bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of the integrated IKTS-MADI complex for design and research of common rail fuel systems of diesel engines with electronic control
Authors: Dunin A U , Shatrov M G , Golubkov L N , Dushkin P V , Yakovenko A L
Published: July 2021

Further tightening of environmental rules and standards regulating the content of toxic substances in diesel exhaust gases, accompanied by an increase in the requirements for their fuel efficiency, creates prerequisites for the creation of Russian common rail fuel systems (CR). The performance of this task is possible with the use of new engineering solutions in combination with computational and experimental research methods implemented on the basis of the integrated computational and experimental complex IKTS-MADI. The complex consists of computing and research components. The computing component of the IKTS-MADI allows calculating the working processes of the entire high-pressure line when the high-pressure fuel pump (HPFP), rail and electro-hydraulic common rail injectors (CRI) work together, taking into account the influence of wave phenomena on the distribution of injection parameters across diesel cylinders. Obtaining new data to expand the library of existing technical solutions and testing of fuel equipment samples designed using mathematical modeling are carried out on the research component of IKTS-MADI. The CR and its components are tested together with the control system (control unit, sensors and wiring harnesses). The injection characteristics required for calculating the diesel operating process are recorded.
Evaluation of SVM modulation methods for indirect two-level three-phase frequency converter and direct frequency converter
Authors: Tung Le Van , An Ngo Van , Hieu Le Dinh , Long Thanh Pham
Published: July 2021

In current practice, indirectly structured frequency converters are popular because of the simple switch and control circuit diagram, and pulse width modulation (PWM) can be used to control the semiconductor switches. The PWM method has the advantage of a simple control circuit but has large switching losses and generates a common-mode voltage that causes motor damage. The development of the space vector modulation (SVM) method takes advantage of the PWM method, reducing the switching loss of the switches and reducing the harmonic at the output of the inverter. With direct converters, there are many types depending on the circuit structure and semiconductor key structure, including matrix frequency converters which are widely studied. The classical modulation method according to the duty-cycle matrix approach for matrix converter has disadvantages such as complex computational algorithms, which require many trigonometric calculations. Based on the PWM and SVM modulation algorithms for indirect converters, a space vector modulation method for matrix converters will be developed. Compared with the indirect converter, the SVM modulation method for the matrix converter will be based on two separate modulation principles: control the input current vector and control the output voltage vector. The relationship between current and voltage at the converter input is closely related to the voltage and current at the output. The relationship between current and voltage at the converter input is closely related to the voltage and current at the output. Make sure at the input of the converter, the power factor cosφ = 1 and can be adjusted, it has the quality of sine input and outputs current and the exchange power in two directions.
The results of the analysis of the current state of the creation and operation of refuelling complexes of wheeled vehicles specially the big carrying capacity, taking into account their environmental, fire and explosion
Authors: Sova A N , Abramov A N , Korobeynikova K R , Krasnobaev Y L , Trofimenko Y V
Published: July 2021

This article presents the results of the analysis of the creation and operation of multi-wheeled vehicle filling stations for the significance of creating a generalized methodological apparatus in order to ensure a sustainable reduction in the risk of accidents, explosions, man-made disasters and reduce the mortality of people at gas stations. More and more people are killed, injured and burned if fire safety measures are not followed when refueling large multi-axle wheeled vehicles. Accidents and explosions cause significant damage directly to the gas station itself, as well as to tankers carrying explosive fuel and substances. The substances used are mainly characterized by fire and explosion hazards. Therefore, in addition to pollution of environmental objects such as soil, air and water resources, and, as a result, changes in the ecosystem, further fire or explosion is possible. In this case, there is both an energy impact on neighboring objects, and their possible destruction. This article discusses the indicators of accidents in the event of accidents on vehicles, primarily on tankers, a preliminary assessment of the consequences of accidents and the possibility of taking measures to prevent the factors leading to them. The creation of a generalized methodological apparatus for assessing the consequences of accidents will make it possible to assess emerging emergencies without dividing them into classes of transported substances.
A method for assessing the cross-country capability of a particularly heavy-duty vehicle with all-wheel control based on the compliance of the support surface during curved movement
Authors: Mazlumyan G S , Yushchuk R V , Sudarikov I O , Sevastyanova T V , Sova A N
Published: July 2021

