bluuebunny/crossref_metadata_2025_split huggingface dataset:
Self-denigration and the mixed messages of ‘ugly’ selfies in Instagram
Authors: Page Ruth 
Published: September 2019

Abstract
This paper sets out a new, multimodal account (both visual and verbal analysis) of how self-denigration is conveyed through ‘ugly selfies’ as posted to the photo-sharing site Instagram. Drawing on 226 Instagram posts categorised by the poster themselves with the hashtag #uglyselfie, the visual analysis compared the persons and setting in the selfie, the person’s facial expression (eye brow position, mouth expression), eye gaze and camera angle. The verbal analysis included the self-denigration found in the image caption and the rapport enhancing or threatening responses found in the comments to the image posted by others. Ugly selfies are found to convey various types of self-denigration, including self-deprecation and self-mockery. The difference between self-deprecation and self-mockery are explained by the types of ‘mixed messages’ generated by the images. In self-deprecation, the mixed messages arise from a contrast between the visual image and the verbal caption. In self-mockery, the mixed messages arise from contrasts within the image itself, where visual exaggeration and incongruity lead to a jocular interpretation of the ugly selfie. Although the focus in this paper is on self-denigration and selfie-taking, the analysis of mixed messages can be used to analyse many different forms of politeness strategies and many kinds of images shared with increasing frequency and importance on social media sites.
Comparison of reaction time between beginners and experienced fencers during quasi‐realistic fencing situations
Authors: Milic Marko , Nedeljkovic Aleksandar , Cuk Ivan , Mudric Milos , García‐Ramos Amador 
Published: September 2019

AbstractThis study aimed (I) to investigate the impact of the number of stimulus‐responses alternatives on reaction time (RT) under quasi‐realistic fencing situations, and (II) to elucidate whether the regression slope based on the RT and the number of stimulus‐responses alternatives could distinguish between beginners and experienced fencers. Ten beginners (7 men) and 10 experienced (6 men) fencers participated in the study. A video‐based method was used to present four typical fencing movement techniques (i.e. “stimulus”) after which the participants had to perform an offensive (high or low attack) or defensive (high or low defence) action (i.e. “response”). The simple‐RT (specific stimulus known in advance), 2Choice‐RT (only defensive or offensive stimuli), and 4Choice‐RT (all possible stimuli) were evaluated. The increase in the number of stimulus‐responses alternatives was associated with higher RT (4Choice‐RT > 2Choice‐RT > Simple‐RT; p < 0.05). Beginners always presented higher RT compared to fencers (range: 25.5–34.8%; p < 0.05) and also showed a steeper slope of the relationship between RT and the number of stimulus‐responses alternatives (range: 35.2–55.2%; p < 0.05). These results suggest that the capability to quickly respond to specific fencing stimuli increases with training experience, being the differences accentuated with increasing number of stimulus‐responses alternatives.
Effect of positron range on PET quantification in diseased and normal lungs
Authors: Emond Elise C , Groves Ashley M , Hutton Brian F , Thielemans Kris 
Published: September 2019

Abstract
The impact of positron range on PET image reconstruction has often been investigated as a blurring effect that can be partly corrected by adding an element to the PET system matrix in the reconstruction, usually based on a Gaussian kernel constructed from the attenuation values. However, the physics involved in PET is more complex. In regions where density does not vary, positron range indeed involves mainly blurring. However, in more heterogeneous media it can cause other effects. This work focuses on positron range in the lungs and its impact on quantification, especially in the case of pathologies such as cancer or pulmonary fibrosis, for which the lungs have localised varying density. Using Monte Carlo simulations, we evaluate the effects of positron range for multiple radionuclides (18F, 15O, 68Ga, 89Zr, 82Rb, 64Cu and 124I) as, for novel radiotracers, the choice of the labelling radionuclide is important. The results demonstrate quantification biases in highly heterogeneous media, where the measured uptake of high-density regions can be increased by the neighbouring radioactivity from regions of lower density, with the effect more noticeable for radionuclides with high-energy positron emission. When the low-density regions are considered to have less radioactive uptake (e.g. due to the presence of air), the effect is less severe.
Public perceptions of how to reduce carbon footprints of consumer food choices
Authors: Kause Astrid , Bruine de Bruin Wändi , Millward-Hopkins Joel , Olsson Henrik 
Published: September 2019

