bluuebunny/crossref_metadata_2025 huggingface dataset:
Unpicking the interplay of turbulence, diffusion, and thermophysics in cryogenic jets at supercritical pressures
Authors: Madana Gopal Jaya Vignesh , Tretola Giovanni , Morgan Robert , Sercey Guillaume de , Lamanna Grazia , Vogiatzaki Konstantina
Published: July 2021

Cryogenic supercritical fluids represent an intriguing category of fluids that combine mechanical and thermophysical properties of both ultralow temperature conditions and phenomena taking place well above the critical point. Recent research has demonstrated that it is a common misconception to consider the supercritical state as one homogeneous state. Instead, these fluids consist of two to four liquid and gas like phases, each with their own unique characteristics. In our work, we investigate numerically single-specie cryogenic fluid jets—initially at subcritical temperatures—which are injected into a supercritical environment (both the pressure and temperature exceed the thermodynamic critical state). For the investigation, a new solver, namely, “CoolFoam,” has been developed, which is designed for compressible non-isothermal two-fluid simulations where diffusive transport of heat and/or mass is accounted for. Real fluid thermodynamics are modeled using a polynomial fitting approach developed in our previous work. We introduce also a new phase characterization framework based on the association of phases with specific temperature ranges (rather than using a single line like the Widom line), which allowed us to better identify the similarity effects between the various conditions. We analyze the inter-dependence of the underlying phenomena: density gradient and diffusive mass transport [molecular and thermo(Soret)-diffusion] and turbulence. We also compared supercritical N2 with subcritical liquid and gas jets to highlight potential differences with respect to how these jets behave. We find that the jet dynamics are largely dictated by the thermodynamic transition of the injected fluid and the associated variation in thermophysical properties.
Correlating structural rules with electronic properties of ligand-protected alloy nanoclusters
Authors: Cowan Michael J. , Nagarajan Anantha Venkataraman , Mpourmpakis Giannis
Published: July 2021

Thiolate protected gold nanoclusters (TPNCs) are a unique class of nanomaterials finding applications in various fields, such as biomedicine, optics, and catalysis. The atomic precision of their structure, characterized through single crystal x-ray diffraction, enables the accurate investigation of their physicochemical properties through electronic structure calculations. Recent experimental efforts have led to the successful heterometal doping of TPNCs, potentially unlocking a large domain of bimetallic TPNCs for targeted applications. However, how TPNC size, bimetallic composition, and location of dopants influence electronic structure is unknown. To this end, we introduce novel structure–property relationships (SPRs) that predict electronic properties such as ionization potential (IP) and electron affinity (EA) of AgAu TPNCs based on physically relevant descriptors. The models are constructed by first generating a hypothetical AgAu TPNC dataset of 368 structures with sizes varying from 36 to 279 metal atoms. Using our dataset calculated with density functional theory (DFT), we employed systematic analyses to unravel size, composition, and, importantly, core–shell effects on TPNC EA and IP behavior. We develop generalized SPRs that are able to predict electronic properties across the AgAu TPNC materials space. The models leverage the same three fundamental descriptors (i.e., size, composition, and core–shell makeup) that do not require DFT calculations and rely only on simple atom counting, opening avenues for high throughput bimetallic TPNC screening for targeted applications. This work is a first step toward finely controlling TPNC electronic properties through heterometal doping using high throughput computational means.
The quasi-algebraic ring of conditions of
Authors: Kazarnovskii B. Ya.
Published: July 2021

An exponential sum is a linear combination of characters of the additive group of

. We regard

as an analogue of the torus

, exponential sums as analogues of Laurent polynomials, and exponential analytic sets (

-sets), that is, the sets of common zeros of finite systems of exponential sums, as analogues of algebraic subvarieties of the torus. Using these analogies, we define the intersection number of

-sets and apply the De Concini–Procesi algorithm to construct the ring of conditions of the corresponding intersection theory. To construct the intersection number and the ring of conditions, we associate an algebraic subvariety of a multidimensional complex torus with every

-set and use the methods of tropical geometry. By computing the intersection number of the divisors of arbitrary exponential sums

, we arrive at a formula for the density of the

-set of common zeros of the perturbed system

, where the perturbation

belongs to a set of relatively full measure in

. This formula is analogous to the formula for the number of common zeros of Laurent polynomials.
Birational geometry of varieties fibred into complete intersections of codimension two
Authors: Pukhlikov A. V.
Published: July 2021

In this paper we prove the birational superrigidity of Fano–Mori fibre spacesall of whose fibres are complete intersections of typein the projective spacesatisfying certain conditions of general position, under the assumption that the fibrationis sufficiently twisted over the base (in particular, under the assumption that the-condition holds). The condition of general position for every fibre guarantees that the global log canonical threshold is equal to one. This condition also bounds the dimension of the baseby a constant depending only on the dimensionof the fibre (this constant grows likeas). The fibres and the varietymay have quadratic and bi-quadratic singularities whose rank is bounded below.
Sulfur amino acid requirements for pullets in growth and pre-laying trials
Authors: Silva E. P. , Sakomura N. K. , Dorigam J. C. P. , Lima M. B. , Malheiros E. B. , Fernandes J. B. K.
Published: July 2021

