bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrically programmable multilevel nonvolatile memories based on solution-processed organic floating-gate transistors
Authors: Higashinakaya Miho , Nagase Takashi , Abe Hayato , Hattori Reitaro , Tazuhara Shion , Kobayashi Takashi , Naito Hiroyoshi
Published: March 2021

The development of nonvolatile organic field-effect transistor (OFET) memories with a satisfactory solution processability is highly desirable to fabricate the data storage media for flexible and printed electronic devices. In this study, we fabricate top-gate/bottom-contact OFET memories having an organic floating-gate structure by a spin-coating process and investigate their memory characteristics. An ambipolar polymer semiconductor of poly(N-alkyldiketopyrrolo-pyrrole-dithienylthieno[3,2-b]thiophene) (DPP-DTT) was used to fabricate an organic semiconductor layer, on which an organic composite of polystyrene and 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) was deposited to form an organic floating-gate structure through vertical phase separation. The existence of a deep lowest unoccupied molecular orbital (LUMO) level and the excellent electron transport property of the DPP-DTT enables the injection of electrons from the Au source-drain electrodes to the DPP-DTT semiconductor layer and the storage of electrons in the LUMO level of the TIPS-pentacene floating gates by programming under dark conditions. A high work function metal oxide layer of MoO3 was inserted at the Al gate electrode/CYTOP gate insulator interface to tune the energy level difference between the Au source-drain and Al gate electrodes. The DPP-DTT FET memories with MoO3/Al gate electrodes exhibit satisfactory retention characteristics and, because of the ambipolar trapping characteristics, allow the storing of holes in the highest occupied molecular orbital level of the TIPS-pentacene floating gates in the erasing process. Furthermore, the molecular floating-gate OFET memories exhibit a high storage capacity for multi-level data, and four state levels can be recorded with stable retention characteristics.
Thresholds of absolute two-plasmon-decay and stimulated Raman scattering instabilities driven by multiple broadband lasers
Authors: Follett R. K. , Shaw J. G. , Myatt J. F. , Wen H. , Froula D. H. , Palastro J. P.
Published: March 2021

Thresholds for the absolute stimulated Raman scattering (SRS) and two-plasma decay (TPD) instabilities driven by multiple broadband laser beams are evaluated using 3D simulations at conditions relevant to inertial confinement fusion experiments. Multibeam TPD and SRS backscatter are found to be easier to mitigate with bandwidth than the corresponding single-beam instabilities. A relative bandwidth of 1% increases the threshold for absolute SRS backscatter by a factor of 4 at conditions relevant to ongoing National Ignition Facility experiments and should be sufficient to keep all of the absolute instabilities below threshold in experiments with similar conditions.
An in situ microtomography apparatus with a laboratory x-ray source for elevated temperatures of up to 1000 °C
Authors: Zhu Rongqi , Qu Zhaoliang , Yang Shuo , Fang Daining
Published: March 2021

An elevated-temperature in situ microtomography apparatus that can measure internal damage parameters under tensile loads at high temperatures up to 1000 °C is developed using a laboratory x-ray source. The maximum resolution of the apparatus can reach 3 µm by a reasonable design. A high-temperature environment is accomplished by means of a heating chamber based on a radiation technique using four halogen lamps with ellipsoidal reflectors. To obtain high resolution, the chamber is much smaller in the direction of the x-ray beam than in the other two directions. Two thin aluminum windows are chosen as the chamber walls perpendicular to and intersecting the x-ray beam. A material testing machine equipped with two synchronous rotating motors is specially designed for mechanical loading and 360° rotation of the specimen, and customized grips are developed to conduct tensile tests. A microfocus x-ray source and a high-resolution detector are used to produce and detect X rays, and the distances among the x-ray source, specimen, and high-resolution detector can be adjusted to obtain different resolutions. To show the main functions and usability of the apparatus, carbon-fiber-reinforced silicon-carbide matrix specimens are subjected to in situ x-ray microtomography tensile tests at 800 °C and 1000 °C, and the crack propagation behavior under thermomechanical coupling loads is studied.
Experimentally calibrated electro-thermal modeling of temperature dynamics in memristors
Authors: Shen Wenqing , Kumar Suhas , Kumar Satish
Published: March 2021

As nanoscale electronic devices are being packed into dense three-dimensional arrays, the effects of the thermal environment of the system during device operation become critical, but are not clearly understood. Predicting the temperature evolution using a robust model will provide critical design guidelines for complex memory and computing systems. Here, we used in-operando thermal and x-ray mapping with sub-micrometer spatial and sub-microsecond temporal resolutions on functioning tantalum oxide memristive switches and observed hot spots corresponding to oxygen concentration gradients, indicating the presence of localized conductive filaments. We constructed a hybrid electro-thermal model comprising 3D heat transfer and 0D resistive switching models to predict electrical characteristics and the temperature rise and calibrated it against the measurements. We also demonstrated thermal crosstalk in an array of memristors to illustrate localized heating. Such a model will guide system design by considering thermal performance, which is critical to most future electronic chips.
Enhanced acoustic pressure sensors based on coherent perfect absorber-laser effect
Authors: Farhat Mohamed , Ahmad Waqas W. , Khelif Abdelkrim , Salama Khaled N. , Wu Ying
Published: March 2021

