bluuebunny/crossref_metadata_2025 huggingface dataset:
An insight into the charge carriers transport properties and electric field distribution of CH3NH3PbBr3 thick single crystals
Authors: Baussens Oriane , Maturana Loli , Amari Smaïl , Zaccaro Julien , Verilhac Jean-Marie , Hirsch Lionel , Gros-Daillon Eric
Published: July 2020

Thanks to their unique combination of semiconducting properties and a large cross section for energetic photons, metal halide perovskites could theoretically achieve high x-ray to charge carriers conversion rates, making them materials of high interest for the direct x-ray detection. In this work, we focus on the transport properties of methylammonium lead tribromide (MAPbBr3) single crystals. Time of Flight measurements and x-ray focused experiments along the edge of the samples were carried out. We report homogenous holes transit throughout the thickness of the samples as well as poor electrons transit. We also report the continuity of the electric field throughout the thickness of the MAPbBr3 samples, and we present preliminary fitting results to discuss its nature.
Janus two-dimensional materials based on group IV monochalcogenides
Authors: Seixas Leandro
Published: July 2020

The discovery and design of two-dimensional (2D) materials has aided the development of novel nanoscale devices for various applications. Here, we show the structural, electronic, and vibrational properties of 15 2D materials based on Janus substitution (atomic layer substitution) of group IV monochalcogenides. Although group IV monochalcogenides have already been extensively studied because of their very promising piezoelectric and thermoelectric properties, these Janus materials appear as potential candidates for similar applications but with a broken symmetry that can enrich their electronic and optical properties and the coupling of these with other physical properties. Based on first-principles calculations, we investigate the stability of the Janus materials according to energetic, dynamical, and mechanical criteria. Understanding of the physical properties of these 2D materials can provide guidance for the development of novel nanoscale electronic devices.
Bimolecular photo-induced electron transfer enlightened by diffusion
Authors: Angulo Gonzalo , Rosspeintner Arnulf
Published: July 2020

Photochemical electron transfer between freely diffusing molecules has been studied extensively. Here, we try to elucidate how much these works have contributed to the understanding of electron transfer. To this end, we have revisited the work performed in the experimental and theoretical areas of concern from the beginning of the 20th century up to the present day. We present a critical look at the major contributions and compile the current picture of a variety of phenomena around electron transfer in solution. This is based on two main developments, besides the theory of Marcus: encounter theories of diffusion and laser techniques in time-resolved spectroscopy.
Molecular dynamics simulations of bacterial outer membrane lipid extraction: Adequate sampling?
Authors: Shearer Jonathan , Marzinek Jan K. , Bond Peter J. , Khalid Syma
Published: July 2020

The outer membrane of Gram-negative bacteria is almost exclusively composed of lipopolysaccharide in its outer leaflet, whereas the inner leaflet contains a mixture of phospholipids. Lipopolysaccharide diffuses at least an order of magnitude slower than phospholipids, which can cause issues for molecular dynamics simulations in terms of adequate sampling. Here, we test a number of simulation protocols for their ability to achieve convergence with reasonable computational effort using the MARTINI coarse-grained force-field. This is tested in the context both of potential of mean force (PMF) calculations for lipid extraction from membranes and of lateral mixing within the membrane phase. We find that decoupling the cations that cross-link the lipopolysaccharide headgroups from the extracted lipid during PMF calculations is the best approach to achieve convergence comparable to that for phospholipid extraction. We also show that lateral lipopolysaccharide mixing/sorting is very slow and not readily addressable even with Hamiltonian replica exchange. We discuss why more sorting may be unrealistic for the short (microseconds) timescales we simulate and provide an outlook for future studies of lipopolysaccharide-containing membranes.
Photoelectron spectroscopic study of dipole-bound and valence-bound nitromethane anions formed by Rydberg electron transfer
Authors: Liu Gaoxiang , Ciborowski Sandra M. , Graham Jacob D. , Buytendyk Allyson M. , Bowen Kit H.
Published: July 2020

Close-lying dipole-bound and valence-bound states in the nitromethane anion make this molecule an ideal system for studying the coupling between these two electronically different states. In this work, dipole-bound and valence-bound nitromethane anions were generated by Rydberg electron transfer and characterized by anion photoelectron spectroscopy. The presence of the dipole-bound state was demonstrated through its photoelectron spectral signature, i.e., a single narrow peak at very low electron binding energy, its strong Rydberg quantum number, n*, dependence, and its relatively large anisotropy parameter, β. This work goes the furthest yet in supporting the doorway model of electron attachment to polar molecules.
No-tillage furrow opener performance: a review of tool geometry, settings and interactions with soil and crop residue
Authors: Aikins Kojo Atta , Barr James B. , Ucgul Mustafa , Jensen Troy A. , Antille Diogenes L. , Desbiolles Jack M. A.
Published: July 2020

