bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of environmental factors on the detection of subsurface green turtles in aerial drone surveys
Authors: Odzer Michael N. , Brooks Annabelle M. L. , Heithaus Michael R. , Whitman Elizabeth R.
Published: February 2022

Abstract Context Aerial video surveys from unpiloted aerial systems (UAS) have become popular in wildlife research because of increased accessibility to remote areas, reduction of anthropogenic disruption to habitats and wildlife, low operating costs, and improved researcher safety. In shallow marine systems, they can provide opportunities to rapidly survey species that cannot easily be surveyed using boat- or land-based techniques. However, detectability of subsurface animals in marine habitats may be affected by environmental factors. Aims We investigated the effects of water depth, seagrass cover, surface glare, and observer numbers and expertise on the probability of detecting subsurface green turtles in UAS video surveys. Methods We deployed inanimate green turtle decoys at randomised intervals along 24 pre-determined transects across a depth gradient in a seagrass-dominated bay off Great Abaco, The Bahamas. We collected aerial videos of the transects by flying a DJI Phantom 3 Advanced quadcopter drone at an altitude of 10 m over each transect. Three independent observers watched each video and recorded decoy sightings to compare detection probabilities across observer experience levels. We used a generalised linear model to test for the effects of glare, water depth, wind speed, and seagrass cover on the detectability of turtle decoys. We also recorded glare conditions with aerial videos taken at 2-h intervals over a still body of water on cloudless days off North Miami, FL. Key results Individual observers performed similarly, but adding one additional observer increased detection by 11–12% and adding a third observer increased detections by up to 15%. Depth, seagrass cover, and glare significantly affected decoy detections. In both summer and fall, the optimal times and directions to minimise glare in aerial video surveys were 0800 hours, facing any direction other than north, and 1800 hours, facing any direction other than south. Conclusions The number of human observers and environmental variables, especially depth, seagrass cover, and glare, are important to explicitly consider when designing and analysing data from UAS surveys of subsurface animal abundances and distribution. Implications Our study draws attention to potential limitations of UAS-acquired data for subsurface observations if environmental conditions are not explicitly accounted for. Quantifying the effects of environmental factors, designing surveys to minimise variance in these factors, and having multiple observers are crucial for optimising UAS use in research and conservation of sea turtles and other marine fauna.
A hyperpromiscuous antitoxin protein domain for the neutralization of diverse toxin domains
Authors: Kurata Tatsuaki , Saha Chayan Kumar , Buttress Jessica A. , Mets Toomas , Brodiazhenko Tetiana , Turnbull Kathryn J. , Awoyomi Ololade F. , Oliveira Sofia Raquel Alves , Jimmy Steffi , Ernits Karin , Delannoy Maxence , Persson Karina , Tenson Tanel , Strahl Henrik , Hauryliuk Vasili , Atkinson Gemma C.
Published: February 2022

Significance

Toxin–antitoxin systems are enigmatic and diverse elements of bacterial and bacteriophage genomes. We have uncovered remarkable versatility in an antitoxin protein domain that has evolved to neutralize dozens of different toxin domains. We find that antitoxins carrying this domain—Panacea—form complexes with their cognate toxins, indicating a direct neutralization mechanism, and that Panacea can be evolved to neutralize a noncognate and nonhomologous toxin with just two amino acid substitutions. This raises the possibility that this domain could be an adaptable universal or semi-universal protein neutralizer with significant biotechnological and medical potential.
Epigenetic state determines inflammatory sensing in neuroblastoma
Authors: Wolpaw Adam J. , Grossmann Liron D. , Dessau Jessica L. , Dong May M. , Aaron Bailey J. , Brafford Patricia A. , Volgina Darya , Pascual-Pasto Guillem , Rodriguez-Garcia Alba , Uzun Yasin , Arsenian-Henriksson Marie , Powell Daniel J. , Bosse Kristopher R. , Kossenkov Andrew , Tan Kai , Hogarty Michael D. , Maris John M. , Dang Chi V.
Published: February 2022

