bluuebunny/crossref_metadata_2025 huggingface dataset:
Fuels Characterization for Use in Internal Combustion Engines
Authors: Lanzafame R. , Messina M.
Published: March 2020

It is important provide mathematical functions able to fit with great precision experimental data on gases properties, in order to obtain reliable results when computerized models on IC engines are used.

On the basis of experimental data on equilibrium constants (for dissociation phenomena occurring during combustion process in IC engines) new mathematical functions have been determined to fit experimental data. In comparison to traditional fitting polynomials, these new mathematical functions present a great accuracy in matching experimental data. These new mathematical functions have the functional forms of a V order Logarithmic Polynomial, and their coefficients have been evaluated on the basis of the least square method. The new V order Logarithmic Polynomials have been determined for several dissociation reactions according to internal combustion processes applications.

V order Logarithmic Polynomials have been implemented also to describe the trend of specific heat at constant pressure Vs temperature and enthalpy Vs temperature. These new Logarithmic Polynomials have been calculated for several gases and fuels for IC engines applications.

The new Logarithmic Polynomials pointed out a better precision in comparison to the others polynomial functions used in literature, and the possibility to utilize a single Logarithmic Polynomial for a wide temperature range, according to a good accuracy with experimental data. Another advantage of the Logarithmic Polynomials is the possibility to extrapolate experimental data on a wide temperature range (25% of experimental T range) in order to supply to the experimental data shortage.
Improvement of the Dynamic Characteristic of an Automotive Engine by a Turbocharger Assisted by an Electric Motor
Authors: Katrašnik Tomaž , Trenc Ferdinand , Rodman Samuel , Hribernik Aleš , Medica Vladimir
Published: March 2020

Increase of the mean effective pressure in an automotive Diesel engine is generally the consequence of the turbocharging and subsequent charge cooling of the working medium. A problem of poor performance during the engine speed and load change is attributed to the nature of energy exchange between the engine and the turbocharger. Filling of the intake and exhaust manifolds, consequent increase of the pressure and acceleration of the rotating components of the turbocharger require a certain period of time. Dynamic performance of the turbocharger can be substantially improved by the assistance of an electric motor attached directly to the turbo shaft. A new concept of asynchronous electric motor with a very thin rotor was applied to support the turbocharger during the transient regimes of the engine. Experimental work for matching an electrically assisted turbocharger to an engine is rather expensive; it was therefore decided to determine general characteristic of the electric motor separately by experiments, whereas transient response of the turbocharged and intercooled Diesel engine was simulated by a zero-dimensional filling and emptying computer simulation method. A lot of experimentally obtained data and empirical formulae for the compressor, gas turbine, flow coefficients of the engine valves, intercooler, high pressure fuel pump with the pneumatic control device (LDA), combustion parameters etc. were applied to overcome deficiency introduced by the zero-dimensional simulation model. As the result a reliable and accurate program compatible with the experimental results in steady and transient engine operation was developed and is presented in the work. Faster transient response of the engine was obtained by applying an electric motor to assist the turbocharger; a few versions were introduced in the simulation program and were also analysed in the work.
A New Approach to Engine Misfire Detection by Crankshaft Speed Variation Analysis
Authors: Abdel Jalil Nashat K. , Das Manohar
Published: March 2020

A new algorithm to detect cylinder misfire in automotive gasoline engines is presented in this paper. It is based on processing the variations in crankshaft speed of the engine. In the algorithm, the crankshaft speed data is preprocessed and then modeled as a Mixture of Gaussian components. The appropriate number of components in the data is determined using a goodness-of-fit measure. When misfire is taking place, two or more Gaussian components will appear in the mixture model. Based on the estimated parameters (mean, variance) of the components and a specified probability of false alarms, a Generalized Likelihood decision rule is designed to classify every data point as a misfire or no-misfire behavior. The algorithm was tested on real engine data and the results were encouraging.
Silicon nitride spacer etching selectively to silicon using CH3F/O2/He/SiCl4 plasma
Authors: Possémé Nicolas , Garcia-Barros Maxime , Arvet Christian , Pollet Olivier , Leverd François , Barnola Sébastien
Published: March 2020

Using CH3F/O2/He based chemistries in high density plasmas for silicon nitride spacer etching, loss of silicon in active source/drain regions of CMOS transistors can be observed. Minimizing the so-called silicon recess during nitride spacer etching is extremely difficult to achieve but mandatory since it directly impacts the device performance. In this work, the authors investigated the benefits of CH3F/O2/He/SiCl4 plasma to limit this recess. Using x-ray photoelectron spectroscopy, the mechanism for high Si3N4/Si selectivity is identified as the formation of a preferential thick SiOxFyClz passivation layer, generated at the silicon surface. The silicon damage is reduced by the growth of this thick layer, limiting the transfer of the reactive layer into the silicon film. These results have been confirmed on pattern structures for fully depleted silicon on insulator 14 nm technology showing the benefit of CH3F/O2/He/SiCl4 etch plasma compared to CH3F/O2/He plasma.
Illuminating Macrophage Contributions to Host-Pathogen Interactions
In Vivo
: the Power of Zebrafish
Authors: Rosowski Emily E.
Published: March 2020

