bluuebunny/crossref_metadata_2025 huggingface dataset:
Local structure, thermodynamics, and phase behavior of asymmetric particle mixtures: Comparison between integral equation theories and simulation
Authors: Zhou Yuxing , Schweizer Kenneth S.
Published: June 2019

We study the structural pair correlations, thermodynamics, and fluid-fluid demixing phase behavior of dense binary sphere mixtures as predicted by integral equation theories with diverse closure approximations. The focus is on mixtures with a large size asymmetry over a wide range of compositions and strengths of interparticle attractive interactions with an emphasis on the nonperturbative strong bridging or network forming regime. Quantitative comparisons with simulations are carried out. At high volume fractions of the larger species, we find that all studied closures are reasonably good. However, large quantitative or even qualitative discrepancies compared with simulations emerge when the large species is the volumetrically minority component, under both entropic depletion and strong enthalpic bridging conditions. Overall, we find that using the modified-Verlet (MV) closure approximation for all three correlation functions leads to good predictions for structure, phase behavior, and the equation-of-state, along with assuring pair correlation functions which are rigorously positive. This symmetric or “triple MV” approximation has the advantage that the same closure can be used for any size ratio in all thermodynamic state regimes, in contrast to asymmetric closures. The good accuracy of the triple MV closure for particle mixtures provides as basis for developing improved theoretical descriptions of polymer nanocomposites and will serve as a crucial input to microscopic theories of slow dynamics in glass and gel forming systems.
Relativistic atomic structure calculations and study of plasma parameters for Na-like Se XXIV
Authors: Singh A. K. , Dawra Dishu , Dimri Mayank , Jha Alok K. S. , Mohan Man
Published: June 2019

Extensive calculations of energy levels and radiative data such as transition wavelengths, radiative rates, oscillator strengths, and line strengths for electric dipole (E1) transitions have been performed for Se XXIV using the multiconfiguration Dirac–Fock method. For other types of transitions, namely, magnetic dipole (M1), electric quadrupole (E2), and magnetic quadrupole (M2), only the radiative rates (A) are listed. The importance and effect of valence-valence and core-valence correlations on the excitation energies have been studied. For additional accuracy assessments, analogous calculations have been carried out by employing the flexible atomic code and configuration interaction technique. Comparisons are made with the available experimental and theoretical data in the literature. Close agreement has been found ensuring the accuracy and reliability of our results. The effect of plasma temperature on the line intensity ratio, electron density, plasma frequency, and skin depth has been analyzed for hot dense plasma (HDP) in local thermodynamic equilibrium. The present work might be beneficial in the modeling and characterization of HDP.
Carbon chain extension processes in cryogenic environments: UV-assisted growth of polyynic nitriles in solidified rare gases
Authors: Kołos Robert
Published: June 2019

As demonstrated in recent years, polyynic nitriles may photochemically arise from smaller unsaturated chain species in an apparently rigid environment of a cryogenic rare gas matrix. Here I summarize the highlights of respective research that has advanced the spectroscopic description of R–(C≡C)n–C≡N molecules (R = H, CN or CH3).
VUV Photolysis of CH4–H2O mixture in methane-rich ices: Formation of large complex organic molecules in astronomical environments
Authors: Krim Lahouari , Jonusas Mindaugas
Published: June 2019

The present work aims to highlight the influence of water molecules in the photo-decomposition of methane ice and reveal the photoproducts formed in solid phase upon VUV irradiation of CH4–H2O mixture in methane-rich ices. The analysis of our IR spectra shows that even with very low concentrations of water in methane ices, several oxygenated hydrocarbons are formed as photoproducts derived from the photodecomposition of water and methane at cryogenic temperatures. We show that both alka[e]nes and oxygen bearing organics are efficiently formed at temperatures as low as 3 K. However, while the IR signatures of the alka[e]nes such as C2H6, C2H4 and C2H2 dominate the IR spectra of the irradiated CH4–H2O ices at temperatures lower than 50 K, the heating of the sample to 110 K reveals the formation of large carbon chain complex organic molecules such as ethanol, pronanol, propanal and glycolaldehyde.
Chloroform–nitrogen aggregates: Upshifted CH and downshifted CCl stretching vibrations observed by matrix isolation and jet expansion infrared spectroscopy
Authors: Oswald S. , Coussan S.
Published: June 2019

Aggregates of chloroform with nitrogen are studied by broad band Fourier transform infrared spectroscopy in neon, argon and nitrogen cryomatrices as well as supersonic jet expansions. The CH stretching vibration v1 shows spectral blue-shifting upon switching from isolated gas phase conditions to bulk nitrogen matrices, which can be reconstructed incrementally by stepwise cluster formation with an increasing amount of N2 both in supersonic expansions and neon or argon matrices. Vice versa, the CCl stretching vibration ν5 is incrementally downshifted. A small CH stretching upshift is observed in the chloroform homodimer as well.
Fluorescence studies of porphycene in various cryogenic environments
Authors: Gil Michał , Gorski Alexandr , Starukhin Alexander , Waluk Jacek
Published: June 2019

