bluuebunny/crossref_metadata_2025 huggingface dataset:
Labor Induction at 39 Weeks Compared with Expectant Management in Low-Risk Parous Women
Authors: Wagner Stephen M. , Sandoval Grecio , Grobman William A. , Bailit Jennifer L. , Wapner Ronald J. , Varner Michael W. , Thorp John M. , Prasad Mona , Tita Alan T. N. , Saade George R. , Sorokin Yoram , Rouse Dwight J. , Tolosa Jorge E. ,   for the Eunice Kennedy Shriver National Institute of Child Health Human Development Maternal-Fetal Medicine Units Network
Published: September 2020

Objective Our objective was to compare outcomes among low-risk parous women who underwent elective labor induction at 39 weeks versus expectant management.

Study Design This is a secondary analysis of an observational cohort of 115,502 mother–infant dyads who delivered at 25 hospitals between 2008 and 2011. The inclusion criteria for this analysis were low-risk parous women with nonanomalous singletons with at least one prior vaginal delivery after 20 weeks, who delivered at ≥390/7 weeks. Women who electively induced between 390/7 and 396/7 weeks were compared with women who expectantly managed ≥390/7 weeks. The primary outcome for this analysis was cesarean delivery. Secondary outcomes were composites of maternal adverse outcome and neonatal adverse outcome. Multivariable logistic regression was used to estimate adjusted odds ratios (aOR).

Results Of 20,822 women who met inclusion criteria, 2,648 (12.7%) were electively induced at 39 weeks. Cesarean delivery was lower among women who underwent elective induction at 39 weeks than those who did not (2.4 vs. 4.6%, adjusted odds ratio [aOR]: 0.70, 95% confidence interval [CI]: 0.53–0.92). The frequency of the composite maternal adverse outcome was significantly lower for the elective induction cohort as well (1.6 vs. 3.1%, aOR: 0.66, 95% CI: 0.47–0.93). The composite neonatal adverse outcome was not significantly different between the two groups (0.3 vs. 0.6%; aOR: 0.60, 95% CI: 0.29–1.23).

Conclusion In low-risk parous women, elective induction of labor at 39 weeks was associated with decreased odds of cesarean delivery and maternal morbidity, without an increase in neonatal adverse outcomes.

Key Points
Coarse-graining strategy for modeling effective, highly diffusive fluids with reduced polydispersity: A dynamical study
Authors: Heinemann Thomas , Jung YounJoon
Published: September 2020

We present a coarse-graining strategy for reducing the number of particle species in mixtures to achieve a simpler system with higher diffusion while preserving the total particle number and characteristic dynamic features. As a system of application, we chose the bidisperse Lennard-Jones-like mixture, discovered by Kob and Andersen [Phys. Rev. Lett. 73, 1376 (1994)], possessing a slow dynamics due to the fluid’s multi-component character with its apparently unconventional choice for the pair potential of the type-A–type-B arrangement. We further established in a so-formed coarse-grained and temperature-independent monodisperse system an equilibrium structure with a radial distribution function resembling its mixture counterpart. This one-component system further possesses similar dynamic features such as glass transition temperature and critical exponents while subjected to Newtonian mechanics. This strategy may finally lead to the manufacturing of new nanoparticle/colloidal fluids by experimentally modeling only the outcoming effective pair potential(s) and no other macroscopic quantity.
An innovative experimental apparatus for the analysis of natural gas hydrate erosion process using cavitating jet
Authors: Zhang Yiqun , Zhao Kexian , Wu Xiaoya , Tian Shouceng , Shi Huaizhong , Wang Wei , Zhang Panpan
Published: September 2020

Natural Gas Hydrate (NGH) develops and exists in pores of soil sediments under deep seabed and permafrost regions. A cavitation jet is an efficient method of rock breaking, especially for soft hydrate sediment erosion. This paper presents an experimental apparatus that was developed to synthesize NGH and hydrate-bearing sediments and analyze the drilling efficiency of the cavitation jet. The visualization study of fluid flow and breaking mechanism can be conducted over a temperature range varying from −20 °C to 100 °C and up to a maximum confining pressure of 20 MPa. This apparatus is mainly composed of the pressure control and injection system, the cooling system, the cavitation system, and the reaction vessels into which the lab-fabricated temperature/pressure/resistivity sensor probe is inserted. The basic principles of this apparatus are discussed, and a series of experiments were performed to verify that the cavitating jet can be practically applied in the exploitation of NGH reservoirs.
A reconfigurable magnetorheological elastomer acoustic metamaterial
Authors: Willey C. L. , Chen V. W. , Scalzi K. J. , Buskohl P. R. , Juhl A. T.
Published: September 2020

Resonant acoustic metamaterials (AMMs) are structures with intrinsic resonances designed to interact with acoustic wavefields to enable applications like low-frequency sound mitigation using materials much smaller than the wavelength affected. However, the addressable frequency range of the AMM is set at the time of manufacture by the geometry, materials, and construction. In this work, a reconfigurable magnetorheological elastomer (MRE)-based AMM is proposed to alter the addressable frequency range without the need for remanufacture. By changing the spatial placement and the mass of neodymium magnets attached to the MRE plate by magnetic attraction, it is possible to engineer the mode shape of the MRE-AMM and tune the absorption, transmission loss, and effective density. It is shown through simulations and experiments that the MRE-AMM can affect wavelengths in air up to 13 170× greater than its own thickness.
Enhancement of figure of merit for Nernst effect in Bi77Sb23 alloy by Te-doping
Authors: Murata Masayuki , Nagase Kazuo , Aoyama Kayo , Yamamoto Atsushi
Published: September 2020