Lasing is a well-established field in optics with several applications. Yet, having lasing or huge amplification in other wave systems remains an elusive goal. Here, we utilize the concept of coherent perfect absorber-laser to realize an acoustic analog of laser with a proven amplification of more than 104 in terms of the scattered acoustic signal at a frequency of a few kHz. The obtained acoustic laser (or the coherent perfect absorber-laser) is shown to possess extremely high sensitivity and figure of merit with regard to ultra-small variations of the pressure (density and compressibility) and suggests its evident potential to build future acoustic pressure devices such as precise sensors.
Identification by deuterium diffusion of a nitrogen-related deep donor preventing the p-type doping of ZnO
Authors: Temahuki N. , Jomard F. , Lusson A. , Stenger I. , Hassani S. , Chevallier J. , Chauveau J. M. , Morhain C. , Barjon J.
Published: March 2021

Deuterium diffusion is investigated in nitrogen-doped homoepitaxial ZnO layers. The samples were grown under slightly Zn-rich growth conditions by plasma-assisted molecular beam epitaxy on m-plane ZnO substrates and have a nitrogen content [N] varied up to 5 × 1018 at cm−3 as measured by secondary ion mass spectrometry (SIMS). All were exposed to a radio frequency deuterium plasma during 1 h at room temperature. Deuterium diffusion is observed in all epilayers, while its penetration depth decreases as the nitrogen concentration increases. This is strong evidence of a diffusion mechanism limited by the trapping of deuterium on a nitrogen-related trap. The SIMS profiles are analyzed using a two-trap model including a shallow trap, associated with a fast diffusion, and a deep trap, related to nitrogen. The capture radius of the nitrogen-related trap is determined to be 20 times smaller than the value expected for nitrogen–deuterium pairs formed by coulombic attraction between D+ and nitrogen-related acceptors. The (N2)O deep donor is proposed as the deep trapping site for deuterium and accounts well for the small capture radius and the observed photoluminescence quenching and recovery after deuteration of the ZnO:N epilayers. It is also found that this defect is by far the N-related defect with the highest concentration in the studied samples.
Interlayer couplings in silicon/oxide/nitride thin films via laser crystallizations
Authors: Kim Minyeong , Kang Min Jin , Hwang Eui Sun , Cheong Byoung-Ho
Published: March 2021

The laser crystallization process that converts amorphous-Si to poly-crystalline-Si has attracted considerable attention owing to its wide industrial applications, such as active matrix organic light-emitting diode displays and photovoltaic devices. Herein, for thin-layer configurations of amorphous-Si/oxide/nitride deposited on a glass substrate, periodic surface ripples on Si induced by irradiation with a solid-state laser at an ultraviolet wavelength of 355 nm were examined using a guided-mode resonance theory. Modeling the periodic textures as one-dimensional gratings demonstrated several resonance peaks in the transmittance spectra, which were similar to the measured spectra. Furthermore, by varying the thickness of oxide (0–300 nm) and nitride (60–120 nm) sublayers, two resonance modes with separations of a few tens of nanometers were predicted for the transverse electric and transverse magnetic polarizations, respectively. The two-dimensional mode plots and electric and magnetic fields at the resonance wavelengths indicated that the mode couplings were mainly owing to the guided modes propagating in the Si and nitride layers. Because the peak positions and intensity of the resonance modes represent the figure-of-merit of the laser crystallization process, the resonance modes may be employed for the evaluation of the laser crystallization process; this will enable a more efficient evaluation compared to the current manual inspection of diffraction images by human eyes.
Inhibition of non-photochemical quenching increases functional absorption cross-section of photosystem II as excitation from closed reaction centres is transferred to open centres, facilitating earlier light saturation of photosynthetic electron transport
Authors: Osmond Charles Barry , Chow Wah Soon , Robinson Sharon A.
Published: March 2021

Induction of non-photochemical quenching (NPQ) of chlorophyll fluorescence in leaves affords photoprotection to the photosynthetic apparatus when, for whatever reason, photon capture in the antennae of photosystems exceeds their capacity to utilise this excitation in photochemistry and ultimately in CO2 assimilation. Here we augment traditional monitoring of NPQ using the fast time resolution, remote and relatively non-intrusive light induced fluorescence transient (LIFT) technique (Kolber et al. 2005; Osmond et al. 2017) that allows direct measurement of functional (σ′PSII) and optical cross-sections (a′PSII) of PSII in situ, and calculates the half saturation light intensity for ETR (Ek). These parameters are obtained from the saturation and relaxation phases of fluorescence transients elicited by a sequence of 270, high intensity 1 μs flashlets at controlled time intervals over a period of 30 ms in the QA flash at intervals of a few seconds. We report that although σ′PSII undergoes large transient increases after transfer from dark to strong white light (WL) it declines little in steady-state as NPQ is induced in shade- and sun-grown spinach and Arabidopsis genotypes Col, OEpsbs, pgr5bkg, stn7 and stn7/8. In contrast, σ′PSII increases by ~30% when induction of NPQ in spinach is inhibited by dithiothreitol and by inhibition of NPQ in Arabidopsis npq1, npq4 and pgr5. We propose this increase in σ′PSII arises as some excitation from closed PSII reaction centres is transferred to open centres when excitation partitioning to photochemistry (YII) and NPQ (YNP) declines, and is indicated by an increased excitation dissipation from closed PSII centres (YNO, including fluorescence emission). Although Ek increases following dissipation of excitation as heat when NPQ is engaged, it declines when NPQ is inhibited. Evidently photochemistry becomes more easily light saturated when excitation is transferred from closed RCIIs to open centres with larger σ′PSII. The NPQ mutant pgr5 is an exception; Ek increases markedly in strong light as electron transport QA → PQ and PQ → PSI accelerate and the PQ pool becomes strongly reduced. These novel in situ observations are discussed in the context of contemporary evidence for functional and structural changes in the photosynthetic apparatus during induction of NPQ.
Dlk1
dosage regulates hippocampal neurogenesis and cognition
Authors: Montalbán-Loro Raquel , Lassi Glenda , Lozano-Ureña Anna , Perez-Villalba Ana , Jiménez-Villalba Esteban , Charalambous Marika , Vallortigara Giorgio , Horner Alexa E. , Saksida Lisa M. , Bussey Timothy J. , Trejo José Luis , Tucci Valter , Ferguson-Smith Anne C. , Ferrón Sacri R.
Published: March 2021