Low temperature fluorescence of porphycene, a structural isomer of porphyrin, has been studied using polymer samples, matrix isolation, and fluorescence line narrowing (FLN) techniques. Contrary to the case of the chromophore embedded in a nitrogen matrix, the emission from polymer samples at temperatures above 10 K exhibits strong dependence on the wavelength of excitation: increasing the excitation energy leads to gradual broadening and, finally, loss of vibrational structure. A rather unusual observation is the similarity of the structured fluorescence spectra obtained for excitations into S1 and S2 states. This finding indicates a correlation between the site distributions in S1 and S2. A similar idea has been put forward earlier for tetraphenylporphyrin [I. Lee, G. J. Small, and J. M. Hayes, J. Phys. Chem. 94, 3376 (1990)]. We propose that the correlation is due to isotropic polarizability in the molecular plane; calculations confirm such hypothesis. For porphycene, an additional factor that can contribute to the effect is a rapid trans-trans tautomerization that leads to the rotation of x and y in-plane axes of the molecule. FLN spectra reveal significant band broadening for excitation into S2. This suggests that the site correlation is not of 1:1 type or that at 4.2 K the site exchange dynamics is frozen in comparison with the situation at higher temperatures.
Hydrogen atom catalyzed ortho-to-para conversion in solid molecular hydrogen
Authors: Strom A. I. , Fillmore K. L. , Anderson D. T.
Published: June 2019

Infrared spectroscopy is used to investigate the process of molecular hydrogen ortho-to-para (o/p) conversion in solid hydrogen samples doped with small concentrations (10–50 ppm) of hydrogen atoms (H-atoms) as an impurity. The H-atoms are generated using the in situ 193 nm photolysis of N2O dopant molecules. For hydrogen crystals with relatively low initial ortho-H2 fractions (Xo ≤ 0.03), the o/p conversion kinetics at temperatures of 1.8 and 4.0 K follow kinetic equations developed previously for H-atom catalyzed o/p conversion. The measured atom catalyzed o/p conversion kinetics indicates the H-atoms are mobile under these conditions in agreement with previous ESR measurements. It has been proposed that the H-atoms diffuse by a quantum tunneling mechanism that is described as chemical diffusion. Detailed fits of the measured o/p conversion kinetic data allow the initial H-atom concentration after photolysis to be extracted assuming literature values for the H-atom recombination rate constant (H + H → H2). The measured o/p conversion kinetics show the observed o/p conversion is much less than expected based on the previously measured H-atom recombination rate constant and thus suggest that the H-atoms do not diffuse randomly through the crystal but rather diffuse preferentially in regions of high para-hydrogen content. The estimated H-atom concentrations from this study are consistent with previous ESR measurements but in conflict with kinetic studies of H-atom reactions with various dopants such as N2O.
Atmospheric-pressure plasma oxidation of aluminum for large-area electronics
Authors: Kuribara Kazunori , Nobeshima Taiki , Kodzasa Takehito , Uemura Sei , Yoshida Manabu
Published: June 2019

We developed an atmospheric pressure plasma (APP) process for forming metal oxides and self-assembled monolayers (SAMs) without a vacuum process. SAMs are frequently utilized for surface modification. In particular, a combination of aluminum oxide (AlOx) and alkylphosphonic acid is used as the gate dielectric in flexible electronics, with a low operating voltage of 2 V because of its simple fabrication process at room temperature in air. However, when using a combination of SAMs and AlOx as the gate dielectric, it is necessary to form a metal oxide with sufficient thickness using a vacuum plasma process to reduce the leakage current, which is not suitable for use in flexible large-area electronics. In this study, we resolved this problem by utilizing an APP process and substrate heating instead of the vacuum plasma process. Heating a substrate above 100 °C forms a sufficient AlOx layer. The leakage current of plasma-processed AlOx with SAMs was reduced by three orders of magnitude compared to that of natural AlOx with SAMs. X-ray photoelectron spectroscopy revealed a time dependence of the thickness of AlOx. An exposure time of 100 s was sufficient to form an AlOx layer with a thickness of 4 nm. An organic transistor with this APP treatment of AlOx and SAMs showed a mobility of 1.4 cm2/V s and an on/off ratio of 104 within 2 V. We also fabricated an inverter and a ring oscillator circuit with an inverter gain of more than 300 and an oscillation frequency of 40 Hz.
AlGaInAs/InP semiconductor lasers with an increased electron barrier
Authors: Marmalyuk A.A. , Ivanov A.V. , Kurnosov V.D. , Kurnosov K.V. , Ladugin M.A. , Lobintsov A.V. , Padalitsa A.A. , Romantsevich V.I. , Ryaboshtan Yu.L. , Sapozhnikov S.M. , Svetogorov V.N. , Simakov V.A.
Published: June 2019

This paper presents an experimental study of AlGaInAs/InP semiconductor lasers with different barrier layers. The use of strained layers with an increased band gap as blocking barriers limiting carrier leakage is shown to increase the output power of the lasers at a given pump current.
Effect of Cd content in barriers on the threshold energy of Auger recombination in waveguide structures with HgTe/CdxHg1 – xTe quantum wells, emitting at a wavelength of 18 μm
Authors: Fadeev M.A. , Dubinov A.A. , Aleshkin V.Ya. , Rumyantsev V.V. , Utochkin V.V. , Gavrilenko V.I. , Teppe F. , Hübers H.-W. , Mikhailov N.N. , Dvoretskii S.A. , Morozov S.V.
Published: June 2019