Macrophages are a key cell type in innate immunity. Years of
in vitro
cell culture studies have unraveled myriad macrophage pathways that combat pathogens and demonstrated how pathogen effectors subvert these mechanisms. However,
in vitro
cell culture studies may not accurately reflect how macrophages fit into the context of an innate immune response in whole animals with multiple cell types and tissues. Larval zebrafish have emerged as an intermediate model of innate immunity and host-pathogen interactions to bridge the gap between cell culture studies and mammalian models.
Redox-Regulated Adaptation of Streptococcus oligofermentans to Hydrogen Peroxide Stress
Authors: Tong Huichun , Dong Yuzhu , Wang Xinhui , Hu Qingqing , Yang Fan , Yi Meiqi , Deng Haiteng , Dong Xiuzhu
Published: March 2020

The catalase-negative streptococci produce as well as tolerate high levels of H
2
O
2
. This work reports the molecular mechanisms of low-H
2
O
2
-concentration-induced adaptation to higher H
2
O
2
stress in a
Streptococcus
species, in which the peroxide-responsive repressor PerR and its redox regulons play the major role. Distinct from the
Bacillus subtilis
PerR, which is inactivated by H
2
O
2
through histidine oxidation by the Fe
2+
-triggered Fenton reaction, the streptococcal PerR is inactivated by H
2
O
2
oxidation of the structural Zn
2+
binding cysteine residues and thus derepresses the expression of genes defending against oxidative stress. The reversible cysteine oxidation could provide flexibility for PerR regulation in streptococci, and the mechanism might be widely used by lactic acid bacteria, including pathogenic streptococci, containing high levels of cellular manganese, in coping with oxidative stress. The adaptation mechanism could also be applied in oral hygiene by facilitating the fitness and adaptability of the oral commensal streptococci to suppress the pathogens.
Ecological Assembly Processes Are Coordinated between Bacterial and Viral Communities in Fractured Shale Ecosystems
Authors: Danczak R. E. , Daly R. A. , Borton M. A. , Stegen J. C. , Roux S. , Wrighton K. C. , Wilkins M. J.
Published: March 2020

Interactions between viral communities and their microbial hosts have been the subject of many recent studies in a wide range of ecosystems. The degree of coordination between ecological assembly processes influencing viral and microbial communities, however, has been explored to a much lesser degree. By using a combined null modeling approach, this study investigated the ecological assembly processes influencing both viral and microbial community structure within hydraulically fractured shale environments. Among other results, significant relationships between the structuring processes affecting both the viral and microbial community were observed, indicating that ecological assembly might be coordinated between these communities despite differing selective pressures. Within this deep subsurface ecosystem, these results reveal a potentially important balance of ecological dynamics that must be maintained to enable long-term microbial community persistence. More broadly, this relationship begins to provide insight into the development of communities across trophic levels.
In VivoThermodynamic Analysis of Glycolysis in Clostridium thermocellum and Thermoanaerobacterium saccharolyticum Using13C and2H Tracers
Authors: Jacobson Tyler B. , Korosh Travis K. , Stevenson David M. , Foster Charles , Maranas Costas , Olson Daniel G. , Lynd Lee R. , Amador-Noguez Daniel
Published: March 2020

Thermodynamics constitutes a key determinant of flux and enzyme efficiency in metabolic networks. Here, we provide new insights into the divergent thermodynamics of the glycolytic pathways ofC. thermocellumandT. saccharolyticum, two industrially relevant thermophilic bacteria whose metabolism still is not well understood. We report that while the glycolytic pathway inT. saccharolyticumis as thermodynamically favorable as that found in model organisms, such asE. coliorSaccharomyces cerevisiae, the glycolytic pathway ofC. thermocellumoperates near equilibrium. The use of a near-equilibrium glycolytic pathway, with potentially increased ATP yield, by this cellulolytic microbe may represent an evolutionary adaptation to growth on cellulose, but it has the drawback of being highly susceptible to product feedback inhibition. The results of this study will facilitate future engineering of high-performance strains capable of transforming cellulosic biomass to biofuels at high yields and titers.
FORENSIC: an Online Platform for Fecal Source Identification
Authors: Roguet Adélaïde , Esen Özcan C. , Eren A. Murat , Newton Ryan J. , McLellan Sandra L.
Published: March 2020

FORENSIC is an online platform to identify sources of fecal pollution without the need to create reference libraries. FORENSIC is based on the ability of random forest classification to extract cohesive source microbial signatures to create classifiers despite individual variability and to detect the signatures in environmental samples. We primarily focused on defining sewage signals, which are associated with a high human health risk in polluted waters. To test for fecal contamination sources, the platform only requires paired-end reads targeting the V4 or V6 regions of the 16S rRNA gene. We demonstrated that we could use V4V5 reads trimmed to the V4 positions to generate the reference signature. The systematic workflow we describe to create and validate the signatures could be applied to many disciplines. With the increasing gap between advancing technology and practical applications, this platform makes sequence-based water quality assessments accessible to the public health and water resource communities.
Constraints from cosmogenic nuclides on the glaciation and erosion history of Dove Bugt, northeast Greenland
Authors: Skov Daniel Søndergaard , Andersen J.L. , Olsen J. , Jacobsen B.H. , Knudsen M.F. , Jansen J.D. , Larsen N.K. , Egholm D.L.
Published: March 2020