The effect of carrier doping on the figure of merit for the Nernst effect zNernst is investigated using Bi77Sb23 alloys, aiming at the enhancement of the dimensionless figure of merit zNernstT at room temperature. Four Bi77Sb23 alloys—undoped, 0.1-, 0.2-, and 0.3-at.% Te-doped—are produced by spark plasma sintering and annealing. The Nernst thermopower, electrical resistivity, and thermal conductivity of undoped and Te-doped Bi77Sb23 alloys are measured in magnetic fields of up to 6 T at temperatures from 10 K to 300 K to determine zNernstT. The magnitude of the Nernst thermopower increases by 102% at 300 K because of the modification of the electron and hole carrier mobility by 0.1-at.% Te-doping. In addition, the magnetoresistance effect is suppressed over the entire temperature range owing to the fact that charge neutrality is destroyed by Te-doping, and this contributes to the enhancement of zNernstT. The thermal conductivity in the magnetic field is increased by Te-doping due to the increased electron thermal conductivity. Thus, zNernstT for the Bi77Sb23 alloy at 300 K is increased by 329% as a result of 0.1-at.% Te-doping.
Role of pre-ordered liquid in the selection mechanism of crystal polymorphs during nucleation
Authors: Menon Sarath , Díaz Leines Grisell , Drautz Ralf , Rogal Jutta
Published: September 2020

We investigate the atomistic mechanism of homogeneous nucleation during solidification in molybdenum employing transition path sampling. The mechanism is characterized by the formation of a pre-structured region of high bond-orientational order in the supercooled liquid followed by the emergence of the crystalline bulk phase within the center of the growing solid cluster. This precursor plays a crucial role in the process as it provides a diffusive interface between the liquid and crystalline core, which lowers the interfacial free energy and facilitates the formation of the bulk phase. Furthermore, the structural features of the pre-ordered regions are distinct from the liquid and solid phases and preselect the specific polymorph that nucleates. The similarity in the nucleation mechanism of Mo with that of metals that exhibit different crystalline bulk phases indicates that the formation of a precursor is a general feature observed in these materials. The strong influence of the structural characteristics of the precursors on the final crystalline bulk phase demonstrates that for the investigated system, polymorph selection takes place in the very early stages of nucleation.
Spin-waves generation at the thickness step of yttrium iron garnet film
Authors: Vysotskii S. L. , Sadovnikov A. V. , Dudko G. M. , Kozhevnikov A. V. , Khivintsev Y. V. , Sakharov V. K. , Novitskii N. N. , Stognij A. I. , Filimonov Y. A.
Published: September 2020

We report on the experimental observation of short, exchange-dominated spin waves (EDSW) generation by a thickness step in the ferrite waveguide under microwave pumping. This effect was explored both experimentally (using mirco-Brillouin light scattering technique) and theoretically (by micromagnetic simulation) for the sample magnetized along the step and for two cases of pumping: a uniform microwave pumping of the step and its pumping through a magnetostatic surface wave (MSSW) traveling across the step. It was shown that efficiency of EDSW generation caused by MSSW scattering on the thickness step increases with the frequency (or wave number) while for the case of the uniform pumping, the generation efficiency demonstrates the opposite behavior.
Pressure effects on the lattice vibrations and ultrafast photocarrier dynamics in 2H–TaS2
Authors: Zhang Kai , Jiang Huachao , Yang Jin , Zhang Jie , Zeng Zhi , Chen Xiaojia , Su Fuhai
Published: September 2020

Vibrational properties and ultrafast photocarrier dynamics of 2H–TaS2 under pressures are studied by the experiments of Raman scattering and femtosecond time resolved spectroscopy. With increasing pressure, the linewidth of two-phonon Raman mode broadens, especially features with a sudden rapid increase above 10 GPa. Meanwhile, the ultrafast dynamics show that the fast decay through optical phonon scattering is significantly suppressed in amplitude and prolonged in lifetime; however, the weight of the slow decay component originating from acoustic phonon scattering is enhanced at high pressures. Furthermore, the electron-phonon (e-ph) coupling constant, λq, and the density of states (DOS) near the Fermi level, N(0), are evaluated qualitatively, which reveals a drastic decrease in e-ph coupling strength and a sudden increase in the DOS beyond 10 GPa. This turning pressure is consistent with the critical point where Tc of superconductivity peaks while the charge density wave (CDW) vanishes, indicating the direct correlations between λq, N(0), superconductivity, and the CDW under pressure. The anomaly of the DOS may imply the occurrence of a topological transition of the electronic structure. Our work not only provides valuable information for the understanding of competition between the CDW and superconductivity in 2H–TaS2 but also may open up a routine to unveil the pressure-induced electronic topological transition.
A comprehensive infrared spectroscopic and theoretical study on phenol-ethyldimethylsilane dihydrogen-bonded clusters in the S and S1 states
Authors: Uchida Masaaki , Shimizu Takutoshi , Shibutani Ryo , Matsumoto Yoshiteru , Ishikawa Haruki
Published: September 2020