The article presents a method for assessing the permissible speed of a particularly heavy-duty vehicle based on a road train using a combined hydraulic transformer in the tractor transmission, as one of the indicators of cross-country ability. In this paper, we consider one of the main ways to increase the cross-country ability of heavy-duty vehicles: the creation of heavy-duty vehicles based on a road train with an active trailer link. Increasing the passability of heavy-duty vehicles is primarily aimed at increasing the permissible speed of heavy-duty vehicles and the maximum angles of ascents to be overcome. When justifying the choice of an algorithm for controlling the voltage of a torque Converter inductor based on the speed of particularly heavy-duty vehicles, it is advisable to use the external characteristics of the torque Converter as evaluation indicators: the dependence of the efficiency coefficient, the dependence of the moment created by the pump, and the dependence of the transformation coefficient on the gear ratio of the torque Converter. As criteria for evaluating the feasibility of using a combined torque Converter for especially heavy-duty vehicles, it is advisable to use the maximum increase in efficiency, the moment created by the pump wheel, and the transformation coefficient of torque converters on magnetic fluid in relation to the efficiency, the moment created by the pump wheel, and the transformation coefficient of the torque Converter based on a conventional working fluid in the operational range of gear ratio changes. The external characteristic is calculated after calculating the blade system and selecting the design to determine whether the main parameters of the characteristic correspond to the parameters specified in the task for designing the torque Converter. Such calculations often have to be performed when fine-tuning torque converters with a known design, when the influence of geometric parameters of individual elements of the blade system (input and output angles, wheel radii, the number of blades in the impellers, etc.) on the transforming and loading properties of the torque Converter is investigated.
Modeling quality criteria for restoring parts of cars, vehicles and road-building machines
Authors: Karelina M Yu , Belyaev A I , Terentev A V , Cherepnina T Yu
Published: July 2021

The article analyzes the types, methods and techniques of parts processing at restoration and quality criteria of parts of cars, other vehicles and road-building machines in terms of efficiency. Correlations between the quality criteria and the functionality of the part have been established, for which the requirements for machine safety and reliability after the restoration of individual parts have been taken. A mathematical model has been developed in the form of an algorithm for selecting the best variant of the restoration technology for a functionally important part, based on a typical restoration technological process, which consists in the development of a multi-criteria problem, the initial postulates of which are matrices: W “wear resistance → durability”; S “safety → reliability”; F “part fragility → machine safety”. New parameters in the form of coefficients describing roughness, hardness and riveting of a part have been proposed. In particular, the authors define the coefficient of technological isotropy of roughness, which evaluates the roughness parameters in the process of technological changes of a part; the coefficient of isotropy of hardness, which compares the hardness parameters on the surface of the part and in the core of it; the coefficient of intensity of hardness, which is a complex parameter and in which there is a change of hardness by the depth of the part and the value of hardness depth (riveting). The purpose of introducing these coefficients is consistent with the model being developed to select the optimal technology for restoring parts of cars, other vehicles and road-building machines.
Tensor analysis of uncertainty in freight transport ULS-systems
Authors: Yurchik P F , Maksimychev O I , Golubkova V B , Volosova A V
Published: July 2021

The article is devoted to the application of the tensor basis for the analysis of uncertainties in decision-making in freight transport ULS-systems. The use of tensors for constructing a mathematical model of the coordinator in the decision-making system is shown. Tensor equations make calculation possible the system parameters for any change in the structure of connections in the basic mathematical model. This provides additional advantages when making decisions in an uncertain environment. The authors also demonstrate the use of a tensor apparatus for constructing a mathematical model of deep uncertainty, which is impossible with traditional methods of analysis. The article shows that tensor analysis can be used to model decision-making under conditions of deep uncertainty in complex conditions, such as a catastrophes. Representing a fuzzy variable as a tensor makes it possible to explore additional properties of this variable. Tensors describing additional properties of the fuzzy variable (deviator, spherical tensor, symmetric tensor, and antisymmetric tensor) can be obtained from the fuzzy variable tensor. Applying special calculations to a fuzzy tensor variable makes it possible to obtain the membership function with high accuracy and find the defuzzified output value of the membership function. Tensor analysis significantly expands the scope of ULS-systems research.
Study of changes in the side clearance between vehicles and cable barriers installed along the highway centre
Authors: Kostsov A V , Lushnikov N A , Zuikov A A
Published: July 2021

In the years ahead, one of the most important tasks of the government of the Russian Federation is to bring the condition of highways of various categories to standard parameters and ensure their safety. This is reflected in the decrees of the President of the Russian Federation and in national projects, for example, in the national project on “Safe and High-Quality Roads”. In order to ensure safety and reduce damage from road traffic accidents on highways, various measures are used, including the installation of technical means of road traffic organization. These measures include cable barriers, which also have become popular recently. According to numerous studies, this kind of barrier has a positive effect on the passive safety of highways and it reduces the number of accidents with serious consequences that occur as a result of vehicles driving in the oncoming lane. However, the incorrect installation of these barriers (non-compliance with the minimum safety lanes at barriers, improper installation of barriers when the number of traffic lanes changes, etc.) and imperfection of the modern regulatory framework can negatively affect both a driver and the traffic flow in general, leading to the increase in the number of road traffic transport accidents. This is explained by the fact that a driver of a car, being afraid of close movement along the cable barriers at high speed, tries to stay away from the barrier as far as possible, increasing the side clearance between the vehicle and the barrier. However, at the same time, the side clearance between vehicles passing in the right lane (where a driver has limited visibility) or any obstacle on the right (for example, cars standing on the side of the road) sharply decreases. The article considers the results of the study of changes in the side clearance between the centre line of a road in the presence of a cable barrier and in its absence. The measurement results were compared. According to the results of the measurements, the authors gave the recommendations to improve road conditions, safety and the recommendations for further study of this issue.
Electrolytic alloying of iron-chromium during deposition of coatings from a sulfate-chloride electrolyte
Authors: Sinelnikov A F , Bomeshko E V , Korneychuk N I , Ianuta A S
Published: July 2021