The intricate interplay between subglacial topography and ice-sheet dynamics is key to the evolution of large ice sheets, but in Greenland as elsewhere the effects of long-term glacial history on landscape evolution remain poorly constrained. Here we measure abundances of cosmogenic 10Be and 26Al in bedrock and transported boulders to unveil the glaciation and erosion history of Dove Bugt, northeast Greenland. In agreement with studies of west Greenland, we find that apparent exposure ages increase with elevation from 9 ka to 13 ka in low-lying valleys to 21 ka to 204 ka on high-elevation, blockfield-covered plateaus. We employ a Markov chain Monte Carlo inversion framework to constrain the probability of various erosion histories, and we quantify the residence time of samples within the upper 2 m of the bedrock subsurface—a measure defined as the cosmogenic nuclide memory. This cosmogenic nuclide memory exceeds 600 ka on the highest plateaus but is limited to less than 500 ka in most other high-elevation samples and to less than 100 ka at low-elevations. Our results define maximum limits for the fraction of ice cover during the past 1 Ma to ∼70% on the Store Koldewey peaks and ∼90% farther inland at Pusterdal, respectively. Minimum limits to ice cover, however, cannot be reliably constrained by the data. Finally, we propose that limited erosion on the highest plateaus of Store Koldewey since 0.6–1.0 Ma indicates a minimum age for fjord-plateau formation within this area of northeast Greenland.
Neoproterozoic Blaini Formation of Lesser Himalaya, India: Fiction and Fact
Authors: Dey Sumit , Dasgupta Prabir , Das Kaushik , Matin Abdul
Published: March 2020

The long-conceived idea of the glacial origin of Blaini diamictite of Lesser Himalayan Neoproterozoic succession reached its maxima when the diamictites and capping pink limestone were attributed to the Neoproterozoic Snowball Earth event and its aftermath, respectively. Occurrences of diamictite-limestone association in two different levels have also been correlated with the Sturtian and Marinoan glaciations. Critical review, however, reveals that the interpretations of the glacial origin of diamictites are not well founded. The diamictite-limestone association, which occurs at the lower part of a thick, light brown shale unit and laterally grades into light brown shale, primarily indicates episodic surge events in an otherwise tranquil condition favorable for hemipelagic sedimentation. The lithology, bed geometry, internal organization, and disposition of the diamictite bodies suggest deposition of debris flow fan lobes along fault scarps in a rift setting. Emplacement of subaqueous debris flows is indicated by the associated deposits of entrained turbidity currents. The limestone also bears the signature of claciturbidites. The appearance of diamictite bodies and associated limestone in two distinct levels is not a stratigraphic disposition; on the contrary, the deposits were dislocated and repeated by two successive regional thrust faults. The Chemical Index of Alteration (CIA) values of the light brown shale and the matrix of the diamictites indicate that these sediments formed through prolonged subaerial weathering. The events leading up to development of the rift system and evidence of prolonged weathering within the basin-fill sediments are consistent with supercontinental break up, the prologue of Snowball Earth.
How do trainee doctors learn about research? Content analysis of Australian specialist colleges’ intended research curricula
Authors: Stehlik Paulina , Noble Christy , Brandenburg Caitlin , Fawzy Peter , Narouz Isaac , Henry David , Glasziou Paul
Published: March 2020

Objectives

Patients do better in research-intense environments. The importance of research is reflected in the accreditation requirements of Australian clinical specialist colleges. The nature of college-mandated research training has not been systematically explored. We examined the intended research curricula of Australian trainee doctors described by specialist colleges, their constructive alignment and the nature of scholarly project requirements.

Design

We undertook content analysis of publicly available documents to characterise college research training curricula.

Setting

We reviewed all publicly accessible information from the websites of Australian specialist colleges and their subspecialty divisions. We retrieved curricula, handbooks and assessment-related documents.

Participants

Fifty-eight Australian specialist colleges and their subspecialty divisions.

Primary and secondary outcome measures

Two reviewers extracted and coded research-related activities as learning outcomes, activities or assessments, by research stage (using, participating in or leading research) and competency based on Bloom’s taxonomy (remembering, understanding, applying, analysing, evaluating, creating). We coded learning and assessment activities by type (eg, formal research training, publication) and whether it was linked to a scholarly project. Requirements related to project supervisors’ research experience were noted.

Results

Fifty-five of 58 Australian college subspecialty divisions had a scholarly project requirement. Only 11 required formal research training; two required an experienced research supervisor. Colleges emphasised a role for trainees in leading research in their learning outcomes and assessments, but not learning activities. Less emphasis was placed on using research, and almost no emphasis on participation. Most learning activities and assessments mapped to the ‘creating’ domain of Bloom’s taxonomy, whereas most learning outcomes mapped to the ‘evaluating’ domain. Overall, most research learning and assessment activities were related to leading a scholarly project.