To investigate microscopic characters of Si–H⋯H–O type dihydrogen bonds, we observed OH and SiH stretch bands in both the S0 and S1 states of phenol-ethyldimethylsilane (PhOH-EDMS) clusters by infrared (IR)–ultraviolet (UV) and UV–IR double resonance spectroscopies. Density functional theory (DFT) calculations and energy decomposition analysis were also performed. Structures of two isomers identified were unambiguously determined through the analysis of IR spectra and DFT calculations. To discuss the strength of dihydrogen bond in various systems, we performed theoretical calculations on clusters of EDMS with several acidic molecules in addition to PhOH. It was revealed that charge-transfer interaction energies from a bonding σ orbital of SiH bond to an anti-bonding σ* orbital of OH bond well reflect strengths of dihydrogen bonds. Additionally, it was found that the red shift of SiH stretch frequencies can be used as a crude measure of the strength of dihydrogen bonds. Relationship between the red shifts of OH/SiH stretch frequencies and various electrostatic components of the interaction energy was examined. In the S1 state, large increases in red shifts were observed for both the OH and SiH stretch frequencies. Since the EDMS moiety is not associated with the electronic excitation in a cluster, the strength of dihydrogen bonds in the S1 and S0 states was able to be directly compared based on the red shifts of the SiH stretch bands. A significant increase in the red shift of SiH stretch frequency indicates a strengthening of the dihydrogen bonds during the electronic excitation of the PhOH moiety.
pH dependent synthesis of TiO2 nanoparticles exerts its effect on bacterial growth inhibition and osteoblasts proliferation
Authors: D. V. Sridevi , K. T. RamyaDevi , Jayakumar Narmadha , E. Sundaravadivel
Published: September 2020

In the current investigation, titanium-dioxide nanoparticles (TiO2-NPs) are prepared through a sol–gel method at varying pH values of 6, 8, and 10. The effects of pH on the preparation of TiO2-NPs and their structural, morphological, and compositional variations were extensively studied by P-XRD, TEM, FE-SEM, and EDS techniques. The calculated optical bandgap (Eg) was in the range of 3.40 eV to 3.15 eV, with an increase in pH, and was observed by the K–M method. The photocatalytic activity of TiO2-NPs is evident from that the degradation of the reactive black 5 (RB5) dye shows 96% photocatalytic activity at 45 min under UV irradiation. The photocatalytic activity of TiO2-NPs is pH-sensitive. The photocatalytic activity of TiO2-NPs increases if the reaction is performed under acidic conditions. Moreover, all the synthesized TiO2-NPs obey pseudo-first-order kinetics. TiO2-NPs could be coated on medical implants to prevent the growth of micro-organisms and facilitate vascular protection. In this context, 100 µg/ml, 200 µg/ml, and 300 μg/ml of TiO2-NPs were coated on materials as a treatment to study the incorporation of bacteria by flow cytometry analysis. Among the treatments, a statistical increase in E. coli and B. subtilis cell incorporation by around 17.3% and 24% was observed in the groups treated with 200 μg/ml of TiO2-NPs synthesized at pH 6. Furthermore, the cytotoxicity of TiO2-NPs on the osteoblasts cell line, C3H10T1/2, was analyzed for cell viability and proliferation by MTT and BrdU assays, respectively. TiO2-NPs were synthesized at different pH values and a high percentage viability is seen in the samples synthesized at a pH of 6.
Ultrahigh conversion efficiency of betavoltaic cell using diamond pn junction
Authors: Shimaoka T. , Umezawa H. , Ichikawa K. , Pernot J. , Koizumi S.
Published: September 2020

A betavoltaic cell, which directly converts beta particles into energy, is composed of a junction diode and a beta-emitting source. Because the cells can deliver electricity over a long operation life ranging from several years to a decade, they are promising devices for applications in remote locations such as outer space, deserts, and underground areas. Herein, we report efficient energy conversion using a diamond pn junction. We characterized the betavoltaic performance under electron-beam irradiation using scanning electron microscopy and observed an open-circuit voltage of 4.26 V, a fill factor of 0.85, and a semiconductor conversion efficiency of 28%. These are the best values reported thus far for betavoltaic cells. The efficiency is close to the theoretical Shockley–Queisser efficiency limit for betavoltaic cells.
Review of Scientific Instruments New Products
Authors: Mandelis Andreas
Published: September 2020

In order to supplement manufacturers’ information, this department will welcome the submission by our readers of brief communications reporting measurements on the physical properties of materials which supersede earlier data or suggest new research applications.
Landau quantized dynamics and spectrum of the diced lattice
Authors: Horing N J M
Published: September 2020

In this work the role of magnetic Landau quantization in the dynamics and spectrum of diced lattice charge carriers is studied in terms of the associated pseudospin 1 Green’s function. The equations of motion for the 9 matrix elements of this Green’s function are formulated in position/frequency representation and are solved explicitly in terms of a closed form integral representation involving only elementary functions. The latter is subsequently expanded in a Laguerre eigenfunction series whose frequency poles identify the discretized energy spectrum for the Landau-quantized diced lattice as

ϵ

n

=
±

2

(

2
n
+
1

)

