bluuebunny/crossref_metadata_2025 huggingface dataset:
Mitochondrial metabolism supports resistance to IDH mutant inhibitors in acute myeloid leukemia
Authors: Stuani Lucille , Sabatier Marie , Saland Estelle , Cognet Guillaume , Poupin Nathalie , Bosc Claudie , Castelli Florence A. , Gales Lara , Turtoi Evgenia , Montersino Camille , Farge Thomas , Boet Emeline , Broin Nicolas , Larrue Clément , Baran Natalia , Cissé Madi Y. , Conti Marc , Loric Sylvain , Kaoma Tony , Hucteau Alexis , Zavoriti Aliki , Sahal Ambrine , Mouchel Pierre-Luc , Gotanègre Mathilde , Cassan Cédric , Fernando Laurent , Wang Feng , Hosseini Mohsen , Chu-Van Emeline , Le Cam Laurent , Carroll Martin , Selak Mary A. , Vey Norbert , Castellano Rémy , Fenaille François , Turtoi Andrei , Cazals Guillaume , Bories Pierre , Gibon Yves , Nicolay Brandon , Ronseaux Sébastien , Marszalek Joseph R. , Takahashi Koichi , DiNardo Courtney D. , Konopleva Marina , Pancaldi Véra , Collette Yves , Bellvert Floriant , Jourdan Fabien , Linares Laetitia K. , Récher Christian , Portais Jean-Charles , Sarry Jean-Emmanuel
Published: March 2021

Mutations in IDH induce epigenetic and transcriptional reprogramming, differentiation bias, and susceptibility to mitochondrial inhibitors in cancer cells. Here, we first show that cell lines, PDXs, and patients with acute myeloid leukemia (AML) harboring an IDH mutation displayed an enhanced mitochondrial oxidative metabolism. Along with an increase in TCA cycle intermediates, this AML-specific metabolic behavior mechanistically occurred through the increase in electron transport chain complex I activity, mitochondrial respiration, and methylation-driven CEBPα-induced fatty acid β-oxidation of IDH1 mutant cells. While IDH1 mutant inhibitor reduced 2-HG oncometabolite and CEBPα methylation, it failed to reverse FAO and OxPHOS. These mitochondrial activities were maintained through the inhibition of Akt and enhanced activation of peroxisome proliferator-activated receptor-γ coactivator-1 PGC1α upon IDH1 mutant inhibitor. Accordingly, OxPHOS inhibitors improved anti-AML efficacy of IDH mutant inhibitors in vivo. This work provides a scientific rationale for combinatory mitochondrial-targeted therapies to treat IDH mutant AML patients, especially those unresponsive to or relapsing from IDH mutant inhibitors.
A method for detecting continuous gravitational wave signals from an ensemble of known pulsars
Authors: Buono M , De Rosa R , D’Onofrio L , Errico L , Palomba C , Piccinni O J , Sequino V
Published: March 2021

This work describes a method to improve the detection efficiency for continuous gravitational waves by combining information from known pulsars, which emission is too low to be individually detectable. We propose a new ensemble statistic t, which combines statistics from individual pulsars, defined through the five-vector method. Using a collection of band sample data files from the LIGO science run O2, we test the method with software injections in order to study the statistical properties of t. We also study the performance of our method by varying the number of injected signals and their amplitude. We propose and test a possible strategy for the application of the ensemble method to a set of real pulsars.
Schrödinger’s cat for de Sitter spacetime
Authors: Foo Joshua , Mann Robert B , Zych Magdalena
Published: March 2021

Quantum gravity is expected to contain descriptions of semiclassical spacetime geometries in quantum superpositions. To date, no framework for modelling such superpositions has been devised. Here, we provide a new phenomenological description for the response of quantum probes (i.e. Unruh–deWitt detectors) on a spacetime manifold in quantum superposition. By introducing an additional control degree of freedom, one can assign a Hilbert space to the spacetime, allowing it to exist in a superposition of spatial or curvature states. Applying this approach to static de Sitter space, we discover scenarios in which the effects produced by the quantum spacetime are operationally indistinguishable from those induced by superpositions of Rindler trajectories in Minkowski spacetime. The distinguishability of such quantum spacetimes from superpositions of trajectories in flat space reduces to the equivalence or non-equivalence of the field correlations between the superposed amplitudes.
Bayesian search for gravitational wave bursts in pulsar timing array data
Authors: Bécsy Bence , Cornish Neil J
Published: March 2021

