bluuebunny/crossref_metadata_2025 huggingface dataset:
Highly stretchable and self-foaming polyurethane composite skeleton with thermally tunable microwave absorption properties
Authors: Ye Fengchao , He Xinsheng , Zheng Jiajia , Li Yancheng , Li Mengjia , Hu Zhonglue , Wang Sisi , Tong Guoxiu , Li Xiping
Published: February 2021

Stretchable and lightweight polymer composite material possessing tunable microwave absorption (MA) properties under thermal radiations remain a significant challenge. Here, we proposed a facile strategy to fabricate stretchable, magnetic composite skeletons by incorporating the tadpole-like CNTs@Fe3O4 nanoparticles into self-foaming polyurethane (PU) matrix and the electromagnetic responsive of CNTs@Fe3O4/PU composite foams with different CNTs contents under heating−cooling cycle in a temperature range of 253 −333 K were carefully investigated. Enhanced complex permittivity and shifting peak frequency were observed at elevated temperatures. For instance, the 70-CNTs@Fe3O4/PU sample with 15 wt% loading content at 333 K exhibits excellent MA properties including a minimum reflection loss (RLm) of −66.9 dB and ultrabroad effective frequency bandwidth (RL ≤ −20 dB) of 9.98 GHz at the thickness of 1.58−3.37 mm. Meanwhile, great recoverability in terms of RL-f profile was achieved in the process of thermal cooling back to 253 K. Such adjustable MA property was attributed to the well-matched impedance and dramatic attenuation ability, benefiting from the temperature-dependant electrical conductivity, abundant interfacial polarization and interior microcellular structures. Besides, the rising temperature increased the sample elongation and electrical conductivity with a slight sacrifice of maximum tensile strength. This stretchable PU skeleton with a unique assembly of CNTs and Fe3O4 nanoparticles are expected to be promising candidates as smart absorbers for application in the harsh environments.
Homemade experiment for understanding the fluid continuity principle
Authors: Nugraha M G , Purwana U , Parwati S , Kirana K H
Published: February 2021

In science learning, the experiment is an essential activity to facilitate students to discover and develop knowledge as well as to enhance scientific process skills and self-confidence. This study aims to create a simple experimental apparatus related to the principle of fluid continuity that can be made and conducted by the teacher and student as a learning media. Basic tools were used to assemble this homemade experiment and a free video analysis software, Tracker, was used to determine and analyse the fluid velocity. The experimental results showed that the fluid flows faster in the small hose than the larger one, which is in line with the fluid continuity principle. Nevertheless, there is a slightly different volumetric water flux (Q) in both hoses.
A novel 2D/3D hierarchical registration framework via principal-directional Fourier transform operator
Authors: Yang Keke , Luo Yang , Zhao Yiwen , Su Shun , Qu Danyang , Zhao Xingang , Song Guoli
Published: February 2021

An effective registration framework between preoperative 3D computed tomography and intraoperative 2D x-ray images is crucial in image-guided therapy. In this paper, a novel 2D/3D hierarchical registration framework via principal-directional Fourier transform operator (HRF-PDFTO) is proposed. First, a PDFTO was established to obtain the in-plane translation and rotation invariance. Then, an initial free template-matching approach based on PDFTO was utilized to avoid initial value assignment and expand the capture range of registration. Finally, the hierarchical registration framework, HRF-PDFTO, was proposed to reduce the dimensions of the registration search space from n
6 to n
2. The experimental results demonstrated that the proposed HRF-PDFTO has good performance with an accuracy of 0.72 mm, and a single registration time of 16 s, which improves the registration efficiency by ten times. Consequently, the HRF-PDFTO can meet the accuracy and efficiency requirements of 2D/3D registration in related clinical applications.
Four-dimensional inverse-geometry computed tomography: a preliminary study
Authors: Kim Kyeong-Hyeon , Shin Dong-Seok , Kang Sang-Won , Kang Seong-Hee , Kim Tae-Ho , Chung Jin-Beom , Suh Tae Suk , Kim Dong-Su
Published: February 2021

This study introduces and evaluates respiratory-correlated four-dimensional (4D) inverse geometry computed tomography (IGCT). The projection data of the IGCT were acquired in a single gantry rotation over 120 s. Three virtual phantoms—static Defrise, 4D Shepp–Logan, and 4D extended cardiac-torso (XCAT)—were used to obtain projection data for the IGCT and cone-beam computed tomography (CBCT). The projection acquisition parameters were determined to eliminate vacancies in the Radon space for an accurate rebinning process. Phase-based sorting was conducted within 10 phase bins, and the sorted projection data were binned into a cone beam geometry. Finally, Feldkamp–Davis–Kress reconstruction was conducted independently at each phase. The reconstructed images were compared using the structural similarity index measure (SSIM) and root mean square error (RMSE). The vertical profile of the Defrise reconstruction image was uniform, and the cone beam artefact was reduced in the IGCT image. Under an ideal projection acquisition condition, the mean coronal plane SSIMs of the Shepp–Logan and 4D XCAT phantoms were 0.899 and 0.706, respectively, which were higher than those of the CBCT (0.784 and 0.623, respectively). Similarly, the mean RMSEs of the coronal plane IGCT (0.036 and 0.158) exhibited an improvement over those of the CBCT (0.165 and 0.261, respectively). The mean standard deviations of the SSIM and RMSE were lower for IGCT than for CBCT. In particular, the SSIM and RMSE of the sagittal and coronal planes of the Shepp–Logan IGCT images were stable in all phase bins; however, those of the CBCT changed depending on the phase bins. Poor image quality was observed for IGCT under inappropriate conditions. This was caused by a vacancy in the Radon space, owing to an inappropriate scan setting. Overall, the proposed 4D IGCT exhibited better image quality than conventional CBCT.
Evaluation of the effectiveness of electrical muscle stimulation on human calf muscles via frequency difference electrical impedance tomography
Authors: Sun Bo , Baidillah Marlin Ramadhan , Darma Panji Nursetia , Shirai Tomoyuki , Narita Kosei , Takei Masahiro
Published: February 2021