The primary features of an effective and efficient furrow opener include controlled soil disturbance and low draught and vertical force requirements. When integrated in a no-tillage seeding system, furrow openers should also have the ability to assist, and not hinder, the functions of seeding system components – such as maintaining adequate surface residue distribution, accurate and uniform placement of seeds and fertiliser, and regular inter-plant spacing. This review highlights how these goals are affected by opener type, geometry and settings, and soil and residue conditions. Typically, tine openers cause greater soil disturbance than disc openers whereas disc openers are likely to cause residue hairpinning. Winged tine openers reduce residue interference with seed placement and support greater lateral seed spread. Inverted-T openers can achieve subsurface soil shattering, which helps conserve moisture and provides good seed–soil contact. A tine opener with concave cutting edge reduces soil disturbance relative to straight and convex cutting edges. Increasing rake angle, tine width and operating depth increase degree of soil disturbance and draught requirement. Increasing forward speed reduces residue interference with sowing but might decrease the accuracy and uniformity of depth and separation of seed and fertiliser placement. Relative to common openers, bentleg openers have lower draught and penetration force requirements while combining minimal lateral soil throw with high furrow backfill, even at speeds of up to 16 km h–1. The performance of bentleg openers need to be evaluated under residue conditions and in cohesive and adhesive soils. Recommendations for future research are presented.
The future of private rhino ownership in South Africa
Authors: Chapman Laura A. , White Piran C. L.
Published: July 2020

Sustained poaching over the past decade has led to significant loss of black (Diceros bicornis) and southern white (Ceratotherium simum simum) rhinoceroses across South Africa. Whereas much research has focussed on the heavily targeted state-owned populations, there is little understanding of the trends and challenges faced by rhino populations held in the private sector. Private rhino ownership has increased substantially across South Africa over the past three decades, with over 42% of the entire rhino population now in private ownership. Although total rhino numbers on private properties are still increasing, the number of properties owning rhinos is declining. This suggests a move away from traditional extensive properties to large, single-species breeding facilities, which are less valuable from a conservation perspective. The economic impact associated with increased poaching of rhinos over the past decade is the major challenge to private rhino ownership and may encourage disinvestment in rhinos. Some private rhino owners advocate for trade in rhino horn to generate the funds necessary for continued protection of their animals. However, other options to reduce disinvestment, such as local community-engagement projects, are likely to be more favourably received by the wider conservation industry.
Flow structure and turbulent kinetic energy of velocity fluctuations in a cylinder near wake at Re = 3900
Authors: Molochnikov V M , Mikheev N I , Mikheev A N , Saushin I I
Published: July 2020

SIV measurements of instantaneous vector fields of velocity have been performed in the near wake behind a circular cylinder in a cross flow at Re = 3900. Patterns of velocity profile evolution with the distance from the cylinder have been refined. Distributions of components of the turbulent production term of the turbulent kinetic energy transport equation have been estimated. Their main patterns and correlation with the formation and motion of large-scale vortices (Karman vortices) have been revealed.
Modeling of characteristics of heat exchangers of heat supply systems in variable operating modes
Authors: Rafalskaya T A , Rudyak V Ya
Published: July 2020

Heat exchangers used in heating systems usually operate under conditions of variable flow rates and temperatures of heat carriers. However, the theory for calculating the variable modes of operation of such devices is based on the use of constant parameters of heat exchangers. At the same time it is clear that the parameter of the heat exchanger can be affected by all quantities that determine the change of the heat transfer coefficient. In addition, the groups of heat exchangers with a tied supply of heat, i.e. with redistribution of the heat flow in a variable mode of operation, are used. A new method for calculating the variable modes of operation of heat points with a tied heat supply has been developed. The method of mathematical modeling defines the dependencies that determine the change in the heat exchanger parameters in variable operating modes. The obtained expressions can be used to configure programmable regulators which will allow the correction of inefficient modes of operation of the heating system.
Experimental investigation of heat transfer during flow boiling with ozone-safe refrigerants in microchannels
Authors: Shamirzaev A S , Kuznetsov V V
Published: July 2020

The results of an experimental investigation of heat transfer during subcooled flow boiling with ozone-safe refrigerants R236fa and R141b in horizontal microchannels are presented. The experiments are performed in a closed loop that re-circulates the refrigerant. The working section is represented by two microchannels with a 2×0.36 mm cross-section separated by the wall with a thickness of 2 mm. The dependences of the heat flux and pressure drop on wall superheat are measured in the range of heat fluxes from 5 to 120 W/cm2 at reduced pressures of 0.2 and 0.044 for the case of R-236fa and R141b accordingly. It was obtained that the heat transfer deterioration arises for moderate reduced pressure when the transition to saturated flow boiling occurs.
Technologies for monitoring and cleaning the return manufacturing condensate in the energy-technological complex of heat power plant – petrochemical facility
Authors: Filimonova A A , Chichirova N D , Chichirov A A , Filimonov A G
Published: July 2020

Condensate reuse as feed water for boilers reduces the costs of the used natural resource, improving the environmental and economic efficiency of the facility. The return condensate during condensation of steam supplied from thermal power plants for the implementation of technological processes at many petrochemical facilities is an aqueous mixture of petroleum products and mechanical components with a small amount of inorganic components. The return condensate samples obtained from plants for the production of butyl rubber, synthetic rubber, styrene and polyester resins were used to determine the quantitative and qualitative composition of organic impurities. On the basis of obtained results, physical and chemical purification methods have been developed. According to the analysis results, it is recommended to bring the return condensate to the required standards by flotation with air bubbles of small diameter.
Physical and chemical methods of organic impurities control in the feed water of waste heat boilers of thermal power plants
Authors: Filimonova A A , Chichirova N D , Chichirov A A , Batalova A A
Published: July 2020