The paper presents the results of studies of the process of electroreduction of alloy iron-chromium from a sulfate-chloride electrolyte, influence of electrolyte composition and electrolysis (acidity, electrolyte temperature and cathode current density) on the process kinetics, the output of the alloy current efficiency and physico-mechanical properties of the coatings (microhardness, morphology). There were determined such parameters as the optimal ratio of concentrations of electrolyte components – 150 g/l of iron chloride (2) and 50 g/l of chromium sulfate (3) and modes of electrical recovery of metals – current density 40 A/dm2; the temperature of the electrolyte is 50°C, the acidity of the solution is 0.5 pH units, which contribute to obtaining a high-quality coating with high tribological characteristics. Assumptions are made about the mechanism of the alloy formation by electrolysis from a mixed electrolyte.
Increasing the level of automation of dispatch control when regulating at the end stops of public transport routes
Authors: Voronov P O , Kudryavtsev A A , Filippova N A
Published: July 2021

The subject of research is automated dispatch control of public transport. Smart systems application on transport started in the second half of the 20th century. Application of such systems aims to improve every aspect of public transportation. However, despite constant development of telematics systems in public transport, this has not been achieved yet. The article discusses the use of telematics in public transport and the existing and actually functioning systems: ASK, NimBus and Navitrans. Authors suggest algorithm for public transport control that should increase the level of automation of dispatch control. The result of such approach is the improved regularity of public transport which is one of the key points to public transport efficiency and comfort to passengers.
The concept of structural steels surface hardening for tribo-joint elements
Authors: Chudina O V , Luzhnov Yu M
Published: July 2021

The concept of surface hardening of structural steels is proposed on the basis of the structural theory of strength and the Charpy principle at the macro-and microgeometric levels for the purposeful formation of a structure that can effectively resist wear and fatigue. An intellectual approach to the rational choice of technological combinations capable of maximally realizing the dislocation, substructural, grain-boundary, solid solution and dispersion mechanisms of steel hardening, which makes it possible to create optimal structures on the surface of tribo-interface elements, is described. As an example of such an approach, the surface laser alloying of structural steels with nitride-forming elements with subsequent nitriding was investigated; an increase in surface hardness, strength, wear resistance by 15 times and fatigue strength by 1.5 times compared with the initial parameters of steels was shown.
Software package for evaluation of efficiency of motor vehicle fleet operation
Authors: Smirnov P I , Subbotin B S , Ptitsyn D A , Volkov A O
Published: July 2021

The article describes an improved approach to assessing the efficiency of using the road transport of enterprises based on the assessment of the technical readiness factor of the fleet using the average daily mileage and specific idle time in maintenance and operation. The software implementation of this method in MS Excel is shown, the results of application and the results obtained are analyzed approbation at the enterprise of the metallurgical industry.
Methods of electrochemical research of corrosion resistance of metal treated with corrosion inhibitors, created on the basis of plant-based raw materials
Authors: Karelina M Y , Didmanidze O N
Published: July 2021

The use of corrosion inhibitors based on raw materials of plant origin has been a poorly studied method of metal processing so far. To show the degree of corrosion protection, it is necessary to examine it. It is possible to do this by means of electrochemical research, the method of which consists of several methods: the extrapolation method; the polarization resistance method; the related methods. As a result of this method, a significant advantage of samples treated with corrosion inhibitors based on raw materials of plant origin was revealed.
Russian national non-commercial vehicle safety rating system RuNCAP
Authors: Ivanov A M , Kristalniy S R , Popov N V
Published: July 2021

The article is devoted to the need to introduce an independent rating system for assessing the safety of cars RuNCAP in the Russian Federation. The introduction of this system will make it possible to more fully take into account the Russian operating conditions when assigning ratings to passive and active safety. RuNCAP will contribute to the wider adoption of intelligent driver assistance systems and their efficiency. The development of RuNCAP is proposed to be carried out taking into account the analysis of the features of the accident statistics for the Russian Federation. The article also presents the development strategy of RuNCAP for the coming years.
Modeling of systems for restoration of parts of cars, other vehicles and road construction machines
Authors: Karelina Yu M , Belyaev A I , Terentev A V , Rogov V R
Published: July 2021