Objectives. The human skeletal muscle responds immediately under electrical muscle stimulation (EMS), and there is an immediate physiological response in human skeletal muscle. Non-invasive quantitative analysis is at the heart of our understanding of the physiological significance of human muscle changes under EMS. Response muscle areas of human calf muscles under EMS have been detected by frequency difference electrical impedance tomography (fd-EIT). Approach. The experimental protocol consists of four parts: pre-training (pre), training (tra), post-training (post), and relaxation (relax) parts. The relaxation part has three relaxation conditions, which are massage relaxation (MR), cold pack relaxation (CR), and hot pack relaxation (HR). Main results. From the experimental results, conductivity distribution images σ

p
(p means protocol = pre, tra, post, or relax) are clearly reconstructed by fd-EIT as response muscle areas, which are called the M
1 response area (composed of gastrocnemius muscle) and the M
2 response area (composed of the tibialis anterior muscle, extensor digitorum longus muscle, and peroneus longus muscle). A paired samples t-test was conducted to elucidate the statistical significance of spatial-mean conductivities 〈σ

p
〉
M1 and 〈σ

p
〉
M2 in M
1 and M
2 with reference to the conventional extracellular water ratio β

p
by bioelectrical impedance analysis. Significance. From the t-test results, 〈σ

p
〉
M1
and 〈σ

p
〉
M2 have good correlation with β

p
. In the post-training part, 〈σ

post
〉 and β

post
were significantly higher than in the pre-training part (n = 24, p < 0.001). The relax–pre difference ratios of spatial-mean conductivity Δ〈σ

relax–pre
〉 and the relax–pre difference ratios of extracellular water ratio Δβ

relax–pre
in both MR and CR were lower; on the contrary, the Δ〈σ

relax–pre
〉 and Δβ

relax–pre
in HR were significantly higher than those in post–pre difference ratios of spatial-mean conductivity Δ〈σ

post–pre
〉 (n = 8, p < 0.05). The reason for the changes in 〈σ

p
〉
M1 and 〈σ

p
〉
M2 are caused by the changes in muscle extracellular volumes. In conclusion, fd-EIT satisfactorily evaluates the effectiveness of human calf muscles under EMS.
Noise suppression for MHD characterization with electron cyclotron emission imaging 1D technique
Authors: Yu G , Kramer G J , Zhu Y , Li X , Wang Y , Diallo A , Ren Y , Yu J H , Chen Y , Liu X , Cao J , Zhao B , Austin M , Luhmann N C
Published: February 2021

Significant noise suppression for magnetohydrodynamics (MHD) mode characterization in the spatial and spectral domain is achieved by processing two-dimensional (2D) electron cyclotron emission imaging (ECEI) data with a one-dimensional (1D) ECEI technique using a short time window (

1

ms

). The technique is applied to detect toroidal Alfven eigenmodes (TAEs) in the temporal spectrum and fit their radial envelope using the data from the DIII-D tokamak W-band 2D ECEI system. Using the data length (time window) of only 1

ms

, the 1D ECEI can clearly detect the TAEs (∼100

kHz

) on the spectrum, while similar spectrum quality requires ∼10

ms

data length with the cross power spectrum between two midplane ECEI channels. The 1D ECEI technique also effectively avoids biased fitting when resolving the fine structure of the TAE’s radial envelope. The radially spatial resolution of 1D ECEI is constrained by the finite ECE radiation volume of the ECEI receiver. With forward radiation modeling, we find the DIII-D ECEI system can sensitively measure the even parity MHD activities, for which the mode width is >15 mm, and tearing modes (odd parity MHD activities), for which the island full width is >30 mm.
A comprehensive test method for measuring actuation performance of McKibben artificial muscles
Authors: Salahuddin Bidita , Warren Holly , Spinks Geoffrey M
Published: February 2021

The versatile nature of artificial muscles and their applications is derived from their ability to actuate in tensile, torsional and bending modes that can mimic the action of hydraulic rams, electric motors and biomimetic curling arms, respectively. Artificial muscles have exhibited great potential for fabricating robotic components and surgical tools due to their resemblance to biological muscles; along with their high actuation force per mass. For further investigation of these artificial muscles as tensile actuators with practical applications, it is imperative to standardise methods for characterising their performance. This article applies an integrated characterization method: simultaneously measuring the free stroke of a McKibben-type hydraulic artificial muscle; the stroke while operating against an externally applied force (isotonic); the blocked force of these muscles while keeping the muscle at constant length (isometric); and the force and displacement change when the muscle operates against a return spring (variable force, pressure). This linear mechanics approach has been verified and allows the prediction of these fundamental actuation characteristics while illustrating the effects of changing external load on the muscle performance. This study proposes an important approach to assist the design of McKibben muscles when used to carry variable loads such as in exoskeletons, prosthetics, and robotics applications.
Shear band formation in magnetorheological elastomer under stress relaxation
Authors: Johari Mohd Aidy Faizal , Mazlan Saiful Amri , Ubaidillah  , Nordin Nur Azmah , Abdul Aziz Siti Aishah , Johari Norhasnidawani , Nazmi Nurhazimah , Homma Koji
Published: February 2021