For the quantitative control of the organic impurities content in deeply purified waters, a simple, effective and inexpensive method with the carbon tetrachloride extraction was developed for waste heat boilers feeding. The presented methodology served to study the organic substances content in the nutrient water of the Kazan CHP-1 and Kazan CHP-3 waste heat boilers. According to the results of various physical and chemical methods, the samples extracted from feedwaters of waste-heat boilers have been were examined for their qualitative composition. The discovered organic substances belonged predominantly to the class of humic substances, which, due to their physicochemical properties, can penetrate into all types of deeply treated water. The proposed method for complex determination of organic impurities by extraction in the feedwaters of a waste-heat boiler may be used as an alternative to the total organic carbon analysis.
Multi-criteria decision making for a large heating system with heat loss
Authors: Korotkova T I , Kolesnik S A , Garibyan B A , Luneva S Yu , Kuzmina Ya V
Published: July 2020

A large heat supply system, which always has a multi-level hierarchical structure, is considered. There are levels of trunk and distribution heating networks with intermediate levels of regulation. Planning and selection of a mode that provides the required heat loads are associated in such a system with a large number of different factors that complicate the decision-making process. The present study investigates heat transfer in a flat anisotropic insulating plate with uniformly distributed internal heat sinks subjected to heat flows. An analytical solution is obtained that allowed us to study and build temperature distribution fields for various orientations of principal axes of thermal conductivity tensor in an insulating plate. The thermal field localization regime is shown to be possible in the presence of thermal energy sinks/sources inside the plate wherein heat propagation is bound with limiting isotherms.
Features of diffusion and convective mixing in mixtures containing hydrocarbons
Authors: Moldabekova M S , Asembaeva M K , Krasikov S A , Nurtay G F
Published: July 2020

Diffusion mixing in mixtures of C3H8 + CO2 - N2O, Ne + C3H8 - N2O + C3H8, N2O + He - C3H8 + CH4 at different pressures has been studied experimentally. It has been found that at a certain pressure in the mixture there are convective flows distorting the expected diffusion transfer. The transition parameters from diffusion to convective mixing type can be determined in terms of stability theory. The numerical results are compared with experimental data.
Heat transfer in turbulized gradient flows
Authors: Davletshin I A , Shakirov R R , Paereliy A A
Published: July 2020

Convective heat transfer in a plane channel with superimposed pressure gradient (converging and diverging channel) has been studied experimentally. The air flow was turbulized by different arrangements at the channel inlet. Distributions of heat transfer coefficients within the gradient part of the channel have been obtained in different regimes. Patterns of the effect of turbulence intensity on heat transfer have been described.
Application of lattice Boltzmann method for studying interaction dynamics of parallel plane minijets
Authors: Sangadiev A L , Terekhov V V
Published: July 2020

In this work, the method of lattice Boltzmann equations was applied to simulate the systems of two and three parallel laminar plane jets. Simulation was carried out for different Reynolds numbers (Re = 20-200). For the case of two jets, the character of jet interaction has been determined to be, in general, non-stationary, but for small Re values, the process becomes stable due to the action of viscosity forces. For the case of three jets, the character of jets interaction is found to differ significantly from the case of two jets and is non-stationary even for small Re numbers.
Calculation methods of the gas flow in the impeller of a turbo-expander of ORC plant used in the heating plant
Authors: Solomin I N , Daminov A Z , Kamalov R F
Published: July 2020

The calculation of a turbo-expander impeller of a thermoelectric plant operating according to organic Rankine cycle (ORC) is given. The calculation was carried out for real gas using the Peng-Robinson model. Freon R245fa was chosen as the working fluid of the plant. The approximation values of the coefficients of polynomial describing the temperature dependence of isobaric heat capacity on Freon R245fa were used in the calculation.
Experimental study of the vibration of vertical rod in liquid flow
Authors: Lobanov P D , Meledin V G , Pribaturin N A , Svetonosov A I , Shchepikhin I V
Published: July 2020

Vibration of the vertical tube, induced by an axial flow, were studied experimentally. Experiments were carried out using the sensors based on the electrical impedance. The time chronology of the pass of the tube axis was reconstructed using four sensors. For various flow rates different modes of fluctuations were found. The amplitude, shape, and characteristic frequencies of signals were found to change depending on the liquid flow rate.
Research of the electro-vortex flows in the liquid metals at different currents
Authors: Mikhailov E A , Teplyakov I O , Fedotov I A
Published: July 2020