α

2

e
B

(

α

2

is the characteristic speed for the diced lattice) which differs significantly from the nonrelativistic linear dependence of ϵ

n
on B, and is similar to the corresponding

B

−

dependence of other Dirac materials (graphene, group VI dichalcogenides).
Comparison between thermophysical and tribological properties of two engine lubricant additives: electrochemically exfoliated graphene and molybdenum disulfide nanoplatelets
Authors: Guimarey María J G , Abdelkader Amor M , Comuñas María J P , Alvarez-Lorenzo Carmen , Thomas Ben , Fernández Josefa , Hadfield Mark
Published: September 2020

Recently graphene and other 2D materials were suggested as nano additives to enhance the performance of nanolubricants and reducing friction and wear-related failures in moving mechanical parts. Nevertheless, to our knowledge there are no previous studies on electrochemical exfoliated nanomaterials as lubricant additives. In this work, engine oil-based nanolubricants were developed via two-steps method using two different 2D nanomaterials: a carbon-based nano additive, graphene nanoplatelets (GNP) and a sulphide nanomaterial, molybdenum disulfide (MoS2) nanoplatelets (MSNP). The influence of these nano additives on the thermophysical properties of the nanolubricants, such as viscosity index, density and wettability, was investigated. The unique features of the electrochemical exfoliated GNP and MSNP allow the formulation of nanolubricant with unusual thermophysical properties. Both the viscosity and density of the nanolubricants decreased by increasing the nanoplatelets loading. The effect of the nano additives loading and temperature on the tribological properties of nanolubricants was investigated using two different test configurations: reciprocating ball-on-plate and rotational ball-on-three-pins. The tribological specimens were analysed by scanning electron microscopy (SEM) and 3D profiler in order to evaluate the wear. The results showed significant improvement in the antifriction and anti-wear properties, for the 2D-materials-based nanolubricants as compared with the engine oil, using different contact conditions. For the reciprocal friction tests, maximum friction and worn area reductions of 20% and 22% were achieved for the concentrations of 0.10 wt% and 0.20 wt% GNP, respectively. Besides, the best anti-wear performance was found for the nanolubricant containing 0.05 wt% MSNP in rotational configuration test, with reductions of 42% and 60% in the scar width and depth, respectively, with respect to the engine oil.
Controllable synthesis of Fe3O4-based magneto-dielectric ternary nanocomposites and their enhanced microwave absorption properties
Authors: Liu Juncen , Yang Zhihong , Li Meng , Yang Lieji , Xue Tong , Xu Guoyue
Published: September 2020

In order to overcome the drawbacks of Fe3O4 composite samples and greatly increase their performance in microwave absorption, magnetic Fe3O4 spindles coated with dielectric SnO2 nanorods and MnO2 nanoflakes have been successfully synthesized by a four-step simple hydrothermal route. This rationally designed magneto-dielectric ternary nanocomposite will introduce multiple reflection and conductive losses caused by its special multilayer structure and the effective complementarity of dielectric loss and magnetic loss. Therefore, its absorbing performance can be greatly improved. It is notable that the as-prepared Fe3O4@SnO2@MnO2 nanocomposites show a minimum reflection loss value of −50.40 dB at 17.92 GHz at a thickness of 3.9 mm and the absorption bandwidth ranges from 3.62 to 12.08 GHz. The as-prepared Fe3O4@SnO2@MnO2 ternary nanocomposite is expected to be a potential candidate for high-performance microwave-absorbing materials with intensive electromagnetic wave absorption and wide effective absorbing bandwidth.
CT-based attenuation correction of whole-body radiotherapy treatment positioning devices in PET/MRI hybrid imaging
Authors: Taeubert Leticia , Berker Yannick , Beuthien-Baumann Bettina , Hoffmann Aswin L , Troost Esther G C , Kachelrieß Marc , Gillmann Clarissa
Published: September 2020

Objective.To implement computed tomography (CT)-based attenuation maps of radiotherapy (RT) positioning hardware and radiofrequency (RF) coils to enable hybrid positron emission tomography/magnetic resonance imaging (PET/MRI)-based RT treatment planning. Materials and Methods. The RT positioning hardware consisted of a flat RT table overlay, coil holders for abdominal scans, coil holders for head and neck scans and an MRI compatible hip and leg immobilization device. CT images of each hardware element were acquired on a CT scanner. Based on the CT images, attenuation maps of the devices were created. Validation measurements were performed on a PET/MR scanner using a 68Ge phantom (48 MBq, 10 min scan time). Scans with each device in treatment position were performed. Then, reference scans containing only the phantom were taken. The scans were reconstructed online (at the PET/MRI scanner) and offline (via e7tools on a PC) using identical reconstruction parameters. Average reconstructed activity concentrations of the device and reference scans were compared. Results. The device attenuation maps were successfully implemented. The RT positioning devices caused an average decrease of reconstructed PET activity concentration in the range between −8.3 ± 2.1% (mean ± SD) (head and neck coil holder with coils) to −1.0 ± 0.5% (abdominal coil holder). With attenuation correction taking into account RT hardware, these values were reduced to −2.0 ± 1.2% and −0.6 ± 0.5%, respectively. The results of the offline and online reconstructions were nearly identical, with a difference of up to 0.2%. Conclusion. The decrease in reconstructed activity concentration caused by the RT positioning devices is clinically relevant and can successfully be corrected using CT-based attenuation maps. Both the offline and online reconstruction methods are viable options.
Fast-ion velocity-space tomography using slowing-down regularization in EAST plasmas with co- and counter-current neutral beam injection
Authors: Madsen B , Huang J , Salewski M , Järleblad H , Hansen P C , Stagner L , Su J , Chang J F , Fu J , Wang J F , Liang L Z , Zhong G Q , Li Y Y , Lyu B , Liu H Q , Zang Q , Luo Z P , Nocente M , Moseev D , Fan T S , Zhang Y M , Yang D , Sun J Q , Liao L Y
Published: September 2020