The nanohertz frequency band explored by pulsar timing arrays provides a unique discovery space for gravitational wave (GW) signals. In addition to signals from anticipated sources, such as those from supermassive black hole binaries, some previously unimagined sources may emit transient GWs (a.k.a. bursts) with unknown morphology. Unmodeled transients are not currently searched for in this frequency band, and they require different techniques from those currently employed. Possible sources of such GW bursts in the nanohertz regime are parabolic encounters of supermassive black holes, cosmic string cusps and kinks, or other, as-yet-unknown phenomena. In this paper we present BayesHopperBurst, a Bayesian search algorithm capable of identifying generic GW bursts by modeling both coherent and incoherent transients as a sum of Morlet–Gabor wavelets. A trans-dimensional reversible jump Markov chain Monte Carlo sampler is used to select the number of wavelets best describing the data. We test BayesHopperBurst on various simulated datasets including different combinations of signals and noise transients. Its capability to run on real data is demonstrated by analyzing data of the pulsar B1855 + 09 from the NANOGrav 9 year dataset. Based on a simulated dataset resembling the NANOGrav 12.5 year data release, we predict that at our most sensitive time–frequency location we will be able to probe GW bursts with a root-sum-squared amplitude higher than ∼5 × 10−11 Hz−1/2, which corresponds to ∼40M
⊙
c
2 emitted in GWs at a fiducial distance of 100 Mpc.
The added mass of a falling coffee filter
Authors: Boyle C , Pantaleone J
Published: March 2021

Falling coffee filters are a common object of study in introductory physics laboratory classes. They are usually used to demonstrate the terminal velocity, and determine how the drag force depends on this velocity. However they can also be used to demonstrate other ways that the air affects the motion of the falling coffee filter. In particular, a qualitatively different fluid force acts during the initial acceleration from rest, and causes this acceleration to be much less than the acceleration of an object in vacuum. This fluid force, commonly known as the ‘added mass’, is easily observable with coffee filters using either a sonic motion sensor or video analysis. Here the added mass is experimentally measured for a falling coffee filter. In addition, the theoretical value for the added mass of a coffee filter moving through an ideal fluid is calculated. The two values agree relatively well. Finally, it is shown how the added mass is relevant to experiments that only measure the terminal velocity.
Laboratory application of sampling approaches to inverse scattering
Authors: Pourahmadian Fatemeh , Yue Hao
Published: March 2021

This study presents an experimental investigation of the recently established generalized linear sampling method (GLSM) (Pourahmadian et al 2017 Inverse Problems
33 055007) for non-destructive evaluation of damage in elastic materials. To this end, ultrasonic shear waves are generated in a prismatic slab of charcoal granite featuring a discontinuity interface induced by the three-point bending (3PB). The interaction of probing waves with the 3PB-induced damage gives rise to transient velocity responses measured on the sample’s boundary by a 3D scanning laser Doppler vibrometer. Thus obtained waveform data are then carefully processed to retrieve the associated spectra of scattered displacement fields. On deploying multifrequency sensory data, the GLSM indicators are computed and their counterparts associated with the classical linear sampling method (LSM) (Cakoni and Colton 2003 Inverse Problems
19 279–95) for comparative analysis. Verified with in situ observations, the GLSM map successfully exposes the support of hidden scatterers in the specimen with a remarkable clarity and resolution compared to its predecessor LSM. It is further shown that the GLSM remains robust for sparse and partial-aperture data inversion, thanks to its rigorous formulation. For completeness, the one-sided reconstruction by both indicators is investigated.
Thin-film lithium niobate-on-insulator (LNOI) shear horizontal surface acoustic wave resonators
Authors: Hsu Tzu-Hsuan , Tseng Kuan-Ju , Li Ming-Huang
Published: March 2021

This work investigates the design methodology to obtain large electromechanical coupling factor (

k

eff

2

) and high quality factor (Q) of shear-horizontal surface acoustic wave (SH-SAW) resonators based on the thin-film lithium niobate-on-insulator (LNOI) technology. The guided SH wave can be excited through interdigital transducers and propagate at the very surface of the material stackings. Such a guided SH wave in LN/SiO2 double layer structure is expected to offer high

k

eff

2

by confining the elastic strain energy in the piezoelectric thin film. To capture the optimum design window for high-performance LNOI SH-SAW devices, the impact of electrode material and its thickness on the

k

eff

2

dispersive characteristics are intensively investigated by finite element method (FEM). In this study, various one-port resonators with wavelengths from 2.8 μm to 8 μm were fabricated on a LNOI wafer with LN and SiO2 thickness of 0.7 and 2 μm, respectively. The 100 nm thick gold film was chosen as the electrode of the devices, which demonstrate a similar

k

eff

2

dispersive behavior to the FEM simulation with small discrepancy. Among the measurement results over several tested samples, a high-

k

eff

2

of 25.5% and Q of 960 was recorded at a resonance frequency of 581 MHz (FOM =

k

eff

2

⋅
Q

= 245), revealing great potential for the application of wide-band frequency selection in telecommunications.
Two-center interference effect on molecular ionization and Rydberg-state excitation
Authors: Liu MingQing , Shu Zheng , Hu ShiLin , Chen Jing
Published: March 2021

We have studied ionization and excitation of model molecules possessing different initial states (1sσ

g
and 1sσ

u
) in 800 nm laser pulses by numerical solution of three-dimensional time-dependent Schrödinger equation and quantum models. Calculations of two methods show good agreement. It is found that the locations of the peaks of total Rydberg-state probability vs laser intensity do not coincide for different initial states, which is ascribed to the fact that the relative contributions from Rydberg states change due to the difference of the ionization time distributions for different initial states induced by the two-center interference effect. In addition, it is demonstrated that the suppression of ionization is more obvious than that of excitation compared the results of 1sσ

u
state with those of 1sσ

g
state, which is attributed to the distinct interference effects for molecular ionization and excitation in strong laser fields.
Post-collision interaction effect in THz-assisted Auger decay of noble gas atoms
Authors: Bermúdez Macias I J , Düsterer S , Ivanov R , Frühling U , Kabachnik N M
Published: March 2021

