GaPAs regions. It was shown that the Fermi level in undoped GaP nanowires was pinned in the middle of the energy gap.
Magnetron sputtering deposition of ultra-thin tungsten coatings onto amorphous graphite for enhancement of horseradish peroxidase adsorption
Authors: Shumov I D , Kanashenko S L , Ziborov V S , Ivanov Y D , Archakov A I , Enikeev D V , Potoldykova N V , O Pleshakova T
Published: December 2019

In the present study, atomic force microscopy (AFM) has been used to investigate the adsorption of horseradish peroxidase (HRP) protein onto the surface of amorphous carbon (graphite). It has been experimentally demonstrated that modification of amorphous carbon surface by magnetron sputtering deposition of ultra-thin (1.3 nm) tungsten coatings allows one to enhance significantly the adsorption of HRP macromolecules onto this surface, as compared with bare carbon.
Synthesis and spectral-optical properties of composite materials based on high-silica porous glasses doped by iodides of silver and erbium
Authors: Girsova M A , Antropova T V , Golovina G F , Anfimova I N , Kurilenko L N , Arsent’ev M Yu
Published: December 2019

Composite materials (CMs) doped by iodides of silver and erbium were synthesized on the base of the thermally modified high-silica porous glasses (PGs) with small additions of P2O5 and fluoride ions. CMs were manufactured by two-stage impregnation of the PGs first with AgNO3 aqueous solution (with or without Er(NO3)3), next in the halide salt (0.6 M KI) aqueous solution. Then the samples of composites were heat treated at the temperatures from 120 to 870°C up to their sintering and closing of the pores. The structure of composites was studied by X-ray powder diffraction (XRD) technique. According to XRD data the CMs doped by iodides of silver and erbium contain the AgI phase. Spectral-optical properties of CMs were investigated by UV-VIS-NIR spectroscopy. Optical density spectra in UV-VIS region have the bands corresponded with the absorption of silver molecular clusters. Peaks at 377, 448, 450–453, 485, 611–622, 647, 668–684 nm answered to the absorption of erbium ions were found. According to NIR transmission spectra, bands caused by the absorption of Si–OH, B–OH and Na–OH groups are found.
Preparation and Properties of Nanocomposites in the Systems S-AgI and S-Ag2S-AgI in Dimethyl Sulfoxide
Authors: Khan N V , Burkitbayev M M , Urakaev F Kh
Published: December 2019

In this research work described synthesis of nanocomposites in the systems S–AgI and S–Ag2S–AgI in dimethyl sulfoxide (DMSO, (CH3)2SO) medium, and its some properties. Nanocomposites were obtained through the solvothermal synthesis at temperature range (T) 25÷160°C. The initial solutions were prepared by dissolution of sulfur (S), silver nitrate (AgNO3
) and ammonium iodine (NH4I) in DMSO. The final products were obtained through the simple exchange reactions between initial solutions. Using the X-ray phase analysis (XRD), energy dispersive X-ray analysis (EDAX) and scanning electron microscopy (SEM) the samples were tested on phase and elemental composition, particle size and morphology, respectively. The results of XRD revealed that nanocomposites represented by S and AgI for system S–AgI, and by S, AgI and Ag2S for S–Ag2S–AgI system. The EDAX analysis showed the presence in composition of the investigated samples such elements like S, Ag and I for both systems. The SEM images demonstrated that both systems have a heterogeneus structure, the particles represented by flat and irregular shape. The size of the particles for S–AgI is fluctuated from 100 to 50000 nm and for S–Ag2S–AgI – from 90 to 4000 nm.
Surface roughness analysis in the drilling of carbon fiber/epoxy composite laminates using hybrid Taguchi-Response experimental design
Authors: Shahabaz S M , Shetty Nagaraja , Shetty S Divakara , Sharma S S
Published: December 2019