The threshold energy of Auger recombination in HgTe/Cd
x
Hg1 – x
Te heterostructures with quantum wells (QWs) is analysed numerically for different compositions of the solid solution in barriers. It is demonstrated that the threshold energy depends nonmonotonically on the cadmium content in barriers and reaches a maximum at x ∼0.6 – 0.7. A comparison of the results of numerical calculations with experimental data on the temperature quenching of stimulated emission in a Cd0.1Hg0.9Te/Cd0.65Hg0.35Te structure gives grounds to expect a more than twofold increase in the quenching temperature of stimulated emission in structures with pure HgTe QWs and barriers with a high (∼0.6) cadmium content.
Corrigendum to: Widening participation of Māori and Pasifika students in health careers: evaluation of two health science academies
Authors: Middleton Lesley , Tanuvasa Ausaga Faasalele , Pledger Megan , Grace Nicola , Smiler Kirsten , Loto-Su’a Tua Taueetia , Cumming Jacqueline
Published: June 2019

Objective
The aim of the present study was to evaluate the short-term outcomes of two health science academies established by a district health board in South Auckland, New Zealand, to create a health workforce pipeline for local Māori and Pasifika students.Methods
A mixed-methods approach was used, involving background discussions with key informants to generate an initial logic model of how the academies work, followed by secondary analysis of students’ records relating to retention and academic achievement, a survey of senior academy students’ interest in particular health careers and face-to-face interviews and focus groups with students, families and teachers.Results
Academy students are collectively achieving better academic results than their contemporaries, although selection decisions are likely to contribute to these results. Academies are retaining students, with over 70% of students transitioning from Year 11 to Years 12 and 13. Senior students are expressing long-term ambitions to work in the health sector.Conclusions
Health science academies show promise as an innovative approach to supporting Māori and Pasifika students prepare for a career in the health professions. Evaluating the long-term outcomes of the academies is required to determine their contribution to addressing inequities in the local health workforce.What is known about the topic?
Despite progress in health workforce participation for underrepresented indigenous and ethnic minority groups in New Zealand, significant disparities persist. Within this context, a workforce development pipeline that targets preparation of secondary school students is recommended to address identified barriers in the pursuit of health careers.What does this paper add?
We provide an evaluation of an innovative district health board initiative supporting high school students that is designed to ensure their future workforce is responsive to the needs of the local community.What are the implications for practitioners?
The findings have implications for decision makers in health workforce planning regarding the benefits of investing at an early stage of the workforce development pipeline in order to build an equitable and diverse health professions workforce.
Present tense verb morphology of Spanish HL and L2 children in dual immersion
Authors: Fernández-Dobao Ana , Herschensohn Julia
Published: June 2019

We provide a snapshot of childhood morphology development in our investigation of two profiles of bilinguals (age 9–10) in an English-Spanish dual immersion academic setting: Spanish heritage language (SHL,n = 21) and second language (SL2,n = 41) children. Three tasks were given to the 62 bilinguals and 15 age-matched controls (Spanish first language, SL1): oral comprehension of 20 singular-plural present verbs, written sentence production of 10 similar verbs, and a meaning-focused writing task. SHL children were comparable to controls in production of number agreement, and showed no asymmetry between comprehension and production. SL2 learners showed lower accuracy than both SHL and SL1 children. A similar pattern was observed when person agreement and tense, aspect, mood and vowel errors were considered. The most common error among SHL and SL2 children was overregularization of stem vowels, a typical developmental error. The Feature Reassembly model of grammar can accommodate the range of possibilities represented by the data we present.
Differential cellular contractility as a mechanism for stiffness sensing
Authors: Dunlop Carina
Published: June 2019

The ability of cells to sense and respond to the mechanical properties of their environments is fundamental to a range of cellular behaviours, with substrate stiffness increasingly being found to be a key signalling factor. Although active contractility of the cytoskeleton is clearly necessary for stiffness sensing in cells, the physical mechanisms connecting contractility with mechanosensing and molecular conformational change are not well understood. Here we present a contractility-driven mechanism for linking changes in substrate stiffness with internal conformational changes. Cellular contractility is often assumed to imply an associated compressive strain. We show, however, that where the contractility is non-uniform, localized areas of internal stretch can be generated as stiffer substrates are encountered. This suggests a physical mechanism for the stretch-activation of mechanotransductive molecules on stiffer substrates. Importantly, the areas of internal stretch occur deep within the cell and not near the cellular perimeter, which region is more traditionally associated with stiffness sensing through e.g. focal adhesions. This supports recent experimental results on whole-cell mechanically-driven mechanotransduction. Considering cellular shape we show that aspect ratio acts as an additional control parameter, so that the onset of positive strain moves to higher stiffness values in elliptical cells.
Synthesis, properties, and applications of large-scale two-dimensional materials by polymer-assisted deposition
Authors: Ren Hongtao , Liu Yachao , Zhang Lei , Liu Kai
Published: June 2019