Auger electron spectra were simulated in the presence of a terahertz streaking field to study post-collision interaction (PCI) effects in the time-evolution of photoinduced Auger decays. The PCI is characterized by the ratio of the spectral line width for Auger electron emission in opposite directions with respect to the THz-field. These calculations have been performed using the analytical semiclassical model developed by Bauch and Bonitz (2012 Physical Review A
85 053416). The results are shown for Ne(KLL), Ar(LMM), Kr(MNN) and Xe(NOO) Auger transitions whereby different possible experimental conditions were evaluated.
Extraction of Ps-formation cross-sections from single-centre positron-scattering calculations
Authors: Utamuratov R , Fursa D V , Kadyrov A S , Abdurakhmanov I B , Bray I
Published: March 2021

Positron scattering on atomic and molecular targets is a two-centre problem due to the possibility of rearrangement (Ps-formation) processes. In certain kinematic regions, single-centre expansion methods can be applied to two-centre scattering problems. In such approaches, however, information about Ps-formation and direct ionization processes are combined into excitation amplitudes of positive-energy pseudostates. In this report we show that Ps-formation amplitudes can be extracted using the total scattering wave function, which we reconstruct from single-centre convergent close-coupling calculations. The method is applied to positron scattering from hydrogen and lithium atomic targets. Excellent agreement with the two-centre theoretical benchmark results show the validity of the proposed technique.
The dose magnifying glass quality assurance system for daily proton therapy range verification
Authors: Debrot E , Mundy D , Guatelli S , Petasecca M , Perevertaylo V , Beltran C , Rosenfeld A B
Published: March 2021

Proton therapy has a distinct dosimetric advantage over conventional photon therapy due to its Bragg peak profile. This allows greater accuracy in dose delivery and dose conformation to the target, however it requires greater precision in setup, delivery and for quality assurance (QA) procedures. The AAPM TG 224 report recommends daily range and spot position checks with tolerance on the order of a millimetre. Daily QA systems must therefore be efficient for daily use and be capable of sub-millimetre precision however few suitable commercial systems are available. In this work, a compact, real-time daily QA system is optimised and characterised for proton range verification using an ad-hoc Geant4 simulation. The system is comprised of a monolithic silicon diode array detector embedded in a perspex phantom. The detector is orientated at an angular offset to the incident proton beam to allow range in perspex to be determined for flat proton fields. The accuracy of the system for proton range in perspex measurements was experimentally evaluated over the full range of clinical proton energies. The mean R
100, R
90 and R
80 ranges measured with the system were accurate within ±0.6 mm of simulated ranges in a perspex phantom for all energies assessed. This system allows real-time read-out of individual detector channels also making it appropriate for temporal beam delivery diagnostics and for spot position monitoring along one axis. The system presented provides a suitable, economical and efficient alternative for daily QA in proton therapy.
Fractional-order model representations of apparent vascular compliance as an alternative in the analysis of arterial stiffness: an in-silico study
Authors: Bahloul Mohamed A , Laleg Kirati Taous-Meriem
Published: March 2021

Objective. Recent studies have demonstrated the advantages of fractional-order calculus tools for probing the viscoelastic properties of collagenous tissue, characterizing the arterial blood flow and red cell membrane mechanics, and modeling the aortic valve cusp. In this article, we present novel lumped-parameter equivalent circuit models for apparent arterial compliance using a fractional-order capacitor (FOC). FOCs, which generalize capacitors and resistors, display a fractional-order behavior that can capture both elastic and viscous properties through a power-law formulation. Approach. The proposed framework describes the dynamic relationship between the blood-pressure input and the blood volume, using linear fractional-order differential equations. Main results. The results show that the proposed models present a reasonable fit with the in-silico data of more than 4000 subjects. Additionally, strong correlations have been identified between the fractional-order parameter estimates and the central hemodynamic determinants as well as the pulse-wave velocity indexes. Significance. Therefore, the fractional-order-based paradigm for arterial compliance shows notable potential as an alternative tool in the analysis of arterial stiffness.
Quantum coherence resonance
Authors: Kato Yuzuru , Nakao Hiroya
Published: March 2021

It is shown that coherence resonance, a phenomenon in which regularity of noise-induced oscillations in nonlinear excitable systems is maximized at a certain optimal noise intensity, can be observed in quantum dissipative systems. We analyze a quantum van der Pol system subjected to squeezing, which exhibits bistable excitability in the classical limit, by numerical simulations of the quantum master equation. We first demonstrate that quantum coherence resonance occurs in the semiclassical regime, namely, the regularity of the system’s oscillatory response is maximized at an optimal intensity of quantum fluctuations, and interpret this phenomenon by analogy with classical noisy excitable systems using semiclassical stochastic differential equations. This resonance persists under moderately strong quantum fluctuations for which the semiclassical description is invalid. Moreover, we investigate even stronger quantum regimes and demonstrate that the regularity of the system’s response can exhibit the second peak as the intensity of the quantum fluctuations is further increased. We show that this second peak of resonance is a strong quantum effect that cannot be interpreted by a semiclassical picture, in which only a few energy states participate in the system dynamics.
Stealth dark energy in scordatura DHOST theory
Authors: Gorji Mohammad Ali , Motohashi Hayato , Mukohyama Shinji
Published: March 2021