The article deals with the application of process typification in the restoration of the most worn-out parts of cars, other vehicles and road construction machines from the point of view of application of optimization of the best quality parameters selection. A typical technological process of part recovery using the solution of a multi-criteria dynamic problem by the zoning method has been proposed with the introduction of the best variant of the matrix technology into the algorithm of selection: W “wear resistance → durability”; S “safety → reliability”; F “part fragility → machine safety”. The goal is to achieve maximum efficiency in structuring the technological process of restoration of parts of cars, other vehicles and road construction machines according to a number of reasonable criteria. While solving the task, the analysis of the existing methods of modeling for solving such tasks has been performed. The authors proposed their own solution in the form of an algorithm of the zoning method based on the principle of compliance with the hierarchical correlation of probabilities of possible states of the external environment in order to select an optimal variant of the required solution. As a result, it has been found that obtaining the maximum efficiency of the technological process of shaft-type parts restoration in cars, other vehicles and road construction machines can be solved by the task of dynamic programming as determining the optimal trajectory of the part transitions during the restoration process.
Crushing and screening digital system
Authors: Ostroukh A V , Kuftinova N G , Pronin C B , Vasiliev Y E , Barinov K.A.
Published: July 2021

The article proposes the structure of the Crushing and Screening Digital System (CSDS). A software implementation of a digital system for a cone crusher has been completed, which allows integrating a set of interfaced technological units in the control of one hardware equipment as part of the controller and installed at the operator station of the SCADA system. The most important functions of the CSDS are the continuous monitoring of the equipment condition of the complex of crusher mechanisms and aggregates in the process of work and the formation of a signal to regulate the productivity of the crusher. CSDS allows you to integrate in the control of one hardware as part of the selected controller and the SCADA-system server crusher installed at the operator station, a set of interfaced technological units, the efficiency of joint work of which is largely determined by the degree of coordination and the speed of two-way information exchange. In the event of malfunctions or abnormal situations, it will notify the operator. All accidents and crusher operation parameters are recorded in an electronic archive. The developed system provided a significant increase in the operator’s comfort, providing him with a single user interface for controlling the cone crusher from one operator station and an additional amount of information and services.
Protection of steel constructions against wear and corrosion in difficult climatic conditions by new techniques of zinc metallization
Authors: Petrova L G , Demin P E , Sergeeva A S , Timofeeva G Y
Published: July 2021

In the paper modernized techniques of zinc metallization of steel in combination with nitriding are considered. Two methods of combined surface modification of low-carbon steel are studied: application of zinc coatings by painting technique and subsequent gas nitriding; simultaneous thermo-diffusion saturation by zinc and nitrogen. Microstructure and microhardness of steel samples were examined; forming of a transition zone was determined under visually observed surface layer/coating with increased concentrations of Zn and N. Combined saturation by zinc and nitrogen forms diffusion layers with increased wear resistance and reduced friction coefficients together with improved corrosion resistance in salt fog. Nitriding of Zn coatings protects the steel both in salt and acid mediums.
Analysis and mathematical modeling of cable barrier mechanics during car impact
Authors: Demiyanushko I V , Karpov I A
Published: July 2021

The article discusses the mechanics of the response of cable barriers used in Russia. The first part of the article describes the general mechanics of the barriers. The second part describes the mechanics of the open-type posts, the most commonly used type worldwide. In the third part, accidents with closed-type posts are classified. The latter are unique structures that were developed in Russia to significantly reduce the deflection of barriers (by 35-50%). Understanding the principles of their response is not required for the further development of their structure only but also for the creation of their digital models since accurate models can only be developed if key physical processes are taken into account.
Justification of efficiency of route fuel consumption norms for trucks operated in tropical conditions
Authors: Rementsov A N , Egorov V A , Vu Fan An
Published: July 2021

Over the past decade, the economies of Southeast Asian countries, including Vietnam, have been developing dynamically, which leads to an increase in demand for the transportation of goods and passengers. At the same time, in a number of countries in this region, there is no state regulation in the field of rationing fuel consumption of trucks in real conditions. Therefore, improving the current fuel rationing system is an urgent task when performing cargo transportation in the tropics. The paper offers a justification for rationing fuel consumption of trucks performing transport work on permanent routes in tropical conditions on the example of Vietnam.
A comprehensive mathematical model and the methodology for assessing technical excellence road trains with active links and all-wheel control
Authors: Sova A N , Eruslankin S A , Valyaev O A , Makeev I M , Sudarikov I O
Published: July 2021