Significance

Making immunotherapy more widely effective requires improved understanding of the pathways that regulate the interactions between tumor and immune cells. This work identified a previously unappreciated difference in these pathways between heterogenous epigenetic states that coexist in neuroblastoma. The generally rarer mesenchymal subpopulation has more active inflammatory sensing and signaling, revealing a potential immunologic vulnerability of these chemotherapy-resistant cells.
A dominant negative variant of
RAB5B
disrupts maturation of surfactant protein B and surfactant protein C
Authors: Huang Huiyan , Pan Jiehong , Spielberg David R. , Hanchard Neil A. , Scott Daryl A. , Burrage Lindsay C. , Dai Hongzheng , Murdock David , Rosenfeld Jill A. , Mohammad Ariz , Huang Tao , Lindsey Anika G. , Kim Hyori , Chen Jian , Ramu Avinash , Morrison Stephanie A. , Dawson Zachary D. , Hu Alex Z. , Tycksen Eric , Silverman Gary A. , Baldridge Dustin , Wambach Jennifer A. ,   Undiagnosed Diseases Network, Pak Stephen C. , Brody Steven L. , Schedl Tim
Published: February 2022

Significance

The Rab5 GTPase functions in early endosome (EE) fusion in the endocytic pathway. Here, we propose that RAB5B also has a noncanonical vesicular fusion function in the regulated secretion pathway that produces mature surfactant proteins SP-B and SP-C in the lung. This function was revealed from investigation of a proband with interstitial lung disease suggestive of a surfactant dysfunction disorder who carried a de novo Asp136His variant in the
RAB5B
gene. Our modeling in
C. elegans
provided information on the genetic and cell biological mechanism, and analyses of proband and normal lung biopsies suggested a function for RAB5B and EEs in surfactant protein processing/trafficking. This work indicates that
RAB5B
p.Asp136His causes a surfactant dysfunction disorder.
MRP5 and MRP9 play a concerted role in male reproduction and mitochondrial function
Authors: Chambers Ian G. , Kumar Praveen , Lichtenberg Jens , Wang Pengcheng , Yu Jianshi , Phillips John D. , Kane Maureen A. , Bodine David , Hamza Iqbal
Published: February 2022

Significance

Multidrug Resistance Proteins (MRPs) are typically implicated in cancer biology. Here, we show that MRP9 and MRP5 localize to mitochondrial-associated membranes and play a concerted role in maintaining mitochondrial homeostasis and male reproductive fitness. Our work fills in significant gaps in our understanding of MRP9 and MRP5 with wider implications in male fertility. It is plausible that variants in these transporters are associated with male reproductive dysfunction.
Transmission potential of human schistosomes can be driven by resource competition among snail intermediate hosts
Authors: Civitello David J. , Angelo Teckla , Nguyen Karena H. , Hartman Rachel B. , Starkloff Naima C. , Mahalila Moses P. , Charles Jenitha , Manrique Andres , Delius Bryan K. , Bradley L. M. , Nisbet Roger M. , Kinung’hi Safari , Rohr Jason R.
Published: February 2022

Significance

Predicting how ecological interactions among vectors or intermediate hosts of human parasites influence transmission potential to humans remains challenging. Here, we focus on human schistosomiasis and demonstrate how resource competition among snails profoundly alters the link between infected snails, the target of control, and schistosome cercariae, the cause of human infections. We integrated an individual-based bioenergetics model of snail and schistosome dynamics with experiments in artificial waterbodies and field observations to anticipate and explain how resource-sensitive schistosome infections and resource competition among snails interact to generate brief peaks in transmission potential when snail populations grow from low densities. A resource-explicit view of snail and schistosome dynamics could maximize the potential for snail control methods to contribute to control of schistosomiasis.
On overtravel and skate in cantilever-based probes for on-wafer measurements
Authors: Arscott Steve
Published: February 2022