The electro-vortex flow is a very important phenomenon, taking place in the different processes in metallurgy, such as electrical welding or electrical melting. It appears in the conducting medium under the action of the electromagnetic force due to interaction of the non-uniform electrical current (which passes through this medium) and self-magnetic field. Here we present the study of the electro-vortex flow for the hemispherical geometry. The equations were solved in variables “vorticity – vector potential of velocity”. We considered the problem using Stokes approximation and non-linear case with a finite size of the central electrode, and compared the results obtained by different methods of solving the equations.
Heat transfer features in a PCM-based system under the time-dependent thermal load
Authors: Bondareva N S , Sheremet M A
Published: July 2020

Present study is devoted to a numerical analysis of heat transfer processes inside a complex radiator system based on phase change materials (PCM) under the influence of unsteady heat generation local element and external convective cooling. The numerical solution has been implemented by the finite difference method using the enthalpy-based approach to solve the energy equation. As a result of the solution, temperature distributions and liquid flow structures for different time moments, as well as integral characteristics of the melting process as a function of time, have been obtained. The effect of the external Newtonian cooling on the melting intensity and heat transfer patterns has been analyzed.
Vertical-plate free convection boundary layer disturbed by a row of circular cylinders: RANS-based numerical simulation
Authors: Kotikova M R , Levchenya A M , Zasimova M A , Smirnov E M
Published: July 2020

This paper presents the results of RANS-based numerical simulation of 3D flow dynamics and heat transfer in the turbulent free-convection boundary layer disturbed by a transverse periodic row of finite-height cylindrical obstacles. The disturbing row elements are mounted on a vertical isothermally heated plate along which the free-convection flow develops starting from a 2D state prescribed at the computational domain inlet. The height-to-diameter ratio of the cylindrical obstacles is varied from 1 to 3, and their surface is treated as adiabatic or isothermal. Vortex flow structures and local heat transfer patterns in the front and in the rear of the introduced macroroughness are analyzed.
Numerical study of cuttings transport by drilling polymer solutions
Authors: Zhigarev A , Minakov A V , Guzei D V , Neverov A L , Nabizhanov Z I , Matveev A V
Published: July 2020

This paper presents the results of laboratory tests and numerical simulation of polymer drilling fluids. The influence of the rotation speed on the values of the pressure ratio and cutting transport is studied. The influence of rheological parameters on the efficiency of cuttings transport is investigated.
Optimization of the thermodynamic and thermophysical properties of the gas turbine cycle working fluid
Authors: Filippov P S , Lazebniy I P , Ryzhkov A F
Published: July 2020

A gas turbine cycle working fluids group based on their production technology and application is presented. The energy parameters analysis procedure of unclosed and closed gas turbine cycles is described. The comparison of the effect of the working fluids thermophysical and thermodynamic properties variations on the useful work l0
of both unclosed and closed gas turbine cycles is presented. The effect of the fuel gas composition variation on the useful cycle work l0
is revealed. The effect of the working fluid thermophysical properties variation on the gas turbine cycle optimal combination of thermodynamic properties (T3
and P3
) is presented.
Free piston pulse tube engine: a numerical and experimental power generation estimation
Authors: Dovgyallo A I , Nekrasova S O , Pulkina A Yu , Sarmin D V
Published: July 2020

The results of theoretical and experimental study of the atmospheric pulse tube engine (PTE), which is a kind of thermal inertial Stirling engine, are presented. The main advantage of the PTE is the absence of the moving design elements in heated part make it a perspective technology for waste heat recovery. Firstly, numerical simulation was conducted to design the system and optimum structure parameters of the system were obtained as well as the values of the free-piston PTE resonant frequency, the levels of the input and rejected heat, and the net power. Comparison of the net power and the thermal efficiency of the pulse tube engine with the crank mechanism and the free piston is provided. A comparison of operating conditions and engine start conditions for different free piston masses and temperatures in the hot heat exchanger is performed. The results are compared to prior numerical studies. The maximum value of the net power of the PTE was achieved for the frequency of 11.8 Hz, the input thermal power of 160 W and the temperature of 640 K.
Impact of climate variabilities on trans-oceanic flight times and emissions during strong NAO and ENSO phases
Authors: Kim Jung-Hoon , Kim Daehyun , Lee Dan-Bi , Chun Hye-Yeong , Sharman Robert D , Williams Paul D , Kim Young-Joon
Published: July 2020

This study investigates the impact of the North Atlantic Oscillation (NAO) and El Niño Southern Oscillation (ENSO) on trans-oceanic round-trip flight times and consequent CO2 emissions over the north Atlantic and eastern Pacific regions. For three strongest winter periods of both polarity during 1979–2016, daily mean wind data are used to compute the wind-optimal flight trajectories at cruising altitudes. Results show that intensified upper-level jet streams during the +NAO winters provide stronger headwinds for westbound flights between the eastern US and the western Europe. This causes 4.24 ∼ 9.35 min increase in an averaged total round-trip journey time during the +NAO compared to −NAO winters. In the eastern Pacific region, the jet stream is extended eastward towards the southwestern US during the +ENSO period, which lengthens the travel time for westbound flights between Hawaii and the west coast of the US. The increase in travel time of westbound flights is greater than the corresponding decrease in travel time for eastbound flights, resulting in a 5.92 ∼ 8.73 min increase of the averaged total round-trip time during the +ENSO compared to the −ENSO periods. Extrapolating these results to overall trans-oceanic air traffic suggests that aircraft will take a total of 1908 ∼ 4207 (888 ∼ 1309) extra hours during the +NAO (+ENSO) than the −NAO (–ENSO) winters over the North Atlantic (Eastern Pacific) regions, requiring 6.9 ∼ 15 (3.2 ∼ 4.7) million US gallons of extra fuel burned at a cost of 21 ∼ 45 (9.6 ∼ 14) million US dollars and 66 ∼ 144 (31 ∼ 45) million kg of extra CO2 emissions to all trans-oceanic traffic. In +ENSO and +NAO winters, the chances of a given flight having a slower round-trip flight time with more fuel burn and CO2 emissions are 2–10 times higher than in a −ENSO or −NAO winter. These results have significant implications for the planning of long-term flight routes with climate variability.
Greenhouse gas balance in global pasturelands and rangelands
Authors: Dangal Shree R S , Tian Hanqin , Pan Shufen , Zhang Lei , Xu Rongting
Published: July 2020