This article presents the main provisions of the new scientific and methodological approach, integrated mathematical model and methodics assessing the technical perfection of wheeled transport means of particularly large capacity based on road trains with active links and all wheeled steering. The results of the research allowed us to justify scientific and methodological approach to the assessment of technical excellence wheeled transport means of particularly large capacity based on road trains with active links and all wheeled steering, which includes implemented conceptual apparatus, scientific concepts and principles, theoretical and practical provisions. Results of justification and developing integrated mathematical model include the total mass equations, and methodics wheeled transport means of particularly large capacity based on road trains with active links and all wheeled steering. Introduced the concept of the integrated mathematical model, justified and developed by the integrated mathematical model wheeled transport means of particularly large capacity based on road trains with active links and all wheeled steering, in which includes the equation of the total mass of transport means in absolute and relative values, equations of dynamics of sprung and unsprung masses of links of wheeled transport means, equations of joint dynamics of wheeled transport means taking into account the applications of the saddle device and all-wheel control, models of interaction of wheel propellers with the support surface, models of the micro-profile and macro-profile of the support surface, and other component parts united comprehensive model. On the basis comprehensive mathematical model proposed metodics assessment of the technical excellence of the road train with active links and all-wheel control, recommendations on the choice of indicators and evaluation criteria are justified.
Statistical means of the assessment of the passive safety of road vehicles
Authors: Balaev E Y , Konovalova T V , Litvinov A E , Mironova M P , Senin I S
Published: July 2021

The article discusses the main criteria for assessing the design of vehicles in the field of passive safety. Road safety is influenced by a large number of factors, among the most negative factors are road accidents and their consequences. All categories of the population die and get injured in road accidents, which entails a decrease in the population of the country and the level of health, life expectancy, length of the working period, and distortion of the age pyramid. Existing methods for assessing measures to improve passive safety do not fully allow establishing a correspondence between the characteristics of vehicle structural elements that ensure its passive safety and the severity of the consequences in an accident. This situation is mainly due to the impossibility of assessing the passive safety of the car as a whole, by one indicator, since the applied assessment is based on the requirements of regulatory documents. In this case, the most optimal analysis will be the analysis of the consequences of real road accidents, which allows to identify the most dangerous conditions of road accidents and traumatic elements of the structure of vehicles. The result of the assessment of measures to improve passive safety is an accurate assessment of the severity of human injury in an accident and the risk of an accident. The existing and prospective criteria governing passive safety indicators cover a small number of all types of road accidents. Therefore, expanding the scope of application of safety criteria to the widest possible range of types of road accidents and taking into account the anthropological parameters of a person is the most significant potential way to reduce the number and severity of injuries in road accidents.
The impact of lean tools on the growth of overall equipment efficiency (OEE) in vehicle manufacturing
Authors: Shmatkov V S , Shmatkova A V
Published: July 2021

The paper considers the organizational activities allowing to improve the return from the equipment at the expense of reducing timely revealed losses. The analysis of the significance of the effect of the proposed measures on the growth of OEE is carried out. The statistics of losses during the operation of the fleet of metal-cutting high-performance equipment used in the production of vehicles for 10 years is given, an analysis is performed. A method for calculating the motivation fund for bonus payments to interested personnel is proposed.
Effect of cyclic heat treatment on microstructure and mechanical properties of Ti–5Al–5Mo–5V–3Cr–1Zr alloy
Authors: Gong-Ye Fan-Jiao , Zhou Jie , Zhang Qian , Long Shuai , Zhou Yu-Ting , Li Shi-shan , Peng Shi-Xin , Deng He-Ping , Zhang Jian-Sheng
Published: July 2021

Cyclic heat treatment was utilized on Ti–5Al–5Mo–5V–3Cr–1Zr (Ti-55531) alloy to investigate the microstructure and mechanical properties of the material. The effect of cyclic heat treatment on microstructure and mechanical properties of Ti-55531 alloy was investigated using x-ray diffraction, scanning electron microscopy and electron back-scattered diffraction. The tensile test was conducted and the results revealed the decrease in strength and hardness and the increase in ductility of samples after cyclic heat treatment, which are primarily induced by the transformation of primary α and the growth of β grain. The cracks of the samples have primarily occurred along the β grain boundaries where the nucleation of microvoids and their coalescence underwent easier. Furthermore, the increasing times of cyclic heat treatment promoted the transformation of low-angle grain boundaries to high-angle grain boundaries and the formation of new β grains. The results of the present work indicated that the method of cyclic heat treatment could significantly affect Ti-55531 alloy in terms of microstructure evolution and mechanical properties.
Understanding superhydrophobic behaviors on hydrophilic materials: a thermodynamic approach
Authors: Li Yufeng , Han Xiaoqing , Jin Haiyun , Li Wen
Published: July 2021