Conclusions

Australian specialist college research curricula appear to emphasise a role for trainees in leading research and producing research deliverables, but do not mandate formal research training and supervision by experienced researchers.
Effect of tart cherry juice on risk of gout attacks: protocol for a randomised controlled trial
Authors: Lamb Kirstie Louise , Lynn Anthony , Russell Jean , Barker Margo E
Published: March 2020

Introduction

Gout is a painful form of inflammatory arthritis associated with several comorbidities, particularly cardiovascular disease. Cherries, which are rich in anti-inflammatory and antioxidative bioactive compounds, are proposed to be efficacious in preventing and treating gout, but recommendations to patients are conflicting. Cherry consumption has been demonstrated to lower serum urate levels and inflammation in several small studies. One observational case cross-over study reported that cherry consumption was associated with reduced risk of recurrent gout attacks. This preliminary evidence requires substantiation. The proposed randomised clinical trial aims to test the effect of consumption of tart cherry juice on risk of gout attacks.

Methods and analysis

This 12-month, parallel, double-blind, randomised, placebo-controlled trial will recruit 120 individuals (aged 18–80 years) with a clinical diagnosis of gout who have self-reported a gout flare in the previous year. Participants will be randomly assigned to an intervention group, which will receive Montmorency tart cherry juice daily for a 12-month period, or a corresponding placebo group, which will receive a cherry-flavoured placebo drink. The primary study outcome is change in frequency of self-reported gout attacks. Secondary outcome measures include attack intensity, serum urate concentration, fractional excretion of uric acid, biomarkers of inflammation, blood lipids and other markers of cardiovascular risk. Other secondary outcome measures will be changes in physical activity and functional status. Statistical analysis will be conducted on an intention-to-treat basis.

Ethics and dissemination

This study has been granted ethical approval by the National Research Ethics Service, Yorkshire and The Humber—Leeds West Research Ethics Committee (ref: 18/SW/0262). Results of the trial will be submitted for publication in a peer-reviewed journal.

Trial registration number

NCT03621215.
Serum Creatinine Trajectories in Real-World Hospitalized Patients: Clinical Context and Short-Term Mortality
Authors: Laszczyńska Olga , Severo Milton , Mascarenhas Joana , Paiva José Artur , Azevedo Ana
Published: March 2020

Fluctuations in serum creatinine (SCr) during hospitalization may provide additional prognostic value beyond baseline renal function. This study aimed to identify groups of patients with distinct creatinine trajectories over hospital stay and assess them in terms of clinical characteristics and short-term mortality. This retrospective study included 35 853 unique adult admissions to a tertiary referral center between January 2012 and January 2016 with at least three SCr measurements within the first 9 days of stay. Individual SCr courses were determined using linear regression or linear-splines model and grouped into clusters. SCr trajectories were described as median SCr courses within clusters. Almost half of the patients presented with changing, mainly declining SCr concentration during hospitalization. In comparison to patients with an increase in SCr, those with a significant decline were younger, more often admitted via the emergency department, more often required a higher level of care, had fewer comorbidities and the more pronounced the fall in SCr, the greater the observed difference. Regardless of baseline renal function, an increase in SCr was related to the highest in-hospital mortality risk among compared clusters. Also, patients with normal renal function at admission followed by decreasing SCr were at higher risk of inpatient death, but lower 90-day postdischarge mortality than patients with a stable SCr. Acute changes in inpatient SCr convey important prognostic information and can only be interpreted by looking at their evolution over time. Recognizing underlying causes and providing adequate care is crucial for improving adverse prognosis.
Intracranial sewing needle in a dog
Authors: Caraty Johan , di Virgilio Fabrizio , Belluzzi Elena , Santos Marisa , Bongartz Alexandre
Published: March 2020

The objective of this clinical case study is to describe the first clinical case of an intracranial sewing needle identified in veterinary medicine and to describe the second case of intracranial foreign body secondary to pharyngeal perforation. A one‐year‐old Maltese dog with acute haemorrhagical vomiting and seizure was evaluated. A cerebral CT scan revealed the presence of a sewing needle inserted into the nasopharynx, which perforated the caudal cranial fossa through the brainstem, cerebellum and caudal part of the forebrain. An emergency surgery was performed, the needle was removed and the dog recovered well during the following 72 hours. One month after the surgery, the dog was still fine. This clinical case reinforces the possibility of cranial perforation after sharp foreign body ingestion. Intracranial foreign body should be part of the differential diagnosis in dogs when acute digestive signs are associated with acute neurological complications.
Effect of aging and obesity on GLUT12 expression in small intestine, adipose tissue, muscle, and kidney and its regulation by docosahexaenoic acid and exercise in mice
Authors: Gil-Iturbe Eva , Félix-Soriano Elisa , Sáinz Neira , Idoate-Bayón Adrián , Castilla-Madrigal Rosa , Moreno-Aliaga María J. , Lostao María Pilar
Published: March 2020