The characteristics and behaviors of magnetorheological elastomer (MRE) within the elastic region are significantly important to demonstrate potentiality toward infinitesimal deformation in various applications. As MRE dynamically shears within an elastic region at constant small deformation, its significant consequence has long been a pending topic, hampered partly by the lack of empirical evidence. Therefore, this paper aimed to investigate the onset microscopically transformation of the MRE sample precipitated to storage modulus behavior under stress relaxation conditions. To achieve the aim, MRE with 70 wt% carbonyl iron particles was dynamically sheared at 1 Hz frequency and 0.01% strain for a designated period of test duration. The morphology evaluation of the sheared sample disclosed the development of permanent microplasticity in a very narrow region of shear bands. The deformation adequately reduced the storing energy ability of the MRE at a dominantly elastic behavior. The results revealed that the ability of MRE to store deformation energy slightly reduced by 0.3%–0.5% for the 2000 s test interval. This interesting onset phenomenon was successfully achieved, and the establishment of this early-stage deformation was undeniably important as preliminary data for catastrophic investigation at a longer duration.
Quantum enhancement to information acquisition speed
Authors: Horvat Sebastian , Dakić Borivoje
Published: February 2021

The speed of the transmission of a physical signal from a sender to a receiver is limited by the speed of light, regardless of the physical system being classical or quantum. In this sense, quantum mechanics can not provide any enhancement of the speed of information transmission. If instead we consider that the information needing to be transmitted is not localized at the sender’s location, but dispersed throughout space, spatial coherence might provide some enhancement. In this work, we demonstrate a quantum mechanical advantage in the speed of acquirement and transmission of information globally encoded in space. We present a task for which we prove a quadratic enhancement to the information acquisition speed using quantum information carriers with respect to their classical counterpart. Our findings can naturally be applied in situations where the information source has limited power, i.e. bounded number of signals that can be sent per unit time.
Stability of charged thin-shell and thin-shell wormholes: a comparison
Authors: Sharif M , Javed Faisal
Published: February 2021

In this paper, we are interested to compare the stability of geometrical structures of self-gravitating charged thin-shell and thin-shell wormholes in the presence of different types of matter distribution. For this purpose, we develop a thin-shell that connects inner Minkowski spacetime and the outer Reissner-Nordström black hole. We also develop a thin-shell wormhole from the matching of two equivalent copies of Reissner-Nordström black hole by using cut and paste approach. The equation of motion of the shell is used to observe the stability of the developed structures through radial perturbation. We assume barotropic type (generalized barotropic) and non-barotropic type (generalized phantomlike and Chaplygin gas model) matter distributions to discuss the stable configuration of the developed structures. It is found that thin-shell is more stable than thin-shell wormhole for both matter distributions with suitable choice of physical parameters.
Energy dissipation of an infinite damping beam supported by saturated poroelastic halfspace
Authors: Liu Kuan , Hu Weipeng , Gao Chong , Ye Wanjun
Published: February 2021

Reproducing the dissipative effects in the non-conservative dynamic system numerically is one of the challenges in the numerical method because that, both the artificial dissipation of the numerical method and the real dissipation of the system are contained in the numerical results. In this paper, a complex structure-preserving numerical approach with tiny artificial dissipation is developed to investigate the energy dissipation in the road-foundation interaction system subjected to a moving load. Simplifying the road as an infinite damping beam with a finite width and the foundation as a saturated poroelastic halfspace with viscosity, the nonlinear coupling damping dynamic model is established. The energy dissipation laws of the road-foundation interaction system are revealed with different parameters of the moving load in the numerical simulations by the complex structure-preserving approach. The complex structure-preserving approach developed in this paper provides a new way to analyze the coupling dissipative problems. In addition, the energy dissipation laws obtained from the numerical results give some suggestions on the road design and the foundation design in engineering.
Pair production in asymmetric Sauter potential well
Authors: Sawut Adiljan , Dulat Sayipjamal , Xie B S
Published: February 2021

Electron-positron pair production in asymmetric Sauter potential well is studied, where the potential well has been built as the width of the right edge fixed but the left side of the well is changeable at different values. We study the momentum spectrum, the location distribution and the total pair numbers in this case of asymmetric potential well and compare them with the symmetric case. The relationship between created electron energy, the level energy in the bound states and the photon energy in the symmetric potential well is used to the studied problem for the created electrons in the asymmetric potential well and its validity is confirmed by this approximation. By the location distribution of the electrons we have also shown the reason why the momentum spectrum has an optimization in the asymmetric well compared with the symmetric one.
Quantization of the band at the surface of charge density wave material 2H-TaSe2
*
Authors: Li Man , Xu Nan , Zhang Jianfeng , Lou Rui , Shi Ming , Li Lijun , Lei Hechang , Petrovic Cedomir , Liu Zhonghao , Liu Kai , Huang Yaobo , Wang Shancai
Published: February 2021