Some experiments have proved that superhydrophobic behaviors can be achieved on inherently hydrophilic substrates without low surface energy modification at micro-scale. However, the thermodynamic mechanisms about these results have not been well-understood. In this work, a 2D analytical model was reported to analyze this unexpected experimental observations and wetting behaviors on trapezoidal, vertical and inverse-trapezoidal microstructure surfaces. Theoretical results showed that intrinsic contact angle, which was restricted by sidewall angle of micropillars, was not an independent parameter to affect superhydrophobicity. And re-entrant structures were critical in the realization of microstructures alone inducing transition from hydrophilicity to superhydrophobicity. The wetting transition criterion was that sidewall angle should be less than intrinsic contact angle. On this occasion, a positive energy barrier could support liquid/vapor interfaces and separate Wenzel and Cassie state on hydrophilic substrates. And the physical explanations can be found that the positive energy barrier mainly came from the growth of the high-energetic solid/vapor interfaces to be wetted by the drop with liquid/vapor interfaces moving down inverse-trapezoidal pillars. As for the optimal design of microstructures, considering the limitation of pillar width and the ‘sag’ transition caused by pillar height, T-shape microstructures could be a good choice.
Synthesis and characterization of PCM based insulated concrete for thermal energy storage
Authors: Ilyas Asharf , Ahad Muhammad Zeeshan , Durrani M A Q Jahangir , Naveed Amir
Published: July 2021

Phase change materials (PCMs) are an innovative solution in a thermal energy storage system that can contribute efficiently to the improvement of the energy performance in the building. The phase change is the latent heat of storage materials that can store a large amount of thermal energy in its phase change from solid to liquid and vice versa. The heat storage/release mechanism of PCM is due to its sensitivity to melting/solidifying processes. Optimized ratios of PCM in concrete is essential for effective thermal storage system and strengthen physical characteristic. In this research work, dip coating of phase change materials of melting temperature 17 °C to 50 °C was done for coarse aggregate in the ratios via 25%, 50%, 75%, and 100 v/v% with the cement. The compressive strength of PCM-based coated coarse aggregated 0%, 25%, 50%, 75%, and 100% was investigated after 7, 14, and 28 days’ ages. Encapsulated coarse aggregates (ECA) of different ratios were compared for thermal energy conductance while keeping compressive strength as a key parameter. Temperature differences of 12.35, 15.25, 16.35, 17.5, and 20.3 °C were observed for ECA-100, ECA-75, ECA-50- ECA-25, and NCA, respectively in 12 h. The encapsulated PCM-based coarse aggregate concrete was characterized for physical, thermal conductance, and surface morphology. It was found that ECA-50 offers optimum storage of latent heat and reasonable compressive strength of concrete. However, an adverse impact was found regarding compressive strength as the PCM ratio increases above 50% v/v%, which can be maintained by bonding additives CNTs and GO.
High throughput software-based gradient tree boosting positioning for PET systems
Authors: Wassermann Christian , Mueller Florian , Dey Thomas , Lambertus Janko , Schug David , Schulz Volkmar , Miller Julian
Published: July 2021

The supervised machine learning technique Gradient Tree Boosting (GTB) has shown good accuracy for position estimation of gamma interaction in PET crystals for bench-top experiments while its computational requirements can easily be adjusted. Transitioning to preclinical and clinical applications requires near real-time processing in the scale of full PET systems. In this work, a high throughput GTB-based singles positioning C++ implementation is proposed and a series of optimizations are evaluated regarding their effect on the achievable processing throughput. Moreover, the crucial feature and parameter selection for GTB is investigated for the segmented detectors of the Hyperion IID PET insert with two main models and a range of GTB hyperparameters. The proposed framework achieves singles positioning throughputs of more than 9.5 GB/s for smaller models and of 240 MB/s for more complex models on a recent Intel Skylake server. Detailed throughput analysis reveals the key performance limiting factors, and an empirical throughput model is derived to guide the GTB model selection process and scanner design decisions. The throughput model allows for throughput estimations with a mean absolute error (MAE) of 175.78 MB/s.
Partner and Relationship Predictors of Longitudinal Physical Activity Trajectories Among Individuals with Osteoarthritis Using Latent Class Growth Analysis
Authors: Soto Sandra H , Hales Derek P , Callahan Leigh F , Rini Christine
Published: July 2021

Background

Physical activity reduces osteoarthritis symptoms, yet many individuals with the disease are insufficiently active.

Purpose

We identified physical activity trajectories over 12 months of individuals with osteoarthritis and examined how their cohabiting spouses’/partners’ baseline physical activity and relationship factors affected trajectory membership.