Significance

Generation of new neurons occurs normally in the adult brain in two locations: the subventricular zone (SVZ) in the walls of the lateral ventricles and the subgranular zone (SGZ) in the dentate gyrus (DG) of the hippocampus. Neurogenesis in the adult hippocampus has been implicated in cognitive functions such as learning, memory, and recovery of stress response. Imprinted genes are highly prevalent in the brain and have adult and developmental important functions. Genetic deletion of the imprinted gene
Dlk1
from either parental allele shows that DLK1 is a key mediator of quiescence in adult hippocampal NSCs. Additionally,
Dlk1
is exquisitely dosage sensitive in the brain with perturbations in levels resulting in impaired NSCs function and cognitive phenotypes.
Passion matters but not equally everywhere: Predicting achievement from interest, enjoyment, and efficacy in 59 societies
Authors: Li Xingyu , Han Miaozhe , Cohen Geoffrey L. , Markus Hazel Rose
Published: March 2021

Significance

In three large-scale datasets representing adolescents from 59 societies across the globe, we find evidence of a systematic cultural variation in the relationship between passion and achievement. In individualistic societies, passion better predicts achievement and explains more variance in achievement outcomes. In collectivistic societies, passion still positively predicts achievement, but it is a much less powerful predictor. There, parents’ support predicts achievement as much as passion. One implication of these findings is that if admission officers, recruiters, and managers rely on only one model of motivation, a Western independent one, they may risk passing over and mismanaging talented students and employees who increasingly come from sociocultural contexts where a more interdependent model of motivation is common and effective.
Identification of earth-abundant materials for selective dehydrogenation of light alkanes to olefins
Authors: Wang Tao , Li Guomin , Cui Xinjiang , Abild-Pedersen Frank
Published: March 2021

Significance

Catalytic alkane dehydrogenation is of considerable importance in the synthesis of olefins industrially. However, discovery of highly active, selective, and stable heterogeneous catalysts to replace noble metal Pt remains challenging. By combining descriptor-based microkinetic modeling, high-throughput computations, machine-learning concepts, and experiments, we efficiently evaluated 1,998 bimetallic alloys and successfully identified Ni
3
Mo as one of the most promising catalysts in selective ethane dehydrogenation. This work will open new possibilities of using earth-abundant materials as catalysts for essential heterogeneous catalytic reactions.
Powder x-ray diffraction and Rietveld analysis of (C2H5NH3)2CuCl4
*
Authors: Liu Yi , Shen Jun , Lu Zunming , Shen Baogen , Yan Liqin
Published: March 2021

Structural properties of the organic-inorganic hybrid (C2H5NH3)2CuCl4 (EA2CuCl4) have been investigated by means of x-ray powder diffraction and Rietveld analysis. A structural phase transition from Pbca to Aba2 occurs at T
4 = 240 K, which results in a paraelectric–ferroelectric phase transition. The release of the Jahn–Teller distortion with increasing temperature toward T
4 is revealed by the structural analysis.
A multi-modal modified feedback self-paced BCI to control the gait of an avatar
Authors: Alchalabi Bilal , Faubert Jocelyn , Labbé David R
Published: March 2021