Two-dimensional (2D) materials have attracted considerable attention because of their novel and tunable electronic, optical, ferromagnetic, and chemical properties. Compared to mechanical exfoliation and chemical vapor deposition, polymer-assisted deposition (PAD) is more suitable for mass production of 2D materials owing to its good reproducibility and reliability. In this review, we summarize the recent development of PAD on syntheses of 2D materials. First, we introduce principles and processing steps of PAD. Second, 2D materials, including graphene, MoS2, and MoS2/glassy-graphene heterostructures, are presented to illustrate the power of PAD and provide readers with the opportunity to assess the method. Last, we discuss the future prospects and challenges in this research field. This review provides a novel technique for preparing 2D layered materials and may inspire new applications of 2D layered materials.
Bilayer tellurene–metal interfaces
Authors: Pang Hua , Yan Jiahuan , Yang Jie , Liu Shiqi , Pan Yuanyuan , Zhang Xiuying , Shi Bowen , Tang Hao , Yang Jinbo , Liu Qihang , Xu Lianqiang , Wang Yangyang , Lv Jing
Published: June 2019

Tellurene, an emerging two-dimensional chain-like semiconductor, stands out for its high switch ratio, carrier mobility and excellent stability in air. Directly contacting the 2D semiconductor materials with metal electrodes is a feasible doping means to inject carriers. However, Schottky barrier often arises at the metal–semiconductors interface, impeding the transport of carriers. Herein, we investigate the interfacial properties of BL tellurene by contacting with various metals including graphene by using ab initio calculations and quantum transport simulations. Vertical Schottky barriers take place in Ag, Al, Au and Cu electrodes according to the maintenance of the noncontact tellurene layer band structure. Besides, a p-type vertical Schottky contact is formed due to the van der Waals interaction for graphene electrode. As for the lateral direction, p-type Schottky contacts take shape for bulk metal electrodes (hole Schottky barrier heights (SBHs) ranging from 0.19 to 0.35 eV). Strong Fermi level pinning takes place with a pinning factor of 0.02. Notably, a desirable p-type quasi-Ohmic contact is developed for graphene electrode with a hole SBH of 0.08 eV. Our work sheds light on the interfacial properties of BL tellurene based transistors and could guide the experimental selections on electrodes.
Substrates and interlayer coupling effects on Mo1−xWxSe2 alloys
Authors: Liang Fang , Xu Hejun , Dong Zuoyuan , Xie Yafeng , Luo Chen , Xia Yin , Zhang Jian , Wang Jun , Wu Xing
Published: June 2019

Two-dimensional (2D) transition metal dichalcogenides alloys are potential materials in the application of photodetectors over a wide spectral range due to their composition-dependent bandgaps. The study of bandgap engineering is important for the application of 2D materials in devices. Here, we grow the Mo1−x
W
x
Se2 alloys on mica, sapphire and SiO2/Si substrates by chemical vapor deposition (CVD) method. Mo1−x
W
x
Se2 alloys are grown on the mica substrates by CVD method for the first time. Photoluminescence (PL) spectroscopy is used to investigate the effects of substrates and interlayer coupling force on the optical bandgaps of as-grown Mo1−x
W
x
Se2 alloys. We find that the substrates used in this work have an ignorable effect on the optical bandgaps of as-grown Mo1−x
W
x
Se2. The interlayer coupling effect on the optical bandgaps of as-grown Mo1−x
W
x
Se2 is larger than the substrates effect. These findings provide a new way for the future study of the growth and physical properties of 2D alloy materials.
Modeling subgrid combustion processes in simulations of thermonuclear supernovae
Authors: Townsley Dean M , Calder Alan C , Miles Broxton J
Published: June 2019

Supernovae of type Ia are thought to arise from the thermonuclear incineration of a carbon-oxygen white dwarf stellar remnant. However, the detailed explosion scenario and stellar evolutionary origin scenario – or scenarios – which lead to observed supernovae are still quite uncertain. One of the principal tests of proposed scenarios is comparison with the explosion products inferred, for example, from the spectrum of the supernovae. Making this comparison requires computation of the combustion dynamics and products through simulation of proposed scenarios. Here we discuss two specific proposed explosion scenarios, the deflagration-detonation transition and the helium shell double detonation, With these two examples in mind, we proceed to discuss challenges to computational modeling of the combustion taking place in these explosions. Both subsonically and supersonically propagating reaction fronts are discussed, called deflagrations and detonations respectively. Several major stages of the combustion occur on length and time scales that are many orders of magnitude smaller than those accessible in simulations of the explosion. Models which attempt to capture this sub-grid behavior and the verification of those models is briefly discussed.
thornado-hydro: towards discontinuous Galerkin methods for supernova hydrodynamics1
Authors: Endeve Eirik , Buffaloe Jesse , Dunham Samuel J , Roberts Nick , Andrew Kristopher , Barker Brandon , Pochik David , Pulsinelli Juliana , Mezzacappa Anthony
Published: June 2019

The toolkit for high-order neutrino-radiation hydrodynamics (thornado) is being developed for simulations of core-collapse supernovae (CCSNe) and related problems. Current capabilities in thornado include solvers for the Euler equations — in non-relativistic and special relativistic limits — and the two-moment model of neutrino transport. The spatial discretization in thornado is based on the discontinuous Galerkin (DG) method, which is receiving increased attention from the computational astrophysics community. In this paper, we provide an overview of the numerical methods for the Euler equations in thornado, and present some encouraging preliminary numerical results from a set of basic tests in one and two spatial dimensions.
Photogrammetry and Remote Sensing for the identification and characterization of trees in urban areas.
Authors: Mueed Choudhury Md Abdul , Costanzini Sofia , Despini Francesca , Rossi Paolo , Galli Andrea , Marcheggiani Ernesto , Teggi Sergio
Published: June 2019

