bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface rheological measurements of isolated food foam systems
Authors: Clarke Christopher , Spyropoulos Fotis , Norton Ian T.
Published: September 2019

Liquid foams represent a key component to a vast range of food industry products, from ice creams to the crema on coffee. Longevity of these foams is a highly desirable attribute; however, in order for foam stability to be effectively controlled, a better understanding of the interdependence of the bulk liquid and air-liquid interfacial rheologies is required. This study follows an increasing trend in experimental investigations made of isolated foam structures at the microscale, where the bulk and surface dynamics of a single foam liquid channel can be accurately assessed. Isolated foam channels with adjoining nodes were studied for aqueous solutions of four food grade surfactants. Existing observations of distortions to sodium dodecyl sulphate channel geometries were confirmed for solutions of Tween 20 (T20) and Tween 80 (T80) and were well described by the theory presented here. Moreover, previously unseen distortions to liquid channels were observed for polymeric surfactant systems (hydroxypropyl methylcellulose and hydrolyzed pea protein blend), which were proposed to result from their high surface viscosities. The apparent surface viscosities, μs, of surfactants tested here ranged from high (10 g/s < μs < 10−3 g/s) for polymeric surfactants to very low (10−10 g/s < μs < 10−8 g/s) for Tweens, clearly demarking the regimes of viscous and inertial dominant flows, respectively. It is recommended that further work seeks to investigate the finding of a strong correlation between μs and channel surface tension, γ, for soluble surfactant systems, which could explain the apparent non-Newtonian values of μs that were consistently measured here.
Boron tribromide provides way to grow boron crystals with molecular beam epitaxy
Authors: Liebendorfer Adam
Published: September 2019

Boron tribromide source yields high-quality thin films, but high levels of bromine impurities limit the application of the produced boron-containing gallium nitride crystals.
On the arithmetic of modified idèle class groups
Authors: Lee Wan , Seo Soogil
Published: September 2019

Let

be a number field and

,

sets of places of

. For each prime

, we define an invariant

related to the Galois group of the maximal abelian extension of

which is unramified outside

and splits completely in

. In the main theorem we interpret

in terms of another arithmetic object

that involves various unit groups and uses genus theory applied to certain modules, which are technically modified from idèle groups. We show that this interpretation is functorial with respect to

and

and thereby provides interesting connections between

and

as

and

vary. The settings and methods are new, and different from the classical genus theoretic methods for idèle groups. The advantage of the new methods at the finite level not only generalizes but also strengthens certain known results involving the maximal

-abelian profinite Galois group of

that is

-ramified and

-split in terms of the arithmetic of certain units of

. At the infinite level, the method relates the deep arithmetic of special units with those of profinite Galois groups. For example, for special cases of

and

, the invariants

are related to the conjectures of Gross (or Kuz’min–Gross) and Leopoldt and accordingly, in these special cases, the functorial interpretation of

as

and

vary involves interesting connections between the conjectures of Gross and Leopoldt in a simpler and more concrete way. As a result, we conjecture that

is finite for all finite disjoint sets

,

over the cyclotomic

-tower of

, which includes the conjectures of Gross and Leopoldt as special cases.
On

-units for valuations of the second degree in hyperelliptic fields
Authors: Fedorov G. V.
Published: September 2019

In this paper we propose a new effective approach to the problem of finding and constructing non-trivial

-units of a hyperelliptic field

for a set

consisting of two conjugate valuations of the second degree. The results obtained are based on a deep connection between the problem of torsion in the Jacobians of hyperelliptic curves and the quasiperiodicity of continued

-fractions, that is, generalized functional continued fractions of special form constructed with respect to a valuation of the second degree. We find algorithms for searching for fundamental

-units which are comparable in effectiveness with known fast algorithms for two linear valuations.
On the rate of approximation in the unit disc of

-functions by logarithmic derivatives of polynomials with zeros on the boundary
Authors: Komarov M. A.
Published: September 2019