Brain–computer interfaces (BCIs) have been used to control the gait of a virtual self-avatar with a proposed application in the field of gait rehabilitation. Some limitations of existing systems are: (a) some systems use mental imagery (MI) of movements other than gait; (b) most systems allow the user to take single steps or to walk but do not allow both; (c) most function in a single BCI mode (cue-paced or self-paced). Objective. The objective of this study was to develop a high performance multi-modal BCI to control single steps and forward walking of an immersive virtual reality avatar. Approach. This system used MI of these actions, in cue-paced and self-paced modes. Twenty healthy participants participated in this study, which was comprised of four sessions across four different days. They were cued to imagine a single step forward with their right or left foot, or to imagine walking forward. They were instructed to reach a target by using the MI of multiple steps (self-paced switch-control mode) or by maintaining MI of forward walking (continuous-control mode). The movement of the avatar was controlled by two calibrated regularized linear discriminate analysis classifiers that used the µ power spectral density over the foot area of the motor cortex as a feature. The classifiers were retrained after every session. For a subset of the trials, positive modified feedback (MDF) was presented to half of the participants, where the avatar moved correctly regardless of the classification of the participants’ MI. The performance of the BCI was computed on each day, using different control modes. Main results. All participants were able to operate the BCI. Their average offline performance, after retraining the classifiers was 86.0 ± 6.1%, showing that the recalibration of the classifiers enhanced the offline performance of the BCI (p < 0.01). The average online performance was 85.9 ± 8.4% showing that MDF enhanced BCI performance (p = 0.001). The average performance was 83% at self-paced switch control and 92% at continuous control mode. Significance. This study reports on a first BCI to use motor imagery of the lower limbs in order to control the gait of an avatar with different control modes and different control commands (single steps or forward walking). BCI performance is increased in a novel way by combining three different performance enhancement techniques, resulting in a single high performance and multi-modal BCI system. This study also showed that the improvements due to the effects of MDF lasted for more than one session.
The Vented-box Effect on Thiele-small Parameter Loudspeaker
Authors: Suyatno  , Putrie W P , Indrawati S , Prajitno G
Published: March 2021

Loudspeaker testing is usually using the Thiele-small parameter. To see the effect of the vented box on loudspeaker quality, Thiele-small parameters in vented box boxes are used. Research carried out by measuring the characteristics of loudspeaker response frequency, impedance, and Thiele small parameters in vented-boxes and panels. One factor affecting the acoustic parameters is the compressed air value generated by the loudspeaker or so-called air compliance. In vented-boxes, there is an effect of compressed air compliance in the box and the air coming from the hole which is causing the pure loudspeaker sound trigger. On the panel, there is no compressed air. From the measurement and results analysis, the ratio of compliance from the box is 8.29: 10.7. This value has impacted the losses of the vented-box. The losses of the vented-box are 0.63% and the losses that happened on the panel is 0,014%. The losses of the enclosure are caused by the shape of the enclosure design and the damping material in it.
Magnetic susceptibility and curie temperature of Co1-xFex alloy nanocube and nanosphere using micromagnetic simulation
Authors: Rohman L , Arkundato A , Mulyani Y T , Djuhana D
Published: March 2021

CoFe alloy is one of the competitive candidates for ferromagnetic material because it has a high value in Curie temperature. Magnetic susceptibility and curie temperature of CoFe alloy have been investigated by using micromagnetic simulation. It had done by using Vampire software with the Monte Carlo method. In this work, we have varied Fe(x) composition for 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, and 90% in 5nm nanocube and nanosphere geometry of Co1-xFex. The result showed that magnetization value changed to temperature changed. The curie temperature point is the point where the magnetization approaches zero. Magnetic susceptibility value also changed to temperature changed. Curie temperature point of CoFe alloy determined by considering the susceptibility point when it gains the peak of magnetic susceptibility value. It has been corresponding to Curie-Weiss law. Alloy Co80Fe20 nanocube had the highest Curie temperature value of 1500 K. Curie temperature values in the nanocube, and nanosphere geometry had almost the same.
Comparison of Boron Carbide, Gadolinium Oxide, and Hafnium as Qualified Molten Salt Reactor’s Control Rods Material
Authors: Mikhaelia L Y , Suharyana  , Riyatun  , Khakim A
Published: March 2021

The development and research of the Molten Salt Reactor (MSR) has recently seize the attention. Lots of MSR designs have been modeled based on its materials, neutronic behaviour, thermal-hydraulic behaviour, and particularly its safety systems. A reactor’s core has been modeled based on the design of ThorCon Reactor using Monte Carlo N-Particle 6 computational code with BeF2-NaF-UF4-ThF4 mixture as the fuelsalt. The core contains 84 hexagonal fuel logs and a hexagonal control rod log. This research compared three different materials of control rods, i.e. B4C, Gd2O3 and Hf. The comparison between those materials are seen according to reactor’s criticality. The keff
at fully withdrawn position is 1.01887 that indicates a critical condition. When the control rods are fully entered the keff
are (0.98293 ± 0.00012); (0.97386 ± 0.00011); (0.99203 ± 0.00012) for control rods’ materials in sequence B4C, Gd2O3 and Hf. The decretion of the criticality shows the materials’ ability to absorb the neutron. The lower the criticality, the better material’s absorption ability.
Groundwater level in the southern part of surakarta city depicted from vertical electrical sounding
Authors: Koesuma Sorja , Sunaryo  , Sutarno Doddy , Handono Ramelan Ari
Published: March 2021