For the last few decades, there have been a lot of studies recognising the significant roles of the urban trees as a high-quality carbon sink. This work is a preliminary study about how remote sensing and photogrammetry could be useful tools to identify urban trees for the purpose of Carbon Storage (CS) computation in urban areas. Our first study area is a typical urban park located in Sassuolo, a municipality in the northern part of Italy in the so-called “Pianura Padana”. We measured the tree Height (H) and the Diameter at Breast Height (DBH), required for the calibration of the CS, based on the tree allometry during the field data collection along with the constructing a 3D model through the photogrammetric approach. A high-resolution WorldView (WV) 3 satellite image of the same area, was classified using an object-oriented approach to count the number of trees varied with different species. This preliminary study will enhance the possibilities of the application of these approaches in case of the larger urban areas to ascertain the accuracy of the tree CS calibration.
Effect of Sensor Type and Positioning on Features for Condition Monitoring of a Mechatronic System
Authors: D’Emilia G. , Gaspari A. , Natale E.
Published: June 2019

In this paper, a methodology is described able to give general suggestions and guide lines in choosing the most suitable parameter, measuring strategy and the feature set for possible use in a condition monitoring procedure. The tests have been carried out on a mechatronic system in real scale, realizing a sinusoidal motion of its end effector. Internal sensors to the controller have been used (encoder and current sensors) and external to it (laser Doppler vibrometer and three-axis accelerometer). A kinematic and dynamic model of the mechanical linkage of the automated system allows the user to correlate the measurements and to compute the other quantities, even though of different type and/or measured in other point of the device. The most suitable quantities and features have been recognized with respect to the capability of identifying different operating statuses of the device, often independently on the measuring point, if the simulation model is used.
Influence of Hybrid Fibers on the Fresh and Hardened Properties of Structural Light Weight Self-Compacting Concrete
Authors: Ibrahim Haider Araby , Abbas Basim Jabbar
Published: June 2019

The scope of this research is certainly to provide some experimental data on the effect of hybrid fiber on fresh and hardened properties of structural pumice lightweight aggregates self-compacting concrete (SLWSCC). Addition of hybrid fibers to concrete properties has changed the state of concrete from brittle to ductile. Slump flow test, L-box test, and V-funnel test were leading to find the (SLWSCC) workability of fresh properties. The mechanical properties of hardened (SLWSCC), including compressive, and splitting tensile, strengths, and moduli of rupture. Eleven concrete mixtures of (SLWSCC) with different mono and hybrid fibers contents of steel fibers (SF) and polypropylene (PP) fibers with a ratio (0%, 0.3%, 0.6%, and 1.2%) of volume fractions were prepared to study the change in its fresh and hardened characteristics. Test results were showed that the fibers whereas used in a hybrid form with (SLWSCC) be able to have as a result of high composite performance compared to their single thing fiber-reinforced concretes. The optimum properties of (SLWSCC) can get form mix (HF8) with 0.6% (SF) content and 0.3% (PP) fibers exhibit higher flexural strength behavior by 206%, and tensile strength of increased by 129%.
Time as a Critic Factor in Architecture
Authors: Almajidi Basim Hasan Hashim , Jasem Aseel Jafer
Published: June 2019

Time is the most important concepts associated with architecture. Architecture is realized through testing, selection, evaluation and judgment through time, it has many different images overtime, as if time overturn the many faces of the architectural text to show its weakness and strongest points, which will produce many images of architecture text that appear and disappear at the same period time. The Processes of testing, evaluation and selection makes time play the role of critic to architecture as the reader or critic examines a text, as such time relates to architecture. The research focuses on the concept of time as a Critic factor to architecture, which highlights the problem of the absence of a clear conception of time as a Critic factor to architecture. The research aims at constructing a theoretical framework and then applying it to selected projects, which leads to the conclusion that time as a critic shows and hides aspects of the creative architectural text gradually recognized in short or long-term according to the social, cultural, economic and technical conditions of production, which resulting in new interpretations of modern readings. This makes time a sustainable factor in architecture
Effects of organic warm mix asphalt additives on marshall properties
Authors: Addahhan A J , Asmael N M , Fattah M Y
Published: June 2019

Warm mix asphalt (WMA) is a new sustainable technology that gives an economic and environmental beneficial value by means of production temperature decrease of the asphalt mixture by (10-40) °C. The difference between conventional Hot Mix Asphalt (HMA) and WMA mixes were analyzed, in this study, in term of marshall properties which conducted on specimens are produced of: Al-Nibaae source aggregate and Al-Dorah Refinery source asphalt binder (40/50 PEN) modified by two organic additives (Asphaltan A and Asphaltan B). The laboratory tests to determine the mechanical properties of asphalt binder and aggregates are conducted. Two types of aggregate gradation mixtures are designed to perform HMA and WMA preparations using Marshall design method. Doses of 1, 2, and 3% of the additives by total weight of asphalt binder were chosen. WMA mixtures are prepared at 40 °C less than HMA specimens and produced by the same procedure. Many changes on mechanical and physical properties are observed due to the existence of the additives and dosages. The results show that the resulted properties are enhanced by using Asphaltan A and Asphaltan B as WMA additives to the Iraqi asphalt binder.
Urban renewal of the historic centre of Rusafa
Authors: Alkinani Amer Shakir
Published: June 2019