Due to the deformability of a microcantilever-based probe, there is an interesting and subtle interplay between the probe overtravel, the tip skate on the surface, and the ultimate tangency of the tip of the probe with the wafer surface. The relationship between these parameters is described here. The scalable model is tested using a macroscopic cantilever and found to be accurate in its predictions. In addition, to avoid potential skate-induced damage to metallisation, the idea of zero-skate using a cantilever-based probe has been introduced; minimal skate is demonstrated using a macroscopic cantilever—the skate can be reduced by a factor of 0.176. As the model is scalable, this information could be of use to the designer of emerging miniature microelectromechanical systems (MEMS) microcantilever-based surface contact probes destined for on-wafer electrical measurements or the test engineer concerned with on-wafer probe contacting—where skate and overtravel are important practical concerns having repercussions in electrical contact quality. Some predictions of the modelling for microcantilever-based probes are provided.
Bipolar resistive switching properties of TiO
x
/graphene oxide doped PVP based bilayer ReRAM
Authors: Lodhi Anil , Saini Shalu , Dwivedi Anurag , Khandelwal Arpit , Tiwari Shree Prakash
Published: February 2022

In this paper, firstly, some recently explored promising materials and processes for resistive random access memory (ReRAM) devices with bipolar switching mechanism along with their performance are discussed. Further, resistive switching behaviour of TiO
x
/graphene oxide (GO):poly(4-vinylphenol) (PVP) based bilayer in ReRAM devices is demonstrated. It was found that bipolar resistive switching behaviour is significantly enhanced by embedding 2D material such as GO in the organic polymer acting as switching layer. ReRAM devices with Ag/PVP:GO/TiO
x
/fluorine doped tin oxide (FTO) structure exhibited high ON/OFF current ratio (>103), low voltage operation, and high retention time. Bipolar resistive switching from these engineered active layers will have great potential for future large area and sustainable electronics.
Low-energy elastic electron scattering cross sections of acrylic acid and its methylated derivatives
Authors: Frighetto Francisco Fernandes , Bettega M H F
Published: February 2022

In the present work we report elastic cross sections for electron scattering from acrylic acid (CH2 = CH-COOH) and its methylated derivatives, crotonic acid (CH3-CH = CH-COOH), methacrylic acid (H2C = C(CH3)COOH) and methyl acrylate (CH2 = CHCOOCH3). The calculations were performed with the Schwinger multichannel method for impact energies up to 15 eV. Two π* shape resonances were found in the component of the integral cross sections (ICSs) for the A″ symmetry of all molecules. The resonance positions obtained for the acrylic acid are compared with existing experimental results for dissociative electron attachment. We investigated the influence of methylation through the comparison of the positions and widths of the shape resonances in the component of the ICS of the A″, and the oscillation patterns in the differential cross sections of all molecules. We also present the momentum transfer cross section for electron scattering from all molecules studied.
An experimental and theoretical study of the Kr 3d correlation satellites
Authors: Kiselev M D , Reinhardt M , Patanen M , Kivimäki A , Powis I , Zatsarinny O , Grum-Grzhimailo A N , Holland D M P
Published: February 2022

The Kr 3d correlation satellites have been studied experimentally by using plane polarized synchrotron radiation to record polarization dependent photoelectron spectra (PES), and theoretically by employing the R-matrix method to calculate photoionization cross sections, PES and angular distributions. The experimental spectra have allowed the photoelectron anisotropy parameters characterizing the angular distributions, and the intensity branching ratios, related to the photoionization partial cross sections, to be evaluated. The results are discussed in terms of normal and conjugate shake-up processes. The experimental and calculated photoelectron angular distributions associated with those correlation satellites that arise predominantly through conjugate shake-up mechanisms are shown to be isotropic. In contrast, the anisotropy parameters associated with satellites due to normal shake-up processes exhibit a dependence on electron kinetic energy similar to that of the anisotropy parameters corresponding to the Kr 3d main lines. The theoretical results include an analysis of the partial waves representing the emitted photoelectron and, for certain correlation satellites, show that a particular ionization continuum dominates. This, in turn, may allow the dominant normal or conjugate shake-up mechanism forming the satellite to be identified.
Effect of mechanical nonlinearity on the electromagnetic response of a microwave tunable metamaterial
Authors: Karimi Mahabadi Rayehe , Goudarzi Taha , Fleury Romain , Orazbayev Bakhtiyar , Naghdabadi Reza
Published: February 2022