Methods

In this longitudinal observational study, we collected data from 168 adults with knee/hip osteoarthritis. We used latent class growth curve analysis to identify physical activity trajectories and logistic regression to predict trajectory membership using partners’ physical activity, relationship satisfaction, and communal coping (belief that both partners are responsible for osteoarthritis management). Measures, including objectively assessed physical activity, were collected at baseline from the couple, who then received an educational class on physical activity and social support. Objectively assessed physical activity was also collected from individuals with osteoarthritis at 1 week, 3 months, 6 months, and 12 months post-baseline.

Results

Three trajectories were identified: stable active, increaser, and stable sedentary (24%, 40%, 37% of participants, respectively). Individuals with osteoarthritis with partners who were more active and who believed they alone were responsible for their osteoarthritis were more likely to follow the stable active (versus stable sedentary) trajectory. Those with partners who were less active and had higher relationship satisfaction were more likely to follow the increaser (vs. stable active) trajectory.

Conclusions

Findings demonstrate the importance of considering partner and relationship factors in physical activity interventions for couples.
Naturally Occurring Consecutive Sleep Loss and Day-to-Day Trajectories of Affective and Physical Well-Being
Authors: Lee Soomi
Published: July 2021

Background

Experimental studies have shown that just 1 night of sleep loss impairs next-day performance, mood, and energy. Yet, little is known about the effects of consecutive sleep loss on daily well-being in participants’ own settings.

Purpose

This study examined whether and how naturally occurring consecutive sleep loss is associated with day-to-day trajectories of affective and physical well-being.

Methods

Participants were adults (N = 1,958) from the Midlife in the United States Study who provided daily diary data for eight consecutive days. Consecutive sleep loss was operationalized as the within-person number of consecutive nights with <6 hr of sleep. Multilevel models evaluated the linear, quadratic, and cubic effects of consecutive sleep loss on daily well-being, after controlling for sociodemographic, health, and daily covariates.

Results

Daily negative affect increased and positive affect decreased in curvilinear fashion as the number of consecutive sleep loss increased. For example, daily negative affect increased (linear), but the rate of increase decelerated as the number of consecutive sleep loss increased (quadratic). Results were consistent for the number and severity of physical symptoms. For negative affect and the severity of physical symptoms, cubic effect was also significant such that the rate of increase accelerated again in the days most distal to baseline (no sleep loss).

Conclusions

Consecutive sleep loss was associated with degraded trajectories of daily affective and physical well-being. Making efforts to break the vicious cycle of sleep loss may protect daily well-being in adults whose sleep time is often compromised.
Plasma Ceramides and Cardiovascular Events in Hypertensive Patients at High Cardiovascular Risk
Authors: Yin Wenjie , Li Fengjuan , Tan Xin , Wang Huimin , Jiang Wenxi , Wang Xue , Li Sijin , Zhang Yanbo , Han Qinghua , Wang Yuan , Du Jie
Published: July 2021

Background

Plasma ceramides (Cer) have been used to evaluate risk of cardiovascular (CV) events in patients with coronary heart disease. We investigated the performance of ceramides and ceramide score (CERT) in hypertensive patients at high CV risk.

Methods

Seven ceramides were analyzed using ultra-performance liquid chromatography–tandem mass spectrometry in 920 essential hypertension patients at high CV risk, who visited Beijing Anzhen Hospital from September 2016 to September 2018 (median age: 49 years, 562 males). All patients were followed up for major adverse cardiovascular events (MACE), which included incident acute coronary syndrome, heart failure, stroke, and CV death.

Results

During mean 2.3-year follow-up, 71 patients experienced MACE. Cer(d18:1/16:0), Cer(d18:1/22:0), and Cer(d18:1/24:0) were highly significant in predicting MACE [multiadjusted hazard ratios (95% confidence interval, CI) per SD were 1.76 (1.34–2.30), 0.55 (0.41–0.73), and 0.66 (0.47–0.92), respectively]. Compared with traditional variables (comprising presence of CV risk factors, hypertension-mediated organ damage, and comorbidities), a novel CERT for hypertensive patients (CERT-HBP), composed of Cer(d18:1/16:0), Cer(d18:1/24:1), and their ratios to Cer(d18:1/24:0) and Cer(d18:1/22:0), respectively, increased the C-statistic from 0.751 (95% CI, 0.697–0.806) to 0.791 (95% CI, 0.737–0.845), P = 0.010. Net reclassification improvement and integrated discrimination improvement were 0.648 (95% CI, 0.421–0.885, P < 0.001) and 0.046 (95% CI, 0.025–0.068, P < 0.001), respectively.

Conclusions

A ceramide-based CERT-HBP was established to evaluate risk of MACE in hypertensive patients at high CV risk. This may improve identification of high-risk patients requiring increased attention and aggressive therapy.