Grassland ecosystems play an essential role in climate regulation through carbon (C) storage in plant and soil. But, anthropogenic practices such as livestock grazing, grazing related excreta nitrogen (N) deposition, and manure/fertilizer N application have the potential to reduce the effectiveness of grassland C sink through increased nitrous oxide (N2O) and methane (CH4) emissions. Although the effect of anthropogenic activities on net greenhouse gas (GHG) fluxes in grassland ecosystems have been investigated at local to regional scales, estimates of net GHG balance at the global scale remains uncertain. With the data-model framework integrating empirical estimates of livestock CH4 emissions with process-based modeling estimates of land CO2, N2O and CH4 fluxes, we examined the overall global warming potential (GWP) of grassland ecosystems during 1961–2010. We then quantified the grassland-specific and regional variations to identify hotspots of GHG fluxes. Our results show that, over a 100-year time horizon, grassland ecosystems sequestered a cumulative total of 113.9 Pg CO2-eq in plant and soil, but then released 91.9 Pg CO2-eq to the atmosphere, offsetting 81% of the net CO2 sink. We also found large grassland-specific variations in net GHG fluxes, with pasturelands acting as a small GHG source of 1.52 ± 143 Tg CO2-eq yr−1 (mean ± 1.0 s.d.) and rangelands a strong GHG sink (−442 ± 266 Tg CO2-eq yr−1) during 1961–2010. Regionally, Europe acted as a GHG source of 23 ± 10 Tg CO2-eq yr−1, while other regions (i.e. Africa, Southern Asia) were strong GHG sinks during 2001–2010. Our study highlights the importance of considering regional and grassland-specific differences in GHG fluxes for guiding future management and climate mitigation strategies in global grasslands.
A Novel Maritime Risk Assessment Model of Waterway Transportation Based on Takagi-Sugeno Fuzzy Logic: Vietnam Case Study
Authors: Le V. T. , Dang X.K. , Nguyen D.H. , Pham T.D.A.
Published: July 2020

In this paper, we analyzed the safety assessment getting from the opinions of captains, pilots and navigators in Ganh Rai Bay. The results showed that the highest risk was caused by unsafe fishing ships and the most unsafe situation was generated by the crossing ships, wind and currents. The influence of human psychology factors was one of the most important factors, which caused the risk of collision. Based on fuzzy logic theory, we proposed risk assessment model which was tested in simulation and compared with the evaluation results of the Experts in Vietnam. The results showed the effectiveness of the novel maritime risk assessment model.
Design and Implementation of Realtime Scour Monitoring of Hangzhou Bay Sea-Crossing Bridge Pier Based on Dual-Axis Scanning Sonar
Authors: Peng Lei
Published: July 2020

This paper introduces the design and implementation of the realtime scour monitoring system for piers of Hangzhou Bay Sea-Crossing Bridge, including the construction of the monitoring system for the scour of the piers and the key technologies of the monitoring system. Through integration of dual axis scanning sonar technology and monitoring software, real-time seabed topography observation, data processing, analysis and data release based on the Internet is realized, qualitative, quantitative and locational decision support for management departments is provided.
Study on Synchronous Effects of Free Surface and Propeller Rotation on Vessel Rudder Force
Authors: Ky Quang Pham , Van Duy Vu , Xuan Tung Trinh , Dinh Chien Dang , Anh Vu Co Tan
Published: July 2020

The paper presents a theoretical foundation of the effects of free surface and propeller rotation on the flow surrounding the rudder of a vessel. This is the scientific ground to evaluate the instability of the rudder force, thence building a research model and applying CFD in simulated to calculate the phenomenon. On the other hand, this paper also issues the idea of designing and creating a test system for carrying out practical experiments on related problems by using ship models similar to M/V TAN CANG FOUNDATION. The input data merely including ship’s lines, ship’s speed, rudder angle… are observed in the period of manoeuvering the vessel in the Haiphong fairway, Vietnam. The results are shown in this article distinctly figure out pulsating air bubbles caused by the synchronous effects of the free surface, the propeller rotation and indicate that the oscillating period of the rudder force at the time cavitation at the leading edge of the rudder which has not been formed is compatible with the revolutions of the propeller.
Surface Water Quality Analysis using Fuzzy Logic Approach: A Case of Inter-provincial Irrigation Network in Vietnam
Authors: Hue N H , Thanh N H
Published: July 2020