Tunable metamaterials functionalities change in response to external stimuli. Mechanical deformation is known to be an efficient approach to tune the electromagnetic response of a deformable metamaterial. However, in the case of large mechanical deformations, which are usually required to fully exploit the potential of the tunable metamaterials, the linear elastic mechanical analysis is no longer suitable. Nevertheless, nonlinear mechanical analysis is missing in the studies of mechanically tunable metamaterials. In this paper, we study the importance of considering nonlinearity in mechanical behavior when analyzing the response of a deformable metamaterial and its effects on electromagnetic behavior. We consider a microwave metamaterial formed by copper four-cut split ring resonators on a Polydimethylsiloxane (PDMS) substrate. Applying both displacement and force stimuli, we show that when the deformation is large, more than 10 percent strain, the use of nonlinear analysis considering the geometrical and material nonlinearities is imperative. We further show that the discrepancies between the linear and nonlinear analyses appear in overestimating the stress, underestimating the tunability of the metamaterial responses, and mispredicting the negative permeability regions.
High-performance CdS@CsPbBr3 core–shell microwire heterostructure photodetector
Authors: Dai Guozhang , Xiang Yang , Mo Xindi , Xiao Zhixing , Yuan Hua , Wan Jiaxing , Liu Biao , Yang Junliang
Published: February 2022

A core–shell heterojunction has been developed to fabricate efficient optoelectronic devices by optimizing the light absorption and promoting the generation and extraction of charge carriers. Herein, the CdS@CsPbBr3 core–shell microwire (MW) heterojunction was structured via a two-step chemical vapor deposition and was further used to fabricate a UV–Vis photodetector. The photodetector performance is greatly dependent on the thickness of the CsPbBr3 shell. Growth time of 60 min could produce about 80 nm thick CsPbBr3 shell with excellent coverage and adhesion, resulting in optimized performance parameters. As compared with bare cadmium sulfide (CdS) MW photodetector, the CdS@CsPbBr3 core–shell MW heterojunction photodetector exhibits relatively high ratio of photocurrent and dark current (104), much higher light responsivity (319.79 A W−1) and faster response time (6.6 ms). The responsivity is 3.3 times to the value of bare CdS photodetector and the photocurrent increases nearly 10 times. The significant performance parameters mainly result from the formation of a type-II energy band structure and the reduction of the defects states on CdS surface, leading to the obviously improved carriers transport process. The results indicate that the CdS@CsPbBr3 core–shell MW heterojunction is a promising potential candidate to construct high-performance electronic and optoelectronic devices.
Investigation of out-of-plane ordered Ti4MoSiB2 from first principles
Authors: Helmer Pernilla , Lind Hans , Dahlqvist Martin , Rosen Johanna
Published: February 2022

The laminated ternary boride Mo5SiB2 of T2 structure have two symmetrically inequivalent metallic sites, 16l and 4c, being occupied in a 4:1 ratio. The phase was recently shown to be stable for 80% substitution of Mo for Ti, at the majority site, forming an out-of-plane chemically ordered quaternary boride: Ti4MoSiB2. Considering that the hypothetical Ti5SiB2 is theoretically predicted as not stable, a key difference in bonding characteristics is indicated for full substitution of Mo for Ti at the metallic sites. To explore the origin of formation of Ti4MoSiB2, we here investigate the electronic properties and bonding characteristics of Mo5SiB2, Ti4MoSiB2 and Ti5SiB2 through their density of states, projected crystal orbital Hamilton population (pCOHP), Bader charge partitioning and second order force constants. The bond between the two different metallic sites is found to be key to the stability of the compounds, evident from the pCOHP of this bond showing a peak of bonding states close to the Fermi level, which is completely filled in Mo5SiB2 and Ti4MoSiB2, while only partially filled in Ti5SiB2. Furthermore, the lower electronegativity of Ti compared to Mo results in charge accumulation at the Si and B sites, which coincides with a reduced bond strength in Ti5SiB2 compared to Mo5SiB2 and Ti4MoSiB2. Bandstructure calculations show that all three structures are metallic. The calculated mechanical and elastic properties show reduced bulk (B) and elastic (E) moduli when introducing Ti in Mo5SiB2, from 279 and 365 GPa to 176 and 258 GPa, respectively. The Pugh criteria indicates also a slight reduction in ductility, with a G/B ratio increasing from 0.51 to 0.59.
Models of Ni- and Co-ion occupation in LiNi0.5Co0.5PO4 orthophosphate and its magnetic structure
Authors: Semkin M A , Urusova N V , Hoser A , Neznakhin D S , Pirogov A N
Published: February 2022