In the last two decades, the city of Surakarta has shown significant population development, as well as in industry and tourism. This development must be accompanied by the provision of water resources for the lives of the population. As we know that in 2015 and 2019, there was a long dry season that resulted in a lack of water for residents and for the hotel industry, where most residents of Surakarta and the hotel industry are located in the southern part of the city of Surakarta. Therefore, the purpose of this study was to determine the level of groundwater aquifers in the south part of the city of Surakarta. We used the vertical electrical sounding (VES) method with the Schlumberger configuration at 10 survey locations. The current electrode interval in the Schlumberger configuration is from 1.5 meters up to 300 meters. With this stretch of electrode current, it is expected to reach target depth of up to 150 meters. Data processing uses the principle of non-linear optimization method which is to minimize errors from measurement data and models. We found that the depth of the groundwater aquifer was at 40 meters at S9 (shallowest), and at 80 meters at S5 (deepest). Then we compared this result with the survey in 2010 in the same location and same method. We found the lowering of the water table in some site surveys around 3 to 10 meters.
Analysis of Sea level Rise by Using Satellite Altimetry Data of West Sumatra Waters in 2009 – 2019
Authors: Vina Chrismiantari Riza , Koesuma Sorja , Legowo Budi
Published: March 2021

The West Sumatra Waters is one of the vulnerable area exposed to impact of Sea Level Rise where the West Sumatra Waters located adjacent to the Indian Ocean Waters and Andaman Sea. Some of the negative impact caused by SLR are coastal abrasion, erosion, and sinking of small islands also increases risk of flooding. Therefore, research about SLR must be continued as an information in management of coastal areas. The technology that is widely used in observing SLR is the satellite altimetry. The data used in this research are Jason 2 and Jason 3 satellite altimetry data from NOAA since 2009 until 2019 and the tidal data of the IOC as a comparator. The research uses linear regression method to get the sea level rise value. From the research results obtained SLR value in the West Sumatera Waters is -2.5 mm/years. The decline of the sea level in the region is caused by many factors such as the Indian Ocean Dipole and ENSO phenomenon.
Very low frequency - electromagnetic (vlf-em) for detecting groundwater river patterns in karst area of kaligambir village
Authors: Iswahyudi A , Prabawa SE , Warnana DD , Widodo A
Published: March 2021

Groundwater flow in the limestone areas through gaps, fractures, and dissolving channels whose dimensions and directions are erratic. If the dimensions and direction of the river flow are known, it will be easier to exploit water to meet the needs of the community. The dimensions and direction of the underground river flow can be mapped using the VLF-EM method. VLF-EM measurements were carried out on 18 trajectories spread across two study areas. Each VLF-EM track has a length of 200 meters, taking data at intervals of 2 meters. Processing of VLF-EM data on each path produces a distribution of resistivity values along the measurement path. Resistivity values around Bleri Cave range between 53 Ωm - 685 Ωm, underground river flow is located at a depth of ± 40 meters and the direction of flow is from northeast to southwest. The distribution of underground river flow around the Bleri Cave with resistivity values around the Lowo Cave ranges from 61 Ωm - 550 Ωm, in the area around the Lowo cave there are no underground anomaly caves that are not drained by water. If you want to exploit underground river water it should be done in the area around Bleri Cave.
Mitigation Strategic of Drought in Central Java Indonesia during Covid-19 Pandemic
Authors: Koesuma Sorja , Azzahra Kusuma Delfina , Widya Harmoko Iis
Published: March 2021

In 2019, most of the areas in Central Java Indonesia experienced drought disaster. There are 3 districts that conduct emergency response due to drought disasters. If there is another drought in this year during Covid-19 pandemic, it will be very fatal due to the need for more water than usual. Besides being used for daily needs, water is also needed for washing hands and bathing during the Covid-19 pandemic. This study aims to determine the level of drought in Central Java province and provide solutions on how to reduce the drought strategy so as not to aggravate the spread of Covid-19. The method used to determine rainfall prediction is the Canonical Correlation Analysis (CCA) method with input data of average monthly rainfall for approximately 30 years in Central Java. Then to determine the drought map using the Standardized Precipitation Index (SPI) method with input data of rainfall prediction for the last 3 months from the CCA method. The results of data processing show that in August to October 2020 there was a drought with normal levels in almost all regions in central Java, except in the Muria peninsula which is still very wet (August-September) and wet (October). In November and December 2020 there was a drought in all regions in Central Java with normal levels. The level of dryness in this period is normal, meaning it is neither too high nor too dry. Meanwhile, based on several references that at the end of the year there will be a La Nina phenomenon, so that at the end of the year there will be no drought but there will be lots of rain. Several recommendations to overcome this situation will be presented in the final section of this paper.
Microzonation Efforts of Disaster Mitigation using Mikrotremor Refraction Method (ReMi) in Kuwu, Grobogan
Authors: Legowo Budi , Harjana  , Wildan Rantanaka Kidura
Published: March 2021

Microtremor refraction is one application of geophysical methods for disaster mitigation microzonation in a region based on dominant frequency value and amplification value. The purpose of this study is to determine microzonation of soil vulnerability index (Kg
) from the result of the dominant frequency value (f0
) and amplification (A0
). This research has been done in the Kuwu of Grobogan District using P.A.S.I Seismograph Mod. 16S24-P and 3D Borehole Geophone Model GFA 60/100. Measurements at each point for 20 minutes and performed for 2 repetitions. The interval of each measurement point is about 350-400 m with a total of 12 points of measurement. Microtremor data processing using Geopsy and Surfer 11 software to create microzonation maps. The result of the dominant frequency value is between 2.14 Hz to 10.26 Hz with an amplification value between 1.47 to 2.40. The value of soil vulnerability index is between 0.23 to 2.20. The location with the highest soil vulnerability index value is at location 5 with a soil vulnerability index value of 2.20.
Development of air temperature and soil moisture monitoring systems with LoRA technology
Authors: Aji Purnomo Fendi , Maulana Yoeseph Nanang , Alim Tri Bawono Sahirul , Hartono Rudi
Published: March 2021