The carbon fiber reinforced polymer composite has made a substantial impact on the manufacturing sectors owing to its excellent mechanical, thermal and corrosion resisting properties. The surface roughness mainly depends on the machining parameters while drilling of carbon fiber reinforced polymer composite laminates. The study concentrates on the impact of uncoated and titanium nitride coated solid carbide drills on minimizing the roughness that is generated while making holes in bi-directional carbon fiber reinforced polymer composite by optimizing the drilling constraints [spindle speed (A), feed rate (B), point angle (C) and drill diameter (D)]. Experimental studies are carried out using Taguchi L

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orthogonal array. The investigation discloses that the drill diameter is one of the most influencing cutting parameters followed by spindle speed and feed rate. The response surface methodology is chosen as a tool for predicting and optimizing the process parameters. The investigation also discloses that the experimental and the predicted results of surface roughness are closely matching with each other. The surface morphology illustrates that titanium nitride coated solid carbide drills minimize the surface roughness compare to that of uncoated solid carbide drills.
Enhanced emission from CH3NH3PbBr3 perovskite films by graphene quantum dot modification
Authors: Guo Xi , Han Bingquan , Gao Yu , Liu Dan , Chen Jiayao , Chen Pengyun , Xu Lingbo , Cui Can
Published: December 2019

Organic-inorganic hybrid perovskites have emerged as promising emitters with the benefits of low cost and high color purity, but their low luminescence efficiency is a drawback for practical application on light emitting devices. Here we show that by incorporating proper amount of graphene quantum dots (GQDs) into perovskite precursor, dense CH3NH3PbBr3 films with reduced grain size and well passivated grain boundaries could be obtained. This gives rise to enhanced emission from GQD modified perovskite films. Our work thus provides a viable way to prepare highly luminescent perovskite films for optoelectronic applications.
Effect of two-step ausforming on bainite transformation and retained austenite in a medium-carbon bainitic steel
Authors: Chen Guanghui , Xu Guang , Hu Haijiang , Tian Junyu , Yuan Qing , Wang Jun
Published: December 2019

It is commonly accepted that single ausforming with small strain at low temperature promotes isothermal bainite transformation and leads to more retained austenite. In the present study, the effects of two-step ausforming on the bainite transformation and retained austenite in a Fe-C-Mn-Si medium-carbon bainitic steel were investigated by thermo-mechanical simulator, x-ray diffraction, scanning electron microscope and transmission electron microscope. The results show that the two-step ausforming cannot further promote the bainite transformation compared with single ausforming. However, the two-step ausforming enhances the mechanical stability of residual austenite due to more dislocations induced by the second deformation and therefore leads to more retained austenite. In addition, when the total strain is constant, the fraction of retained austenite increases with the increasing second strain. Moreover, the thickness of bainite plates treated with two-step ausforming is larger compared with single-step ausforming when the total strain is the same.
A photocatalytic and electrochemical study of gold nanoparticles synthesized by a green approach
Authors: Herrero-Calvillo R , Santoveña-Uribe A , Esparza R , Rosas G
Published: December 2019

Quasi-spherical gold nanoparticles mixed with a controlled amount of gold nano triangles were obtained through a green chemical method using leaf extract of Loeselia mexicana. Moreover, the influence of the extract and HAuCl4 solution concentration in the morphology of the nanoparticles was studied. The nanoparticle preparation was performed by varying the concentration of the extract and precursor salt. The catalytic activity of the as-prepared nanoparticles was studied by the reduction of methylene blue, rhodamine B, and gentian violet organic dyes. Also, cyclic voltammetry profiles were obtained in order to analyze the electrochemical response of the nanoparticles. The morphology and structural characterization were analyzed by UV–vis, SEM, TEM, FTIR, and XRD. The SEM analysis reveals gold nanoparticles with spherical and triangular morphologies. The UV–vis spectra revealed that the extract concentration influenced the morphology and amount of the obtained gold nanoparticles. The XRD and TEM analysis showed that gold nanoparticles presented a face-centered cubic lattice structure. The cyclic voltammetry analysis confirms a high-sensitivity electrochemical response and stability corresponding to the gold nano triangles. Finally, the presence of gold nano triangles shapes influenced the efficiency of the degradation of the dyes due to their high specific surface area.
A study on machinability of nickel based superalloy using micro-textured tungsten carbide cutting tools
Authors: Khan M Adam , Gupta Kapil
Published: December 2019