The neutron diffraction, magnetic and heat capacity measurements have been carried out to study the polycrystalline sample LiNi0.5Co0.5PO4 prepared by the glycerol-nitrate synthesis method. Models of Ni- and Co-ion occupation the 4c octahedral position in a crystal structure LiNi0.5Co0.5PO4 are calculated for a paramagnetic state. The best model is the Ni- and Co-ions occupy the 4c site in Pnma patent space-group in sequence Ni–Co–Ni–Co or Co–Ni–Co–Ni. It is shown that nickel ions form ab planes alternating with the planes of cobalt ions in the direction of the c crystallographic axis. At 7 K, an average magnetic moment of 3d-ions is equal to 1.90 (9) μ
B. The moments are ordering antiferromagnetically and parallel to the bc plane decreasing to zero at 15 K. In the high-spin state a temperature dependence of the Ni2+/Co2+ ion-magnetic moment is well described within the 2D Ising model with order parameter β = 0.198 and Néel temperature T
N = 14.1 (1) K, obtained from heat capacity data. This temperature agrees well with T
cr = 14.3 (2) K, determined with magnetic measurement. Maybe the short-range magnetic order exists in LiNi0.5Co0.5PO4 over temperature region (14–16) K, that is confirmed by the maximum on a temperature dependence of the magnetization at 16.1 (5) K.
Scattering theory of non-equilibrium noise and delta T current fluctuations through a quantum dot
Authors: Popoff A , Rech J , Jonckheere T , Raymond L , Grémaud B , Malherbe S , Martin T
Published: February 2022

We consider the non-equilibrium zero frequency noise generated by a temperature gradient applied on a device composed of two normal leads separated by a quantum dot. We recall the derivation of the scattering theory for non-equilibrium noise for a general situation where both a bias voltage and a temperature gradient can coexist and put it in a historical perspective. We provide a microscopic derivation of zero frequency noise through a quantum dot based on a tight binding Hamiltonian, which constitutes a generalization of the seminal result obtained for the current in the context of the Keldysh formalism. For a single level quantum dot, the obtained transmission coefficient entering the scattering formula for the non-equilibrium noise corresponds to a Breit–Wigner resonance. We compute the delta-T noise as a function of the dot level position, and for a broad range of values of the dot level width, in the Breit–Wigner case, for two relevant situations which were considered recently in two separate experiments. In the regime where the two reservoir temperatures are comparable, our gradient expansion shows that the delta-T noise is dominated by its quadratic contribution, and is minimal close to resonance. In the opposite regime where one reservoir is much colder, the gradient expansion fails and we find the noise to be typically linear in temperature before saturating. In both situations, we conclude with a short discussion of the case where both a voltage bias and a temperature gradient are present, in order to address the potential competition with thermoelectric effects.
Monoclinic–triclinic phase transition induced by pressure in fergusonite-type YbNbO4
Authors: Garg A B , Liang A , Errandonea D , Rodríguez-Hernández P , Muñoz A
Published: February 2022

We have carried out a high-pressure study on monoclinic fergusonite-type YbNbO4. Synchrotron powder x-ray diffraction experiments and density-functional theory simulations have been performed. We found a gradual increase of symmetry under compression, with calculations predicting a second-order monoclinic–tetragonal transition at 15 GPa. However, experiments provided evidence of a transition at 11.6 GPa to a triclinic structure, described by space group

P

1

¯

. The appearance of the triclinic phase, which according to calculations is dynamically unstable under hydrostatic conditions, seems to be related to the presence of non-hydrostatic stresses. The triclinic high-pressure phase remains stable up to 31.9 GPa and the phase transition is not reversible. We have determined the pressure dependence of unit-cell parameters of both phases and calculated their room-temperature equation of state. For the fergusonite-phase we have also obtained the isothermal compressibility tensor. In addition to the high-pressure studies, we report ambient-pressure Raman and infrared spectroscopy measurements which have been compared with density-functional theory calculations.
Research on angle sensitivity of the boron-lined multilayer converter neutron detector
Authors: Deng Chao , Liu Fule , Wang Qibiao , Tuo Xianguo , Peng Shuming , Wu Yang , Yang Hongchao , Dai Heng
Published: February 2022