One of the problems in agriculture is the difficulty of monitoring agricultural field because its location is far from the farmer’s house. Factors affecting agricultural crops are air temperature and soil moisture. Both factors are important to be maintained so that agricultural output can be optimized. LoRA is a spread spectrum modulation technique derived from spread spectrum chirp technology and the first low cost implementation of spread spectrum chirp. LoRA s able to transmit data within a distance of 7.5 km with a frequency of 433 MHz. In this study, machine-to-machine method with LoRA technology was used to send air temperature and soil moisture data. This method is advantageous because communication can be carried out at frequency of 433 MHz and thus does not depend on cellular frequencies. Monitoring via the internet can be done by connecting LoRA with the ESP32 microcontroller which connected to an access point for sending data online through the Ceyene application. Test environment is build by giving variations in air temperature and variations in the depth of the sensor that was planted in the soil. The research proves that monitoring of soil temperature and humidity can be done with LoRA technology at a low cost.
Electrical Signal Propagation in Four Probes System Measuring at The Range of 20Hz - 600Hz
Authors: Hidayat Samsul , Santoso Didik R , Maryanto Sukir , Nadhir Ahmad
Published: March 2021

The electrical-supply on the earth’s surface are propagate from the positive electrode to the negative electrode. The electrons flow from the negative electrode to the positive electrode. In the conductor wire, an electric current tends to pass through the wire shell. The charge density decreases in proportion to the depth, the increase in frequency, and the material permeability. Based on these factors, practically, the conductor surface is often extended by making fibbers. If one of the trajectories on the earth gives an electric voltage, then the earth is not a perfect conductor, the earth as a large object with a surface is predicted to be relatively difficult to deliver an alternating electric current. Based on the previous statement, the granting of an electric current, and will more difficult to flow when the frequency is increased. The aim of this research is to find out the phenomena of earth resistance in the range of 20Hz-600Hz. It is expected that this data are useful for determining the frequency of effective exploration or also as a consideration when interpreting data. The study is conducted by giving an electric field to two electrodes with a measured current. Two electrodes are plugged into the ground for injecting current, and two others electrodes to pick up voltage which was reached. The measurements were made with an oscilloscope. The frequency was varied while recording the current that flow. The current flowed from the square wave current source that could be varied from 20Hz to 600Hz. From this experiment, it is found that the voltage decreases relatives along with the increase in the frequency.
Characteristics of The Type 5076100 Lithium-ion Battery for Integration System of Stand-alone Solar Street Lighting
Authors: Saputra M , Supriyanto A , Ramelan A H , Nugraheni E , Aga A
Published: March 2021

There is still little rearch that pays attention to the problem of integrating battery packs into stand-alone solar street lighting systems. In this paper, we will conduct a study of the characteristics of the 5076100 type Lithium-ion battery for integration systems of standalone solar street lighting systems. The hope of this study can be useful to provide a basic understanding of the integration of battery packs into the stand-alone solar street lighting systems and serve as a reference for selecting battery pack modules. 12-cell lithium-ion type 5076100 will be tested for its characteristics in terms of open circuit voltage (Voc ) and maximum capacity. Next, we integrated the battery pack into 6 model, namely 1S12P, 2S6P, 3S4P, 4S3P, 6S2P, 12S1P. We get the results that the 3S4P model is a battery pack model that is suitable for stand-alone solar street lighting systems. Battery performance is able to provide energy reserves of more than 20 hours for a 7 watt LED load at full charge.
Crystal structure and corrosion properties of alumunium organoclay composite by the hotpress method
Authors: Rofa Z M , Soegijono B
Published: March 2021

Alumunium Matrix Composite (AMC) is a material that has great potential especially in automotive industry. AMC has good corrosion resistance, density, electrical conductivity and heat properties. This paper will study the crystal structure form composite materials and the corrosion properties of the sample. Composite material made with Alumunium as a matrix and reinforcement in the of organoclay variations 0%, 1%, 2%, 3% wt by the hotpress method at 600°C for 1 hour. Characterization of crystal structure and phase using X-Ray diffraction. The corrosion properties of the samples were examine by potentiodynamic curves in 3,5 % wt NaCl solution. The results showed that the addition of weight percent composition of organoclay produce different characteristics and corrosion properties. Corrosion properties can be seen form the rate of corrosion slower along with the addition composition of the organoclay. The smallest corrosion rate results found in alumunium composites with reinforcement variations of 3% by 1,776 x 10−4 mm/year.
Effects of Nd and Mn Co-dopant on the Micro Structure and Optical Properties of BiFeO3 Thin Films Elaborated by Chemical Solution Deposition (CSD)
Authors: Noviastuti M D , Kusumandari  , Suryana R , Iriani Y , Fasquelle D.
Published: March 2021