We demonstrate 2D reconstructions of the fast-ion velocity distribution from two-view fast-ion D-alpha (FIDA) measurements at the EAST tokamak. By expressing the distribution in a basis relying on the fast-ion slowing-down process in fusion plasmas, the smoothness and velocity-space resolution of reconstructions are improved. We reconstruct distributions of fast ions born from simultaneous co- and counter-current neutral beam injection and detect the expected distinct change in fast-ion birth pitch when comparing discharges utilizing different neutral beam injectors. For purely co-current injection, we find a good agreement between TRANSP-predicted and reconstructed fast-ion densities, pressures and current densities for energies above 20 keV. We furthermore illustrate the improvement of the reconstructed high-energy range (> 40 keV) of the distribution by combining FIDA with neutron emission spectroscopy measurements with the compact single-plate EJ301 scintillator.
Persistence of the Nb(100) surface oxide reconstruction at elevated temperatures
Authors: McMillan Alison A , Graham Jacob D , Willson Sarah A , Farber Rachael G , Thompson Caleb J , Sibener S J
Published: September 2020

Helium atom scattering and Auger electron spectroscopy (AES) are used to characterize the (3 × 1)-O reconstruction of the Nb(100) surface at elevated temperatures. Persistent helium diffraction peaks and specular lineshape analysis indicate that the oxide structure persists, apparently unchanged, until surface temperatures of at least 1130 K. In a complementary experiment, AES oxygen to niobium ratios for Nb(100) show little to no change when the surface temperature is varied from 300 K to 1150 K. These data inform future development of superconducting radio frequency (SRF) cavities. In particular, these findings demonstrate the important role that persistent niobium oxides will play in the optimization of thin film growth strategies and coating procedures for Nb3Sn and other next–generation SRF superconducting alloy materials.
Fast and efficient critical state modelling of field-cooled bulk high-temperature superconductors using a backward computation method
Authors: Zhang Kai , Ainslie Mark , Calvi Marco , Hellmann Sebastian , Kinjo Ryota , Schmidt Thomas
Published: September 2020

A backward computation method has been developed to accelerate modelling of the critical state magnetization current in a staggered-array bulk high-temperature superconducting (HTS) undulator. The key concept is as follows: (i) a large magnetization current is first generated on the surface of the HTS bulks after rapid field-cooling (FC) magnetization; (ii) the magnetization current then relaxes inwards step-by-step obeying the critical state model; (iii) after tens of backward iterations the magnetization current reaches a steady state. The simulation results show excellent agreement with the
H
-formulation method for both the electromagnetic and electromagnetic-mechanical coupled analyses, but with significantly faster computation speed. The simulation results using the backward computation method are further validated by the recent experimental results of a five-period Gd–Ba–Cu–O (GdBCO) bulk undulator. Solving the finite element analysis (FEA) model with 1.8 million degrees of freedom (DOFs), the backward computation method takes less than 1.4 h, an order of magnitude or higher faster than other state-of-the-art numerical methods. Finally, the models are used to investigate the influence of the mechanical stress on the distribution of the critical state magnetization current and the undulator field along the central axis.
Optoelectronic and photocatalytic properties of I–III–VI QDs: Bridging between traditional and emerging new QDs
Authors: Liu Yanhong , Li Fenghua , Huang Hui , Mao Baodong , Liu Yang , Kang Zhenhui
Published: September 2020

Due to the quantum size effect and other unique photoelectric properties, quantum dots (QDs) have attracted tremendous interest in nanoscience, leading a lot of milestone works. Meantime, the scope and scientific connotation of QDs are constantly expanding, which demonstrated amazing development vitality. Besides the well-developed Cd-containing II–VI semiconductors, QDs of environmentally friendly I–III–VI (I = Cu, Ag; III = Ga, In; VI = S, Se) chalcogenides have been a hot spot in the QDs family, which are different from traditional II–VI QDs in terms of multi-composition, complex defect structure, synthetic chemistry and optical properties, bringing a series of new laws, new phenomena and new challenges. The composition of I–III–VI chalcogenides and their solid solutions can be adjusted within a very large range while the anion framework remains stable, giving them excellent capability of photoelectric property manipulation. The important features of I–III–VI QDs include wide-range bandgap tuning, large Stokes shift and long photoluminescence (PL) lifetime, which are crucial for biological, optoelectronic and energy applications. This is due to the coexistence of two or more metal cations leading to a large number of intrinsic defects within the crystal lattice also known as deep-donor-acceptor states, besides the commonly observed surface defects in all QDs. However, a profound understanding of their structure and optoelectronic properties remains a huge challenge with many key issues unclear. On one hand, the achievements and experience of traditional QD research are expected to provide vital value for further development of I–III–VI QDs. On the other hand, the understanding of the emerging new QDs, such as carbon and other 2D materials, are even more challenging because of the dramatically different composition and structure from II–VI semiconductors. For this, I–III–VI QDs, as a close relative to II–VI QDs but with much more complex composition and structure variation, provide a great opportunity as a gradual bridge to make up the big gap between traditional QDs and emerging new QDs, such as carbon dots. Here, we hope to compare the research progress of I–III–VI QDs and II–VI QDs, in an effort to comprehensively understand their structure, synthetic chemistry, optical electronic and photocatalytic properties. We further give insights on the key potential issues of I–III–VI QDs from the perspective of bridging between traditional QDs and emerging carbon dots, especially the profound principles behind synthetic chemistry, PL mechanism and optoelectronic applications.
Perylene diimide self-assembly: From electronic structural modulation to photocatalytic applications
Authors: Wei Weiqin , Ouyang Shuxin , Zhang Tierui
Published: September 2020

