bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of the trailbuilder hydraulic drive thermal preparation
Authors: Konev V V 
Published: March 2021

Abstract
One of the main problems in operation of road-building machines in conditions of low negative ambient temperatures is the hydraulic drive thermal preparation. The hydraulic equipment is located throughout the machine and need a local thermal warming otherwise its cold start results in its intense wear. We propose the warming method that comprises circulation of a prewarmed hydraulic fluid from the hydraulic tank through the piston and rod chambers of hydraulic cylinder without rod motion. This is ensured by installation of a bypass pipe and a valve connecting the hydraulic cylinder piston and rod chambers. To evaluate operability of the hydraulic cylinder warming system we determined the fluid circulation conditions depending on the fluid flow rate and its temperature. To check these conditions, we made calculations for a trailbuilder hydraulic drive with a ripper.
Technology of making asphalt concrete using sand slag
Authors: Kovalev N S , Otarova E N , Gladnev V V , Sadygov E A , Demidov P V , Yaurova I V 
Published: March 2021

Abstract
In the Central Black Earth Region, there are settlements that do not have hard-surfaced access roads, and existing access roads require major repairs. In order to reduce the cost of construction, it is proposed to use asphalt concrete mixtures from slag materials for the construction of road pavements. Slag materials have hydraulic binding properties; the processes of structure formation in them take a long time. The study of the properties of asphalt concrete was carried out depending on the time from the moment of manufacture, after prolonged water saturation and the number of freeze-thaw cycles. The obtained results indicate an increased durability of asphalt concrete road pavements made of slag materials.
Modeling the stress-strain state of crane metal structures
Authors: Lenivtsev A G , Dudanov I V 
Published: March 2021

Abstract
The intensification of construction production imposes very strict requirements on the safety of construction machines. When carrying out lifting and hoisting operations using overhead cranes, production safety is primarily determined by the technical condition of the undercarriage and crane runways, as well as metal constructions. The authors deal with the issues related to modeling and research of the stress-strain state of metal structures of an overhead crane. A model of the crane metal structure is proposed, which includes the main and end box-section crane girders. To study possible geometric movements of the crane, a model of an overhead crane was designed in KOMPAS-3D software environment. The model contains main and end box-section girders. The model allows determining the maximum possible misalignment of the crane and runout of one of the sides. To determine the bending, tensile and compressive stresses in the bridge truss and the deformations of the crane metal structures, depending on the working loads, a 3D model of the bridge crane was created in the ADW Winmachine software environment. With its help, the bending stiffness of the crane bridge was established. These values are necessary to compile a mathematical model of an overhead crane as a control object in the synthesis of an automatic control system.
Mathematical modeling of thermal processes in building enclosures
Authors: Maslyanitsyn A P , Galitskov K S , Fadeev A S 
Published: March 2021

Abstract
In the development of automatic control systems (ACS) for heat supply of buildings, mathematical models of their control objects play a significant role, one of the most important elements of which being the enclosing structures. The existing models of thermal processes indoors either do not take into account the dynamic effect of the enclosing structures, or are complex analytical expressions, the use of which in the engineering practice of the synthesis of ACS for the indoor thermal regime is difficult. The purpose of the study was to create a linear mathematical model of the thermal interaction of the external and internal air environment through the enclosing structures. To achieve this goal, a functional diagram of a heated room as a control object was developed, which describes the mechanism of thermal interaction of its elements. On its basis, design schemes of thermal processes for external and internal enclosing structures were developed. They were used to create systems of equations linking temperatures on the surfaces of layers of external enclosing structures and air temperatures outside and inside the premises. At the same time, the assumption was introduced that the dynamic temperature distribution over the thickness of the enclosing structure is linear. To find the temperatures at the boundaries of the layers, the average temperature value over the thickness of the structure was used. As a result of the study, equations for the dynamics of heat transfer processes were obtained, and a generalized structure of a model of multilayer external enclosing structures of a room as an element of a control object was developed. The resulting model can be used to develop a generalized mathematical model of the thermal regime of both individual rooms and the building as a whole.
Design of prefabricated reinforced concrete structures: comparative analysis of prefabricated reinforced concrete floor slab
Authors: Evstratova A V , Krishtalevich A K , Belov V V , Nikitin S E 
Published: March 2021