Bismuth Ferrite (BiFeO3), Neodymium (Nd) and Manganese (Mn) (Bi1-xNdxFe1-yMnyO3) with (x, y = 0.03, 0.03; 0.03, 0.05; 0.05, 0.03; 0.05, 0.05) were prepared by Chemical Solution Deposition (CSD) method at annealing temperatures of 550 °C. The effects of addition of Nd and Mn co-dopants in the BiFeO3 on the crystal structure and optical properties are presented. The results of X-Ray Diffraction (XRD) characterization showed that the addition of Nd and Mn co-dopants leads the diffraction angles to shift to smaller angles and to decrease the crystal size. Doped-BiFeO3 samples were characterized by UV-vis in the wavelength range of 200 nm-800 nm. The transmittance value of Bi1-xNdxFe1-yMnyO3 samples decreased in the wavelength range of 400-800 nm (UV light). The addition of Nd and Mn co-dopants to BiFeO3 caused light dispersion and refractive index to decrease.
The addition of bismuth (Bi) to the barium titanate (BaTiO3) prepared by chemical solution deposition
Authors: Rini R P , Nurosyid F , Iriani Y , Fasquelle D.
Published: March 2021

The manufacture of BaTiO3 thin films and Ba1-xBixTiO3 have been conducted successfully on the quartz substrate using Chemical Solution Deposition method. The results of characterization using XRD showed that the crystals of BaTiO3 and Ba1-xBixTiO3 were perovskite. The diffraction angle shift between BaTiO3 and Ba1-xBixTiO3 shifts to the right as the mole concentration of Bi. The crystallinity of the Ba1-xBixTiO3 sample increases along with the increase of Bi mole concentration. The higher the sample annealing temperature, the crystallinity decreases. The addition of Bi mole concentrations and the increase of annealing temperature in Ba1-xBixTiO3 samples causes the crystal size of the thin film to increase. Lattice strain is greater with the addition of Bi concentration and the increase of annealing temperature. The result of UV-Vis showed that the transmittance of the thin film was relatively small. Therefore, the thin film made has a high ability to absorb light in the UV area. The greater the addition of Bi mole concentration, the greater the ability of light absorption. When the thin film was given an additional concentration of Bi mol, the refractive index value was greater. The addition of Bi mole concentrations in Ba1-xBixTiO3 thin films leads to an increase in dispersion values.
Development of electro-optics method for evaluation of quality degradation of some vegetable oils
Authors: Winarno  , Richardina V , Sugito H , Azam M , Soesanto Q M B , Firdausi K S
Published: March 2021

In this research we present a development of electro-optics effect to evaluate vegetable oil quality degradation. Some vegetable cooking oil samples after heating were placed in an external electric field to obtain the electro-optical characteristics, by measuring the polarization change using green pointer laser (532 nm). The results showed that the change on natural polarization and electro-optics effect were proportional to the duration of heating. An important result showed that the percentage of reduction in the quality of olive oil is the greatest from palm oil, rice bran oil, and corn oil. This provides electro-optics as a very potential method in the cooking oil quality test system and provides a new perspective for further research improvement in other relevant fields.
Mapping flooded risk area in East Java Indonesia using remote sensing data
Authors: Cahyono B E , Cahyatri P , Purwandari E , Misto  , Febrianti N
Published: March 2021

Flooded risk area describes the potential ease of an area to experiencing flooding. Several natural factors such as intensity, duration, and distribution of rainfall, land use / land cover, slope of the area, and soil type can affect the risk of flooding. This study aims to create the flooding risk map level of an area. Those parameters which affect the risk level are classified to be marked and weighted. The equation called Kingma algorithm is then applied to the weighted parameters to get the risk level value. The results are then classified and mapped into 3 classes of risk level that are safe, risky, and highly risk. This study showed that the highly risk areas are located in the flat area, low infiltration soil, and high intensity of rainfall. In contrast, the steep slope areas with high infiltration level of soil and still have a lot of vegetation growing.
Microstructure and corrosion behaviour of ultrafine-grained pure magnesium by severe plastic deformation as a biodegradable material
Authors: Rifai M , Prasetya A D , Mujamilah  , Miyamoto H
Published: March 2021

Microstructure and corrosion behaviour of ultrafine-grained pure magnesium by severe plastic deformation has been investigated in term on initial deformation process as a biodegradable material. Equal channel angular pressing (ECAP) has been chosen as severe plastic deformation which can be introduced into the material without changing the material geometry. The ECAP process was carried out at 523 K. The microstructure was characterized by scanning electron microscope which is equipped by electron backscatter diffraction, and the corrosion behaviour was investigated by electrochemical test. The ECAP processed sample show that the deformation structures has sub boundaries in one pass and a high fraction of high angle grain boundary due to high misorientation in the grain boundaries. The corrosion behaviour exhibited that ECAP processed sample has a lower corrosion rate than that as-annealed sample due to deformed structure.
Physical-chemical and antibacterial properties of green-synthesized silver nanoparticles mediated by leaf extract of Syzygium aromaticum L
Authors: Wattimena S C , Reniwuryaan A A , Patty P J
Published: March 2021