Obesity is characterized by excessive fat accumulation and inflammation. Aging has also been characterized as an inflammatory condition, frequently accompanied by accumulation of visceral fat. Beneficial effects of exercise and n-3 long-chain polyunsaturated fatty acids in metabolic disorders have been described. Glucose transporter 12 (GLUT12) is one of the less investigated members of the GLUT family. Glucose, insulin, and tumor necrosis factor alpha (TNF-α) induce GLUT12 translocation to the membrane in muscle, adipose tissue, and intestine. We aimed to investigate GLUT12 expression in obesity and aging, and under diet supplementation with docosahexaenoic acid (DHA) alone or in combination with physical exercise in mice. Aging increased GLUT12 expression in intestine, kidney, and adipose tissue, whereas obesity reduced it. No changes on the transporter occurred in skeletal muscle. In obese 18-month-old mice, DHA further decreased GLUT12 in the 4 organs. Aerobic exercise alone did not modify GLUT12, but the changes triggered by exercise were able to prevent the DHA-diminishing effect, and almost restored GLUT12 basal levels. In conclusion, the downregulation of metabolism in aging would be a stimulus to upregulate GLUT12 expression. Contrary, obesity, an excessive energy condition, would induce GLUT12 downregulation. The combination of exercise and DHA would contribute to restore basal function of GLUT12.

Novelty In small intestine, kidney and adipose tissue aging increases GLUT12 protein expression whereas obesity reduces it. Dietary DHA decreases GLUT12 in small intestine, kidney, adipose tissue and skeletal muscle. Exercise alone does not modify GLUT12 expression, nevertheless exercise prevents the DHA-diminishing effect on GLUT12.
Temperature effects on dredged slurry performance under vacuum preloading
Authors: Wang Jun , Cai Yuanqiang , Yuan Guohui , Fu Hongtao , Sun Wentao , Hu Xiuqing , Wang Peng , Ni Junfeng
Published: March 2020

Under appropriate temperature conditions, vacuum preloading can effectively accelerate the rate of soil consolidation. If the temperature is low (30 °C), vacuum preloading is less effective at consolidating the soil. If temperature is extremely high, vacuum preloading is less efficient at consolidating the soil due to the consummation of excess energy consumed. In this study, a series of laboratory tests was conducted to analyse the effects that temperature has on dredged slurry consolidation via vacuum pressure using constant and variable heating modes. During these tests, heat transfer, water discharge, surface settlement, and pore-water pressure dissipation were observed in the soil samples. Based on the laboratory test measurements, each soil sample’s horizontal coefficient of consolidation, water content, and shear strength were determined. To quantify the energy consumption of the different heating modes, the ratios of energy consumption as a function of the soil’s total water discharge and mean shear strength were determined. Using these parameters, an optimal soil consolidation temperature was obtained. The results indicated that vacuum preloading was most effective in consolidating the soil under a constant temperature of 75 °C rather than variable temperatures.
Enhanced detectability of spinning primordial black holes
Authors: Kühnel Florian
Published: March 2020

Primordial black holes which are produced during an epoch of matter domination are expected to spin rapidly. It is shown that this leads to an enhancement of the detectability of the stochastic gravitational-wave background from their mergers. For a specific model, we explicitly demonstrate that this yields a $$50\,\%$$50% increase of the gravitational-wave amplitude as compared to the non-spinning case.
Octonions, triality, the exceptional Lie algebra F4 and polar actions on the Cayley hyperbolic plane
Authors: Kollross Andreas
Published: March 2020

Using octonions and the triality property of Spin(8), we find explicit formulae for the Lie brackets of the exceptional simple real Lie algebras [Formula: see text] and [Formula: see text], i.e. the Lie algebras of the isometry groups of the Cayley projective plane and the Cayley hyperbolic plane. As an application, we determine all polar actions on the Cayley hyperbolic plane which leave a totally geodesic subspace invariant.
OWNERSHIP STRUCTURE, ACQUISITIONS AND EXECUTIVE COMPENSATION: EVIDENCE FROM PUBLICLY LISTED CHINESE COMPANIES
Authors: KANG LILI , ANWAR SAJID , PENG FEI
Published: March 2020

Using panel data from China’s publicly listed companies (PLCs), this paper investigates the relationship between acquisitions and executive compensation. Empirical analysis based on panel regression reveals that acquisitions lead to a significant increase in executive compensation. Further evaluation, using disaggregated data, shows that acquisitions have a significant and positive impact of executive compensation of state-owned PLCs, but its effect on executive compensation paid by private-owned PLCs is statistically insignificant. The state-owned PLCs give less weight to financial performance compared with private-owned PLCs. State ownership and shareholding concentration increase the executive compensation, which gives rise to a principal–principal type problem. Moreover, using the generalized propensity score (GPS) methodology, which allows one to control for the presence of the selection bias, we find that the compensation-increasing effect of acquisitions for the top executive managers is higher than the effect for the top board directors. Finally, once the selection bias is taken into account, we find that acquisitions have almost no effect on the compensation of lower level executive managers and board directors, which suggests the presence of a principal–agent type problem in the two-tiered governance structure of the Chinese PLCs.
FACTORS LEADING TO INCREASED CARBON DIOXIDE EMISSIONS OF THE APEC COUNTRIES: THE LMDI DECOMPOSITION ANALYSIS
Authors: CHANG YU-FANG , HUANG BWO-NUNG
Published: March 2020