By using angle-resolved photoemission spectroscopy (ARPES) combined with the first-principles electronic structure calculations, we report the quantized states at the surface of a single crystal 2H-TaSe2. We have observed sub-bands of quantized states at the three-dimensional Brillouin zone center due to a highly dispersive band with light effective mass along kz
direction. The quantized sub-bands shift upward towards E
F while the bulk band at Γ shifts downward with the decrease of temperature across charge density wave (CDW) formation. The band shifts could be intimately related to the CDW. While neither the two-dimensional Fermi-surface nesting nor purely strong electron–phonon coupling can explain the mechanism of CDW in 2H-TaSe2, our experiment may ignite the interest in understanding the CDW mechanism in this family.
In situ formed FeS2@CoS cathode for long cycling life lithium-ion battery*
Authors: Wang Xin , Wang Bojun , Yang Jiachao , Ran Qiwen , Zou Jian , Chen Pengyu , Li Li , Wang Liping , Niu Xiaobin
Published: February 2021

Pyrite FeS2 exhibits an ultrahigh energy density (1671 W⋅h⋅kg−1, for the reaction of FeS2 + 4Li = Fe + 2Li2S) in secondary lithium-ion batteries, but its poor cycling stability, huge volume expansion, the shuttle effect of polysulfides, and slow kinetic properties limit its practical application. In this work, we synthesize a composite structure material CoS on FeS2 surface (FeS
x
@CoS, 1 < x ≤ 2) by using a cobalt-containing MOF to improve its cycle stability. It is found that CoS inhibits the side reactions and adsorbs polysulfides. As a result, the modified FeS2 shows a higher discharge capacity of 577 mA⋅h⋅g−1 (919 W⋅h⋅kg−1) after 60 cycles than 484 mA⋅h⋅g−1 (778 W⋅h⋅kg−1) of bare pyrite FeS2. This efficient strategy provides a valuable step toward the realization of high cycling stability FeS2 cathode materials for secondary lithium-ion batteries and enriches the basic understanding of the influence of FeS2 interfacial stability on its electrochemical performances.
Proton-halo breakup dynamics for the breakup threshold in the ε
0 → 0 limit
Authors: Mukeru B.
Published: February 2021

Proton-halo breakup behavior in the

limit (where

is the ground-state binding energy) is studied around the Coulomb barrier in the

reaction for the first time. For practical purposes, apart from the experimental

binding energy of 137 keV, three more arbitrarily chosen values (1, 0.1, 0.01 keV) are considered. It is first shown that the Coulomb barrier between the core and the proton prevents the

system from reaching the state of an open proton-halo system, which, among other factors, would require the ground-state wave function to extend to infinity in the asymptotic region, as

. The elastic scattering cross section, which depends on the density of the ground-state wave function, is found to have a negligible dependence on the binding energy in this limit. The total, Coulomb and nuclear breakup cross sections are all reported to increase significantly from

to 1.0 keV, and converge to their maximum values as

. This increase is mainly understood as coming from a longer tail of the ground-state wave function for

keV, compared to that for

keV. It is also found that the effect of the continuum-continuum couplings is to slightly delay the convergence of the breakup cross section. The analysis of the reaction cross section indicates a convergence of all the breakup observables as

. These results provide a better sense of the dependence of the breakup process on the breakup threshold.
Text Mining Analysis on Users’ Reviews for News Aggregator Toutiao
Authors: Li Jia , Wang Bifeng , Ni Alexandra Jingsi , Liu Qian
Published: February 2021

This paper intent to improve consumer communication by text mining analysis with users’ reviews. The news aggregator we focus on is: Toutiao, known as “today’s headlines” in Chinese. It is the top news aggregator application run by Bytedance company in China. It utilizes AI algorithms to provide numerous news feed for its users. As new technologies are shaping the business strategy studies as well as online communication analysis, it requires innovative and effective analyses of unconventional data, such as the 12,290 online reviews on Toutiao we collected from Apple’s App Store. Through the LDA topic modelling and sentiment analysis, our research has identified three major negative complains the consumers have regarding Toutiao application, namely: too many unsolicited advertisements, contents (vulgar content, time consuming video, privacy and copyrights infringement issue) and incompatibility with the latest Apple digital devices.
Study on HPLC Fingerprint of Atractylodes macrocephala and Atractylodes macrocephala dispensing granules
Authors: Lv Lijuan , Wang Xiangpei , Zhong Ke , kong Juan , Zhang Lingling , Yang Xiaosong , Zhang Yanyan , Wu Hongmei
Published: February 2021