Clinical trials registration

Trial Number NCT03708601.
Stability-indicating HPLC method to determine the stability of extemporaneously prepared vancomycin oral solution cups
Authors: Rochani Ankit , Nguyen Vinh , Becker Robin , Kaushal Gagan
Published: July 2021

Purpose

To determine the stability of compounded sweetened vancomycin oral formulations in plastic unit dose cups stored up to 180 days under 2 temperature conditions: refrigeration (2°C-6°C) and room temperature (25°C with 60% relative humidity).

Methodology

A stability-indicating high-performance liquid chromatography (HPLC) method was developed to analyze vancomycin in the presence of degradation peaks. The stability of extemporaneously compounded vancomycin solution stored in oral unit dose cups was investigated using this method. The tested vancomycin oral solutions were compounded formulations of 125 mg/2.5 mL and 500 mg/10 mL. Three oral unit dose cups from each storage condition were withdrawn and assessed for stability on days 0, 3, 7, 15, 22, 30, 90, 120, 150, and 180 as per United States Pharmacopeia guidelines. The assay of vancomycin was carried out by using a calibrated stability-indicating HPLC method.

Results

The stability-indicating HPLC assay showed that vancomycin completely degraded within 2 hours when exposed to highly acidic or basic pH conditions. No precipitation, cloudiness, or color changes were observed during the study under either temperature condition. The HPLC assay revealed that vancomycin oral solution cups retained greater than 90% of the initial concentrations of vancomycin for 30 days when stored at room temperature (25°C and 60% relative humidity) and for 180 days with refrigeration (2°C-6°C).

Conclusion

Vancomycin oral formulations were stable for long-term storage periods beyond those specified in manufacture guidelines. Our data suggests the extended stability of vancomycin oral solutions compounded for hospital use can be extended.
Phenolic profile of a Parma violet unveiled by chemical and fluorescence imaging
Authors: Khatib Moustafa , Pouzet Cécile , Lafitte Claude , Chervin Justine , Bonzon-Ponnet Valérie , Jauneau Alain , Esquerré-Tugayé Marie-Thérèse
Published: July 2021

The ability of phenolic compounds to autofluoresce upon illumination by UV or blue light was exploited to explore the nature and distribution of these metabolites within the flower petals, leaves and roots of the violet, Viola alba subsp. dehnhardtii. This was achieved through a dual complementary approach that combined fluorescence microscopy imaging of living intact tissues and chemical extraction of pulverized material. The blue to red fluorescence displayed by living tissues upon illumination was indicative of their richness in phenolic compounds. Phenolic acids were found in all tissues, while flavonoids characterized the aerial part of the plant, anthocyanidins being restricted to the petals. The chemical quantification of phenolics in plant extracts confirmed their tissue-specific distribution and abundance. A key finding was that the spectral signatures obtained through confocal microscopy of endogenous fluorophores in living tissues and their counterpart extracts share the same fluorescence patterns, pointing out the potential of fluorescence imaging of intact organs for a proper estimation of their phenolic content. In addition, this study highlighted a few distinct morphology cell types, in particular foliar-glandular-like structures, and jagged petal cell walls. Altogether, these data provide a comprehensive histochemical localization of phenolics in living tissues of a violet. Converting fluorescence imaging into a chemical imprint indicated that one can rely on fluorescence microscopy of intact living tissues as a rapid, non-destructive means to follow their phenolic imprint under various environmental conditions.
High-performance deep learning pipeline predicts individuals in mixtures of DNA using sequencing data
Authors: Phan Nam Nhut , Chattopadhyay Amrita , Lee Tsui-Ting , Yin Hsiang-I , Lu Tzu-Pin , Lai Liang-Chuan , Hwa Hsiao-Lin , Tsai Mong-Hsun , Chuang Eric Y
Published: July 2021

In this study, we proposed a deep learning (DL) model for classifying individuals from mixtures of DNA samples using 27 short tandem repeats and 94 single nucleotide polymorphisms obtained through massively parallel sequencing protocol. The model was trained/tested/validated with sequenced data from 6 individuals and then evaluated using mixtures from forensic DNA samples. The model successfully identified both the major and the minor contributors with 100% accuracy for 90 DNA mixtures, that were manually prepared by mixing sequence reads of 3 individuals at different ratios. Furthermore, the model identified 100% of the major contributors and 50–80% of the minor contributors in 20 two-sample external-mixed-samples at ratios of 1:39 and 1:9, respectively. To further demonstrate the versatility and applicability of the pipeline, we tested it on whole exome sequence data to classify subtypes of 20 breast cancer patients and achieved an area under curve of 0.85. Overall, we present, for the first time, a complete pipeline, including sequencing data processing steps and DL steps, that is applicable across different NGS platforms. We also introduced a sliding window approach, to overcome the sequence length variation problem of sequencing data, and demonstrate that it improves the model performance dramatically.