Context To obtain a good performance of the hens in the laying phase, adequate nutrition in the growth and pre-laying phase is necessary, especially for meeting amino acid requirements that are related to development of reproductive organs (ovary and oviduct). Aims The objective of the present study was to predict the requirements for methionine (Met) plus cystine (Cys) from the growth of the body, feathers and reproductive organs of laying hens. Methods The model estimates Met+Cys requirements as the relationship between the deposition of Met+Cys into three compartments (body, feathers, and reproductive organs) and their utilisation efficiency. The efficiency of utilisation was determined by a linear regression between Met+Cys deposition and intake for pullets aged 14–28, 56–70 and 98–112 days. Protein weight and deposition in the body and feathers were determined by the comparative slaughter method. The Gompertz function was used to model body, feathers, ovary, oviduct and liver weight against age. Key results Our results showed that the inclusion of parameters descriptive of the growth of reproductive organs and the correction for feather losses in the model enabled Met+Cys requirements for growth in pre-laying trials to be predicted with a greater precision. Conclusions The model developed in this study for determining the Met+Cys requirements for Dekalb White pullets could be extended, provided the necessary adjustments are made, to other amino acids, strains and species. Implications Meeting Met+Cys requirements in the phase of maximum growth of the reproductive organs (weeks) contributes to the uniformity of the age when the pullets reach sexual maturity and, consequently, start the egg production.
Can community monitoring save the commons? Evidence on forest use and displacement
Authors: Eisenbarth Sabrina , Graham Louis , Rigterink Anouk S.
Published: July 2021

Significance

To halt deforestation, communities are increasingly being given the authority to manage their own forests. Although standard economic theory predicts that community management leads to overexploitation, field studies have reported that communities can sustainably manage their forests if specific conditions are present. One condition that is correlated with successful common pool forest management is community-led monitoring of the forest. However, whether such monitoring causes improvements in forest conditions is unclear. Using a randomized controlled trial, we provide causal evidence about the impact of community-led monitoring on forest use. Unlike prior studies, we estimate the effects of monitoring on both monitored and unmonitored forests. The results suggest that monitoring may simply displace forest loss to unmonitored forests, rather than reduce it.
DNA barcoding identifies cryptic animal tool materials
Authors: Steele Matthew P. , Neaves Linda E. , Klump Barbara C. , St Clair James J. H. , Fernandes Joana R. S. M. , Hequet Vanessa , Shaw Phil , Hollingsworth Peter M. , Rutz Christian
Published: July 2021

Some animals fashion tools or constructions out of plant materials to aid foraging, reproduction, self-maintenance, or protection. Their choice of raw materials can affect the structure and properties of the resulting artifacts, with considerable fitness consequences. Documenting animals’ material preferences is challenging, however, as manufacture behavior is often difficult to observe directly, and materials may be processed so heavily that they lack identifying features. Here, we use DNA barcoding to identify, from just a few recovered tool specimens, the plant species New Caledonian crows (Corvus moneduloides) use for crafting elaborate hooked stick tools in one of our long-term study populations. The method succeeded where extensive fieldwork using an array of conventional approaches—including targeted observations, camera traps, radio-tracking, bird-mounted video cameras, and behavioral experiments with wild and temporarily captive subjects—had failed. We believe that DNA barcoding will prove useful for investigating many other tool and construction behaviors, helping to unlock significant research potential across a wide range of study systems.
Role of Dot1L and H3K79 methylation in regulating somatic hypermutation of immunoglobulin genes
Authors: Duan Zhi , Baughn Linda B. , Wang Xiaohua , Zhang Yongwei , Gupta Varun , MacCarthy Thomas , Scharff Matthew D. , Yu Guojun
Published: July 2021

Significance

The somatic hypermutation of immunoglobulin (Ig) genes is usually required to make antibodies that protect us from foreign and toxic substances. This mutational process is mediated by activation-induced deaminase (AID) and is targeted to the variable (V) part of the Ig genes that encode the antigen-binding site of antibody molecules, leading to higher affinity and more effective antibodies. AID acts on single-stranded DNA that is created during the transcription of the V region. Here, we show that multiple factors that are involved in the release, from pausing to elongation of transcription, contribute to the hypermutation process, supporting the likelihood that transcriptional pausing and elongation make V region single-stranded DNA available to AID-induced mutations.
Ideology, positionality and war
Authors: Martin Anne , Gómez-Amich María
Published: July 2021

The objective of this article is to explore issues of ideology in situations of interpreting in conflict zones. Research into interpreting in conflict zones is quite recent and has shed light on interesting aspects. Ideology is clearly present in war situations and may condition the interpreter’s role. This article seeks to identify examples of power relations and ideology by drawing on the narratives of five local interpreters who worked with Spanish troops stationed in Afghanistan as part of the International Security Assistance Force between 2003 and 2015. The narratives were collected using a semi-structured interview technique. The findings indicate that ideology is reflected in the interpreters’ perception of their own role as agents working for the good of their country against a common enemy, even though they were potentially perceived by both sides in the conflict as possible traitors. The traditional narrative of the interpreter as an invisible and impartial facilitator of communication would not appear to be applicable in this context.
Channel parameters-independent multi-hop nondestructive teleportation
Authors: Li Hua-Yang , Wei Yu-Zhen , Ding Yi , Jiang Min
Published: July 2021