Water quality assessment plays an essential role in sustainable management and development of river systems. However, this process is highly complicated that requires professional expertise. The fuzzy water quality index (FWQI) based on fuzzy logic is computational method categorizing water quality into various categories for different water uses. In this study, a method based on fuzzy inference systems (FIS) to assess water quality in the Nhue River, an inter-provincial irrigation network in Northern Vietnam, using fuzzy logic is proposed. Nine fuzzy variables namely dissolved oxygen (DO), biological oxygen demand (BOD5), chemical oxygen demand (COD), pH, ammonium (

NH

4
+

), phosphates (

PO

4

3
−

), total suspended solids (TSS), turbidity, and total coliform (Tco) on the potable quality of the river water are employed for the quality assessment. The fuzzy inference system is composed by 3250 rules with a score from 0 to 100 and five verbal categories. The FWQI was validated by comparison with Vietnam national water quality index. The result of the study clearly shows that the Fuzzy Inference System (FIS) approach was a practical, simple and useful tool to assess surface water quality in river as well as irrigation networks.
Research on the Trend of Landfill Ecological Restoration Technology Based on Patent Analysis
Authors: Xie Q S , Sun H Y , Li Z , Chai T
Published: July 2020

Ecological restoration, as one of the important technologies for landfill treatment, has attracted much attention from governments and the academy of science and technology. In this paper, the focus is the analysis of the trends of ecological restoration technology of landfill, we make a comparative analysis of domestic and foreign patents from the perspective of application trends, major technical fields, main patentees, competition and risks by comprehensively using the platforms and tools such as the Chinese Patent Database, Derwent World Patent Index Database, and the European Patent Office Patent Literature Database. Our work is of referential significance for the development of China in this field.
Effects of Dibutyl Phthalate on Physiological and Biochemical Behaviors of Electroactive Biofilm
Authors: Dong Yue , Wang Peifang , Zhang Yixuan
Published: July 2020

Microbial electrochemical systems (MESs) are a promising clean energy source to directly convert waste chemicals in domestic wastewater to available electric power with synchronous pollutant removal. The physiological and biochemical behaviors of electroactive microorganisms (EAMs) is the key factor of the MESs. Dibutyl phthalate (DBP), as the emerging pollutant, widely exists in municipal wastewater which has strong ecological toxicity. So, utilization of MESs in the engineering practice of wastewater treatment must consider the impact of DBP on the physiological and biochemical behaviors of electroactive biofilm. The output voltage and power density of the MES decreased significantly with the increase of DBP in the synthetic wastewater. In addition, the EAMs resisted the stimulation of DBP by secreting more extracellular polymer substances (EPS) by microscopic observation. The composition and structure of the EPS also changed, mainly reflected in the increase of β-polysaccharide content and the expansion of its coverage area.
Fertilizers from monosodium glutamate waste encapsulated with chitosan nano-zeolite
Authors: Dosirjon I , Rahayu K L , Apriliana L , Ismiyarto
Published: July 2020

Fertilizers that are safe for the environment are highly necessary to increase the agricultural productivity in handling critical land conditions, where nutrients contained in the soil are far below the normal levels of 4–5 %. This nutrient crushing occurs due to the use of synthetic chemical fertilizers, pesticides, and excessive chemical drugs. Therefore, the authors make fertilizer with a high slow release of zeolite, chitosan from the skin shell and monosodium glutamate (MSG) waste. The method used is demineralization, deproteination, and deacetylation to obtain chitosan. After that, the zeolite encapsulation was activated by chitosan and MSG waste. The product obtained is in the form of a milling solid using HEM to obtain the results of nanoparticles. These results were characterized by FTIR, SEM-EDX, XRD. XRD results refer at (angle (2θ): 20) containing NH2 compounds, at (angle (2θ): 21–23) containing SiO2, then at spectra (angles (2θ): 25–28) containing LiAl SiO4 compounds then at (angle (2θ): 30–34) containing C and at (angle (2θ): 42–44) containing FeO4 P. SEM results show MSG micrographs wrapped in nano-zeolite and nano-chitosan fertilizers with a sample size of 90-100nm and it is known that in MSG waste fertilizer encapsulated with nano zeolite-chitosan containing micronutrients in fertilizers such as Si as much as 10.7 %, sodium 11.8 %, nitrogen 11.8 %, 1.2 % iron, potassium 0.3 % and 0.1 % phosphorus. The FTIR results showed a peak in the fingerprint area of the MSG-zeolite-chitosan waste spectra that identified the presence of macro nutrients N, P, K, Ca, Mg and several micro elements such as Cu, and Zn in addition to other elements needed in slow release fertilizers.
The extraction of lineaments from satellite images in Phayao-fault zone
Authors: Sukphornsawan N , Suwanprasit C , Wongpornchai P
Published: July 2020