Atractylodes macrocephala as a commonly used Chinese medicinal materials, its average annual demand is about 7000 tons. Therefore, it is necessary to develop and utilize Atractylodes macrocephala. Atractylodes macrocephala dispensing granules are widely favored by patients because of its accuracy and convenience in prescription formulation, but its quality control needs to be improved. High performance liquid chromatography (HPLC) can be used to separate the components of traditional Chinese medicine dispensing granules, and significantly improve the accuracy of measuring of effective component. Based on this, HPLC fingerprints of Atractylodis Macrocephalae and dispensing granules were established in this study. Taking the characteristic spectrum as the control, and evaluating the correlation of the medicinal materials and the formula granules. Analysis showed that Atractylodes macrocephala and formula granules showed 7 common characteristic peaks, presenting a good correlation. It reflected the overall appearance of multi-component of Atractylodes macrocephala and formula granules, and provided reference for quality control of Atractylodes macrocephala dispensing granules.
Research on Computer Network Security Emergency Response Systematization
Authors: Yang Xue , Zhu Ai’nan
Published: February 2021

with the acceleration of information process, computer information system and network has become an important social infrastructure. Based on the study of the basic theory, technology and application of computer network security emergency response, this paper focuses on the relevant strategies to guide the establishment of effective computer network security emergency response mechanism, analyzes the strategy composition, function object and action process of the system framework, and designs the framework of computer network security emergency response strategy system.
Retraction: 3D printed cellulose-based high-efficiency oil-water separation mesh (IOP Conf. Ser.: Earth Environ. Sci.
514 022088)
Authors: Zhang Xinqi , Wu Yifei , Gao Yuan
Published: February 2021

This article has been retracted by IOP Publishing at the request of the authors, who have identified errors in both the measurements and treatment processes of the mesh samples. These errors suggest the results and conclusions presented in the article may not be reliable. IOP Publishing has investigated in accordance with the Committee for Publication Ethics (COPE) guidelines and it was agreed the article should be retracted. The authors apologise to the readers, conference organisers and IOP Publishing for these errors.

Retraction published: 25 February 2021
Performance evaluation of a major thermal power plant in Nigeria
Authors: Babatunde Damilola E. , Anozie Ambrose N. , Omoleye James A. , Odejobi Oludare J.
Published: February 2021

Electric power is the bedrock of sustainable development in modern society. The demand for its adequate and reliable supply at a very competitive price is continuously increasing with population increase and the industrial revolution. A significant limitation to meeting this demand, is the inefficient operation of several of the existing power plants, resulting in their inability to generate electricity equivalent to their installed capacity. In this study, the exergy based performance evaluation of a major power plant in Nigeria was conducted to identify opportunities for thermodynamic improvement. Historical data of the plant was fed into HYSYS 8.8 to simulate its operations and obtain necessary thermodynamic data for assessing its performance. With the aid of codes embedded in HYSYS and the use of Ms Excel, the synthesized plant’s thermodynamics data was used for its performance evaluation. Components-wise evaluation revealed that apart from the turbines, exergy efficiencies were lower than energy efficiencies. The overall energy efficiency of the plant was found to be 33.19% while the corresponding exergy efficiency was 31.94%. The boiler was identified as the unit with the highest irreversibility and most significant contributor to overall plant’s inefficiency. It is posited that adequate knowledge of the effect of changes in operating parameters and load variation on performances will be handy in addressing inefficiencies in the boiler and other components of the plant.
Investigation of groundwater contamination from leachate migration: a case study of Bowen University dumpsite, Nigeria
Authors: Ajani O. O. , Adagunodo T. A. , Adeniji A. A. , Fashae B. , Omeje M. , Adewoyin O. O.
Published: February 2021

A microstudy of soil physical properties in combination with geoelectric delineation were adopted for the evaluation of groundwater contamination prospect from leachate migration at Bowen University dumpsite location. Samples of soil were collected from five different locations, with five locations within the dumpsite and one control sample which is 200 m far away from the dumpsite locations. A core sampler which is attached to the soil auger is used to obtain each sample within 60 cm depth. Each sample is collected into a sample bag and properly labeled for laboratory analysis. Schlumberger electrode configuration was employed for the survey spread to delineate total of four (4) Vertical electrical sounding (VES) points with electrode spacing varying 60 to 100 m. This was done to obtain resistivity, thickness and depth within the dumpsite location. The results of the average value of the soil properties between the control and the dumpsite are compared such that the soil properties for control site reveal a bulk density (BD) of 1.45 g/cm3, particle density (PD) of 2.63 g/cm3 and porosity (PO) of 44.90%, respectively. Whereas, the mean soil properties of the dumpsite show that BD is 1.35 g/cm3, PD is 2.93 g/cm3, and PO is 54.07%, respectively. This signifies that the control location has high BD, low PD and low PO, while the dumpsite reveals an inverse of the control results. Also, the results from the interpreted VES data reveal the prospect of migration of contaminants from the topsoil to the alluvium, which could further percolate to the aquifer with time. It could be concluded that groundwater contamination is feasible within the study area, since an alluvium and porous soils could permit leachate migration to the aquifer.
Geochemical characteristics and genesis of crude oils with complex physical properties in the eastern part of the southern gentle slope of Dongying Sag
Authors: Liu Ge , Niu Zicheng , Wang Xiuhong , Liu Haining , Wang Ru , Wang Juan
Published: February 2021