A multi-hop nondestructive teleportation scheme independent of channel parameters based on Bell pairs is presented, where the coefficients of the quantum channel are unknown to all the communication nodes. With Bell measurement and channel matching technology the unknown channel parameters can be eliminated probabilistically with the help of the intermediate nodes. Then the source node Alice can teleport an unknown state to the remote destination node Bob. In our scheme the teleportation is generalized first to the scenario independent of channel parameters, which makes the requirement of quantum channel reduced. Our scheme still preserves the initial unknown state even if this teleportation fails. Moreover, performance analysis shows that our scheme has a higher communication efficiency.
Quality factor enhancement of plasmonic surface lattice resonance by using asymmetric periods
Authors: Shi Yunjie , Xiong Lei , Dong Yuming , Sun Degui , Li Guangyuan
Published: July 2021

We report that using asymmetric lattice periods can enhance the quality factor of plasmonic surface lattice resonances (SLRs) in two-dimensional array of metal-insulator-metalnanopillars in asymmetric dielectric environment. Simulation results show that by adopting appropriate asymmetric lattice periods, the SLR quality factor can be enhanced by 24\% compared with the scenario of symmetric periods. We find that the SLR quality factor is optimized when the resonance wavelength is closest to the Rayleigh cutoff wavelength. We also find that the SLRs effect is polarization sensitive in the proposed structure. We expect this work will advance the engineering of SLRs especially in asymmetric dielectric environments, and will promote their applications in sensing.
Ferromagnetic Heisenberg spin chain in a resonator
Authors: Cao Yusong , Cao Junpeng , Fan Heng
Published: July 2021

We investigate the properties of a generalized Rabi model by replacing the two-level atom in Rabi model with a ferromagnetic Heisenberg spin chain. We find that the dynamical behavior of the system can be divided into four categories. The energy spectrum of the ground state and some low excited states are obtained. When the magnons and the photon are in resonance, the model is exactly solvable and the rigorous solution is obtained. Near the resonance point where the detuning is small, the system is studied with the help of perturbation theory. This model has a spontaneously breaking of parity symmetry, suggesting the existence of a quantum phase transition. The critical exponent from the normal phase is computed.
Synthesis and Characterization of TiO2 Thin Film Based on Iron Sand of Lampung Province - Indonesia
Authors: Marjunus R. , Febriyanti N. , Stevani A. , Handayani Y.N. , Firdaus I. , Manurung P.
Published: July 2021

This study aims to make a thin layer of TiO2 based on ilmenite stored in iron sand of Lampung Province, Indonesia. The TiO2 powder, which was used to make the thin layer, was obtained from the extraction of iron sand using the leaching method with a purity of 60,7%. The preparation of TiO2 thin layers was carried out by the Chemical Bath Deposition (CBD) method with immersion time variations of 2, 3, 4, and 5 hours for samples A, B, C, and D respectively. Afterward, the samples were calcined at 500°C for 4 hours. The characterizations involved X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), X-Ray Fluorescence (XRF), and four-point probe to measure the resistivity of the film. The XRD results in samples A (immersion time 2 hours) and D (immersion time 5 hours) show that the amorphous phase still dominates even though the diffraction peaks indicate that the presence of crystals has started to grow at several angles of scattering. The identification results of the phase presence show that the thin layer of TiO2 at sample D is the brookite phase. The results of characterization using SEM show that the surface of the TiO2 thin layer forms a porous structure. The average thickness of the thin film at sample B based on SEM analysis is 1.9 μm. The electrical resistivity increased with an increasing immersion time.
The Effect of Deposition of MoSe2 Nanosheets on the Performance of a ZnO-based UV Detector
Authors: Larasati Dion Margaretha Chandrika , Fauzia Vivi , Imawan Cuk
Published: July 2021

ZnO is a promising candidate for ultraviolet (UV) detectors due to its wide bandgap, good transparency, non-toxicity, low cost, and simple preparation. However, the performance of ZnO is low because of its high recombination rate. One alternative solution is fabricating a heterostructure of ZnO with a transition metal dichalcogenide (TMD) compound. This study proposes the facile fabrication of ZnO nanorods decorated with MoSe2 nanosheets. MoSe2 nanosheets were synthesized using the liquid-phase exfoliation method and added to the surface of ZnO nanorods via spin coating. The photodetector performance was enhanced with the addition of MoSe2 nanosheets because the MoSe2 could trap the electrons of defect sites of ZnO; hence, it decreased the dark current and slightly increased the photocurrent. The responsivity increased from 1.03 to 1.25 A/W, the detectivity increased from 0.82 x 109 to 1.9 x 109 Jones, and the sensitivity increased from 1261% to 5701%.
Characterization and Classification of Purity of Limestone in Madura Island for Industrial Application
Authors: Munawaroh F , Muharrami L K , Triwikantoro  , Arifin Z
Published: July 2021