Abstract
The article describes application of precast, cast-in-situ and composite structures on construction site. Importance of Analysis of Russian (SP) and European design standards (EuroCodes) is underlined. Historical review of Russian codes for composite reinforced concrete structures is given. Methods of composite structures calculating according to current Russian Codes are given. Ultimate and service limits states are listed for describing structures. Advantages and disadvantages of cast-in-situ, prefabricated and complex technologies are discussed. Comparison of prefabricated, monolithic and complex technologies is given on example of intermediate floor slab. Examples of sections of prefabricated reinforced concrete composite structures are summarized. Composite structures detailing is given on example of real project of Parking building of Okhta-Mall shopping and entertainment center, Saint-Petersburg. Constructive solutions are presented that increase the bearing capacity and resistance to progressive collapse of structures. Manufacturing photos of prefabricated ready-made reinforced concrete slabs as a part of future composite slab are presented. Examples of detail drawings for composite concrete slabs, executed in accordance to Eurocode, are given. Suggestions for improving the existing Code of Practice are given. Reference to similar scientific papers is presented related to composite reinforced concrete elements. Article is developed with financial and technical information support of AFRY Oy Finland.
Transport hubs as experimental ground for new construction materials
Authors: Guzhov S , Korchagin A 
Published: March 2021

Abstract
The research purpose is to clarify the role, significance and problems inherent in transport hubs in the implementation of engineering solutions using new construction materials. The traditional scheme of commutation of passenger traffic between different modes of transport allows building physical models. However, the efficiency of materials in structures and the study of their operational properties are additional tasks for the calculation in new conditions. Historically, many large cities are characterized by a lag in the development of transport infrastructure in comparison with the growth rates of cities. The material and technical supply of construction inevitably faces the problem of the depletion of materials from their operational properties. Massive daily movement of the population to places of job and high operational loads reveal disadvantages primarily in terms of the traditional materials. The way out of this situation is the development of transport interchange hubs, while the use of traditional constructive and technological solutions causes additional difficulties for transport companies and businesses. The presentation of the key elements of the transport infrastructure as a testing ground for testing the properties of new materials such as high-alloy steels, composite materials, superplasticized concretes allows solving the problems of construction engineering in a new way. The constructed transport hubs rarely comply with the loading standards, which is caused by the incorrect approach to their design: the existing construction rules are not comparable with the functional needs of new type facilities. For the assessment, such factors as material consumption, creation of regulatory conditions, quality and safety of materials, reduction in construction time, stability of functioning and others are used. The risks associated with the creation of transport interchange hub (TIH) are noted. The development of transport hubs in a megalopolis can be implemented during simultaneous improvement of the quality of applied construction materials and satisfaction of the commercial interest of investors. In addition to the direct technological effects, there are accompanying operational consequences in various areas of urban life.
Reasonable choice of materials for project management in transport construction
Authors: Solovev V 
Published: March 2021

AbstractMaterial and technical supply is traditionally considered as a set of activities united by one project purpose. As a rule, a hierarchical approach to management functions is not applied and the links between management functions are determined by the classical form of the implementation of a construction project. The selection of the best types of material resources and its component that is the costs determined by the properties of the applied materials are becoming a key link in project management in modern Russia. This is an important scientific phenomenon. The research of this phenomenon allows finding the problem points in costing and the solution to the problems of the increase in the efficiency of building materials assembly through them. The relevance of this research is important for those countries where there is strong regulation of the estimated cost. The authors of the paper propose the measures to improve the efficiency of the choice of construction materials due to a more reliable determination of the estimated cost. For this, there are two ways to improve the project bill of materials: through the improvement of the regulatory framework and management of the process of the application of this framework. The quality level of resource and cost norms is a paramount problem in conditions of state regulation. This is intensified by the use of the basic costing method. The lag of norms calculated at the basic cost level can not be compensated for the use of conversion indices due to territorial and industrial classification. The attempts to create in Russia a unified information system for setting costs for construction products have not yet had measurable results. This results in a large percentage of outdated regulations that take into account materials with insufficient usability. The participants of the construction process have to spend large human resources to manage material resources in projects. The process of management in terms of material and technical equipment of construction is on top in terms of importance in the field of project management in transport construction. The quality of the projects being implemented largely depends on the success in the improvement of the regulatory framework.
Numerical analysis on motion of microparticles passing through straight and tortuous fibrous layers
Authors: Otomo Ryoko , Mori Kazuki 
Published: March 2021