The crude oil in the eastern part of the southern gentle slope of Dongying Sag has complex physical properties, and various crude oils with different properties such as heavy oil, high sulfur oil, and high wax oil have developed. The complexity of the physical properties reflects the influence of the source rock properties, crude oil migration process, and secondary alteration after accumulation on crude oil characteristics. Through systematic analysis of geochemical data, the formation mechanism of crude oil with these special physical properties has been clarified. The result of hydrocarbon generation at an early stage from source rocks rich in high-sulfur kerogen deposited in a euxinic waterbody is the cause of high-sulfur crude oil with low maturity in Wangjiagang oil field. While the shallow reservoir burial depth and the resulting biodegradation is the mechanism of the formation of high-sulfur crude oil in Le’an oil field with higher maturity. Biodegradation is the main mechanism of the formation of heavy oil, and the recharge of hydrocarbons into the degraded crude oil reservoirs leads to the complication of crude oil density. Both the hydrocarbon generation of organic matter rich in terrestrial higher plants and phase-controlled fractionation during hydrocarbon migration lead to the generation of high wax crude oil.
Gas Slug Compound Flooding in Low and Ultra-low Permeability Layer
Authors: Chen Taoping , Sun Wen , Bi Jiaqi , Zhao Bin , He Ru
Published: February 2021

In order to improve the recovery of gas slug compound flooding in low permeability and ultra-low permeability reservoirs, two methods of the carbon dioxide-nitrogen and the rich gas-nitrogen compound flooding are studied. The results show that in low permeability and ultra-low permeability reservoirs, the use of a single injection of a reasonable pre-slug(carbon dioxide or rich gas) + subsequent nitrogen slug compound flooding can reduce the size of the pre-slug, give full play to the advantages of both the pre-slug and nitrogen, and obtain a better flooding efficiency. Under the same conditions, the recovery of the ultra-low permeability cores used in this experiment is 7.6% higher than the recovery of the low permeability cores on average. However, since the reasonable size of the rich gas pre-slug is 0.6 PV, twice as much as the reasonable size of the carbon dioxide pre-slug, and the price of unit volume of the rich gas slug is 1.82 times as much as the price of the carbon dioxide slug under the condition of injection, the final input-output ratio of the carbon dioxide-nitrogen compound flooding is 2.0∼2.69 times as much as that of the rich gas-nitrogen compound flooding.
Establishment of free surface related multiple migration method based on PSPI theory
Authors: Zou Jiaqi
Published: February 2021

Seismic exploration will be affected in many ways, leading to the phenomenon of missing seismic data. Conventional imaging cannot accurately reflect the structure of underground media. This paper is based on the data to data migration which purpose of this method is used to compensate for the missing seismic data. The illumination of the underground media is reduced by rarefying the shot gathers. The seismic data containing primaries and free-surface related multiples are employed in upward and downward extrapolation simultaneously. And the field data has been transformed into frequency domain. Finally, using cross-correlation imaging conditions, the shallow imaging effect obtained is consistent with conventional imaging, and the deep imaging can provide more abundant imaging information. This method has a high imaging accuracy and does not require multiples prediction processing, which greatly reduces the operation process and avoids the possible errors of multiples prediction. Meanwhile, it uses multiples imaging to enhance the processing capacity of underground structures and obtain more structural information. In the case of missing seismic data, the numerical simulation test shows that the data to data migration imaging method can play a key role in the imaging results.
Research on Multi-scale Segmentation of Remote Sensing Images of Typical Feature in Rare Earth Mining Area
Authors: Zhiqiang Liu , Peihong Li , Yimin Yuan
Published: February 2021

Remote sensing image information extraction is very important for mine surface monitoring. And Image segmentation is the key technology for remote sensing image information extraction. In this paper, taking the GF-1 image data of a rare earth mine in southern Jiangxi as an example, using the scale comparison method combined with ESP tools to determine the optimal segmentation scale of the target feature quickly, and evaluate the classification results of mine images. The results show that the accuracy can be improved when compared with the traditional single-scale segmentation, and it can provide a new solution for the extraction of remote sensing image information from the mine surface.
Effect of NaOH Concentration in Alkaline Treatment Process for Producing Nano Crystal Cellulose-Based Biosorbent for Methylene Blue
Authors: Mustikaningrum Mega , Cahyono Rochim Bakti , Yuliansyah Ahmad T.
Published: February 2021

The development of textile industry in Indonesia has been increasing rapidly. The vast and continuous development of the textile industry results in an evitable increase of wastewater. One of the wastewater ingredients that difficult to be treated is dye. Dye is a pollutant with complex aromatic structure that is difficult to degrade. There are many dyes could be used, however, methylene blue is mostly used. To treat MB, several treatment methods are available. Among the methods, adsorption has been widely applied, due to its simplicity and effectiveness. In this research, nano crystal cellulose (NCC), which has a large surface area dan better mechanical properties, was prepared from the oil palm trunk and it was proposed to adsorb the methylene blue. Briefly, the process of making NCC as a biosorbent consists of the raw material pretreatment, alkaline treatment, bleaching, hydrolysis, and sonication steps. Alkaline treatment plays an important role for extracting hemicellulose, lignin and other extractive substances, so that NCC is expected to have high cellulose purity. The alkaline treatment was conducted by extraction methode using NaOH at 80 °C for 2 hours. The result showed that the percent of removal of hemicellulose dan lignin were 50.0, 55.6, and 51.73 % for NaOH concentration of 3, 4, and 5 % (w/v) respectively. This result was also supported by the result of FTIR spectra analysis on each corresponding sample. Based on these data, it can be confirmed that the optimum NaOH concentration for alkaline treatment of oil palm trunk is 4 % (w/v). Furthermore, adsorption test of NCC using methylene blue solution gave percent removal of methylene blue in the range of 69.46-72.51%.
Prediction of continuous adsorption performance of cellulose acetate butyrate/poly(L-lactid acid) composite beads for dye removal
Authors: Rofaudin Muhammad Naufal Fatkhi , Qoidani Azizul Pradna , Puspitasari Desy , Arnanda Helmi Kurnia , Ni’mah Hikmatun , Roesyadi Achmad , Kurniawansyah Firman , Ningrum Eva Oktavia
Published: February 2021