The characterization and classification of purity of limestone at Madura Island was investigated. Sampling was taken from nine quarries from different areas. The chemical analysis was carried out by X-ray fluorescence (XRF); the crystalline phase was characterized by X-ray diffraction (XRD). Analysis of purity classification based on XRF and XRD results according to British Geological Survey. Limestone has different purity, there are very high, medium, low and impure purity. The sample has a very high purity from Pamekasan (P.1) with CaO content of 99.06 wt% and 100% calcite. The samples are medium purity from Bangkalan (B.1, B.3), Pamekasan (P.2), Sumenep (S.1, and S.3) with CaO content of 91.61- 93.67 wt%. The samples are low purity from S.2 with CaO content 85.79 wt% and 100% dolomite. And the sample has impurities from P.3 and B.2 with CaO content 82.3 wt% and 84.7 wt%. Limestone with very high and medium purity which is processed into PCC can be applied in many industries as filler in rubber, paper making, plastic, paint, food, pharmaceutical, ceramic, adhesives, sealants, agriculture, and animal feed.
Effect of Aqueous Electrolyte to the Supercapacitor Electrode Performance Made from Sugar Palm Fronds Waste
Authors: Awitdrus  , Suwandi Decha Apriliany , Agustino  , Taer Erman , Farma Rakhmawati , Syahputra Romi Fadli
Published: July 2021

The effect of aqueous electrolyte to the supercapacitor electrode performance made from Sugar palm (Arenga pinnata) fronds waste has been successfully analyzed. The preparation of the activated carbon was used a combination of chemical and physical activation methods. The chemical activation was conducted using potassium hydroxide with 0.5 M of concentration and the physical activation using CO2gas. The electrochemical performance of the sugar palm fronds (SPFs) electrode was tested using the cyclic voltammetry method with two-electrode configuration. The 1.0 M H2SO4, 6.0 M KOH, and 0.5 M Na2SO4were used as aqueous electrolytic solutions in this study. The specific capacitance of the SPFs electrodes obtained are 130 F/g for 1.0 M H2SO4electrolyte, 110 F/g for 6.0 M KOH electrolyte, and 79 F/g for 0.5 M Na2SO4, respectively. In addition, the physical properties of the SPFs electrode were also analyzed. The physical parameter of the SPFs electrode indicated a shrinkage after the physical activation processes. Based on the XRD pattern, the SPFs electrode has a semicrystalline structure. The characteristic peaks of the SPFs electrode for the pre-carbonization and after physical activation based on the FTIR spectra show slightly different.
The Role of Temperature in the Hydrothermal Synthesis on the Structural and Morphological Properties of MoS2
Authors: Hasmin Hudya Fitra , Imawan Cuk , Fauzia Vivi
Published: July 2021

Molybdenum disulfide (MoS2) generally has two main phases: semiconducting 2H-MoS2, with trigonal prismatic geometry, and metallic 1T-MoS2, with octahedral geometry. However, the 1T-MoS2 phase is metastable, and improvements are still needed in the synthesis process. In this study, we synthesized MoS2 using a simple hydrothermal method at either 180°C or 200°C for 24 h, using sodium molybdate dihydrate (Na2MoO4.2H2O) and thiourea (NH2CSNH2) as the Mo and S precursors. The study found that synthesis at 180°C produces flower-like MoS2 microspheres with an average diameter of 10 µm and a 1T phase, while MoS2 produced at 200°C has irregular lumps with a size range of 1–10 µm in a 2H phase with slightly higher (002) d-spacing (6.78Å).
Thermomechanical properties of PEG-based composites with micro-quartz fillers
Authors: Fauziyah Nur Aini , Fajra Dewi Nora , Wulansari Lila Dina , Pratapa Suminar
Published: July 2021

Micro-quartz-reinforced - polyethylene glycol (PEG) composites were fabricated by a simple liquid method. This study reveals the thermomechanical properties of the PEG/quartz composites around its melting transition temperature. The quartz microparticles were prepared from natural silica sand collected from Tanah Laut Pelaihari, South Kalimantan, by magnetic separation, HCl immersion, and water cleaning. Then, quartz powders were heated in various temperatures, i.e., at 500, 1000, and 1200 °C where we found quartz particle sizes of 168, 217, and 249 nm, respectively. PEG/quartz composites with 10 wt% of these sizes were synthesized and a pure PEG sample was also prepared for comparison. The Fourier-transform infra-red spectroscopy (FTIR) and x-ray diffraction (XRD) data showed that there was no additional peak in composite patterns which verified the successful synthesis of the PEG/micro-quartz composites. Meanwhile, the dynamic mechanical analysis (DMA) data and analysis revealed that the maximum storage moduli (G’) and melting transition temperature (T

m
) exhibited by the composite with quartz heated at 500 °C, i.e., 610.78 MPa and 53.4 °C, respectively. This value is almost six times of that of pure PEG. In general, quartz particle size shifted the G’and T

m
to the higher values.
Modified structural properties in Nickel substituted Cobalt Ferrite nanoparticles
Authors: Dasi Y H K , Arilasita R , Riyatun  , Utari  , Purnama B
Published: July 2021

Modified structural properties of nickel content in NixCo1-xFe2O4 with x = 0,0.2 and x = 0.4 were studied. The co-precipitation method was performed for the whole sample. After annealing of 600°C for 4 hours, the nanoparticles samples evaluated their structural properties by using Fourier Transform Infra-Red (FTIR) and X-Ray Diffraction (XRD). The XRD pattern confirms that the whole samples have the crystalline structure of the face-centered cubic (fcc) inverse spinel. Furthermore, the lattice and crystallite size parameters change with the enhancement of the Ni-concentration. The FTIR spectrum showed two prominent absorption bands i.e. at around k of 400 cm−1 and 600 cm−1, where metals at tetrahedral and octahedral sites reflect intrinsic vibrations, respectively. Finally, the decrease of saturated magnetization M
S from 77.3 emu/g to 33.9 emu/g replacement of Co2+ cation with Ni2+.
Simulation of Hydrogenated Amorphous Silicon-based Solar Cell: Investigation of J-V Characteristic in Optimum Thickness
Authors: Purwandari Endhah , Mutma’inah Siti , Maulina Wenny , Arkundato Artoto , Rohman Lutfi , Syarifah Ratna Dewi
Published: July 2021