As an emerging organic semiconductor, perylene diimide (PDI) self-assembly has attracted tremendous attention in the aspects of solar cells, sensors, fluorescence probes and n-transistors, etc. In term of photocatalysis, various photocatalysts based on PDI self-assembly exhibit some unique properties, such as intrinsic Π-Π stacking structure, fast internal charge transfer, band-like electronic structure, flexible structural modifiability, well-defined morphological adjustability and excellent light absorption. This paper mainly presents recent progress on PDI self-assembly regarding how to regulate the electronic structure of PDI self-assembly. In addition, the photocatalytic applications of PDI self-assembly and its complexes were reviewed, such as environmental remedy, energy productions, organic synthesis and photodynamic/photothermal therapy, further highlighting related photocatalytic mechanisms. Finally, the review contents and some perspectives on photocatalytic research of PDI self-assembly were summarized, and some key scientific problems were put forward to direct related photocatalytic research in future.
Highly-rough surface carbon nanofibers film as an effective interlayer for lithium–sulfur batteries
Authors: Zhu Hongfan , Sha Mo , Zhao Huaping , Nie Yuting , Sun Xuhui , Lei Yong
Published: September 2020

Lithium–sulfur (Li–S) battery with a new configuration is demonstrated by inserting a flexible nitrogen-doping carbon nanofiber (N-CNFs) interlayer between the sulfur cathode and the separator. The N-CNFs film with high surface roughness and surface area is fabricated by electrospinning and a subsequent calcination process. The N-CNFs film interlayer not only effectively traps the shuttling migration of polysulfides but also gives the whole battery reliable electronic conductivity, which can effectively enhance the electrochemical performance of Li–S batteries. Finally, Li–S batteries with long cycling stability of 785 mAh/g after 200 cycles and good rate capability of 573 mAh/g at 5 C are achieved.
Improving Shallow-Deep Foundation with Reinforcement by Geogrids for Tall Building
Authors: Al-Laban H. E. , Fakhraldin M. K.
Published: September 2020

This research has studied the effect of the vertical load, it has acted at the center of the raft foundation and piled raft foundation. Stresses resistance and displacements were significant parts to examine the behavior of improving foundation. These are important parts of life the structure. The study focuses on different cases of the embedded layer in tension zone with concrete grade B20 of (MD/XMD) Tensor SS2 geogrids in raft and piled raft foundation for a tall building in Incheon Tower in South Korea, it was treated to solve those problems. Stresses resistance of raft and piled raft foundation were greater than vertical stress applied of dead and live loads, also the stress value of XMD was greater than the value of MD.
Comparison of Single and Group Jet Grout Columns Settlement Based on Field Test and Theoretical Methods
Authors: Al-Kinani Ali M. , Ahmed Mahmood D.
Published: September 2020

The settlement evaluation for the jet grouted columns (JGC) in soft soils is a problematic matter, because it is influenced by the number of aspects such as soil type, effect mixture between soil and grouting materials, nozzle energy, jet grouting, water flow rate, rotation and lifting speed. Most methods of design the jet-grouting column based on experience. In this study, a prototype single and group jet grouting models (single, 1*2, and 2*2) with the total length and diameter were (2000 and 150 mm) respectively and clear spacing (3D) has been constructed in soft clay and subjected to vertical axial loads. Furthermore, different theoretical methods have been used for the estimation of (JGC) settlement. Pile load settlement analysis of the jet grout columns showed that the average settlement values were (0.41, 0.663, and 1.5 mm) for the single, group (1*2) and group (2*2) jet grouted columns respectively. While, in the theoretical methods give a higher value of the settlement (2.0, 3.48, and 5.24 mm) for the single, group (1*2) and group (2*2) jet grouted columns compared with the settlement results acquired from field pile load test data. Therefore, it is not recommended to be used for soft clay. On the other hand, Fuller and Hoy’s, Hansen’s 90%, and Butler and Hoy’s results may be considered faithful interpretation methods for the single and group (1*2 and 2*2) (JGC).
Numerical Simulation of Predicting the Shaft Capacity of Single Pile in Unsaturated Soil
Authors: Albusoda Bushra S. , Abbas Mohammad F. , Al-Hamdani Durgham A.
Published: September 2020