In this research, an investigation on machinability of nickel-based superalloy (Inconel 600) under the influence of textured tungsten carbide cutting tools is conducted. Two main machinability indicators, namely, wear and life, have been investigated. Three types of micro-texture patterns i.e. dimples, lines and splines are laser engraved on the flank face of the cutting tool. Experiments are done with different cutting velocities, feed rate and depth of cut considering the texture pattern one among the input parameters. Firstly, while machining Inconel 600 with plain (non-textured) tungsten carbide cutting tool, it is investigated that at low velocity, the cutting nose caused damage due to abrasion and friction between the tool-chip interface. Severity in tool edge has increased along with adhesive wear and built-up edge at the cutting radius with increase in velocity. Thereafter, using textured on the tools, it is observed that the cutting tool wear resistance has tremendously increased with different textured patterns due to significant reduction in friction and heat. At low velocity (50 m min−1) the tool wear measured is in the range of 100–150 μm and maximum of 394 μm at high cutting velocity of 150 m min−1. The tool life was calculated using Taylor’s equation based on Gaussian method. Tool lives for dimple and line textures are found superior. It is concluded that textured tools have potential to machine hard materials like Inconel superalloys with longer tool life.
Numerical analysis of subwavelength field effects in photonic crystal slab cavities
Authors: Mertin Paul , Römer Friedhard , Witzigmann Bernd
Published: December 2019

Surface coupling of single quantum emitters to optical cavities consisting of a photonic crystal slab is a delicate yet crucial task for photonic quantum applications. By coupling through the evanescent surface field only small Purcell factors can be achieved. Here, we propose to introduce a pit in the slab to position the emitter closer to the mode field maximum. Photonic crystal slab L3 cavities are investigated with respect to quality factor and Purcell effect, using finite element calculations in the frequency domain. That way the spatial distribution of the Purcell factor can be calculated. Introducing a small sized pit to the surface of the photonic crystal cavity can evoke subwavelength field effects, confining the field maximum inside the pit. By engineering a pit in the center of the cavity the Purcell factor can be increased from 176 to 1331, albeit reducing the Q factor from 20769 to 16696.
Large genus asymptotics for volumes of strata of abelian differentials
Authors: Aggarwal Amol
Published: December 2019

In this paper we consider the large genus asymptotics for Masur-Veech volumes of arbitrary strata of Abelian differentials. Through a combinatorial analysis of an algorithm proposed in 2002 by Eskin-Okounkov to exactly evaluate these quantities, we show that the volume

ν
1

(

H

1

(
m
)

)

\nu _1 \big ( \mathcal {H}_1 (m) \big )

of a stratum indexed by a partition

m
=
(

m
1

,

m
2

,
…
,

m
n

)

m = (m_1, m_2, \ldots , m_n)

is

(

4
+
o
(
1
)

)

∏

i
=
1

n

(

m
i

+
1

)

−
1

\big ( 4 + o(1) \big ) \prod _{i = 1}^n (m_i + 1)^{-1}

, as

2
g
−
2
=

∑

i
=
1

n

m
i

2g - 2 = \sum _{i = 1}^n m_i

tends to

∞
\infty

. This confirms a prediction of Eskin-Zorich and generalizes some of the recent results of Chen-Möller-Zagier and Sauvaget, who established these limiting statements in the special cases

m
=

1

2
g
−
2

m = 1^{2g - 2}

and

m
=
(
2
g
−
2
)

m = (2g - 2)

, respectively.