Abstract
Carbon footprints—the greenhouse gas (GHG) emissions associated with consumer food choices—substantially contribute to climate change. Life cycle analyses from climate and environmental sciences have identified effective rules for reducing these food-related GHG emissions, including eating seasonal produce and replacing dairy and red meat with plant-based products. In a national UK survey, we studied how many and which rules our participants generated for reducing GHG emissions of produce, dairy, and protein-rich products. We also asked participants to estimate GHG emission reductions associated with pre-selected rules, expressed in either grams or percentages. We found that participants generated few and relatively less effective rules, including ambiguous ones like ‘Buy local’. Furthermore, participants’ numerical estimates of pre-selected rules were less accurate when they assessed GHG emission reductions in grams rather than in percentages. Findings suggest a need for communicating fewer rules in percentages, for informing consumers about reducing food-related GHG emissions.
Mitigating CO2 emissions of concrete manufacturing through CO2-enabled binder reduction
Authors: Lim Tae , Ellis Brian R , Skerlos Steven J 
Published: September 2019

Abstract
Past studies on CO2 utilization in the concrete industry have primarily focused on maximizing sequestered CO2, while focusing less on CO2 avoidance possible by reducing binder use through the addition of CO2 to concrete formulations. In this paper, we study the net CO2 reduction and cost benefits achievable by reducing binder loading while adding CO2 via three approaches: carbonation during curing, carbonation during mixing, or carbonation with recycled concrete aggregate. These techniques are evaluated for a cohort of concrete formulations representing the diverse mixture designs found in the US ready-mixed and precast industries. Each formulation is optimized for reduced binder loading where the use of CO2 directly in the formulation recovers the lost compressive strength from reduced binder. We show that over an order of magnitude more CO2 can be avoided when binder reduction is jointly implemented with CO2 utilization compared to utilizing CO2 alone. As a result, nearly 40% of the annual CO2 emissions from the US concrete industry could, in principle, be eliminated without relying on novel supplemental materials, alternative binder, or carbon capture and sequestration. The recently amended 45Q tax credit will not incentivize this strategy, as it only considers carbon sequestration. However, we find that the saved material cost from reduced binder use on its own may provide a significant economic incentive to promote the joint strategy in practice. We conclude that the real value of CO2 utilization in concrete hinges on exploiting CO2-induced property changes to yield additional emission reduction, not by maximizing absorbed CO2.
Application areas and calculation method for capillary-porous heat exchangers of the new heat-removing class
Authors: Genbach A , Jamankulova N , Iliev I 
Published: September 2019

Abstract
The paper is centered on research focused on the fundamental studies of capillary-porous systems working in the mass forces field. Examined are the effects of pressure, excess fluid, the methods for heating and for supplying coolant, as well as the type of material used, in addition to the intensifier type amongst others, on the integral and thermo-hydraulic characteristics of the heat transfer process. The information obtained from the research can be used in the design, engineering calculations and operation of different energy installations of power plants. Experimentally obtained approximation for the law of the growth of a bubble in a cell of a porous structure, taking into account the influence of underheating, velocity and thermal properties of liquid and a heating surface, was used for determination of the radius of a “dry” spot. The heat transfer control permits to form a new class in the system for heat removing. Devices for heat exchange were built to raise their efficiency, reliability and to be loyal to environment. Capillary-porous heat exchanger shaped as a box provides safety from an explosion. The engineering method for calculation is done for limiting and operational characteristics of capillary-porous heat exchanger. The heat transfer control permits the development of a new class in the system for heat removal. Devices for heat exchange were built with the purpose of increasing both efficiency and dependability in an environmentally conscious manner. A capillary-porous heat exchanger shaped as a box provides protection against an explosion. Obtaining Its limiting and operational characteristics is done by means of an engineering method for calculation.
Experimental validation data for CFD of heat transfer processes in a heat exchanger thermosyphon type with complex geometry
Authors: Terziev A K , Iliev C I , Iliev I K , Beloev I H , Velkov E V 
Published: September 2019