This paper explores the factors that lead to increased carbon dioxide emissions in the 18 countries of the APEC. We apply the LMDI multiplicative decomposing method to 18 countries between 1971 and 2012. We summarize these factors that are as follows: (1) population increase and economic growth play a key role in increased carbon dioxide emissions. (2) All the 18 countries of the APEC have improved their energy efficiency as manifested in the change of energy intensity ([Formula: see text]), which is less than 1 in the 42 years; (3) In terms of energy substitution effect ([Formula: see text]) and fuel coefficient effect ([Formula: see text]), the decomposition results point out that Hong Kong, Indonesia, and Malaysia witnessed growth in [Formula: see text] and [Formula: see text], indicating the only factor to reduce the emissions for these three countries is intensity effect, which gives rise to relatively higher emission for these three countries during the period. In the case of Peru, the Philippines, Singapore, Thailand, and Vietnam, we witnessed increases in [Formula: see text], but decreases in [Formula: see text]; In the case of Australia, Canada, Chile, China, Japan, South Korea, Mexico, New Zealand, Taiwan, and the US, there seem to decrease in [Formula: see text], but increases in [Formula: see text] during the 42-year period.
Molecular dynamics simulation of sintering of Cu and Au nanoparticles
Authors: Wu Zhuangjun , Li Maoxiang , Tian Sen , Zhang Linxing
Published: March 2020

Particle coalescence has wide applications in nature and industry. In this study, molecular dynamics (MDs) simulations were employed to examine the sintering of Cu and Au nanoparticles, as well as two other systems, namely, Cu nanoparticles and Au nanoparticles. The results suggested that, the Au atoms diffused through the outer area of the sintering neck before the nanoparticles were fused into one sphere. The possible reason was that the Au atoms resembled fluid, which could be ascribed to the local thermal energy at the contact area. Typically, the change in energy per atom from 300 K to the contact temperature denoted that less energy was required for the atoms in the pure Cu system to contact with each other than those in the other two systems.
Local and 2-local derivations of solvable Leibniz algebras
Authors: Ayupov Shavkat , Khudoyberdiyev Abror , Yusupov Bakhtiyor
Published: March 2020

We show that any local derivation on the solvable Leibniz algebras with model or abelian nilradicals, whose dimension of complementary space is maximal is a derivation. We show that solvable Leibniz algebras with abelian nilradicals, which have [Formula: see text] dimension complementary space, admit local derivations which are not derivations. Moreover, similar problem concerning [Formula: see text]-local derivations of such algebras is investigated and an example of solvable Leibniz algebra is given such that any [Formula: see text]-local derivation on it is a derivation, but which admits local derivations which are not derivations.
Noncommutative Friedmann equations in effective LQC
Authors: Díaz-Barrón Luis Rey , Espinoza-García Abraham , Pérez-Payán S. , Socorro J.
Published: March 2020

In this work, we construct a noncommutative version of the Friedmann equations in the framework of effective loop quantum cosmology, extending and applying the ideas presented in a previous proposal by some of the authors. The model under consideration is a flat FRW spacetime with a free scalar field. First, noncommutativity in the momentum sector is introduced. We establish the noncommutative equations of motion and obtain the corresponding exact solutions. Such solutions indicate that the bounce is preserved, in particular, the energy density is the same as in the standard LQC. We also construct an extension of the modified Friedmann equations arising in effective LQC which incorporates corrections due to noncommutativity, and argue that an effective potential is induced. This, in turn, leads us to investigate the possibility of an inflationary era. Finally, we obtain the Friedmann and the Raychaudhuri equations when implementing noncommutativity in the configuration sector. In this case, no effective potential is induced.
Surface charges toolkit for gravity
Authors: Frodden Ernesto , Hidalgo Diego
Published: March 2020

These notes provide a detailed catalog of surface charge formulas for different classes of gravity theories. The present catalog reviews and extends the existing literature on the topic. Part of the focus is on reviewing the method to compute quasi-local surface charges for gauge theories in order to clarify conceptual issues and their range of applicability. Many surface charge formulas for gravity theories are expressed in metric, tetrads-connection, Chern–Simons connection, and even BF variables. For most of them, the language of differential forms is exploited and contrasted with the more popular metric components language. The gravity theory is coupled with matter fields as scalar, Maxwell, Skyrme, Yang–Mills, and spinors. Furthermore, three examples with ready-to-download notebook codes, show the method in full action. Several new results are highlighted through the notes.
Friedmann equations for deformed entropic gravity
Authors: Kibaroğlu Salih , Senay Mustafa
Published: March 2020

In this study, we investigate the effects of the one- and two-parameters deformed systems on the Friedmann equations of the Friedmann–Robertson–Walker (FRW) universe by using the entropic gravity approach in the framework of the early universe era. We give simplified forms for the deformed Unruh temperature and Einstein field equations for three different deformed systems. Based on these compact equations, we derive the Friedmann equations with the effective gravitational and cosmological terms.
GRB 161017A, the circumburst environment is an intermediate regime between the homogeneous interstellar medium and wind-type medium
Authors: Zhou Qi-Qi , Yi Shuang-Xi , Huang Xiao-Li , Zhong Shu-Qing , Zou Yuan-Chuan , Tang Qing-Wen , Chen Zhi-Fu
Published: March 2020