The historical centers represent the present of the past, which is embodied in its buildings and spaces, which are places of continuous life bearing the history of the city with all its material and objective dimensions, making it living centers that form an essential part of the body of the city and give it a vision for another time and it represents a cultural heritage that should be preserved and maintained. The research started from the reality that indicates the great change in the land uses of the region and the deterioration of the situation and change in use in addition to the neglect of its role and historical status, the study aims to study the subject of urban renewal of heritage areas in general and urban development and the area of Senk in particular. The problem of research is to determine a policy of urban renewal that is most suitable for interacting with the region and preserving its cultural heritage as one of the constituent parts of the historic center of Baghdad. Therefore, the objective of the research is to achieve real development of the region (the Senak region) by reviving the role commercial and vital as one of the parts of the center of the city of Baghdad to propose a plan for the development of the region and the development of the commercial area in which is the area between the square Khalani and Hafiz al-Qadi Square extended to Al-Rashid Street in light of the developments that have occurred and the current need for the region form and function and solve current and expected problems and find more types of uses Convenient to the area.
Nonlinear Finite Element Analysis of Concrete Beam Reinforced with Fiber Reinforced Polymer (FRM)
Authors: Sammen Saad Sh , Ahmed Q W. , Al-Karawi S N
Published: June 2019

Due to the corrosion that occurs in internal steel reinforcement; many of steel reinforced concrete structure are at risk of collapse. The budget that will be developed to address this risk in terms of replacement or repair of damaged concrete structures will be very high for the owner or responsible authorities. Alternatives to bare steel have been used including stainless steel, galvanized steel, epoxy-coated steel and cathodic protection, with limited effectiveness. The characteristics of fiber reinforced polymer (FRP) bars like the high tensile strength, inability to corrode, and light weight; it has become the focus of decision-makers to use it instead of steel in internal reinforcement for future concrete structures. In this research, we have investigated flexural behavior in reinforced concrete beams with bars from bars from carbon fiber-reinforced polymer (CFRP), bars from high tensile steel (HTS), and glass fiber-reinforced polymer (GFRP) under static load. Two groups from samples were used, in the first group will show the effect of the type of reinforcement. In the second group will show the effect of the type of reinforcement with different concrete strength. It found these kinds of materials to be very is effective to deal with analysis and the proposed simulation of the material in this study are able of forecast the real behavior of reinforced concrete beam by FRP bars in terms of failure load, and load-deflection behavior.
Convection Heat Transfer Enhancement in Square Cross-Section with Obstacle Using Nanofluids
Authors: Jehhef Kadhum Audaa , Khanjar Rehab H. , Siba M A
Published: June 2019

The characteristics of heat transfer and pressure drop in turbulent flow of Al2O3 and CuO/water nanofluid that flowing in a horizontal straight square cross-section duct with obstacle has been studied experimentally and numerically. The experimental work is attempted by using a water and nanoparticles concentration of (φ = 0.5 to 2.0 % vol.) that flows in an aluminium square duct with side dimensions of a = 20 mm and length of L = 1000 mm. The obstacle located at the middle of the duct with different obstacle height to pipe side ratio varied as (h/a = 0.0, 0.25, 0.5 and 0.75). The water entered to the duct with inlet Reynolds number of turbulent flow of 3500, 4300, 5200 and 6800. Constant heat flux of 6500 W/m2 is applied upon the external walls of the duct. The numerical finite volume method with appropriate boundary conditions used with ANSYS-Fluent v.16.2 was employed to simulate the temperatures and velocity of the nanofluids. The experimental and numerical results showed that the average Nusselt number increases with increasing the obstacle height ratio and with using nanofluids as compared with pure water. Moreover, the Nusselt number increases with increasing the nanoparticles concentrations in the nanofluids. In addition, the results indicated that increasing in the obstacle height ratio and increasing the nanoparticles, concentration leads to increasing the friction factor and pressure drop. Finally, the numerical results give good indication to the presence of the recirculation cell zone behind the obstacle.
Reducing Exhaust Gas Emissions of Stationary Diesel Engines Using Water Bath
Authors: Majeed Waleed , Ibrahim Ahmed , Abdullah Muthana
Published: June 2019