One of the factors that influence the current density-voltage (J-V) characteristics of solar cells is the thickness of the constituent material’s layers. Thus, when the solar cell is constructed using p/i/n junctions type, each layer thickness will contribute to the resulting electrical characteristics. In this research, a simulation of solar cell’s electric current density calculation based on amorphous hydrogenated silicon has been carried out. The simulation is conducted to determine the numerical solution of the two-dimensional semiconductor equation, which is the distribution of the number of electron charge carriers and holes in the simulated solar cell device. It was started by determining the optimum thickness producing the best performance from each layer. Material performance indicators are seen based on the Jsc and Voc values. The p layer thickness in the p/i/n junction was simulated with the variation (70-220)Å/5500Å/300Å. The active layer was manufactured with variations of 150Å/(4500-7500)Å/300Å. Finally, we have also simulated the J-V characteristic of a solar cell by thickness variation for the n layer in the p/i/n junction is 150Å/5500Å/(100-350)Å. The results obtained from each simulation process are then re-simulated in each layer’s optimum thickness combination. Through a series of simulated processes of each layer, the best results were obtained when solar cells based on hydrogenated amorphous silicon were made at a thickness of 190Å/7500Å/150Å, with Jsc and Voc of 5.33 A/m and 0.65 V, respectively.
The Analysis of Room Acoustic Parameters of Karaoke Rooms in Surabaya
Authors: Indrawati Susilo , Arinie Vina Dwi , Nuryaqin Anis , Prajitno Gontjang , Suyatno  , Yuwana Lila
Published: July 2021

This research is performed to evaluate the acoustic parameter and noise of several karaoke rooms in Surabaya. The type of rooms can be classified into small rooms and large rooms. All the measurements were conducted at 12:00 to 16:00 GMT+7:00. Based on the measurement results, noise criteria (NC) values range between 45 and 50. These values are quite high if compared to standard NC value, i.e., 25. This statement is in accordance with the low values of noise reduction (NR) of evaluated rooms: walls with glass accessories (12 – 16.5 dBA); door gap (8 – 13.9 dBA); wall (10 – 18 dBA); and door hinge (6.9 – 9 dBA) in the frequency of 1000 Hz. Therefore, the low values of NR lead to NC value exceeds the recommended value. According to the observation and the analysis, we obtain there are some rooms using special doors that are very well to absorb noise. However, those doors still have a drawback because they are equipped with glass which has a low value of NR. The addition of glass to the doors reduces NR value. Moreover, the ranges of reverberation time of small rooms and large rooms are 0.3 – 0.4 s and 0.6 – 0.7 s, respectively. This difference range is caused by the volume of rooms. In addition, the speakers of all rooms are the same, i.e., woofer speakers. It could be understood from the sound spectrum that has a range of 100 – 500 Hz. Lastly, all the analyzed rooms have a high value of noise. The measurement results 94 d
B
A of L

eq
and 104.3 d
B
A of L

max
. Regarding the health regulation, the sound that has those intensities is harmful to the human hearing.
Optimization of CO and CO2 Gas Reduction System Based on Electrostatic Precipitator (ESP)
Authors: Anggoro Diky , Rifki Hidayat M , Putra Ryan Permana , Wiranata Rozaq A , Fatimah Iim
Published: July 2021

Various attempts have been made to reduce pollutants from being released into the environment in large numbers, one of the most recent research using an electrostatic precipitator (ESP). By utilizing ionization in the Electrostatic Precipitator (ESP), pollutants can be reduced to a minimum amount at a certain voltage and air flow velocity, and for this research, reduction measurements have been carried out. Measurement of reduction by flowing the pollutant smoke sample that is accommodated in the inlet tube to the Electrostatic Precipitator (ESP) and the smoke sample that comes out of the Electrostatic Precipitator (ESP) will be accommodated in the outlet container. The levels of CO and CO2 in the two tubes before and after being flowed were compared to get a reduction value So that the highest measurement is obtained at the highest CO reduction of 80.72% reduction when the voltage is 25 kV, and the gas discharge is 2 L/minute. Meanwhile, the highest CO2 reduction obtained in the type of ESP plate was parallel with reduction of 79.09% when the voltage was 25 kV, and the gas discharge was 2 L/minute. The ability of ESP reduction is directly proportional to the mains voltage. The ability of ESP reduction is inversely proportional to gas discharge.
Detection of temperature change using optical fiber splitter 1×2 by stripping the cladding at the end of the optical fiber
Authors: Sudarsono  , Salsabila Nisrina Kamilia , Anggoro Diky , Yudoyono Gatut
Published: July 2021