Lineament mapping is an important part of structural geological investigation that are important features showing subsurface elements or structural weakness, such as geological faults. Most of lineament features are normally extracted by visual interpretation of enhanced image data. The main objective of this work was to develop a method for semi-automatically extracting lineament using remote sensing data. Landsat 8 OLI original image (excluded band 1, 8, 10 and 11) of Phayao-fault zone was operated. There were three main steps in the study including 1) improve quality of dataset using Principal Component Analysis (PCA), 2) delineate lines from the result of quality improvement and 3) classify lineament using visual interpretation. The results from PCA – Band 3 showed the most correlated when compared with existing data. The extracted lineaments were correlated to geological lineament, stream and road network about 42.46 %, 20.52 % and 7.22 % respectively.
Pseudo-3D seismic construction using tau-p transform interpolation
Authors: Novrizal  , Riyanto A , Yulianto E , Abdullah F
Published: July 2020

Three dimensional (3D) seismic imaging is very important in hydrocarbon exploration. However, 3D seismic data acquisition costs more expensive than 2D seismic data acquisition. Therefore, the explorations are mostly done with some 2D seismic lines and requiring some interpolation method to construct the 3D seismic model called Pseudo-3D Seismic. In other word, the 3D model depends much on the interpolation process for a more reliable result. There have been many interpolation methods used to construct the 3D seismic model. Tau-P Transform is one of the methods that can be used to construct a 3D seismic model. It has been used to reconstruct seismic data and fill the near-offset gap in marine seismic data for decades. In this research, the method is done by having the crossline of some 2D seismic lines and performing the transformation from t-x domain to the tau-p domain. After the transformation, by inverse-transformation from tau-p to t-x domain, we might perform interpolation along the line to construct more traces with regular and near spacing. This method can be performed to all crosslines and construct Pseudo-3D Seismic. The results show constructed crosslines with well-lineated layers. The crosslines show developed layers are like those of the inline implying that the interpolation successfully construct the layers based on the inline.
Petrology and petrogenesis of igneous rock in Mount Endut, Banten Province
Authors: Adikusuma R , Sahdarani D N , Sihombing F M H , Supriyanto  , Kadja G T M
Published: July 2020

Mount Endut is a volcano located in the eastern part of Banten Province. Previous studies revealed that Mount Endut consists mainly of Quaternary volcanic and Tertiary plutonic igneous rocks respectively. This research focuses on the petrology of igneous rocks found in the southern region of Mount Endut in order to determine the type of igneous rocks, evolution of magma, and reconfirming historical geological process occurring in Mount Endut area. Petrographic analysis was performed on 11 samples and geochemical analysis was performed on 30 samples. Petrographic analysis revealed three types of igneous rocks, andesite porphyry, diorite porphyry, and dacite porphyry. Furthermore, geochemical analysis revealed that the igneous rocks in Mount Endut are comprised of basaltic andesite, andesite, dacite, basaltic trachy-andesite, trachy-andesite, and trachyte or trachydacite which originated from calc-alkaline magma series. The integration of petrographic and geochemical analysis supports the regional geological process where Mount Endut was formed either in an island arc or an active continental margin. The first section in your paper.
Justification of windward and leeward carbonate geometry using experimental approach
Authors: Andrean F , Prasojo O A , Indra T L
Published: July 2020

Windward and leeward positioning on carbonate system gives significant effect on structure formation. Since the location of oil and gas reserve is affected by the position, it is important to establish the relation between surface and subsurface carbonate geometry. An experimental approach using flume tank modelling was performed to replicate the natural process which formed the windward and leeward geometry. The model was based on actual recent atoll with ideal characteristics, scaled down spatially and temporally to lab-sized experiment. The effect of windward and leeward positioning was replicated successfully and the density difference between the sediments used in the experiment was proven not to give any observable effects on geometry formation. Given the same ocean condition between the present and the past, the model gives insight to the shape of subsurface carbonate geometry found by seismic imagery.
2D source rock maturity model with integrated geology, geophysics and geochemistry data in HL field Jambi Sub Basin, South Sumatra Basin
Authors: Lazuardi H , Supriyanto  , Praditiyo  , Julikah
Published: July 2020

South Sumatra basin is one of the back arc tertiary basin in western part of Indonesia. It consists of 31 grabens and 2 grabens complexes which are divided into three general basin systems. Modeling of maturity generation has been performed in Jambi sub basin with Talang Akar formation as source rock target from 5 well along in HL field. This study aims to examine their hydrocarbon generation and expulsion history. Geochemical evaluation showed that Talang Akar formation is very potential as a source rock, with an average TOC value of around 1–8 wt %. The reconstruction of 2D modeling and thermal show that HL field evolved initially as a rift basin in Miocene with uplift in the Oligocene. The present-day calculation of heat flow in HL Field shows 7.27 HFU. The differences in the present-day heat flow with paleo heat flow have been corrected using vitrinite reflectance to know validate the paleo heat flow. In Paleo heat flow increased since the main rifting form late Oligocene until early Miocene. rifting finished, paleo heat flow will indirectly reduce the heat. During Middle Miocene there was a post rift phase which considered as influence on source rock maturation and hydrocarbon generation as quite Talang Akar formation is currently passing oil generation window. Thermal maturation model indicated that Talang Akar formation ware passed late oil generation stage and generated with oils to convert dry gas with the result % Ro is 2 %. The hydrocarbon explosion got result from transformation ratio model that source rock unit have probably completed all potential hydrocarbon since Pleistocene that in regional Sumatra has even inversion stage.
Liquefaction potential identification in the Central Sulawesi using gravity inversion model
Authors: Fauzik D , Haris A , Martha A A , Riyanto A
Published: July 2020