Abstract
The behavior of microparticle assemblage moving through the saturated pores in a fibrous layer has been investigated numerically. We adopted a particle model to express the straight and tortuous fibrous layers and calculated the velocities of individual microparticles using the Stokesian dynamics approach assuming the Stokes flow. The simulation results showed that the particles spread as they moved through the layer. This is interpreted as hydrodynamic diffusion caused by the hydrodynamic interaction dominant in the Stokes flow. More pronounced diffusion was observed in the tortuous fibrous layer than in the straight one. It was found that the velocity of each particle deviated more from the ensemble average velocity of the assemblage in the tortuous fibrous layer. It was also observed that the tortuous fibrous layers exhibited greater variation in the size of the pores where particles passed. Our results quantitatively indicated that the tortuous fibrous layer consisted of a wide variety of pore sizes, which affects the velocity of the particles passing through it. Consequently, the difference in each particle velocity causes the hydrodynamic diffusion. It was also revealed that the subtle difference in the fiber shape substantially influences the hydrodynamic behavior of the particles moving inside.
Multiple mode-locked regimes of an Er/Yb double-clad fiber laser based on NPR
Authors: Durán-Sánchez Manuel , Pottiez Olivier , Posada-Ramírez Berenice , Álvarez-Tamayo Ricardo I , Armas-Rivera Iván , Bello-Jiménez Miguel , García-Flores Yasser A , Montiel-Piña E , Ibarra-Escamilla Baldemar 
Published: March 2021

Abstract
In this paper, we experimentally demonstrate generation of diverse structures of robust optical pulses obtained with a ring cavity passively mode-locked fiber laser based on a double-clad erbium-ytterbium doped fiber, and operating at net-anomalous cavity dispersion. A half-wave and a quarter-wave retarder plates allow adjustable saturable absorbing action by the nonlinear polarization rotation technique. Pulsed laser operation in quasi- continuous wave, molecules of solitons, and single-wavelength noise-like pulses (NLPs) regimes is obtained by properly adjusting the wave retarders. In the soliton and NLPs operating regimes, the central laser wavelength lies in the 1540 nm region. The obtained NLPs exhibit narrow peak coherence of ∼231 fs.
A review on the different types of electrode materials for aqueous supercapacitor applications
Authors: Chaudhary Swati , Raja Mohan , Sinha O P 
Published: March 2021

Abstract
The recent advancements in living standards impose massive pressure on existing energy resources such as fossil fuels. Also, the increasing number of inhabitants arises the need to develop eco-friendly and sustainable energy storage systems. In this regard, a large number of researchers have paid increasing attention to the different methods for sustainable energy like the use of solar cells, LEDs, energy-efficient electronic devices, and supercapacitor technology. Since supercapacitors belong to the class of energy storage systems that provides high capacitive performance and charging-discharging stability during long cycles. They also offer higher power density than batteries and higher energy density than capacitors. Since the selection of electrode material and its electrochemical performance is the most determined parameter for supercapacitor performance. The present review focuses on the different types of aqueous electrolyte based electrode material which is differentiated based on energy storage mechanisms for aqueous supercapacitors. Furthermore, the latest nanocomposites reported have been reviewed and differentiated based on their electrochemical performance for aqueous supercapacitor applications. Their future implications have also been discussed.
Surface plasmon polaritons broadband band-stop filter based on EIT effect modulation
Authors: Niu Junhao , Luo Weiyu , Zhu Aijun , Wang Jiajie , Zhang Benxin 
Published: March 2021