Abstract
The paper explores the validation of experimental studies by means of numerical modelling of heat transfer processes occurring in a two-phase thermosyphon air heater. The object analysed is an air heater, used for the utilisation of the heat from flue gases emitted by a steam generator running on solid fuel with nominal load of 125 t/h, and temperature of the flue gases at nominal load 220C. The experimental study performed shows heat transfer coefficients of the evaporation and condensation zones of hfgas
= 104.9 and hfgas
= 84.9 W(m2 · K) respectively, and a reduction of the exhaust gas temperature down to 184°C. The numerical study pertains to a thermosyphon tube with complex geometry. Three zones can be distinguished for the air heater in question. In the evaporation zone the tube is inclined at 30 degrees in the direction of the flue gasses, in addition to the inclines of the adiabatic zone – 30 degrees, and the evaporation zone of the thermosyphon – 90 degrees to the horizon. The commercial software Ansys Fluent was used to perform the numerical calculations.
Analytical and numerical investigation of heat exchange in fin-tube refrigerating heat exchanger
Authors: Georgieva M , Raynov P , Atanasov D , Tashev I 
Published: September 2019

Abstract
Intensification by tube fin is intended to increase the heat exchange surface between the heat exchange surface and surrounding fluid. This method of intensification is applied to the heat exchangers type air coolers (refrigeration heat exchanger with indirect cooling). The interaction of cooled air in refrigeration equipment is most often a natural convection (quiet cooling). For the purposes of this work, a finned tube heat exchanger with a coolant a brine solution of CaCl2 was viewed. The numerical studies for ribbed cross sections at three different heights were done. On the basis of the results obtained for heat flow in a rib and throughout the exchanger, the effectiveness of the apparatus was determined. The model studies in Flow Simulation were carried out. For the purpose of the simulations a geometric models of two elements from cooling fin - tubes at three different heights (h) of the ribs (10 mm, 20 mm and 30 mm) were made. Numerical studies to investigate the velocity and temperature distribution at different rib height were carried out.
Two-dimensions finite-difference heat transfer study for a single borehole heat storage system during a seasonal charge-discharge cycle
Authors: Horbaniuc B , Dumitraşcu G , Dumencu A 
Published: September 2019

Abstract
Borehole heat exchangers are used to remove and/or add heat from/into the ground in different applications involving low-temperature heat usage, such as residential or social buildings heating by means of heat pumps. In such types of applications, seasonal heat storage is necessary since during the warm season an additional solar system is used to charge heat into the ground via the borehole system in order to regenerate the heat source for usage during the cold season. Heat transfer in the ground by means of the borehole results in both radial and axial propagations of the perturbation (ground heating/cooling). The magnitude of this perturbation and the added/removed heat are important parameters of the process that must be evaluated. The theoretical model presented in the paper uses the decomposition finite difference technique to determine the temperature distribution in the ground at different moments (1, 2, 4, and 6 months) during a charge/discharge cycle of the heat storage. The numerical results are necessary in order to evaluate the penetration depth of the thermal perturbation along the radial and longitudinal axes and the amount of stored/extracted heat.
Development of the highly boosted capillary porous foam generator for gas (steam) mechanical foam
Authors: Genbach A A , Shokoloakov K K , Iliev I K , Terziev A K 
Published: September 2019