Liquefaction is one of the effects following an earthquake, it is the soil strength loss due to the vibration of an earthquake. The earthquake which struck with a 7.7 magnitude on September 28th 2018 in Donggala and Palu, Sulawesi caused a series of disastrous events including a tsunami and aftershock liquefaction in Balaroa and Petobo, causing many casualties. The liquefaction can be investigated and possibly predicted by identifying and interpreting the subsurface structures. This paper identifies the geological structures in the subsurface using the gravity method. The study was carried out by 3D inversion modelling at locations 119.6–120.2 BT and 0.6–1.2 LS based on gravity data. The gravity data was gained from Global Gravity Model plus (GGMplus). The study from satellite and the Bouguer anomaly in the Central Sulawesi shows that it has gravity of -50 to 130 mGal. The 3D inversion model of the subsurface shows low density contrast around the areas of Palu, Balaroa, and Petobo with values of -0.055 to -0.05 gram/cm3 where these low density depths have been identified from 0–125 meters below the surface and even deeper to the southern part of the study area. This low density contrast is in accordance with the geological conditions of the Palu which is dominated by porous sediment layers which are capable of storing fluids that are the main factor in causing the liquefaction.
Syn-Rift sequence and depositional environment analysis using spectral decomposition in field “G” North West Java Basin
Authors: Putri G E , Riyanto A , Putra P R
Published: July 2020

Study about depositional environments is one of the purposes of many researches which is done for academic and economic purposes in oil and gas exploration. This study needs enough comprehensive analysis to generate more detail interpretation. In this case we analyze syn-rift sequence framework, syn-rift depositional architecture, and its depositional system in Field “G” Talang Akar Formation (TAF), Ciputat, North West Java Basin. The ability to analyze seismic data in the frequency domain through spectral decomposition allows the user to extract additional geological information that may be missed by using more traditional methods, for instance amplitude extraction and attribute analysis. By using spectral decomposition as an enhanced seismic attribute, in correlation with more conventional interpretation methods through log data and seismic sections, it is possible to identify distributary channels that have previously been inferred from seismic reflection data. It is found that the best frequencies which can help well in interpreting the seismic is 25 Hz, 35 Hz and 45 Hz.
Submarine channel initiation using realistic computational fluid dynamic simulation
Authors: Mujiyanto A A , Prasojo O A , Indra T L
Published: July 2020

Submarine channel initiation is the process that involved turbulence fluid flow and sculpting submarine channels. The fundamental factor that affects this process is fluid flow velocity and grain-size deposit that the fluid itself carry. This study presents a realistic computational fluid dynamic simulation to simulate the process of submarine channel initiation in a time-dependent equation. This study uses a standard slope model but with the novel approach of adjusted parameters of the actual condition of the submarine channel initiation such as depth hydrostatic pressure, fluid density, and fluid velocity. The result of the simulation showed the correlation between fluid flow velocity and deposited grain-size distribution, which resulting bigger grain size are deposited along with higher fluid flow velocity at the highest activity of 14 m/s and smaller grain size are deposited at lower fluid flow velocity at the lowest activity of 0 m/s among the geometry of the submarine fan.
A fully integrated approach through petrophysical analysis, hydraulic flow units and seismic inversion to map good quality flow unit of globigerina limestone gas reservoir in C field, Madura Straits
Authors: Himawan H , Haris A , Riyanto A
Published: July 2020

The common problem for reservoir characterization usually related to understanding of vertical and lateral heterogeneity of reservoir. Understanding the vertical reservoir heterogeneity generally can be solved based on petrophysical analysis combined with hydraulic flow unit analysis result. HFU’s analysis based on indicator of flow zone which reflect to rock quality that influenced by the mineralogical composition and texture of lithology. Whereas to understand the lateral heterogeneity, generally solve based on the quantitative seismic analysis as results from model based seismic inversion. The purpose of this study is to determine the lateral good flow unit distribution so that the development well placement and targets can be optimized. The petrophysical results obtain 370.5ftMD gross thickness with net pay = 346.0 ftMD, NtG = 93.4 %, Vclay = 6.9 %, Phie = 38.7 %, permeability = 22.6 mD and Sw = 46.6 %. From hydraulic flow units results obtain five flow units with the fifth flow unit has best quality. Characteristics of the fifth flow unit has FZI = 0.727, Vclay = 3.9 %, Phie = 45.1 %, Permeability = 229.6 mD and Sw = 31.1 %, with grainstone as dominant lithology. The good flow units have AI value 3600–4300 gr/cc*m/s and have lateral distribution relatively Northwest–Southeast. Going to the crest of structure, the thickness of good flow unit will be thinner because it is truncated by the fault.