Abstract
The filter is one of the most important key elements of electronic circuit. With the rapid development of information, traditional electrical filters can no longer meet the requirements of fast information processing speed and low loss. All optical information processing is considered as one of the solutions to solve this problem. Therefore, there is great significance for studying the all-optical filter. Here, we put forward a kind of broadband band-stop filter which based on surface plasmon polaritons (SPPs) metal - insulator - metal (MIM) modulating by electromagnetically induced transparency (EIT) resonance. We use the finite element method for numerical simulation, and further research on the factors influencing the transmission characteristics of this structure by adjusting the geometric structure. Compared with similar SPPs-based filters, the proposed structure realizes broad stopband, and we can change the EIT resonance to modulate the band-stop filter wavelength range. The proposed broadband band-stop filter based on EIT effect modulation may have great potential in the next generation of all-optical information processing and communication.
The high thermal conductive and flexible boron nitride/silicone rubber composites with segregated structure
Authors: Ding Jiwan , Zheng Ruobing , Zhang Yajie , Zhang Xian , Liu Gang , Zheng Kang 
Published: March 2021

Abstract
Silicone rubber (SR) composites filled with silicone rubber particles (SRP) and functionalized h-BN platelets were successfully prepared, which have high thermal conductivities and flexibility. The functionalization of h-BN adopts the combination of non-covalent and covalent modification. The Non-covalent functionalization of poly(dopamine) (PDA), which is deposited on the surface of h-BN platelets, improves the interfacial adhesion for grafting (3-aminopropyl) triethoxy-silan (KH550) by covalent modification (BN-PDA-KH550). To construct the thermal conductive pathway, silicone rubber particles are added. so that the fillers can distribute along the particle circumference by volume exclusion, which is advantageous for improving heat conduction of SR composites. The as-prepared 30 vol% BN-PDA-KH550@silicone rubber particles/silicone rubber composites (m-BN@SRP/SR) exhibited a relatively high thermal conductivity (2.24 W m−1·K−1), which is about 112 times of pure SR (0.20 W m−1·K−1). Besides, the m-BN@SRP/SR composites possessed satisfactory softness and excellent dielectric properties, which presented a broad application prospect in the field of electronic packaging.
Construction of the targeted and pH-sensitive paclitaxel drug delivery system RGD/PTX@ZIF-90 and anti-tumor activity research
Authors: Ge Fei , Qiao Rui , Song Ping , Tao Yugui , Zhu Longbao , Zhang Weiwei , Li Wanzhen , Gui Lin 
Published: March 2021

Abstract
Tumors area common cause of morbidity and mortality. High treatment efficiency and low drug toxicity are key for effective tumor treatment. Here, the pH-sensitive material ZIF-90 was synthesized by the liquid-phase diffusion method for loading paclitaxel (PTX), and the targeting peptide (RGD) was prepared by the solid-phase synthesis method to modify it (RGD/PTX@ZIF-90). The skeleton of RGD/PTX@ZIF-90 collapses in the acidic tumor microenvironment, thereby releasing PTX and mediating the controlled release of the drug. ZIF-90 below 300 nm was obtained by adjusting the ratio of metal ions and organic ligands in the characterization experiment. In addition, in vitro drug release experiments showed that the drug release rate was greater at pH = 5.5 than at pH = 7.4. The lethal rate of RGD/PTX@ZIF-90 to human breast cancer cells (MCF-7) was 44.5%, which was higher than the lethal rate of PTX alone (37.3%) in the cytotoxicity experiment and apoptosis experiment. Uptake experiments revealed that RGD/PTX@ZIF-90 mainly existed in the cytoplasm of MCF-7, which suggests that the drug had successfully entered the cell to achieve the therapeutic effect. The loading of the nano-medicine carrier ZIF-90 and the modification of the targeting peptide RGD significantly improve the therapeutic effect of PTX and indicate that this system could be used to treat breast cancer.
Pt-Sb2Te as high speed phase-change materials with excellent thermal stability
Authors: Song Zhihao , Guo Junmei , Chen Jialin , Wen Ming , Tan ZhiLong , Wang Chuanjun , Guan Weiming , Zhang Kunhua 
Published: March 2021