We also include an appendix by Anton Zorich that uses our main result to deduce the large genus asymptotics for Siegel-Veech constants that count certain types of saddle connections.
Quantifying the importance of a realistic tomato (Solanum lycopersicum) leaflet shape for 3-D light modelling
Authors: Vermeiren Jonathan , Villers Selwyn L Y , Wittemans Lieve , Vanlommel Wendy , van Roy Jeroen , Marien Herman , Coussement Jonas R , Steppe Kathy
Published: December 2019

Background and Aims

Leaflet shapes of tomato plants (Solanum lycopersicum) have been reduced to simple geometric shapes in previous functional–structural plant models (FSPMs) in order to facilitate measurements and reduce the time required to reconstruct the plant virtually. The level of error that such simplifications introduce remains unaddressed. This study therefore aims to quantify the modelling error associated with simplifying leaflet shapes.

Methods

Realistic shapes were implemented in a static tomato FSPM based on leaflet scans, and simulation results were compared to simple geometric shapes used in previous tomato FSPMs in terms of light absorption and gross photosynthesis, for both a single plant and a glasshouse scenario.

Key Results

The effect of simplifying leaflet shapes in FSPMs leads to small but significant differences in light absorption, alterations of canopy light conditions and differences in photosynthesis. The magnitude of these differences depends on both the type of leaflet shape simplification used and the canopy shape and density. Incorporation of realistic shapes requires a small increase in initial measurement and modelling work to establish a shape database and comes at the cost of a slight increase in computation time.

Conclusions

Our findings indicate that the error associated with leaflet shape simplification is small, but often unpredictable, and is affected by plant structure but also lamp placement, which is often a primary optimization goal of these static models. Assessment of the cost–benefit of realistic shape inclusion shows relatively little drawbacks for a decrease in model uncertainty.
An Organic Syntactic Complexity Measure for the Chinese Language: The TC-Unit
Authors: Yu Qiaona
Published: December 2019

Language complexity reveals the ability to use a wide and varied range of sophisticated structures and vocabulary. Although different languages compose complexity differently, complexity measures such as the T-unit have typically been based on clause subordination, which may underrepresent complexity and threaten the validity of studies. This study argues that an organic complexity measure should avoid the assumption of clause subordination and instead consider the typological features of the target language. Therefore, this study proposes the TC-unit in recognition of the topic chain as the underlying unit of Chinese complexity. It further validates TC-unit-based measures by investigating how accurately they predict proficiency group membership. Discriminant analyses of L1 and L2 Chinese speakers’ spoken (N = 115) and written (N = 116) output elicited from a designed timed online test, revealed that TC-unit-based measures classified proficiency group membership with high efficiency (61.2–75.7 per cent). Mean length of terminable TC-unit proved the most effective indicator of spoken Chinese syntactic complexity, while mean length of terminable TC-unit and single TC-units per terminable TC-unit in combination proved the most effective for written Chinese syntactic complexity.
Reproductive workers insufficiently signal their reproductive ability in a paper wasp
Authors: Tsuchida Koji , Saigo Takaharu , Asai Kazuyuki , Okamoto Tomoko , Ando Masaki , Ando Tetsu , Sasaki Ken , Yokoi Kakeru , Watanabe Dai , Sugime Yasuhiro , Miura Toru
Published: December 2019

Why workers forfeit direct reproduction is a crucial question in eusocial evolution. Worker reproduction provides an excellent opportunity to understand the mechanism of kin conflict resolution between the queen and workers. We evaluated behavioral and physiological differences among females in the paper wasp Polistes chinensis antennalis to examine why some workers reproduce under queenright conditions. Reproductive workers were old and foraged less early in the season; their cuticular hydrocarbon (CHC) profiles overlapped with those of queens but were significantly different. The distinct CHC profile of the eggs of the queen likely represented a cue for policing against those by workers. Juvenile hormone (JH) and dopamine seemed to be associated with gonadotropic function, and the JH level of reproductive workers was similar to that of the queen. The high JH level of reproductive workers likely facilitated their reproduction even under queenright conditions. Gene expression levels of the queen and reproductive workers differed only in vitellogenin. These results suggest that worker reproduction is facilitated by an increase in JH level; however, CHC is not a fertility-linked signal, but a queen-linked signal; consequently, reproductive workers without a queen-linked signal might be allowed to stay within the colony.