We study uniform approximation in the open unit disc

by logarithmic derivatives of

-polynomials, that is, polynomials whose zeros lie on the unit circle

. We find bounds for the rate of approximation for functions in Hardy class

and certain subclasses. We prove bounds for the rate of uniform approximation (either in

or its closure) by

-sums

with parameters

.
Dietary nitrate metabolism and enteric methane mitigation in sheep consuming a protein-deficient diet
Authors: Villar L. , Hegarty R. , Van Tol M. , Godwin I. , Nolan J.
Published: September 2019

It was hypothesised that the inclusion of nitrate (NO3–) or cysteamine hydrochloride (CSH) in a protein deficient diet (4.8% crude protein; CP) would improve the productivity of sheep while reducing enteric methane (CH4) emissions. A complete randomised designed experiment was conducted with yearling Merino sheep (n = 24) consuming a protein-deficient wheaten chaff control diet (CON) alone or supplemented with 1.8% nitrate (NO3–; DM basis), 0.098% urea (Ur, DM basis) or 80 mg cysteamine hydrochloride/kg liveweight (CSH). Feed intake, CH4 emissions, volatile fatty acids (VFA), digesta kinetics and NO3–, nitrite (NO2–) and urea concentrations in plasma, saliva and urine samples were measured. There was no dietary effect on animal performance or digesta kinetics (P > 0.05), but adding NO3– to the CON diet reduced methane yield (MY) by 26% (P = 0.01). Nitrate supplementation increased blood MetHb, plasma NO3– and NO2– concentrations (P < 0.05), but there was no indication of NO2– toxicity. Overall, salivary NO3– concentration was greater than plasma NO3– (P < 0.05), indicating that NO3– was concentrated into saliva. Our results confirm the role of NO3– as an effective additive to reduce CH4 emissions, even in a highly protein-deficient diet and as a source of additional nitrogen (N) for microbial protein synthesis via N-recycling into saliva and the gut. The role of CSH as an additive in low quality diets for improving animal performance and reducing CH4 emissions is still unclear.
Analysis of spermatogenesis and fertility in adult mice with a hypomorphic mutation in the Mtrr gene
Authors: Blake Georgina E. T. , Hall Jessica , Petkovic Grace E. , Watson Erica D.
Published: September 2019

Recent research has focussed on the significance of folate metabolism in male fertility. Knocking down the mouse gene Mtrr impedes the progression of folate and methionine metabolism and results in hyperhomocysteinaemia, dysregulation of DNA methylation and developmental phenotypes (e.g. neural tube, heart and placenta defects). The Mtrrgt mouse line is a model of transgenerational epigenetic inheritance (TEI), the hypothesised cause of which is the inheritance of a yet-to-be determined epigenetic factor via the germline. We investigated Mtrrgt/gt testes and sperm function compared with control C57Bl/6J testes to explore potential defects that might confound our understanding of TEI in the Mtrrgt model. Histological analysis revealed that adult Mtrrgt/gt testes are more spherical in shape than C57Bl/6J testes, though serum testosterone levels were normal and spermatogenesis progressed in a typical manner. Spermatozoa collected from the cauda epididymis showed normal morphology, counts, and viability in Mtrrgt/gt males. Correspondingly, Mtrrgt spermatozoa contributed to normal pregnancy rates. Similar parameters were assessed in Mtrr+/+ and Mtrr+/gt males, which were normal compared with controls. Overall, our data showed that the Mtrrgt allele is unlikely to alter spermatogenesis or male fertility. Therefore, it is improbable that these factors confound the mechanistic study of TEI in Mtrrgt mice.
Self-denigration and the mixed messages of ‘ugly’ selfies in Instagram
Authors: Page Ruth
Published: September 2019

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.
Type and Severity of Intimate Partner Violence in Offenders with and without ADHD
Authors: Buitelaar Nannet , Posthumus Jocelyne , Bijlenga Denise , Ferdinand Robert , Buitelaar Jan
Published: September 2019