A stealth de Sitter solution in scalar-tensor theories has an exact de Sitter background metric and a nontrivial scalar field profile. Recently, in the context of Degenerate Higher-Order Scalar-Tensor (DHOST) theories it was shown that stealth de Sitter solutions suffer from either infinite strong coupling or gradient instability for scalar field perturbations. The sound speed squared is either vanishing or negative. In the first case, the strong coupling scale is zero and thus lower than the energy scale of any physical phenomena. From the viewpoint of effective field theory, this issue is naturally resolved by introducing a controlled detuning of the degeneracy condition dubbed scordatura, recovering a version of ghost condensation. In this paper we construct a viable dark energy model in the scordatura DHOST theory based on a stealth cosmological solution, in which the metric is the same as in the standard ΛCDM model and the scalar field profile is linearly time-dependent. We show that the scordatura mechanism resolves the strong coupling and gradient instability. Further, we find that the scordatura is also necessary to make the quasi-static limit well-defined, which implies that the subhorizon observables are inevitably affected by the scordatura. We derive the effective gravitational coupling and the correction to the friction term for the subhorizon evolution of the linear dark matter energy density contrast as well as the Weyl potential and the gravitational slip parameter. In the absence of the scordatura, the quasi-static approximation would break down at all scales around stealth cosmological solutions even if the issue of the infinite strong coupling is unjustly disregarded. Therefore previous estimations of the subhorizon evolution of matter density contrast in modified gravity in the literature need to be revisited by taking into account the scordatura effect.
Theoretical investigation of fluorescence changes caused by methanol bridge based on ESIPT reaction*
Authors: Zhang Xinglei , Zhu Lixia , Wang Zhengran , Cao Bifa , Zhou Qiao , Li You , Li Bo , Yin Hang , Shi Ying
Published: March 2021

The different fluorescence behavior caused by the excited state proton transfer in 3-hydroxy-4-pyridylisoquinoline (2a) compound has been theoretically investigated. Our calculation results illustrate that the 2a monomer in tetrahydrofuran solvent would not occur proton transfer spontaneously, while the 2a complex in methanol (MeOH) solvent can undergo an asynchronous excited state intramolecular proton transfer (ESIPT) process. The result was confirmed by analyzing the related structural parameters, infrared vibration spectrum and reduced density gradient isosurfaces. Moreover, the potential curves revealed that with the bridging of single MeOH molecular the energy barrier of ESIPT was modulated effectively. It was distinctly reduced to 4.80 kcal/mol in 2a-MeOH complex from 25.01 kcal/mol in 2a monomer. Accordingly, the ESIPT process induced a fluorochromic phenomenon with the assistant of proton-bridge. The elucidation of the mechanism of solvent discoloration will contribute to the design and synthesis of fluorogenic dyes as environment-sensitive probes.
Numerical simulations and analysis of the zig-zag maneuvers of an oil tanker based on a body-force propeller
Authors: Hao Hao , Weimin Chen , Zixin Wu
Published: March 2021

The course change quality is a crucial measure of ships’ maneuverability and is closely related to the ship navigation safety. Research on zig-zag motion of ships is essential to voyage safety. STARCCM+ based on the ship 6-DOF motion and overset grid technology are used to numerically simulate the zig-zag maneuver of an oil tanker. To simulate the zig-zag motion, a body-force propeller model is adopted instead of the real propeller. The rotation speed of virtual propeller is controlled to achieve the steady self-propulsion state of the ship model and then the rudder turns from 10° to -10° according to the orientation of the ship model. By solving viscous flow field, the motion state and detailed flow field information of the ship model are presented. To verify the accuracy of numerical prediction results, ship model test is launched. Through comparison of results, the numerical simulation can provide reference for preliminary assessment for the course change quality of ships.
A study of particle separation system of hazardous materials collection truck
Authors: Zhou Shuwen , Yang Shuo , Wang Yu
Published: March 2021

A three-stage dust removal technology is adopted in the hazardous materials collection truck proposed in this paper, including the inertial separator in the main storage tank, the cyclone separator and the pleated element filter. The inertial separator housed in the main tank is designed to be detachable to avoid inconvenience caused when collecting liquid hazardous materials. The leaked hazardous materials pulled by vacuum enter the main tank with the air flow, and the heavy particles of the hazardous materials are intercepted in the main tank under the action of the inertial separator. The remaining hazardous particles are removed from the air flow in the cyclone separator. The remaining particles of very small size and density enter pleated element filter, and most of the particles are intercepted by the filter cartridge. The particle separation process is established in this paper and its fluid dynamics simulation analysis is carried out. The simulation results show that the particle separation system proposed in this paper can separate and intercept the collected solid hazardous materials, avoiding secondary pollution to the environment.
Study on rollover risk of the tanker with different liquid filling coefficient in emergency turn
Authors: Zuo Yonggang , Zhang Zhen , Yang Jing , Zhao Xiang
Published: March 2021