We investigate the multi-band properties of the GRB 161017A with [Formula: see text], which was detected by Swift and Fermi satellites, and other instruments. The optical and X-ray afterglows were all detected at early times after the prompt emission. The optical light curve shows a very bright onset peak at about 100 s for 13 mag of [Formula: see text]-band, while the X-ray light curve occurs several flares at the beginning. We investigate the origin of X-ray and optical afterglows by analyzing the optical and X-ray data. Considering the smooth onset bump in the early time of the optical band and the erratic pulses for the X-ray lightcurve, we suppose that the early optical afterglow may be produced by the external shock, while the early time of X-ray light curve is dominated by flares. Therefore, GRB optical afterglows with smooth onset bump features at early time are possibly produced by external — forward shock (FS). According to the fireball external-model, the temporal slopes of the onset bumps are determined by both the medium density profile and the electron spectral index. Therefore, the afterglow onset bumps would be an ideal probe to study the properties of the fireball and the circumburst medium. The density profile has a slope of [Formula: see text], which suggests that the circumburst environment of the GRB 161017A would be an intermediate regime that are between the homogeneous interstellar medium (ISM) and wind-type medium. In addition, the optical light curve of the GRB 161017A exhibits a plateau feature and rebrightening after the onset bump, which may be related to the long-acting central engine of GRBs.
Unique factorization in polynomial rings with zero divisors
Authors: Anderson D. D. , Edmonds Ranthony A. C.
Published: March 2020

Given a certain factorization property of a ring [Formula: see text], we can ask if this property extends to the polynomial ring over [Formula: see text] or vice versa. For example, it is well known that [Formula: see text] is a unique factorization domain if and only if [Formula: see text] is a unique factorization domain. If [Formula: see text] is not a domain, this is no longer true. In this paper, we survey unique factorization in commutative rings with zero divisors, and characterize when a polynomial ring over an arbitrary commutative ring has unique factorization.
Integer-valued skew polynomials
Authors: Werner Nicholas J.
Published: March 2020

For a commutative integral domain [Formula: see text] with field of fractions [Formula: see text], the ring of integer-valued polynomials on [Formula: see text] is [Formula: see text]. In this paper, we extend this construction to skew polynomial rings. Given an automorphism [Formula: see text] of [Formula: see text], the skew polynomial ring [Formula: see text] consists of polynomials with coefficients from [Formula: see text], and with multiplication given by [Formula: see text] for all [Formula: see text]. We define [Formula: see text], which is the set of integer-valued skew polynomials on [Formula: see text]. When [Formula: see text] is not the identity, [Formula: see text] is noncommutative and evaluation behaves differently than it does for ordinary polynomials. Nevertheless, we are able to prove that [Formula: see text] has a ring structure in many cases. We show how to produce elements of [Formula: see text] and investigate its properties regarding localization and Noetherian conditions. Particular attention is paid to the case where [Formula: see text] is a discrete valuation ring with finite residue field.
Optically-excited simultaneous photoacoustic and ultrasound imaging based on a flexible gold-PDMS film
Authors: Cui Dandan , Zhang Zhenhui , Shi Yujiao
Published: March 2020

We constructed a flexible gold-polydimethylsiloxane (gold-PDMS) nanocomposites film with controllable thickness and light transmittance, to realize optically-excited simultaneous photoacoustic (PA) and ultrasound (US) imaging under a single laser pulse irradiation. Benefiting from the excellent thermoelastic properties, the gold-PDMS film absorbs part of the incident laser energy and produces a high-intensity US, which is used to realize US imaging. Meanwhile, the partly transmitted light is used to excite samples for PA imaging. By controlling the thickness of the gold-PDMS, we can control the center frequency in the US imaging. We experimentally analyzed the frequency of the produced US signal by the gold-PDMS film and compared it with the finite element analysis (FEA) method, where the experiments agree with the FEA results. This method is demonstrated by the experiments on phantoms and a mouse model. Our work provides a cost-effective methodology for simultaneous PA and US imaging.
Distance-based indices of complete m-ary trees
Authors: Masre Mesfin , Fufa Samuel Asefa , Vetrík Tomáš
Published: March 2020

Binary and [Formula: see text]-ary trees have extensive applications, particularly in computer science and chemistry. We present exact values of all important distance-based indices for complete [Formula: see text]-ary trees. We solve recurrence relations to obtain the value of the most well-known index called the Wiener index. New methods are used to express the other indices (the degree distance, the eccentric distance sum, the Gutman index, the edge-Wiener index, the hyper-Wiener index and the edge-hyper-Wiener index) as well. Values of distance-based indices for complete binary trees are corollaries of the main results.
Generalized displacement correlation method for mechanical and thermal fracture of FGM
Authors: Ait Ferhat Y. , Boulenouar A. , Benamara N. , Benabou L.
Published: March 2020