Abstract
A highly boosted capillary porous foam generator for gas (steam) mechanical foam is developed. It contains the inlet and outlet nozzles, nozzles for supply of the foam generating solution and foam discharge, package of the foam generating meshes with increased sizes and sprayer. In order to increase capacity and improve the foam characteristics, the generator is equipped with a capillary patch and forming channel. The capillary patch is located at the external surface of perforated pipe that supplies the foam generating solution, and the forming channel is installed outside of the capillary patch with feeder. Additionally, the foam generator has control plates located at both sides of the feeding device, where the plates at both sides pass into a spring guiding viewfinder, also the packet of foamed grids with increasing size in the direction of gas flow is made with dimensions 0.4x0.55.
Investigation of the energy consumption in regulating the flow rate of fan systems
Authors: Popov G S , Klimentov K V , Kostov B Z 
Published: September 2019

Abstract
The ensuring of the required parameters of the air, used in air-conditioning systems, is directly related to the change of the flow rate of each fan that is installed in these systems. This change can be achieved by using different methods of flow rate regulation. However, it is well-known that the selected method determines the energy efficiency of the given fan system. This work represents a comparative theoretical analysis, concerning the energy efficiency of three different methods of regulating a fan’s flow rate: by throttling, by using inlet guide vanes and by changing the voltage frequency - the motor’s speed of rotation has been changed with the help of a variable frequency drive (VFD). For the aims of this research, the change of the coefficient of efficiency for some of the key system elements – fan, motor and VFD, at different work regimes, have also been indicated. To fulfil the objectives of this research a given number of fans, having different specific speeds of rotations: nq
= 3.31; 7.11 and 8.82 min−1, have been selected. As a criteria of effectiveness, concerning the different methods of flow rate regulation, the specific fan power PSFP
- the invested energy in transporting a unit volume of fluid (gas), has been used:

P

S
F
P

=

p

η

t
o
t

[

k
W

m
3

/
s

]

, where p is the total pressure of the fan; ηtot
is the overall efficiency of the fan. As a result of this theoretical investigation some graphics representing the change of the specific energy consumption, when the three different methods of flow rate regulation are used and indicating the fan’s initial work regime and its specific speed of rotation, have been given.
Oxy-combustion simulation of ethylene
Authors: Grigorean S , Dumitrascu G , Predoi S 
Published: September 2019

Abstract
The paper presents the simulation of the combustion of ethylene intended to be used in hybrid rocket propulsion. The simulation, was performed in ANSYS numerical codes, considering the following assumptions: fuel temperature 700 K and 800 K; pressure in the combustion chamber 1 to 3 bar; overall excess air from 1.5 to 5, in order to determine the case with lowest pollutant species. The simulation displayed the combustion temperature field, the flame OH concentration field, the exhaust gases composition fields, the gases velocity field, NO, CO, CO2 concentration fields and the gases pressure field. The simulation showed the influence of fuel temperature upon the combustion spatial features.
The melting temperature of BCC perfect ternary alloy FeCrC under pressure
Authors: Tran C D , Coman G , Nguyen H Q , Nguyen H T , Dinh V Q 
Published: September 2019

Abstract
The analytic expressions of the mean nearest neighbour distance, the free energy, the absolute stabilizing temperature of alloy state and the melting temperature for substitution alloy AB with interstitial atom C and body-cantered cubic structure under pressure are derived by the statistical moment method. The theoretical results are applied to alloy FeCrC. Our calculated results are compared with other calculations and experimental data.
Thermodynamic properties of interstitial alloy FeC with BCC structure under pressure
Authors: Nguyen H T , Tran C D , Coman G , Nguyen H Q , Dinh V Q 
Published: September 2019

Abstract
The analytic expressions for the thermodynamic quantities such as the mean nearest neighbor distance, the free energy, the isothermal compressibility, the thermal expansion coefficient, the heat capacities at constant volume and at constant pressure of binary interstitial alloy with body-centered cubic (BCC) structure and the small concentration are derived by the statistical moment method. The theoretical results are applied to the interstitial FeC alloy in the interval of temperature from 50 to 1000K and in the interval of interstitial atom concentration from 0 to 5%. In special cases, we obtain the thermodynamic quantities of the main Fe metal. Our calculated results for the thermal expansion coefficient and the heat capacity under constant pressure of main metal Fe are in good agreement with experiments.
Heat transfer characteristics of a gas cooler
Authors: Dima D , Bucsa S , Ionita C , Vasilescu E E , Dobrovicescu A , Niculae E 
Published: September 2019