Pile foundations that placed above the groundwater table zone where the soil is typically in a state of the partially saturated case have been considered in this study. To appreciate the effect of the matric suction on the skin resistance of single pile foundations that placed in unsaturated clayey soil. A series of small scale and full-scale single model pile are simulated using the software Plaxis 3 D. Mohr-Coulomb model (Elastic-perfectly plastic model) that takes into account the effect of the matric suction has adopted in the analysis. Also, in this study comparison among numerical models and laboratory, small scale single and full-scale pile models have done. In general, the value of shaft capacity obtained by the numerical investigations are in good agreement with laboratory model pile test results.
Strength and Compressibility of Screw Piles Constructed in Gypseous Soil
Authors: Mukhlef Omar J. , Karkush Mahdi O. , Zhussupbekov Askar
Published: September 2020

The present work deals with the performance of screw piles constructed in gypseous soil of medium relative density; such piles are extensively used in piles foundations supported structures subjected to axial forces. The carrying capacity and settlement of a single screw pile model of several diameters (20, 30, and 40) mm inserted in gypseous soil is investigated in the present study. The gypsum content of soil used in tests was 40%. The bedding soil used in tests was prepared by raining technique with a relative density of 40%. A physical model was manufactured to demonstrate the tests in the laboratory. The model of screw pile has been manufactured of steel with a total length of 500 mm and helix diameters of 20, 30, and 40 mm continuous over the embedded depth of pile (400 mm). The results of tests showed decreasing the ratio of length to diameter (L/D) resulted in a higher axial carrying capacity of screw piles and low corresponding settlement.
Comparison among Different Methods to Estimate Ultimate Capacity of Bored Pile
Authors: Albusoda Bushra S. , Mohammed S. M , Abbas Mohammad F.
Published: September 2020

This study investigates the ultimate load capacity of concrete 1.5 m diameter bored pile based on three methods: field-loading test, field Standard Penetration Test results, and numerical modeling. A comparison of the ultimate load capacities from these methods was made (the measured large-scale field-loading test, the correlated SPT N values applying Novo SPT software and numerical modeling where Plaxis3D software with Mohr-Coulomb model was utilized). The result of the pile field-loading test was more accurate than the other methods and used as a reference for comparison among their results. In general, the value of ultimate load capacity calculated from Novo SPT software and that obtained from numerical analysis were compatible in comparison with field load results.
Effects of Soil-structure Interaction and Different Simulation on the Response of Concrete Box Culverts
Authors: Al-Zaidee Salah R. , Alsalmani Ashraf Hameed , Salam Alhusain
Published: September 2020

This paper shows how different simulation and soil-structure interaction can affect the response of concrete culverts embedded in dry cohesionless soils. Three simulations have been considered. In the first, second, and third simulations, the applied loads have been determined based on empirical relations of PCA without including the soil-structure interaction. The differences between these simulations are in using the beam element for the first one while using the frame element for the second one and the plane strain element for the third one. In addition to neglect the soil-structure interaction, the axial and shear deformations have been neglected in the first simulation. The axial deformations have been included in the second simulation; finally, all of the axial and shear deformations are included in the third simulation.
Two-Way Bubbled Slabs Strengthened by Prestressing Strands
Authors: Al-Rashedi Durai H. , Al-Ahmed Ali H. Ali
Published: September 2020

Nine proposed two-way simply supported slabs were numerically tested by finite element method using ABAQUS commercial software to investigate the behavior of two-way slabs strengthened by prestressing strands, one-third of them were solid and the other two-third were bubbled. All slabs have the same dimensions of (1600 ×1600 ×140) mm. Some of these specimens were strengthened by using two or three strands with nominal diameter (6.4) mm in both directions. The slabs were divided into three groups depending on the type of slab (solid or bubbled) and the bubble diameter to slab thickness ratios (D/H). From the numerical tests, it was found that the ultimate load capacity for the bubbled slab at D/H ratio 0.64 and 0.80 was decreased to 12.6 and 14% respectively, while, the maximum deflection for bubbled slab at D/H ratio 0.64 and 0.8 was increased to 3-4 times as compared with the conventional solid slab.
Analysis of Hyperspectral Remote Sensing Images for Extraction Geological Rock Types Maps by Geospatial Techniques
Authors: Hussein Sabah Jaber , Fakhri Merzah Zainab
Published: September 2020

Hyperspectral images involve a wealth of data, but interpreting them needs an understanding of exactly what properties of ground materials that it is trying to measure and how to relate to the measurements made by the hyperspectral sensor. The purpose of the study is to use hyperspectral remote sensing data for finding of geological locations and the creation of geological rock types map. In this research, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) image has been used and analyzed using geospatial techniques such as ENVI software. These techniques include: enhancement, de-correlation stretch, band ratio and classification. All these techniques have been performed to produce geological rock kinds map. Also, 3D surface for ASTER data can be displayed using ENVI software.
Employ 6D-BIM Model Features for Buildings Sustainability Assessment
Authors: Habib Hussain M. , Kadhim R. Erzaij
Published: September 2020