Continuous adsorption of methylene blue (MB) from aqueous solution was studied by using cellulose acetate butyrate (CAB) and poly(L-lactic acid) (PLLA) composite beads. Various parameters such as PLLA composition (0 wt.% and 30 wt.%) and flowrate (7, 13, 23 ml/min) were applied in this experiment. Three different kinetic models, such as Adam-Bohart, Thomas, and Yoon Nelson were applied to the experimental data to analyze the column performance and predict the breakthrough curve of MB adsorption onto adsorbent beads. The value of adsorption capacity increased with the increase of flowrate. The highest maximum capacity was reached by adsorbent of pure CAB (0 wt.% of PLLA) at flowrate of 23 mL/min. Statistical methods such as Sigma Squared Error (SSE), Sigma Absolute Error (SAE) and percentage error were utilized to evaluate the obtained prediction data with the experimental data and to find out the fitted kinetic model for this continuous adsorption. The prediction results indicated that Thomas and Yoon-Nelson models fit well to the experimental data based on the correlation coefficient and error analysis.
Improvement of PES Nanocomposit Membrane Performance Through UV and ZNO Concentration for Refinery Waste Water Purification
Authors: Hidayah Malikhatul , Kusworo Tutuk Djoko , Susanto Heru
Published: February 2021

Wastewater is generated from the process of purifying large amounts of water. Refinery wastewater can be purified with PES-ZnO nanocomposite membrane technology. Membrane modification to reduce membrane fouling. Therefore, it is important to provide a low-fouling (non-fouling) membrane. However, currently the formation of fouling and clean water quality standards has not been met. Therefore, researchers studied the use of materials that can overcome membrane impurities and an efficient clean water production system. In addition, one alternative to improve membrane performance is to use nanocomposites (ZnO). The membrane was made with a concentration of PES 18 wt% and ZnO 0.5; 1; 1.5% by weight. with the influence of UV light on the membrane for 1,5,10 minutes at a temperature of 180°C. SEM analysis was used to show that the PES membrane has larger pores. Angle contact analysis was also carried out to show ZnO nanoparticles can improve the hydrophilic properties of membranes. For this reason, a TDS analysis is carried out, namely Cl−, S2
− and turbidity. From this analysis shows significant results with membrane performance, modification with UV radiation and the addition of PVA / PEG have interrelated effects to improve membrane performance.
The Effect of Natural Rubber Composite using Monomer Diene Ethylene Propylene on Mechanical Properties in Tubes Collar
Authors: Nasruddin  , Agustini Sri
Published: February 2021

Tube collar is a part of quad cane type patient sticks. Its function is to adjust the height of the stick when used. The materials widely used to make tube collars are plastic. This study aims to study the mechanical properties of tube collars made from natural rubber composite materials with ethylene propylene diene monomers. Natural rubber and ethylene propylene diene monomers vary in ratios (70: 30; 80: 20; 90: 10; and 100: 0) phr. The activator, coactivator, softener, filler, accelerator, antioxidant and vulcanizing agent are conditioned. The experiments were carried out through the process of mastication, compounding and vulcanization. Vulcanization is carried out at 135 °C for 8 minutes. Curing characteristic test results with a rheometer at a temperature of 150 °C showed ΔS maximum of 9.70 kg/cm, maturation time (t90) 4.59 min, and scorch time (ts2) 0.02 min. The results of testing the mechanical properties of vulcanized rubber showed that the difference in the ratio of natural rubber with ethylene propylene diene monomer affects the mechanical properties of vulcanized rubber.
Operational parameters of small-scale anaerobic digester for rural areas in Indonesia to support sustainable development goals (SDGs)
Authors: Habibie Muhammad Haekal , Louhenapessy Bendjamin Benny , Aristiawan Yosi , Yopi  , Lenggono Agung
Published: February 2021

Small-scale anaerobic digester (AD) has been widely used by society in rural areas of Indonesia to produce biogas. The use of biogas as a renewable energy source is in line with the Sustainable Development Goals (SDGs) program, especially regarding Affordable and Clean Energy. In rural areas, biogas produced by small-scale AD is needed to produce fuel for cooking, produce the fertilizer for agriculture activities and as solution to environmental problems related to livestock manure disposal. This paper discusses the operational parameters of small-scale AD in Indonesia. These operational parameters are important to establish for standardizing the quality requirements of small-scale AD installed in rural areas of Indonesia. The research was conducted by review the literature from several previous studies that related to similar topic and discussed with biogas experts and practitioners to determine operational parameters for small-scale AD. The results of this research are obtaining the hydraulic retention time, pH value, temperature, and loading rate as operational parameters with respective range values. Information on the operational parameters of small-scale AD can be used as input for developing the Indonesian National Standards for the quality requirements of low-pressure biogas that is in line with this research.
Phytochemical Compound of Garlic (Allium sativum) as an Antibacterial to Staphylococcus aureus Growth
Authors: Yunus F T , Suwondo A , Martini
Published: February 2021