Measurement of temperature changes is very important in the fields of physics, chemistry, biology, and industrial applications. The development of temperature sensors also continues to be developed both on an electric and optical basis. In this research, the detection of temperature changes based on optics is successfully detected using optical fiber splitter 1 × 2 by utilizing a plane mirror as a reflector and by stripping the cladding at the end optical fiber. Measurement of the power transmission of reflection to changes in temperature using an optical spectrum analyzer (OSA) at wavelength 1550 nm. This research showed that a linear relationship between transmission power and temperature increase from 40°C to 200°C on the sensor probe with a stripping length of 35 mm.
S-wave velocity (Vs) model uncertainty derived from multiple equations of Vs and number of blows (N) at Institut Teknologi Sepuluh Nopember, Surabaya, Indonesia
Authors: Saifuddin  , Sungkono  , Widodo Amien
Published: July 2021

To reduce hazard risk in earthquake-prone areas, it is crucial to conduct ground motion prediction for a future earthquake. It is well understood that a shear wave velocity (Vs) profile of soil at site interest is significant for ground motion estimation. In this study, we examine uncertainty in a Vs derived from the from Standard Penetration Test (SPT)-N value at a borehole site of Institut Teknologi Sepuluh Nopember (ITS), Surabaya, Indonesia. Here, we used various empirical Vs and N equations from different authors to determine variations in the Vs profile. We found that the estimated S-wave velocity profile errors are about 20% at depths of 0 – 30 m. These uncertainties are helpful for the determination of variability of ground motion prediction at ITS.
Accretionary wedge and oceanic crust thickness effect on surface deformation: Study case the Mentawai segment
Authors: Kuncoro Alvina Kusumadewi , Srigutomo Wahyu , Fauzi Umar , Aoudia Abdelkrim , Hananto Nugroho
Published: July 2021

Southern Sumatra forearc is classified as a compressional accretionary type. The existence of the accretionary wedge has a significant role in sediment deformation. This sediment deformation may contribute to generating higher tsunami generation. A two-dimensional crustal deformation modeling was performed to analyze the influence of the accretionary wedge. Furthermore, oceanic crust thickness variations are also simulated in this modeling as the incoming plate’s role in surface deformation is poorly understood. The crustal deformation modeling consists of two types of earthquake period: interseismic period and coseismic period. Various geometry features were applied for each earthquake period. The crustal deformation modeling itself is based on the finite element method. The result shows that there are different effects on the geometrical model being used. The pattern and amount of surface deformation also depend on at which the fault is activated. Extended geometry models such as three-dimensional modeling will be required for further study.
Mapping of weathered layer thickness and Seismic Vulnerability in Tegal using HVSR method
Authors: Tanjung NAF , Permatasari I , Yuniarto AHP
Published: July 2021

The Baribis-Kendeng-Tegal fault is part of the Baribis-Kendeng fault segment that extends from West to East in the north of Java Island. The existence of this fault segment affects seismic activity in Tegal. The research was conducted by microtremor measurement to determine the earthquake susceptibility index and the thickness of the weathered layer in Tegal City. The data collection method in the study used the HVSR (Horizontal-to-Vertical Spectral Ratio) method to determine the subsurface conditions of the study area. The results of the horizontal component analysis of the vertical component showed a spectrum peak at the dominant frequency and amplification factor. The thickness of the weathered layer was obtained from the comparison of the value of Vs 30 of the study area to its natural frequency value. The seismic vulnerability index was obtained by squaring the amplification and dividing it into its natural frequency. Measurements carried out at 37 points in Tegal City obtained varying thickness of the weathered layer, ranging from 4.29 meters to 88.14 meters and seismic vulnerability values ranging from 0.08 to 16.65.
Determining model parameter from self-potential data using quantum-behaved particle swarm optimization
Authors: Candra Arya Dwi , Widyaningrum Yekti , Sungkono
Published: July 2021

A new approach for quantitative analysis of self-potential (SP) data is introduced. In this paper, anomaly of SP is associated with simple geometric models such as a vertical cylinder, a horizontal cylinder and a sphere object. Then, in order to estimate the depth, the electric dipole moment, the anomaly body’s centre, the geometrical form factor and polarization of the anomaly, the method was developed and implemented. The development and implementation of the method is based on the global optimization concept. This method uses Quantum-behaved Particle Swarm Optimization (QPSO) algorithm to overcome the inversion problem on SP anomaly modelling. The QPSO algorithm was randomly tested on synthetic data which consist of different random noise levels. The result shows a close agreement between the assumed and the measured parameters. At last, the validity of the method was tested on real SP anomaly data and compared to the results given by other advanced inversion approaches.
Radiation Microwave-Alkali Pretreatment of the Sawdust for the Glucose Production
Authors: Sutiari D K , Zulfadlih L S , Abidin M S
Published: July 2021