To translate sustainable concepts into sustainable structure, there is a require a collaborative work and technology to be innovated, such as BIM, to connect and organize different levels of industry e.g. decision-makers, contractors, economists, architects, urban planners, construction supplies and a series of urban planning and strategic infrastructure for operate, manage and maintain the facilities. This paper will investigate the BIM benefits as a project management tool, its effectiveness in sustainable decision making, also the benefit for the local industry key stakeholders by encouraging the BIM use as a project management tool to produce a sustainable building project. This paper presented a basic idea about the Building Information Model (BIM) technique and explain the levels of BIM and its dimension, the potential of BIM in sustainability design and the role of BIM in sustainability aspects had been discussed. The role of BIM in the planning and design stages explained the BIM role in sustainability rating system and grant credits in classification processes. Processing of creating 6D had been detailly explaining starting from the framework (ISO 1440) which adopted in the processing of establishing 6D complete system, phases of this system, and development steps from 3D to 4D, 4D to 5D and 5D to 6D. The 6D model features in the sustainability buildings had been explained in this research. As a result, many conclusions have been reached, the most important is there are still significant constraints in adopting of the integration approach between the (BIM) technology with sustainability in Iraqi buildings projects, both are facing great challenges in terms of economic, technical and the awareness level of government and society.
The Factors Affecting on Earned Value Management
Authors: Rezouki Sedqi Esmaeel , Mortadha Sabreen Baqer
Published: September 2020

Earned price management (EVM) is an associate degree business customary for observance the performance of in progress comes. The performance baseline is about up within the coming up with part to live any time and value deviations throughout project execution. EVM solely focuses on the project schedule (SPI) and value (CPI), and doesn’t address alternative vital aspects of quality, Risk, safety and social factors. Therefore, this paper will explain the statistical study aims to know the most important factors that affect in implementation of EVM in a construction project in Iraq and it will be consisting of two main tools which are the assessment of the questionnaire and checklist to obtain real weights affecting the Iraqi construction projects. There is a need for understanding all affecting factors on estimate at completion in EVM. This will develop the equation of EVM. It will be necessary to study affecting factors to achieve major factors of EVM. Based on previous studies and interviews, 207 influential factors were identified. After the first questionnaire, the number was reduced to 73. Based on the interviews with experts, weights were determined and the most influential factors were 37 and were adopted as a checklist.
Analyzing the Obstacles of Investment Process in Iraq Using (5 Whys) and Focus Group Discussion (FQD) Techniques
Authors: Jaber Asmaa M. , Burhan Abbas M.
Published: September 2020

The Iraqi government faces fluctuations in the investment process with oil revenues of the country and other revenues as these revenues cover only the operational budget and salaries of employees. The government seeks to overcome the financial crisis that hit the country through investment and privatization of some projects. The Iraqi plan for sustainable development (2030) Launched by the Ministry of Planning. But the implementation of this plan collides with a series of obstacles. This research aims to analyze the obstacles facing investment projects by using several approved techniques in managing construction engineering projects such as (5 whys) and (FGD) techniques. The open questionnaire was the theoretical source that the researcher adopted to arrive at to identify obstacles, which is conducting personal interviews and field visits and asking several questions to a group of experts in the Investment Authority through which (15) a obstacles was reached that caused delays in the implementation of construction investment projects. The most prominent of these obstacles was routine and slowed procedures Admin. The responses of the experts were arranged in a closed questionnaire form and distributed to the research sample for which a statistical analysis was conducted. These obstacles were arranged based on the importance of relativity in descending order. The researcher concluded that there is a benefit from using techniques that help analyze constraints such as (5 whys) through reaching the main roots and technique (FGD) is a panel discussion for several experts to arrive at through which corrective actions are possible.
Application of Root Causes Analysis Techniques in The Contractor Selection for Highway Projects
Authors: Ahmed Mustafa I. , Rezouki Sedqi Esmaeel
Published: September 2020

Highway projects are one of the most important projects in this decade in Iraq. Highway projects suffer from corruption factors in the contractor selection phase. To succeed in transparency and best value contractor selection for awarding procedure for highway projects, the researcher used root cause analysis techniques to specify the main factors that lead to bad selection for the highway projects in Iraq. Many tools techniques used for the root cause analysis techniques like Fishbone, Pareto chart, and 5-Why. This study conducts the causes of bad contractor selection and analysis by root cause analysis techniques, Pareto chart conducted that internal relationships and administrative corruption are the main causes that covered near than 80% of the problem, and 5-Why conducted that the acceptance of the lowest price is the main cause for bad selection.
Achieving the Benefits and Requirements of Integrated Project Delivery Method Using BIM
Authors: Salim Mahdi S. , Raoof Mahjoob Ahmed Mohammed
Published: September 2020

Through the last decade, Integrated Project Delivery (IPD) methodology considers one of the new contractual relations that are also on the way to further integrate the process of combining design and instruction. On the other hand, Building Information Modeling (BIM) made significant advancements in coordinating the planning and construction processes. It is being used more often in conjunction with traditional delivery methods. In this paper, the researcher will present the achievement of IPD methodology by using BIM through applying on the design of the financial commission building in Mayssan Oil Company in Iraq. The building has not been constructed yet and it was designed by using 2D CAD drawings. The researcher will redesign the project by using BIM to eliciting the abilities that are consistent with the requirements and benefits of integrated project delivery (IPD). The results show that BIM is an appropriate technology that can be used with the IPD method because it has achieved most of the requirements and benefits of IPD.