Abstract
The paper deals with the design and simulation of a gas-water heat exchanger used for heating purposes. The heat exchanger represents the gas-cooler/water heater of a transcritical CO2 heat pump. The log-mean temperature difference and the NTU-ε methods are comparatively analyzed. The heat transfer area can be calculated through both methods but the true strength and what makes the difference when using the NTU-ε method is that based on it the simulation of the behaviour of an existing heat exchanger can be easily performed.
Kinematic Beta-Type Stirling Motor-Driven Compressor
Authors: Homutescu V M , Bălănescu D T , Panaite C E , Lupu A G 
Published: September 2019

Abstract
The theoretical functioning of a kinematic one-stage beta-type Stirling motor-driven compressor was analyzed. This machine comprises a kinematic Stirling engine and a reciprocating compressor in one single block. A double acting cylinder houses a piston that plays both the roles of the power piston of the Stirling engine and of the compressor’s piston. The maximum performances of this machine are determined through numerical modelling. For a certain compression ratio of the compressor, a functioning regime for which the work produced by the Stirling engine is equal to the absolute value of the work consumed by the compressor can be found.
Reducing CO2 emissions from tractor engines by using the diesel fuel and rapeseed oil blend
Authors: Burciu S M , Lupchian M , Neacșu M 
Published: September 2019

Abstract
The paper presents the results of some experimental research that led to the conclusion that diesel engines that fit agricultural tractors can reduce CO2 emissions by using a fuel oil mixture made up of 50% diesel and 50% refined rapeseed oil. Following the experimental determinations made and presented in the paper, both in load and idle operation, using a fuel mixture consisting of diesel and rapeseed oil, a reduction of up to 25% of CO2 emissions was obtained. Such a reduction in CO2 emissions is important because this gas belongs to the greenhouse effect category, and at the moment, a large number of U650 tractors are still being used in agriculture.
Study of the thermal stability of biodiesel and diesel fuel
Authors: Gheorghe D , Tutunea D , Bică M , Gruia A , Călbureanu M 
Published: September 2019

Abstract
In this study the physico-chemistry characterization and the thermal behaviour of biodiesel and diesel fuel were carried out. Biodiesel is currently the most suitable fuel as alternative for diesel engines due to the environmental and technical advantages. In Romania the use of blends of biodiesel/diesel as fuels is growing every year mainly to the implementation of Kyoto protocol and to the similar properties to diesel fuel. The tests were realized under atmospheric conditions of pure air flow at various heating rates. The thermogravimetric profile indicates that diesel has three mass losses events and biodiesel of sunflower oil has five mass loss events.
Study on performance of an innovative power system for hybrid propulsion consisting in a gas turbine with heat exchanger and steam turbine
Authors: Balanescu D T , Homutescu V M , Panaite C E , Popescu A 
Published: September 2019

Abstract
Hybrid electric vehicles are currently considered a viable solution for fossil fuel saving and pollutant emissions reduction in transportation sector. The typical configuration of a hybrid electric propulsion system contains a reciprocating internal combustion engine – gasoline or diesel. Aiming to increase performance and to reduce pollution in road transport, a hybrid electric propulsion system based on a micro gas and steam turbine system operating with compressed natural gas is proposed in the paper. The micro gas turbine has a recuperative heat exchanger and the steam cycle has one pressure level. The study analysed the performance of the proposed system as a function of gas turbine engine pressure ratio and temperature difference of the gas turbine engine heat exchanger. Results indicate that, at equal power, the analysed system is more performant than internal combustion engines currently used in hybrid electric propulsion, so they could represent a viable solution in this field.