3D simulation model of petroleum sloshing in off-road tanker based on the VOF method, moving coordinate system and the actual size of the internal petroleum and tank structure is established in this paper. The mathematical model of the petroleum sloshing in tank is established, lateral rollover torque of petroleum sloshing in emergency turning is researched, the effects of the cross section shape and baffle area in tank on the dynamic characteristics of petroleum sloshing is studied.
The mega city of Tehran water quantity assessment based on DPSIR model
Authors: Sarmadi Hajar , Salehi Esmaeil , Kusari Nick
Published: March 2021

One of the most important factors of urbanization is healthy water supplement. Tehran as a megacity suffers from not only overcrowding but also lack of water. Tehran water supplements are both groundwater and surface resources. Surface water resources are including Karaj, Lar, Latian, Taleghan Dams and Tehran-Karaj Plain is its groundwater resources. Therefore, Tehran-Karaj Plain is considered as a target area in this study. The target area is located between 51°05′ and 51°10′ longitude and 35°02′ and 35° 57′ latitude with approximately 2704Km2. The urban rivers are originated from the Alborz Mountains and received urban runoff, and secondary effluent of Tehran Wastewater Treatment Plants which ultimately collected in Bande Alikhan in the southern part of Tehran. The evaluation of Tehran water quantity by DPSIR Model is considered in this paper. Driving forces, Pressures and the Status of water quantity will represent and their impacts on the city will also investigate.
The effect of time discretization on the propeller hydrodynamic performance simulation in self-propulsion and open water conditions
Authors: Fan Yang , Kunpeng Chen , Weimin Chen , Guoxiang Dong
Published: March 2021

Numerical simulation technology is widely used in the field of naval architect and marine engineering. The flow induced by the propeller is unsteady. In order to demonstrate the effect of time discretization format and time step on the simulation of the flow, this paper takes an oil tanker and its propeller as the research objects, and simulations have been conducted by using OpenFoam. By comparing the thrust, torque and the vortex after the propeller, the effects of the time discretization format and time step on the numerical simulations are analyzed. This paper believes that changing the discretization format of the time term while keep the time step unchanged has little effect on the calculation results in the condition of open water test simulation. It is beneficial to simulate of the vortex after the propeller hub by using a small time step. The first-order backward Euler discretization format in the condition of self propulsion simulation is recommended. If the error of thrust compared with experiment data is larger than expected, the second-order discretization format should be considered. In order to improve the accuracy of numerical simulation, a smaller time step could be considered.
RANS CFD seakeeping simulation for an 82k DWT vessel in head and oblique waves
Authors: Kunpeng Chen , Fan Yang , Yunlong Du
Published: March 2021

Numerical seakeeping simulation of an 82k DWT vessel is carried out to investigate its ship motions and added resistance in head waves and oblique waves. By applying the Reynolds-Average Navier-Stokes (RANS) calculations, both viscous and rotational effects are included in current seakeeping simulation. In this study the Navier-Stokes and continuity equations are the governing equations and they are discretized by finite volume method. The free surface is tracked by volume of fluid (VOF) method, volume fractions were used together with fluid’s incompressibility. The turbulence model was k - ω SST. In this simulation, Wave Forcing technic is applied to reduce the size of the computational domain and reduce the computing resources needed. The solution of the 3D Navier-Stokes equations is forced towards a solution in the boundary zone, this forcing also eliminates problems that are associated with reflections of surface waves at boundaries. The validation studies are carried out by comparing the current simulations’ results with towing tank experiments. This study established the viscos method with 3 degree of freedom for evaluating 82k DWT vessel’s seakeeping performance. The authors also gave the suggested length of the wave forcing area for the 82k DWT ship.
Full scale KCS self-propulsion simulation using different propulsion models
Authors: Yu Jiawei , Wu Zhiqi , Wang Luqun , Zhou Yujie , Zhang Zhiguo
Published: March 2021

It is critical to be able to estimate the full-scale ship self-propulsion, since the more real sailing performance of the ship can be assessed. Results of scaling model are used to predict full-scale self-propulsion performance. However, the difference between the full-scale prediction and reality would be caused by scale effect. URANS simulations is conducted to predict self-propulsion of a full-scale KRISO Container Ship with the propeller KP505. Design speed is selected as simulation working condition according to Gothenburg 2010. In house CFD code HUST-Ship will be used to solve RANS equation coupled with two degrees of freedom (2DOF) solid body motion equations including heave and pitch. RANS equations are discretized by finite difference method and solved by PISO algorithm. The discretized propeller model and improved body-force model are used as the propulsion models. Grid and time step sensitivity analysis of full-scale propeller and hull is conducted separately. The self-propulsion indexes of full-scale simulation are compared with the extrapolation of model experimental data and full-scale simulation results from literatures. The prediction self-propulsion indexes based on different propulsion models are compared and discussed.
Ocean – A vast reserve of renewable energy
Authors: Shaw Surupa
Published: March 2021