Intimate partner violence (IPV) offenders were clinically assessed for ADHD, other psychiatric diagnoses, and frequency of different types of IPV. Of the 347 participants (16.4% women), n = 210 (61%) were clinically diagnosed with ADHD. The ADHD group showed a higher frequency of psychological, minor physical and clinician rated IPV, and also higher rates of comorbid anxiety or mood disorder, substance use disorder, and borderline and antisocial personality disorders. Hierarchical multiple regression analyses revealed that ADHD accounted for significant change of variance in frequency of psychological and clinician rated IPV above the effects of age, gender, and comorbid disorders.
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

This 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.
Magnetic and Magnetocaloric Properties of Polycrystalline and Oriented

Mn

2
−
δ

Sn

*
Authors: Li Kun , Wang Fanggui , Lai Youfang , Xue Mingzhu , Li Xin , Yang Jinbo , Wang Changsheng , Han Jingzhi , Liu Shunquan , Yang Wenyun , Yang Yingchang , Du Honglin
Published: September 2019

Mn-based Heusler alloys have attracted significant research attention as half-metallic materials because of their giant magnetocrystalline anisotropy and magnetocaloric properties. We investigate the crystal structure and magnetic properties of polycrystalline, [101]-oriented, and [100]-oriented

Mn

2
−
δ

Sn

prepared separately by arc melting, the Bridgeman method, and the flux method. All of these compounds crystallize in a Ni2In-type structure. In the

Mn

2
−
δ

Sn

lattice, Mn atoms occupy all of the 2a and a fraction of the 2d sites. Site disorder exists between Mn and Sn atoms in the 2c sites. In addition, these compounds undergo a re-entrant spin-glass-like transition at low temperatures, which is caused by frustration and randomness within the spin system. The magnetic properties of these systems depend on the crystal directions, which means that the magnetic interactions differ significantly along different directions. Furthermore, these materials exhibit a giant magnetocaloric effect near the Curie temperature. The largest value of maximum of magnetic entropy change (

−
Δ

S

M

)

occurs perpendicular to the [100] direction. Specifically, at 252 K, maximum

−
Δ

S

M

is 2.91 and

3.64

J
·

kg

−
1

K

−
1

for a magnetic field of 5 and 7 T, respectively. The working temperature span over 80 K and the relative cooling power reaches 302 J/kg for a magnetic field of 7 T, which makes the

Mn

2
−
δ

Sn

compound a promising candidate for a magnetic refrigerator.
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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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.
Energy characteristics of the char obtained by two steps pyrolysis of chicken manure
Authors: Pop E , Mihăescu L , Lăzăroiu G , Pîșă I , Negreanu G , Berbece V
Published: September 2019

The thermal treatment of chicken manure is an ecological alternative of neutralizing this kind of waste with energy recovery. In this regard, a two-stage pyrolysis process was chosen, the first stage having the purpose of preheating and moisture elimination. The drying process up to the starting point of volatile matter release, about 200-250°C was taken into consideration. As a result of the moisture elimination in the first step of the pyrolysis process, a gas fuel riched in CO, CH4, H2 will be obtained. The experimental determinations consisted in the proximate and ultimate analysis of the initial residue and tests of the pyrolysis process in a pilot plant that allows the pyrolysis of a quantity of waste in range of 40-200g. A sample of a 140 g was subjected to the pyrolysis process at 500°C and the char (an organic, solid, consistent and odourless product) was obtained. The carbon (C), nitrogen (N), hydrogen (H) and sulphur (S) contents of the final product of pyrolysis were determined by a Costech 4120 Elemental Analyser that allows us to calculate the Lower Heating Value (LHV) of the char. For the evaluation of the energy potential, a theoretical balance of the energy consumption in the process of pyrolysis and the energy developed by combustion of the char, has been made. This theoretical balance was verified by determining the energy developed by combustion of char based on the composition determined in the laboratory. The laboratory results confirmed the existence of an energy potential of the pyrolysis product, which offers a technological alternative.
Equilibrium moisture content of pumpkin seeds
Authors: Kiryakov I , Georgieva M , Atanasov D
Published: September 2019