Antibiotics use to bacterial infection control causes many side effects from mild to severe. In addition to severe side effects such as shock, antibiotics can cause resistance. Therefore we need an alternative medicine that functions as an antimicrobial derived from plants. Garlic has minimal side effects and can be consumed daily. This study aims to know the phytochemical content and antibacterial effectiveness of Garlic in inhibiting the growth of Staphylococcus aureus. This study used a pure experimental design with randomized posttest. The control group design are giving fresh garlic, garlic extract and garlic powder to bacterial culture media through the dilution method. The phytochemical content in 3 types of preparations are tested using Flavonoid, GCMS, FTIR and HPLC Tests. Data analysis uses Kruskal Wallis test while the Mann Whitney test is used to measure the concentration significance. Out of the 3 types of preparations the one that has more phytochemical compound through the GCMS test is fresh garlic (18 active ingredients) compared to garlic extracts (14 active ingredients) and garlic powders (13 active ingredients). Fresh garlic with a concentration of 50% has more antibacterial activity compared to garlic extracts and garlic powder. When compared with positive control (amoxcilin), fresh garlic has not been able to provide effective results in inhibiting Staphylococcus aureus growth. Phytochemical compound in fresh garlic are more numerous compared to the 2 other preparations and fresh garlic has not been able to provide effective results in inhibiting the Staphylococcus aureus.
Hydrolysis optimization of tobacco stems with ultrasonic-assisted hydrolysis method
Authors: Palupi B , Fachri B A , Fadilah S N , Telussa M M
Published: February 2021

The development of biofuel in Indonesia is rife to reduce the consumption of fuel oil. Bioethanol has advantages compared to fuel oil, such as lower carbon monoxide emissions making it environmentally friendly. Besides that, from being used as a fuel, bioethanol is used as raw material for alcohol, pharmaceutical, and cosmetics derivatives. Biomass is one of the bioethanol’s raw materials available in Indonesia, one of which is tobacco stem. In this research, the tobacco stem hydrolysis process carried out using the ultrasonic-assisted hydrolysis method. The variable of the hydrolysis process is H2SO4 solution, particle size, and time. The data analysis used Design Expert with a Central Composite Design method. The purpose of this research was to determine the optimum of particle size, H2SO4 concentration, and the time in the hydrolysis process of tobacco stems with the ultrasonic-assisted hydrolysis method. The optimum resulting in reducing sugar of ultrasonic-assisted hydrolysis is 6.921 µg/µL.
Intrinsic Viscosity and Reducing Sugar Profiles of Degraded Glucomannan using Cellulase
Authors: Wardhani D H , Cahyono H , Ulya H N , Kumoro A C , Aryanti N
Published: February 2021

High viscosity of glucomannan has been limit its applications. Hence, the long polysaccharide glucomannan which consists of β-linked glucoses and mannoses needs to be degraded to broaden its utilizations. Enzymatic degradation is known as a safe method for food material treatment. Specifically targeting at 1,4-β-D-glycosidic linkages, cellulase has potential as a cleavage for glucomannan. This work aimed to study performance of cellulase in degrading glucomannan. The change in intrinsic viscosity and reducing sugar during degradation was observed. Degradation of 1% glucomannan by 20 ppm cellulase for 300 min decreased the viscosity from 12,420 to 353 cps. This degradation was also confirmed by the increase of reducing sugar amount from 1,238.57 to 8,510.00 µg/ml. This work showed the success of glucomannan degradation by cellulase.
Modification of morphology and optic properties of TiO2 as photoreforming catalyst for H2 production from biomass derivatives: a review
Authors: Anggoro Didi Dwi , Udaibah Wirda , Prasetyaningrum Aji
Published: February 2021

Hydrogen is one of the solutions to overcome the problems facing the world today, the energy crisis and a decrease in environmental quality. Its has high chemical energy per mass and its combustion only results water and does not emit greenhouse gas. Nevertheless, hydrogen doesn’t exist in nature as H2form. Hence, it requires a sustainable production methods. Biomass (lignocellulose) and its derivatives can be renewable feedstock for producing biohydrogen via clean process i.e photoreforming. One of the keys to the success of this technology is the development of suitable photocatalysts that are able to maximize light harvesting from solar and hydrogen production. TiO2is the establish material because of its high photocatalytic activity, not toxic, biologically and chemically inert. Its main drawback are its band gap value (ca. 3.2 eV) and fast recombination of electron–hole that detrimental to the photocatalytic activity. The alternative to overcome these problems are modification of TiO2by nanotubes structure and doping of metals. In this paper, we will review about TiO2nanotubes and its preparation strategies. Then, we will describe role of metal to enhance photocatalytic performance of TiO2nanotubes. The Impact of both modification to morphology and optic properties and enhancement of H2production from biomass and its derivatives will be study. The future direction for photoreforming of biomass and its derivatives were also suggested. Modification of Titania by nanotube structure and doping it with bi-metal consist of transition metal like Ni-Cu opens up opportunities and challenges for other researchers.