Silver nanoparticles have played an important role in many applications due to their unique properties, and green synthesis of the particles has been a popular choice as opposed to chemical and physical methods. In this study, the physical, chemical, and antibacterial properties of green synthesized silver nanoparticles mediated by leaf extract of Syzygium aromaticum L were examined. Initially, the formation of silver nanoparticles was indicated by the yellowish-brown color of the mixture of the extract and silver nitrate solution, followed by the UV-VIS spectrum of the mixture showing the surface plasmon resonance at 415 nm. The samples then were analyzed using TEM showing the particle diameters varying from 2.9 nm to 33.6 nm with the mean diameter of 20.5 ± 4.9 nm. The FTIR spectrum showed the presence of chemical bonding of organic materials on the particles indicating the involvement of the extract as reducing and capping agents in the formation of the particles. The antibacterial activity on Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli were examined using disc diffusion and spectrophotometric methods, and the results show that the silver nanoparticles inhibit the growth of S. aureus and E. coli. Results from the disc diffusion method show that the particles inhibit the growth of S. aureus and E. coli equally, while from the spectrophotometric method, the particles inhibit the growth of E. coli faster than they inhibit the growth of S. aureus.
High power particle accelerator for driving the nuclear waste transmutation system at nuclear power plant
Authors: Pudjorahardjo D S , Wahyono P I
Published: March 2021

The existing technology for treatment of NPP nuclear waste is a deep geological disposal technology. But this technology is still has possibility of leakage due to heating caused by radioactivity process from long lived elements of nuclear waste. The development of high power particle accelerator technology which can produce high power proton beam to induce nuclear spallation reaction has introduced a new accelerator-based technology for treatment of nuclear waste from NPP named the Accelerator-driven Transmutation Waste (ATW). This paper describes result of study on status of accelerator based transmutation system for NPP nuclear waste. ATW is subcritical nuclear reactor combined with high power proton accelerator for transmutation of nuclear waste utilizing neutrons from spallation reaction due to collision of high power proton beam with heavy metal material as spallation target. The types of accelerators used for ATW are cyclotron, linac and synchrotron which able to produce proton beam of 10 up to 100 MW beam power, 10 up to 100 mA beam current and 0.6 up to 1.5 GeV beam energy. Demonstration scale ATW requires 1 up to 2 MW of proton beam power to generate 50 up to 100 MWth of thermal power in subcritical reactor. Whereas industrial ATW requires 10 up to 75 MW of proton beam power to generate hundred MWth of thermal power in subcritical reactor. Several countries have roadmap of ADS research and development which the main goal of nuclear waste transmutation using ADS called ATW. ATW also can be used for electrical energy production which is safer and more reliable.
Study of the Effectiveness of Radiation Retaining Materials for the Entrance of LINAC 6 MV Radiotherapy Room
Authors: Setiawati E , Arifin Z , Richardina V , Setiawan W A , Margiantono A
Published: March 2021

LINAC radiotherapy devices can produce scattering radiation and leak radiation from the gantry. The doses of scattering radiation result from the scattering radiations from the wall (HST) and the patient (HPS). Gantry leak radiation is gantry leak radiation through the labyrinth hall (HLS) and the one that goes directly to the entrance (HLT). These four components play a role in producing radiation doses at the entrance. The scattering radiation in the LINAC 6 MV radiotherapy installation can spread in all directions. Therefore, there is a need for a special review to examine the scattering radiation to the entrance of the room. The constituent of the radiation retaining wall also influences the reflection coefficient of the wall (α). Therefore, it is important to pay attention to the α value in evaluating the radiation dose at the labyrinth entrance. Radiation protection efforts for radiation workers and the community around the radiotherapy room need to be considered by creating a radiation barrier that can minimize the radiation received. With that in mind, the purpose of this study is to examine several possible materials for radiation shielding, especially at the entrance of the radiotherapy room. Materials used for the entrance are lead (Pb), borated polyethylene (BPE), aluminum (Al), and iron (Fe) with a thickness of 6 mm, respectively. The variation of the reflected angle used in the calculation of HST, HLS, and HPS values starts from an angle of 50° to 80°. The result showed that the most effective material for reducing the amount of radiation is lead with effectiveness of 86.79%.
Utilization of livestock manure as a source of biogas for renewable energy
Authors: Kusumandari K. , Iriani Y. , Suryana R. , Nurosyid F. , Widiyandari H. , Khairuddin K.
Published: March 2021

Research on energy resources other than oil and gas continues to be conducted. Indonesia as an agricultural country has abundant natural resources that can be used as an alternative energy source, namely bioenergy. One type of bioenergy is biogas which is derived from organic waste from plants and livestock manure. In this study, optimization of the utilization of livestock manure as a source of biogas is carried out by creating a household biogas system. The type of reactor in this study is a fixed digester. Livestock manure came from five cattle with the amount of around 15 kg/day of each. The ratio of livestock manure and water is of 1: 1 Optimization is done by functional test and combustion test on the 15th day. The range of tests is 30 – 40 of pressure. And it reaches an optimum value at a pressure of 40. The temporary gas reservoir made from tires that are connected between the digester tank and the stove is used to maintain the gas supply from the digester tank. Moreover, the flame can burn steadily for up to more than one hour of use. Finally, this biogas system from livestock manure is expected to be used as alternative energy for a rural area.