In our previous work, a new design for a gaseous neutron detector composed of a boron-lined multilayer converter was proposed to replace the 3He proportional counter, and a prototype detector was constructed to test its performance and characteristics. The neutron detection efficiency varies for different incident angles of neutrons to the converter surface, mainly due to the effective area of the converter and the emitting probability of the alpha and 7Li. Hence, the variation of detection efficiency with the incident angle is analyzed theoretically in this work, and then the GEANT4 simulations and preliminary experimental tests are conducted to verify the calculation results. The highest detection efficiency is obtained at 1.72° (100 mm length, 3 mm gap, and θ = atan (3/100) ≈ 1.72°), the detection efficiency decreases sharply when the angle approaches 0°, and the detection efficiency decreases gradually when the incident angle is larger than 1.72°. The simulation results and experimental results are consistent with the trend of theoretical calculation. Therefore, the proposed detector is suitable for angle-sensitive applications, such as small angle neutron scattering and locating the isotopic neutron sources.
Comparison of volume measurements of mass standards at low pressures and in liquids
Authors: Zůda Jaroslav
Published: February 2022

The determination of the volumes of mass standards is key to the precise determination of their masses, due to the effect of the air buoyancy force. The buoyancy force can either be reduced by mass determination at low pressure or enlarged for a determination of the apparent mass using a vessel filled with liquid. The standard method for the volume calibration of weights is comparison in liquid, as described in the document OIML R111. This report presents the results of calibrating the volumes of stainless-steel mass standards with a nominal mass of 1 kg at low pressure and in a liquid. The authors showed that both methods produced comparable results with maximum differences of 0.002 cm3 when adjusted for a standard temperature of 20 °C. The typical uncertainty in the volumes given by both methods is 0.002 cm3. A major source of uncertainty is the volume of the reference weight. The authors conclude that both methods produce consistent results, so that the method of volume calibration at low pressure can be used instead of hydrostatic weighing. The advantage of this approach is that both the masses and volumes of the weights are measured using the same mass comparator, which requires less manipulation. This study will help to establish the procedures for the dissemination and transfer of the mass unit from vacuum to ambient conditions in the institute of the author.
An all-fiber diaphragm-based extrinsic Fabry–Perot sensor for the measurement of pressure at ultra-low temperature
Authors: Zhang Yutong , Jiang Yi , Cui Yang , Feng Xinxing , Hu Jie
Published: February 2022

An all-fiber diaphragm-based extrinsic Fabry–Perot interferometer (EFPI) sensor for the measurement of pressure at ultra-low temperature is proposed and experimentally demonstrated. The sensor head is manufactured at the end of a single mode fiber with a micro hole and a fiber diaphragm. By femtosecond (fs) laser micromachining, sensors with different sensitivities can be fabricated with different diameter of the micro hole and different thickness of the diaphragm. The deformation of the diaphragm has a linear relationship with the applied pressure. This EFPI is used to measure the pressure at temperature of −196 °C by monitoring the cavity length of the interferometer. Experiment results show the sensor exhibits good linearity within a pressure range from 0 to 7 MPa, and the pressure sensitivities at −196 °C during the process of pressure increasing and decreasing are 111.17 and 111.22 nm MPa−1, respectively. The proposed all-fiber pressure sensor can find applications in ultra-low temperature environment.
State-of-the-art nanotechnologies used in the development of SARS-CoV-2 biosensors: a review
Authors: Lee Dongtak , Lee Taeha , Hong Ji Hye , Jung Hyo Gi , Lee Sang Won , Lee Gyudo , Yoon Dae Sung
Published: February 2022