This work was conducted with the aim of reducing exhaust gas emissions of stationary diesel engines, particularly those used locally by the private sector for electric power generation. A specially designed water bath equipped with perforated tubes submerged in water and supplied with water circulation to maintain the cleanness of water was used for this purpose. The diesel engine exhaust gas was admitted to the water bath through the perforated tubes such that the exhaust gas is “cleaned up” thoroughly before being released to the atmosphere. An experimental work was conducted on a four-stroke, air-cooled, one-cylinder diesel engine to verify the feasibility of using this technique in reducing exhaust gas emissions before applying it to large size diesel engines. The experimental results indicated that the use of the proposed water bath led to enormous reductions in oxides of Nitrogen (NOx), unburnt Hydrocarbons (HC), Carbon Monoxide (CO), and exhaust gas temperatures. In addition to a relatively small reduction in exhaust noise. For the engine power range considered in this work (0.4-2 kW), NOx was reduced by 62-73%, unburned HC was reduced by 72-85%, CO was reduced by 41-68%, exhaust gas temperature was reduced by 89-91% and exhaust noise was reduced by 1-7%.
Characteristics Performance Prediction of PV Panel Using Cuckoo Search Algorithm
Authors: Hasan Ibtisam A. , Jawad Mohammed , Abdullah Basma
Published: June 2019

This paper focuses on prediction and evaluation the correlation factors of PV panel characteristics in order to determine the implicit correlation forms for the efficiency and temperature of the system under Iraq climate conditions. Implicit correlation forms consisted on the ambient temperature, solar radiation, wind speed and humidity. Cuckoo search algorithm was employed as an intelligent optimization method to predict the correlation factors of each variable under different evaluation method which are, mean square error (MSE), integrate absolute error (IAE) and integrate square error (ISE). The results appeared that the proposed method was succeeded to predict both of the PV panel temperature and efficiency with MSE evaluation method compared with other methods. Where, the lowest MSE was recorded lower the 1 % for each characteristic.
Efficiency of photoelectric converters intellectual system application on ground electric transport
Authors: Kolbasov A F , Karpuchin K E , Terenchenko A S , Girutskiy O I
Published: June 2019

The development of environmentally friendly road transport is now directly related to the introduction of electric actuators, high-voltage storage systems and the accumulation of electricity in transport. Thus, a significant variety of hybrid traction drive circuits appears, which can be charged from an external power source. However, all of them use hydrocarbon fuel for charging and storage of electricity, which emits CO2 while burning. Clean electric vehicles are the most efficient in terms of environmental indicators, since they use only electricity produced in power plants located far from the operation aureole of the electric vehicle, which allows to improve the environmental situation in megapolises significantly. As you know, energy complexes in different countries have different environmental efficiency and CO2 emissions during power generation are also present. Transition to the use of renewable energy sources, such as solar power plants, can give its effect, since at present, their productivity in the world reaches 400 GW, but the transmission of energy over distances reduces the efficiency. Thus, based on the development trends of solar power plants, it is important to consider the use of photovoltaic cells, the so-called “solar cells” directly on the electric vehicle itself in order to improve environmental friendliness.
Development of the upper-layer electronic control unit based on a production-type unit for a commercial vehicle
Authors: Astapenko D A , Butarovich D O , Smirnov A A
Published: June 2019

The development of a modern vehicle is associated with the need to co-operate with a variety of components from different manufacturers, due to the fact that companies mainly specialize in the manufacture of specific equipment (powertrain, steering, braking system, dashboard, etc.). Majority of manufacturers of automotive electronic units do not allow changes to their finished products, therefore, when integrating components into a single vehicle, there is a problem with the coordination of control signals and communication protocols. In response to this problem, it is required to use an additional electronic unit - the electronic control unit of the upper layer (ECU). This device generates signals for each component in accordance with the requirements of manufacturers. This unit may have different components and different functionality depending on the requirements. The unit is based on a microcontroller with a control program. To control the power discrete output, power transistor MOSFET keys are used. Optocouplers or specialized microchips are used for processing discrete digital signals. Moreover, the unit is equipped with specialized microcircuits, which allow the exchange of information with other electronic units via digital protocols.
Basic principles of vehicle suspension control
Authors: Yurlin D , Bakhmutov S , Girutskiy O
Published: June 2019

The paper is devoted to the description of the basic operation principles of control systems over suspension (cushioning) system elements of a vehicle. The basic operation algorithms, as well as the basic principles of change of properties of suspension or cushioning components under different vehicle driving conditions, are presented. The list of sensors and signals, which shall be present in the system to ensure its effective operation, is proposed. The results of experimental analysis of the pneumatic elastic element (air bellows) stiffness and the results of computer simulation of the vehicle behavior when turning are additionally presented.
Automation of wheeled vehicles load bearing frames finite-element models loading procedure by using inertia relief method and vehicle multi-body dynamics model
Authors: Vdovin D S , Chichekin I V , Levenkov Y Y , Shabolin M L
Published: June 2019

The paper presents a technique for strain-stress calculation using finite element analysis for wheeled vehicle’s load bearing frames with the use of loads, obtained from full vehicle multi body dynamics models (MBD models). In this technique, boundary conditions need not to be defined, as the inertia relief method used. Frame and suspension parts are imposed in MBD model as flexible bodies to increase accuracy of loads calculations. The presented method is capable to automatize loading procedure of finite-element models, thus decreasing computational costs and results processing costs while analyzing numerous load cases. As an example, strength analysis of 6x6 articulated vehicle frame is presented. Proposed method compared to “classic” finite-element frame modelling technique, which use conventional loads formulation and fixed boundary conditions. In load case “standing on ground”, calculation results with the use of two methods demonstrate high convergence in zones, located far from suspension and frame mounting joints. For load case “hanging of second axis” results are significantly different, due to ability of MBD-model to capture behavior of suspension links, and calculate true vehicle frame movement in space in particular load case. Loading procedure of frame finite element model is automated, using script, which transfer loads from MDB-model.
On the real-analyticity of rigid spherical hypersurfaces in ℂ²
Authors: Isaev Alexander , Merker Joël
Published: June 2019