This research aims at the investigation of the effect of microwave radiation and low concentration alkali (NaOH) pretreatment to sawdust in a production process of glucose. The experiment has been conducted by varying the time period of heating and microwave power. Twenty grams of white teak sawdust collected in the South Konawe region have been heated by means of microwave radiation. Besides that, some pretreatment has also been carried out without heating. It has been obtained that at high power the longer the heating time the higher the concentration of the resulting glucose is. When the heating time of sawdust has been set for 2 minutes the concentration of the glucose is 7.09 mg/mL. The concentration in amount of 12.97 mg/mL has been obtained for the heating time 24 minutes. Under low power treatment, the experiment result showed that microwave energy did not have a significant effect on the glucose concentration. The same result has been also performed by the samples without heating. This experiment indicated that the variations of the combination between time and the power of microwave give significant influence to the increment of the glucose concentration. The result shows that giving pretreatment using microwave radiation can increase the glucose concentration of sawdust.
A Dynamic Model of Glioma Tumor Growth Based on Changes in Blood Glucose Concentration using Runge-Kutta Order 45
Authors: Handoko  , Wahyudi S T , Setiawan A A , Kartono A
Published: July 2021

The aggressive nature of the glioma tumor and the low survival rate of glioma sufferers make it very difficult to cure glioma tumors. The use of biomarkers in the blood to detect early glioma tumors is necessary for the evaluation of special treatment in patients with these tumors. Because there is a relationship between blood glucose concentrations and glioma tumors. This also opens up opportunities for the early detection of glioma tumors using the dynamic model method. This study presents the model of coupled ordinary differential equations to describe glioma growth based on changes in blood glucose concentration. This dynamic model contains glioma-glucose-immune interaction. The Runge-Kutta Order 45 function that has been created gives similar results with the MATLAB ode solver (ode45, ode23s, and ode15s). The simulation results indicate that there is an inverse relationship between glioma tumor growth (active state not in a dormant state) and a decrease in blood glucose serum levels. Also, there is a relationship between glioma growth and the immune system, which is an important element in controlling glioma tumor growth.
Study of Diffusion Weighted Imaging in Magnetic Resonance Imaging: Quantification of Apparent Diffusion Coefficient (ADC) from b-value in Agarose
Authors: Hakim Randy Ivanal , Dwihapsari Yanurita
Published: July 2021

Diffusion Magnetic Resonance Imaging (MRI) is one of the promising methods to observe molecular structure and diffusion properties of materials and tissues inside human body. The experiments with diffusion MRI had been conducted on 11 agarose gel inside tubes with the solution percentages of 0% - 5% with an increment of 0.5% to obtain apparent diffusion coefficient (ADC) of agarose gel. Images were acquired using 1.5 Tesla MRI machine with a spin-echo sequence. The parameters used are TR 5000 ms, TE 50 ms, b-value with variations of (10, 50, 75, 125, 250, 500, 750, and 1000) s/mm2, slice thickness 5 mm and field of view 36 mm × 36 mm. Image processing was carried out using ImageJ software to determine the average signal intensity for each sample. After signal intensities from all variations of b-value were obtained, the linear curve fitting with b-value was performed using Matlab to obtain ADC. From the experimental results, it is found that the signal intensity decreases with increasing b-value and ADC of agarose gel is not linearly proportional to agarose concentration.
A comparison on the use of Perlin-noise and Gaussian noise based augmentation on X-ray classification of lung cancer patient
Authors: Haekal M , Septiawan RR , Haryanto F , Arif I
Published: July 2021

The use of deep learning in medical image classification has become an important study in the past few years. The proper use of this method, however, is still hindered by many problems, one of it being the imbalance of dataset available for training which resulted in small-set database. In this study, the effect of noise-based augmentation on the performance of deep learning based classification will be studied. The noises which were used for the augmentation method were Perlin-noise and Gaussian noise. The modality of medical image used in this study is X-ray. 174 X-ray images (87 cancer, 87 normal) were used in this study and will be classified by using transfer learning from previously trained deep learning architecture. The deep learning architecture used was vgg-19. The images were divided into two groups, 138 (69 cancer, 69 normal) images were used for training phase and 36 (18 cancer, 18 normal) were images used for testing phase. Three deep learning models were used for the classification tasks, the first one was retrained to classify the original images, the second one was retrained by using mix of original images and images with Perlin-noise, and the third one was retrained by using mix of original images and images with Gaussian noise. The results showed that the three models returned similar accuracy of 0.8 which indicate that the use of noise-based augmentation can increase the performance of deep learning in classifying medical images with small set training database.
Modeling evidence for large, ENSO-driven interannual wintertime AMOC variability
Authors: Smith K L , Polvani L M
Published: July 2021

Recently established North Atlantic ocean observing arrays, such as RAPID/MOCHA, have revealed a large degree of high-frequency variability in the Atlantic Meridional Overturning Circulation (AMOC). Climate modeling studies of the AMOC, however, have traditionally focused on the low-frequency variability of the annual mean AMOC, with an emphasis on multi-decadal and longer time-scale variability. Thus, little is known about the sources of interannual wintertime, wind-driven AMOC variability. Analyzing the Community Earth System Model, we here show the existence of a robust leading mode of interannual variability in the wintertime AMOC that is distinct from the leading mode of the annual mean. We further show that this mode of variability is significantly linked to the El Niño-Southern Oscillation via the North Atlantic Oscillation.
A brown wave of riparian woodland mortality following groundwater declines during the 2012–2019 California drought
Authors: Kibler Christopher L , Schmidt E Claire , Roberts Dar A , Stella John C , Kui Li , Lambert Adam M , Singer Michael Bliss
Published: July 2021