Abstract
Phase change memory (PCM) has been regarded as one of the most promising candidates for the next-generation nonvolatile memory. In this paper, we propose PtSb2Te (PST) phase change material for phase change memory. The doping of Pt improves the crystallization temperature and Ten-year data-retention temperature of Sb2Te to 180 °C, 192 °C, 204 °C and 117 °C,123 °C,137 °C, and refines the grain to about 10 nm. At the same time, the density change of Sb2Te film after phase transition is reduced to 4.19% due to the addition of Pt. There are no other new phases formed in PST film except hexagonal Sb2Te phase. For PST-based phase change memory cell, only 10 ns electrical pulse is required to complete the reversible operation with a Reset voltage lower than 4.3 V. At the same time, the number of cycle operations of the memory cell exceeds 105 and it has a lower resistance drift coefficient as 0.019.
Charged surfaces and slabs in periodic boundary conditions
Authors: Rutter M J 
Published: March 2021

Abstract
Plane wave density functional theory codes generally assume periodicity in all three dimensions. This causes difficulties when studying charged systems, for instance energies per unit cell become infinite, and, even after being renormalised by the introduction of a uniform neutralising background, are very slow to converge with cell size. The periodicity introduces spurious electric fields which decay slowly with cell size and which also slow the convergence of other properties relating to the ground state charge density. This paper presents a simple self-consistent technique for producing rapid convergence of both energies and charge distribution in the particular geometry of 2D periodicity, as used for studying surfaces.
On lower bounds for Erdős-Szekeres products
Authors: Billsborough C. , Freedman M. , Hart S. , Kowalsky G. , Lubinsky D. , Pomeranz A. , Sammel A. 
Published: March 2021

Let

{

s

j

}

j
=
1

n

\left \{ s_{j}\right \} _{j=1}^{n}

be positive integers. We show that for any

1
≤
L
≤
n
,

1\leq L\leq n,

‖

∏

j
=
1

n

(
1
−

z

s

j

)

‖

L

∞

(

|
z
|

=
1
)

≥
exp
⁡

(

1

2
e

L

(

s

1

s

2

…

s

L

)

1

/

L

)

.

\begin{equation*} \left \Vert \prod _{j=1}^{n}\left ( 1-z^{s_{j}}\right ) \right \Vert _{L_{\infty }\left ( \left \vert z\right \vert =1\right ) }\geq \exp \left ( \frac {1}{2e}\frac {L}{\left ( s_{1}s_{2}\ldots s_{L}\right ) ^{1/L}}\right ) . \end{equation*}

In particular, this gives geometric growth if a positive proportion of the

{

s

j

}

\left \{ s_{j}\right \}

are bounded. We also show that when the

{

s

j

}

\left \{ s_{j}\right \}

grow regularly and faster than

j

(
log
⁡
j
)

2
+
ε

j\left ( \log j\right ) ^{2+\varepsilon }

, some

ε
>
0

\varepsilon >0

, then the norms grow faster than

exp
⁡

(

(
log
⁡
n
)

1
+
δ

)

\exp \left ( \left ( \log n\right ) ^{1+\delta }\right )

for some

δ
>
0

\delta >0

.
On a conjecture by Mbekhta about best approximation by polar factors
Authors: Chiumiento Eduardo 
Published: March 2021

The polar factor of a bounded operator acting on a Hilbert space is the unique partial isometry arising in the polar decomposition. It is well known that the polar factor might not be a best approximant to its associated operator in the set of all partial isometries, when the distance is measured in the operator norm. We show that the polar factor of an arbitrary operator

T
T

is a best approximant to

T
T

in the set of all partial isometries

X
X

such that

dim
⁡
(
ker
⁡
(
X
)
∩
ker
⁡
(
T

)
⊥

)
≤
dim
⁡
(
ker
⁡
(
X

)
⊥

∩
ker
⁡
(
T
)
)

\dim (\ker (X)\cap \ker (T)^\perp )\leq \dim (\ker (X)^\perp \cap \ker (T))

. We also provide a characterization of best approximations. This work is motivated by a recent conjecture by M. Mbekhta, which can be answered using our results.