The equilibrium moisture content of Pumpkin Seeds is studied and the sorption and desorption curves at temperature 20°C are obtained. The strain measurement method for taking down of sorption curves is used for the aim. Analytic dependences describing the sorption and desorption curves are derived. Values of equilibrium moisture contents for temperatures higher than 20°C (40°C, 60°C, 80°C) are obtained by using the method of Pass-Slepchenko. The results are presented in graphical and table form.
Wastewater sludge to energy production. A review
Authors: Vatachi N
Published: September 2019

Global economic and social development involves increasing demands for water use for various purposes: domestic, public, industrial. Wastewater treatment in these processes results in increasing volumes of sewage sludge. The elimination of this sludge is a permanent concern at global level because of the dangers to the environment, consisting of the high content of organic pollutants, toxic and heavy metals. However, a significant amount of renewable energy can be recovered from sludge from sewage treatment, with several paths being possible: anaerobic digestion, combustion and co-combustion, pyrolysis, gasification. Each of these pathways is characterized by advantages and disadvantages, benefits and technological limitations. This paper proposes a review of current conversion methods and technologies for energy recovery from sewage sludge, anaerobic digestion, incineration and co-combustion especially. Processes present in current literature and practice are described, resulting in the influence of the properties of sludge fuels and their impact on the energy recovery process when these fuels are used in combustion plants. There are also scientific researchers conducted to improve operational and environmental performance and cost competitiveness.
Examination of natural noise signals: preliminary results for aquatic environment
Authors: Zhivomirov H , Nedelchev I
Published: September 2019

The present article treats the signal analysis and the revealing of the properties of noise signals which are caused by cavitation, boiling, flow and motion of water (aquatic environment) in natural conditions. All examined signals are not of androgenic and/or technogenic origin and corresponds to a few natural processes e.g., boiling water, rain, sea surf. All analyses are conducted in the Matlab® environment and include: computation of the mean and RMS values, dynamic range, crest factor, skewness and kurtosis, autocorrelation time; test for stationarity; plot of the oscillogram, correlogram, histogram, periodogram and spectrogram. Finally, some common conclusions are drawn, based on the analyses results.
Kinetics coefficients of solid-liquid extraction of resinoid from tobacco leaves
Authors: Tasheva S , Popova V , Ivanova T , Stoyanova A , Valtchev G
Published: September 2019

Cured tobacco leaves (Nicotiana tabacum L.) from three commercial types – flue cured Virginia, Burley and Oriental, were processed by extraction to obtain the concentrated aromatic product resinoid, which is used in cosmetics and other areas. The objective of the study was to characterize the kinetics of the process of tobacco resinoid extraction by two basic indices – the coefficient of internal molecular diffusion (Dint
) and the coefficient of mass transfer (β). For that purpose, extraction was carried out at different temperatures (in the range between 20°C and 70°C), and the process was divided into a series of consecutive 10-minute intervals, for which the respective values of the kinetics coefficients were calculated. Based on the established variations of Dint
by tobacco type, time and temperature, the respective regression models were derived. The coefficients of mass transfer, as well as the kinetic indices of the extraction process – the Biot diffusion number (Bi) and the Fourier diffusion number (Fo), were calculated for the three tobacco types. Data from the applied calculation procedures are presented in the study.
From symbiont to parasite: the evolution of for-profit science publishing
Authors: Walter Peter , Mullins Dyche
Published: September 2019

Two 17th century institutions—learned societies and scientific journals—transformed science in ways that still dominate our professional lives today. Learned societies like the American Society for Cell Biology remain relevant because they provide forums for sharing results, discussing the practice of science, and projecting our voices to the public and the policy makers. Scientific journals still disseminate our work, but in the Internet-connected world of the 21st century, this is no longer their critical function. Journals remain relevant almost entirely because they provide a playing field for scientific and professional competition: to claim credit for a discovery, we publish it in a peer-reviewed journal; to get a job in academia or money to run a lab, we present these published papers to universities and funding agencies. Publishing is so embedded in the practice of science that whoever controls the journals controls access to the entire profession. We must reform our methods for evaluating the contributions of younger scientists and deflate the power of a small number of "elite" journals. More generally, given the recent failure of research institutions around the world to strike satisfactory deals with publishing giant Elsevier, the time has come to examine the motives and methods of those to whom we have entrusted the keys to the kingdom of science.
Integrating Pharmacokinetics and Pharmacodynamics in Operational Research to End Tuberculosis
Authors: Alffenaar Jan-Willem C , Gumbo Tawanda , Dooley Kelly E , Peloquin Charles A , Mcilleron Helen , Zagorski Andre , Cirillo Daniela M , Heysell Scott K , Silva Denise Rossato , Migliori Giovanni Battista
Published: September 2019