The main objective of this work is to present a numerical modeling of mixed-mode fracture in isotropic functionally graded materials (FGMs), under mechanical and thermal loading conditions. In this paper, the displacement-based method, termed the generalized displacement correlation (GDC) method, is investigated for estimating stress intensity factor (SIF). Using the ANSYS Parametric Design Language (APDL), the continuous variations of the material properties are incorporated by specified parameters at the centroid of each element. This paper presents various numerical examples in which the accuracy of the present method is verified. Comparisons have been made between the SIFs predicted by the GDC method and the available reference solutions in the current literature. A good agreement is achieved between the results of the GDC method and the reference solutions.
China’s Building of Overseas Military Bases: Rationale and Challenges
Authors: Guifang Xue , Jie Zheng
Published: March 2020

China’s military capability to perform out-of-area operations and provide international public goods falls short of the increasing need to protect its expanding economic, political, and security interests abroad. Overseas military bases can not only facilitate the soft application of China’s growing hard power, but also benefit the host nations in terms of national security, economic development, and job creation. A strong case can be made on both legal and precedential grounds for China’s construction of overseas military bases in the future. It is irreproachable for a great power like China to have overseas military installations as long as the Charter of the United Nations, host nations’ laws, and the longstanding non-intervention policy are upheld. Planning for overseas base-building must involve shaping an international environment that accepts Chinese military presence and conducting systemic risk assessments and practical solutions on such related matters as the location, size, functions, law enforcement, and maintenance of each military base.
Public-Private Partnership: Toward More Effective International Development Cooperation
Authors: Lu Jiang , Zetao Wu
Published: March 2020

In the 21st century, the traditional model of official development assistance (ODA) promoted by developed countries is faced with many challenges. One of them is the emergence of the “public-private partnership (PPP)” model for international development cooperation (IDC), which has become increasingly popular among developed countries and international organizations over the past decade. This article explores the origin, meaning, and mechanism of the PPP model, and discusses the major obstacles it encounters in practice. The article also compares PPP with China’s “development package” model, and puts forward some policy recommendations on China’s participation in IDC. Although China is a pioneer in carrying out public-private cooperation in international development, it needs to fully reflect on its experience, so as to formulate clearer guiding principles and management rules on public-private cooperation. It is also imperative for the country to set up relevant institutions and mechanisms to promote PPP practices.
Advances in the use of isotopes in geochemical exploration: instrumentation and applications in understanding geochemical processes
Authors: Kyser T. Kurt , Leybourne Matthew I. , Layton-Matthews Daniel
Published: March 2020

Among the emerging techniques to detect the real footprint of buried ore deposits is isotope tracing. Novel and automated preparation systems such as continuous flow isotope ratio mass spectrometry, off-axis integrated cavity output spectroscopy for isotopic compositions of selected molecules, multi-collector inductively coupled-plasma mass spectrometry (ICP-MS), triple quadrupole ICP-MS, laser ablation ICP-MS, and a multitude of inline preparation systems have facilitated the use of isotopes as tracers in mineral exploration, as costs for isotope analyses have decreased and the time required for the analyses has improved. In addition, the isotope systems being used have expanded beyond the traditional light stable and Pb isotopes to include a multitude of elements that behave differently during processes that promote the mobilization of elements during both primary and secondary dispersion. Isotopes are also being used to understand barren areas that lack a critical process to form an ore deposit and to reveal precise redox mechanisms. The goal is to be able to use isotopes to reflect a definitive process that occurs in association with the deposit and not in barren systems, and then to relate these to something that is easier to measure, namely elemental concentrations. As new generations of exploration and environmental scientists are becoming more comfortable with the application of isotopes to effectively trace processes involved in geoscience, and new technologies for rapid and inexpensive analyses of isotopes are continually being developed, novel applications of isotope tracing are becoming more mainstream.

Thematic collection:
This article is part of the Exploration 17 collection available at:
https://www.lyellcollection.org/cc/exploration-17
Energy Modeling for the Bluetooth Low Energy Protocol
Authors: Kindt Philipp H. , Yunge Daniel , Diemer Robert , Chakraborty Samarjit
Published: March 2020

Bluetooth Low Energy (BLE) is a wireless protocol optimized for low-power communication. To design energy-efficient devices, the protocol provides a number of parameters that need to be optimized within an energy, latency, and throughput design space. Therefore, an energy model that can predict the energy consumption of a BLE-based wireless device for different parameter value settings is needed. As BLE differs from the well-known Bluetooth Basic Rate (BR) significantly, models for Bluetooth BR cannot be easily applied to the BLE protocol. In past years, there have been a couple of proposals on energy models for BLE. However, none of them can model all the operating modes of the protocol. This article presents an energy model of the BLE protocol, which allows the computation of a device’s power consumption in all possible operating modes. To the best of our knowledge, our proposed model is not only one of the most accurate ones known so far (because it accounts for all protocol parameters), but it is also the only one that models all the operating modes of BLE. Based on this model, guidelines for system designers are presented that help choose the right parameters for optimizing the energy consumption. The model is publicly available as a software library for download.