Ocean has an immense potential to be exploited as an energy resource. The advancement in the renewable energy technologies have opened several avenues for exploring the ocean to combat the rising concern of the global climate change and the worldwide energy supply. The renewable energy is the inevitable choice for a sustainable economic growth in times of economic crisis, and the ocean environment is an inadequately utilized domain for the application of renewable technologies. This paper strongly focuses on the importance of the various forms of energy from the ocean environment like wave energy, wind energy, tidal energy, ocean thermal energy. A strong assessment of the current renewable technologies that can be strategically deployed to the ocean environment with minimal influence on the marine ecosystem, has been presented here. The current work targets the ocean environment for its availability as a promising resource to assist in the effort of tackling the world energy issues. The history of continued research on the requirement and consequence of enhancing the already existing renewable technologies, in the ocean has been traced in this paper. This study provides an overview of the key parameters responsible for the accurate choice of ocean energy harnessing site, that will eventually serve as an excellent reference for the rational deployment guidelines of the future renewable technologies. Ocean energy through waves, tides and thermal gradients is a powerful source of abundant clean, renewable energy and the essential information needed for the conversion of the ocean energy to usable form is presented in this paper.
Experimental investigation on the effects of machining parameters on surface integrity in form grinding of rail material
Authors: Liu Peijie , Quan Yanming , Wan Junjie
Published: March 2021

Rail grinding is an essential measure for the maintenance of railway infrastructure, and the machined surface integrity of rail material plays a crucial role in ensuring the safety, stability and service performance of the railway network. In this paper, an electroplated diamond grinding wheel was employed to re-profile the rail surface. Meanwhile, single-factor experiments on the form grinding of rail material were designed and carried out by virtue of the self-developed rail grinding platform under dry grinding condition based on proper machining parameters. The effects of machining parameters on the surface roughness, subsurface micro-hardness, plastic deformation, and surface morphology were investigated, respectively. The experimental results revealed that the surface roughness and subsurface micro-hardness increase with the increase of feed speed and grinding depth, while decrease with the increase of wheel peripheral speed. The thickness of subsurface plastic deformation layer and the degree of plastic flow increase with the increase of grinding depth, and the thickness of subsurface plastic deformation layer ranges from 7 μm to 14 μm with the change of grinding depth.
COVID-19 induced lower-tropospheric ozone changes
Authors: Mertens Mariano , Jöckel Patrick , Matthes Sigrun , Nützel Matthias , Grewe Volker , Sausen Robert
Published: March 2021

The recent COVID-19 pandemic with its countermeasures, e.g. lock-downs, resulted in decreases in emissions of various trace gases. Here we investigate the changes of ozone over Europe associated with these emission reductions using a coupled global/regional chemistry climate model. We conducted and analysed a business as usual and a sensitivity (COVID19) simulation. A source apportionment (tagging) technique allows us to make a sector-wise attribution of these changes, e.g. to natural and anthropogenic sectors such as land transport. Our simulation results show a decrease of ozone of 8% over Europe in May 2020 due to the emission reductions. The simulated reductions are in line with observed changes in ground-level ozone. The source apportionment results show that this decrease is mainly due to the decreased ozone precursors from anthropogenic origin. Further, our results show that the ozone reduction is much smaller than the reduction of the total NO
x
emissions (around 20%), mainly caused by an increased ozone production efficiency. This means that more ozone is produced for each emitted NO
x
molecule. Hence, more ozone is formed from natural emissions and the ozone productivities of the remaining anthropogenic emissions increase. Our results show that politically induced emissions reductions cannot be transferred directly to ozone reductions, which needs to be considered when designing mitigation strategies.
Information Communication Technology Access And Use Towards Energy Consumption In Selected Sub Saharan Africa
Authors: Ihayere O. , Alege P. , Obindah G. , Ejemeyovwi J. , Daramola P.
Published: March 2021

Major new opportunities abound from energy integration among regions in Africa with the sole aim of reducing transaction costs and with the role of ICT, it would take energy from where it is easily affordable to places where it is needed. This study takes on a new perspective, that is, employing household energy consumption, to ascertain the use of ICT by household in accessing energy. The study explores the degree to which energy integration among the five regional power pools in Africa can achieve ending energy poverty among regional adherents. The study utilizes the Pooled Ordinary Least Squares technique on data from the SSA economies over the period 2000-2019. The study confirms the viability of the ICT adoption – Energy Consumption hypothesis statistically at five (5) percent level of significance. More specifically, the findings show that a one-unit increase in household mobile technology will lead to an average of 1.4 unit increase in energy consumption. The findings indicate that the adoption of such mobile technology impacts energy consumption, which suggests the need for the acceleration of ICT development in Africa (Sub-Saharan) nations, given the universal communal mission of sustainable energy consumption.
Degradation Potentials Of Tropical Soil Bacteria On Detergents
Authors: Nwinyi Obinna C , Umane Phoebe O
Published: March 2021