We prove that every smooth rigid spherical hypersurface in

C

2

\mathbb {C}^2

is in fact real-analytic. As an application of this result, it follows that the classification of real-analytic rigid spherical hypersurfaces in

C

2

\mathbb {C}^2

found by V. Ezhov and G. Schmalz applies in the smooth case.
Eremenko points and the structure of the escaping set
Authors: Rippon P. , Stallard G.
Published: June 2019

Much recent work on the iterates of a transcendental entire function 

f
f

has been motivated by Eremenko’s conjecture that all the components of the escaping set

I
(
f
)

I(f)

are unbounded. We prove several general results about the topological structure of

I
(
f
)

I(f)

including the fact that if

I
(
f
)

I(f)

is disconnected, then it contains uncountably many pairwise disjoint unbounded continua, all of which are subsets of the fast escaping set. We give analogous results for the intersection of

I
(
f
)

I(f)

with the Julia set when multiply connected wandering domains are not present, and show that completely different results hold when such wandering domains are present. In proving these, we obtain the unexpected result that some types of multiply connected wandering domains have complementary components with no interior, indeed uncountably many.
Mirror symmetry for honeycombs
Authors: Gammage Benjamin , Nadler David
Published: June 2019

We prove a homological mirror symmetry equivalence between the

A
A

-brane category of the pair of pants, computed as a wrapped microlocal sheaf category, and the

B
B

-brane category of its mirror LG model, understood as a category of matrix factorizations. The equivalence improves upon prior results in two ways: it intertwines evident affine Weyl group symmetries on both sides, and it exhibits the relation of wrapped microlocal sheaves along different types of Lagrangian skeleta for the same hypersurface. The equivalence proceeds through the construction of a combinatorial realization of the

A
A

-model via arboreal singularities. The constructions here represent the start of a program to generalize to higher dimensions many of the structures which have appeared in topological approaches to Fukaya categories of surfaces.
Protein folding state-dependent sorting at the Golgi apparatus
Authors: Hellerschmied Doris , Serebrenik Yevgeniy V. , Shao Lin , Burslem George M. , Crews Craig M.
Published: June 2019

In eukaryotic cells, organelle-specific protein quality control (PQC) is critical for maintaining cellular homeostasis. Despite the Golgi apparatus being the major protein processing and sorting site within the secretory pathway, how it contributes to PQC has remained largely unknown. Using different chemical biology-based protein unfolding systems, we reveal the segregation of unfolded proteins from folded proteins in the Golgi. Quality control (QC) substrates are subsequently exported in distinct carriers, which likely contain unfolded proteins as well as highly oligomerized cargo that mimic protein aggregates. At an additional sorting step, oligomerized proteins are committed to lysosomal degradation, while unfolded proteins localize to the endoplasmic reticulum (ER) and associate with chaperones. These results highlight the existence of checkpoints at which QC substrates are selected for Golgi export and lysosomal degradation. Our data also suggest that the steady-state ER localization of misfolded proteins, observed for several disease-causing mutants, may have different origins.
Mindfulness-Based Interventions for Adults with Cardiovascular Disease: A Systematic Review and Meta-Analysis
Authors: Scott-Sheldon Lori A J , Gathright Emily C , Donahue Marissa L , Balletto Brittany , Feulner Melissa M , DeCosta Julie , Cruess Dean G , Wing Rena R , Carey Michael P , Salmoirago-Blotcher Elena
Published: June 2019

Background

Individuals with cardiovascular disease (CVD) report psychological distress and poor physical functioning and may benefit from mindfulness training.

Purpose

To examine the effects of mindfulness-based interventions (MBIs) on psychological and physiological measures in adults with CVD using meta-analysis.

Methods

Comprehensive searches identified studies that (a) evaluated MBIs in adults with CVD or who had experienced a cardiac event, (b) included a comparison condition, and (c) assessed psychological (e.g., anxiety and depression) or physiological (e.g., systolic or diastolic blood pressure [BP]) outcomes. Independent raters coded methodological (e.g., design and quality) and intervention features (e.g., intervention content) as potential moderators. Weighted mean effect sizes (d+), using full information maximum likelihood estimation, were calculated.

Results

Of the 1,507 records reviewed, 16 studies met inclusion criteria (N = 1,476; M age = 56 years; 40% women). Compared to controls, participants who received an MBI reported greater improvements in psychological outcomes (i.e., anxiety, depression, distress, and perceived stress: d+s = 0.49 to 0.64). MBI recipients also reduced their systolic (d+ = 0.89, 95% confidence interval [CI] = 0.26, 1.51; k = 7) but not diastolic (d+ = 0.07, 95% CI = −0.47, 0.60; k = 6) BP relative to controls.

Conclusions

MBIs demonstrated favorable effects on psychological and physiological outcomes among adults with CVD. Future research should investigate if such benefits lead to improvements in disease outcomes in studies with longer follow-ups.