Tuberculosis (TB) elimination requires innovative approaches. The new Global Tuberculosis Network (GTN) aims to conduct research on key unmet therapeutic and diagnostic needs in the field of TB elimination using multidisciplinary, multisectorial approaches. The TB Pharmacology section within the new GTN aims to detect and study the current knowledge gaps, test potential solutions using human pharmacokinetics informed through preclinical infection systems, and return those findings to the bedside. Moreover, this approach would allow prospective identification and validation of optimal shorter therapeutic durations with new regimens. Optimized treatment using available and repurposed drugs may have an increased impact when prioritizing a person-centered approach and acknowledge the importance of age, gender, comorbidities, and both social and programmatic environments. In this viewpoint article, we present an in-depth discussion on how TB pharmacology and the related strategies will contribute to TB elimination.
Patient-generated health data management and quality challenges in remote patient monitoring
Authors: Abdolkhani Robab , Gray Kathleen , Borda Ann , DeSouza Ruth
Published: September 2019

Background

Patient-Generated Health Data (PGHD) in remote monitoring programs is a promising source of precise, personalized data, encouraged by expanding growth in the health technologies market. However, PGHD utilization in clinical settings is low. One of the critical challenges that impedes confident clinical use of PGHD is that these data are not managed according to any recognized approach for data quality assurance.

Objective

This article aims to identify the PGHD management and quality challenges that such an approach must address, as these are expressed by key PGHD stakeholder groups.

Materials and Methods

In-depth interviews were conducted with 20 experts who have experience in the use of PGHD in remote patient monitoring, including: healthcare providers, health information professionals within clinical settings, and commercial providers of remote monitoring solutions. Participants were asked to describe PGHD management processes in the remote monitoring programs in which they are involved, and to express their perspectives on PGHD quality challenges during the data management stages.

Results

The remote monitoring programs in the study did not follow clear PGHD management or quality assurance approach. Participants were not fully aware of all the considerations of PGHD quality. Digital health literacy, wearable accuracy, difficulty in data interpretation, and lack of PGHD integration with electronic medical record systems were among the key challenges identified that impact PGHD quality.

Conclusion

Co-development of PGHD quality guidelines with relevant stakeholders, including patients, is needed to ensure that quality remote monitoring data from wearables is available for use in more precise and personalized patient care.
Challenges to electronic clinical quality measurement using third-party platforms in primary care practices: the healthy hearts in the heartland experience
Authors: Ahmad Faraz S , Rasmussen Luke V , Persell Stephen D , Richardson Joshua E , Liss David T , Kenly Pauline , Chung Isabel , French Dustin D , Walunas Theresa L , Schriever Andy , Kho Abel N
Published: September 2019

Third-party platforms have emerged to support small primary care practices for calculating and reporting electronic clinical quality measures (eCQM) for federal programs like The Medicare Access and CHIP Reauthorization Act of 2015 (MACRA) and Merit-based Incentive Payment System (MIPS). Yet little is known about the capabilities and limitations of electronic health record systems (EHRs) to enable data access for these programs. We connected 116 small- to medium-sized practices with seven different EHRs to popHealth, an open-source eCQM platform. We identified the prevalence of following problems with eCQM data for data extraction in seven different EHRs: (1) Lack of coded data in five of seven; (2) Incorrectly categorized data in four of seven; (3) Isosemantic data (data within the incorrect context) in four of seven; (4) Coding that could not be directly evaluated in six of seven; (5) Errors in date assignment and labeled as historical values in five of seven; and (6) Inadequate data to assign the correct code in two of seven. We recommend specific enhancements to EHR systems that can promote effective eCQM implementation and reporting to MACRA and MIPS.