Detergents are chemicals of high environmental importance owing to their production volumes. They are mainly released into the environment through wastewater pathway and it could severely affect the soil environment. In this study, we examined the degradation potentials of soil bacteria in liquid culture media induced with detergents. Using conventional enrichment methods, via contaminated soil slurry enrichment with selected alkyl-benzene sulphonates (detergents), we obtained pure bacteria species capable of using alkyl-benzene sulphonates as the sole source of carbon and energy. From the morphological and biochemical characterization and comparison with respect to the standard reference organisms, the bacteria isolates were presumably Corynebacterium, Pseudomonas, and Bacillus species. Different concentrations 5.0, 10.0 15.0, and 20.0 w/v of the branded detergents were prepared as sole carbon and energy and screened against our bacteria species to determine their physiological gradient fluxes after 96hours of incubation. Data obtained showed an increase in Optical density (OD) as well as increases in pH flux values. The mean OD data obtained ranged between 0.017- 0.818, with a pH of 7.47-8.95. From this study, tropical soils possess unique bacteria species capable of utilizing alkyl-benzene sulphonates (detergents).
Development of android-based counseling media oriented problem solving in sheep livestock groups
Authors: Nurdayati  , Subektia Rahayu , Susanto
Published: March 2021

Goats are commodities that have good development prospects that can play a dual role as dairy producers and meat, but in their operations in farmer groups usually do not take into account the feasibility of their business so that farmers never know whether their business is in a profit or loss position. The price simulation application is expected to be used to calculate business feasibility, which is practical and easy to use. Such conditions encourage to provide counseling about price simulation applications with Android-based smartphone media. The study was conducted to find out (1) describing Android-based electronic counseling products as an interactive media; (2) knowing the farmers’ response to the use of an Android-based smartphone as an interactive media. (3) determine the effect of internal and external factors on the response. This type of research is Research & Development using the 4D model. The sample used was 33 respondents with a purposive random sampling method. Measurement of responses using a questionnaire containing knowledge, attitudes, and skills with analysis using descriptive statistics followed by inferential statistics. Research Results that the response of farmers to the use of smartphones as interactive media is 1,809 and included in the high category. The results of the study show that exogenous variables (i.e. age with a coefficient value of 0.205, education with a coefficient value of 0.293, breeding experience with a coefficient of -0.185, and innovation characteristics with a coefficient value of 0.209) directly influence endogenous variables (response). The educational variable has a significant effect through the innovation characteristic variable with a coefficient value of 0.177. That is, the variable characteristic of innovation as an intervening/intermediary between education to farmers’ responses, while the other variables do not pass through the innovation characteristic variable as an intervening variable.
Active and Passive Cooling Comparison of PV Panels Applied in Tropical City: Case Study Palembang, South Sumatra
Authors: Dewi Tresna , Taqwa Ahmad , Sitompul Carlos , Kusumanto RD , Rusdianasari
Published: March 2021

The renewable energy generation is currently a trending topic due to the reduced availability of conventional fossil fuel while the demand for energy keeps on increasing. This condition insists on a particular action in search of renewable energy to substitute fossil fuel. One of the unlimited energy offered by nature is the energy from the sun, which also environmentally friendly. Palembang is located in equator blessed with abundant of sun rays which can be utilized maximally by eliminating things that can cause adverse effects such as overheated solar panels. Tropical weather comes with high temperature, and this heat is even more on the surface of the solar panel. The overheated solar panels lead to the reduction of power output and efficiency. Therefore, the cooling system should be applied to ensure the surface temperature is below 35°C, which an average ambient temperature for solar panels. The cooling system can be active that needs power and passive, which naturally generated from the surrounding environment. This paper discusses the comparison of the cooling system applied to solar panels, the passive (heatsink application) and active (water cooling). The active cooling system produced 8.64 Watt higher than a normally installed panel, and passive cooling is 2.7 Watt higher. The active cooling system efficiency is 0.33% more than regular panels, and passive cooling system has 1,2% more. This paper can be a reference to the choice of cooling system for solar panels installed in a city with a tropical climate.
Influence of Geometry and Separation Walls on The Behaviours of Pull-out Pipe Piles Embedded in Sandy Soil
Authors: Hamadi Hanaa Sh. , Abdul-Husain Husain A.
Published: March 2021

Predicting of piles capacity and their behavior is always an important and serious problem for a safe geotechnical engineering design. In the present study, experimental model tests have been conducted on a single steel pipe piles driven in sandy soil and subjected to pull-out force. The experimental tests were conducted on vertical open-ended piles with circular and square cross-sectional area and three various diameters 3 cm, 4 cm and 5 cm in a steel soil box have been used. The tested pile’s model has embedment with thr

ee penetration ratios (PR=L/D) of 10, 15 and 20. All tests were done in medium density soil (Dr = 50%) with open ended pipe pile to study the effect of pile geometry on pile behavior, and three other tests were conducted on the 5cm diameter and 10 penetration ratio in medium soil density to study the importance of addition of separating wall. The study discovered that the capacity of single piles with circle cross-section area under pull-out force increasing by 211% and 458% with the increasing of pile diameter (width) from 3cm to 4cm and 5cm respectively, and increasing by 210%, 448% and by 112%, 288%. Also, by 79% and 211% with increasing penetrating ratio (PR) from 10 to 15 and 20 for diameters 3cm, 4cm and 5cm respectively, with respect to reference pile. And the same behavior for square cross-section pipe pile, when the pull-out capacity increasing with the increase of pile width and penetration ratio due to the increasing in the friction area. Besides that, It was also found that the separation walls increased the coefficient of lateral pressure in addition to the friction area. At the same time, there are an optimum number of separation walls that can be used to increase the pile pull-out capacity and that when using three separation walls.
The Significant Variables of Effluent Constructed Wetlands Treated Domestic Wastewater by Statistical Tests
Authors: Hussein A , Al-Daffaie K
Published: March 2021