As droughts become more frequent and more severe under anthropogenic climate change, water stress due to diminished subsurface supplies may threaten the health and function of semi-arid riparian woodlands, which are assumed to be largely groundwater dependent. To better support the management of riparian woodlands under changing climatic conditions, it is essential to understand the sensitivity of riparian woodlands to depth to groundwater (DTG) across space and time. In this study, we examined six stands of riparian woodland along 28 km of the Santa Clara River in southern California. Combining remote sensing data of fractional land cover, based on spectral mixture analysis, with historical groundwater data, we assessed changes in riparian woodland health in response to DTG during the unprecedented 2012–2019 California drought. We observed a coherent ‘brown wave’ of tree mortality, characterized by decreases in healthy vegetation cover and increases in dead/woody vegetation cover, which progressed downstream through the Santa Clara River corridor between 2012 and 2016. We also found consistent, significant relationships between DTG and healthy vegetation cover, and separately between DTG and dead/woody vegetation cover, indicating that woodland health deteriorated in a predictable fashion as the water table declined at different sites and different times. Based on these findings, we conclude that the brown wave of vegetation dieback was likely caused by local changes in DTG associated with the propagation of precipitation deficits into a depleted shallow alluvial aquifer. These factors suggest that semi-arid riparian woodlands are strongly dependent on shallow groundwater availability, which is in turn sensitive to climate forcing.
Fleet diversity of squid fisheries in Indonesia Fisheries Management Area – 711
Authors: Suryanto  , Oktaviani D , Nugroho D , Anggawangsa R F
Published: July 2021

Indonesia’s Fisheries Management Areas (IFMA) 711, which is geographically located in the north-west of Indonesia and bordered by several ASEAN countries. Squid resource is one of the economically targeted species. Four types of fishing gears were applied. This study aims to illustrate the prospects of capturing fisheries businesses with emphasized fleet tonnage and fishing gear diversity indices, volume, and export values. The source of data was derived from various digital sources available. The analysis was carried out through graphical and tabulation approaches. The dominant fishing gears were Cast Net and Bouke Ami, with a 31-60 GT size. The results showed that Bouke Ami, with a size of 91-120 GT and all class of Cast Net fleet, had a trend of decreasing fleet diversity in 2015-2019. Riau Islands, Riau, Jambi, South Sumatra, Bangka Belitung, and West Kalimantan provinces share the IFMA squid resources. The squid ratio to the total fish landing shows that the West Kalimantan, Bangka Belitung, and Riau Islands increased. Jambi province tends to decrease during the period 2014-2018, and the other two provinces were relatively constant. These findings indicated that squid fisheries management in IFMA 711 could play a significant role in supporting the coastal community’s long-term economic resilience sustainably.
Water physical factor analysis using aqua-modis image data to determine the tour ship route in Karimunjawa
Authors: Wibawa B E , Bambang A N , Purwanti F , Suprapto D
Published: July 2021

Tourism development is closely related to the sustainable development that has been declared by the Government. The development of the tourism sector is in line with national development goals. The tourism development must be based on sustainability criteria, which means that development which was environmentally supported in the long-term as well as economically feasible, ethically fair, and socially fair to society. The condition of sea transportation (accessibility) of the Karimunjawa Islands people toward mainland (Java Island) was very limited, that was an average of 10 trips / week in and out of the Karimunjawa port, until the end of 2012. The Inter-island transportation was using fishing boats. This become an obstacle for economic activity, fulfilled the needs of coastal communities and the limited number of tourist visits. The purpose of this research was to identify the average range of water parameters for the route of the tour ship using aqua-modis and to analyze the average range of the waters suitability for determining the port of tour ship. The results of the study used aqua-modis image data, the range of average water temperature in Karimunjawa was ranged from 27 - 320C, the average depth measurement was ranged from 2 - 3 meters at high and low tide, while the average current was ranged from 0.8 - 1.0 m / s. The results of this study proved that the physical parameters of Karimunjawa water were very suitable for tour routes with the category of long vessel capacity with 12 m dimensions, 10 m width, 2.1 m and with an engine size of 5 GT.
Study on phytoplankton diversity of Batang Toru River and its surrounding, North Sumatra, Indonesia
Authors: Asriansyah A , Wildan D M , Pratiwi N T M , Simanjuntak C P H , Sulistiono  , Hestirianoto T , Shafrudin D , Nugroho T
Published: July 2021

Batang Toru River which is located in South Tapanuli, North Sumatra, is quite widely used for various purposes, i.e. domestic uses, fisheries and tourism activities. Phytoplankton study at 13-14 stations which are distributed from the area near the upstream to the estuary of Batang Toru River was conducted for 3 months i.e. April, July, and October 2019. In each sampling station, water quality environment i.e. temperature, transparency, turbidity, pH and DO were also observed. Data analysis including phytoplankton abundance, diversity index (H’), evenness index (E), and dominance index (C) of the organism. Generally, water quality in all stations were still in accordance with the quality standards for aquatic life. During the study period, a total of five classes of phytoplankton were recorded, namely Bacillariophyceae (represented by 26 genera), Chlorophyceae (15 genera), Cyanophyceae (7 genera), Dinophyceae (1 genus), and Eiglenophyceae (2 genera). Diversity, Evenness and Dominance Indices varied with range of 0.377-1.847, 0.503-1.000 and 0.187-0.781, respectively. Based on the status of the phytoplankton community structure, the ecological status of the Batang Toru River is classified as moderate.