Domestic wastewater was treated by vertical flow constructed wetlands under different set-up designs and operation conditions. These conditions include different aggregate diameters, contact time, resting time, and chemical oxygen demand. The physical and chemical measurements of effluents were obtained. These measurements are Chemical oxygen demand; Biochemical oxygen demand; Ammonia-Nitrogen; Nitrate-Nitrogen; Ortho-Phosphate-Phosphorous; Suspended solids; Turbidity and ph. This research aims to find out which variables are significantly effective by using ANOVA with POST HOC tests. The results showed Chemical oxygen demand; Biochemical oxygen demand, Ammonia-Nitrogen, Nitrate-Nitrogen, Ortho-Phosphate-Phosphorous, and Suspended Solids have significantly effective (P<0.05).
The Correlation Among Land Cover Spectral Indices and Surface Temperature Using Remote Sensing Techniques
Authors: Abdalkadhum Aysar Jameel , Salih Mohammed Mejbel , Jasim Oday Zakariya
Published: March 2021

Land cover explains the physical nature of the Earth’s surface in a specific area. Land cover is a reflection of the Earth’s surface’s observable spatial cover comprising complex classes such as agricultural areas, built-up areas, barren lands, forests, water bodies, as well as wetlands. change detection and monitoring of the land cover assist decision-makers to understand the dynamics of the environmental change to assure sustainability development. Hence land cover feature classification has appeared as a serious research aspect and thus, an accurate methodology for land cover categorizing it became an urgent necessity at this time. This study focuses to find the association between surface temperature and the spectral indices of the land cover. The spectral indices of the land cover such as (NDVI, NDBI, NDBAI, and NDWI) were compared with land surface temperature (LST) and computed the correlation coefficient, just using three images on March 18, July 24 as well as 31 December in 2018, indicating a high positive correlation coefficient among (NDBI, NDBAI) and (LST) and recorded (by built-up areas R= 0.99, R= 0.97 and R= 0.98) ) and (with bare areas R= 0.94, R= 0.98 and R= 0.99), respectively. An inverse correlation coefficient among (NDVI, NDWI) and (LST) where the results recorded a correlation coefficient with (the agricultural areas R= - 0.97, R= - 0.96 and R= - 0.95) and the correlation coefficient with (water bodies R = - 0.93, R= - 0.90 and R= - 0.58) respectively.
Compressive and Flexural Behaviour of Mortar Infiltrated Fiber Concrete Using Different Types of Fibres
Authors: Al-Baghdadi Haider M. , Helal Rawnaq Abbas , Ali Al-Salim Nabeel Hasan
Published: March 2021

This paper examined the comparison between the mechanical properties of mortar infiltrated fibers concrete with two types of fibers (End hooked steel fiber and Synthetic fiber) with varying fibre volume. The difference in properties of the concrete with steel fiber, concrete without fiber and concrete with Synthetic fiber was determined. Compressive strength and flexural strength (Modulus of rupture) of concrete were determined. The concrete mixing containing [0% control, (2,4 and 6%)] fibre volume of (End Hooked) and Synthetic fiber were used for compressive and flexural strengths tests. Steel fiber was (30 mm) in length and (0.5mm) diameter, while Synthetic fiber was (60mm) in length and (0.84mm) diameter. the concrete cube used was (100×100mm) for compressive strength test, also beam used for flexural strength test with dimensions (400×100×100mm). The results showed that with increasing volumetric ratio of fiber, the compressive strength and flexural strength increase. The compressive strength and flexural strength of hooked fiber have a much higher extent increasing than that of synthetic fiber.
Influence of High Volume RHA on Properties of Cement Mortar
Authors: Al-Khafaji Zainab S. , Majdi Ali , Shubbar Ali A. , Nasr Mohammed Salah , Al-Mamoori Shahad F. , Alkhayyat Ahmed , Al-Rifaie Ali , Al-Emadi Nasser , Al-Mufti Rafal Latif , Sadique Monower , Hashim Khalid
Published: March 2021

This work study the impact of partial cement replacement by high volume Rice Husk Ash (RHA) on some characteristics of cement mortar like compressive strength and flexural strength at different ages. In this research, RHA was used in three different ratios (20, 40, and 60)% as a cement substitution and the findings were compared with control mixture (0% RHA). The findings demonstrated that the replacement of cement by RHA reduced the compressive strength of all selected ratios and the increase in the content of RHA lead to reduce compressive strength comparative to control sample with 100% cement as a binder at all ages. However, the flexural strength results indicated that the RHA in 20% showed approximately same results as control sample at early ages while increasing the curing period lead to improve flexural strength. Increasing RHA higher than 20% lead to decrease Flexural strength at all selected ages.