The coronavirus disease (COVID-19) pandemic has spread to nearly every corner of the globe, significantly impacting economies and societies. Despite advances in detection technologies that target viral pathogens, all countries are facing an unprecedented need to perform biosensing in a rapid, sensitive, selective, and reliable way to deal with global and urgent problems. To date, the reverse transcription-polymerase chain reaction has been the gold-standard method for COVID-19 diagnosis. However, it requires complex facilities and elaborate training and is hampered by limited testing capacity and delayed results. Herein, we review state-of-the-art research into point-of-care biosensors for early severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection. We include a general description of the nanotechnological techniques used to develop biosensors, along with the latest research into various biosensors for SARS-CoV-2 detection and a summary of their limitations for practical use. Finally, we discuss future perspectives and directions. This critical review offers the biosensor community insight into how to progress the present research, which may streamline the removal of the problems facing rapid and large-scale SARS-CoV-2 screening.
Comparison of electrical characteristics of Schottky junctions based on CdS nanowires and thin film
Authors: Dang Hongmei , Ososanya Esther , Zhang Nian
Published: February 2022

CdS nanowires and film Schottky diodes are fabricated and diode properties are compared. Effect of SnO2 on CdS film diode properties is investigated. CdS film/Au on 100 nm SnO2 substrate demonstrates like-resistor characteristics and increase in SnO2 thickness corrects resistor behavior, however the effective reverse saturation current density J
o is significantly high and shunt resistance are considerably low, implying that SnO2 slightly prevents impurities migration from CdS films into ITO but cause additional issues. Thickness of CdS film on diode properties is further investigated and increasing CdS film thickness improved J
o by one order of magnitude, however shunt resistance is obviously low, suggesting intrinsic issues in CdS film. 100 nm CdS nanowire/Au diodes reduce J
o by three orders of magnitude in the dark and two orders of magnitude in the light respectively and their shunt resistance is significantly enhanced by 70 times when comparing with those of the CdS film diodes. The wide difference can be attributed to the fact that CdS nanowires overcome intrinsic issues in CdS film and thus demonstrate significantly well- defined diode behavior. Simulation found that CdS nanowire diodes have low compensating acceptor type traps and interface state density of 5.0 × 109 cm−2, indicating that interface recombination is not a dominated current transport mechanism in the nanowire diodes. CdS film diodes are simulated with acceptor traps and interface state density increased by two order of magnitude and shunt resistance reduced by one order of magnitude, indicating that high density of interface states and shunt paths occur in the CdS film diodes.
Determination of the band gap of germanium and silicon using ExpEYES-17 kit
Authors: Biswas Subhrajyoti
Published: February 2022

In this article we present a simple experimental set-up to determine the band gap of germanium and silicon using the ExpEYES-17 kit. The experiment is based on the temperature dependence of the reverse current through germanium and silicon diodes at different temperatures. The experimental values are found to agree well with accepted values.
Elongation effect on the recorded moving bar analysis using Tracker
Authors: Santosa I E
Published: February 2022

The image of free-falling bar has been recorded to study the effect of the motion on its observed length. This moving bar image is analysed using the Tracker software to determine its length and the end bar’s position. An elongated appearance of the bar has been observed with movement. This effect relies on the speed and the exposure time during image recording. When recording at 25 fps with exposure time of 0.04 s, the 33 cm bar’s apparent size becomes (54.4 ± 0.6) cm at speed of 5.88 m s−1. The elongation is shorter with a shorter exposure time.
Enhancing sustainability and elasticity of synthetic fibers by tandem repeat proteins
Authors: Dursun Burcu , Mazeed Tarek El-Sayed , Colak Oguzhan , Boy Ramiz , Demirel Melik C
Published: February 2022

Protein fiber production in heterologous organisms, such as bacteria, provides a new possibility for engineering high-performance materials and composites. The discovery and design of sustainable materials that are biological or inspired by biological principles are essential for the development and production of the next generation of circular bioeconomy. Here, we created a hybrid of biological and synthetic materials by combining bio-engineered proteins with synthetic acrylic polymers to enhance the sustainability and elasticity of the blend fibers. First, we developed an optimized expression (i.e. yield exceeding 1 g l−1) and purification method (>80% purity) for squid ring teeth inspired by tandem proteins at the facility scale. We showed that our protein-based powder, produced via industrial fermentation, can be manufactured into braided yarns with acrylic using wet-spinning. Our fibers have enhanced elasticity when hydrated due to the hydrogen network between the protein and acrylic fibers.
Short wavelength infrared InPSb/InAs superlattice photodiode grown by metalorganic chemical vapor deposition
Authors: Zhu Hong , Zhu He , Liu Jiafeng , Hao Xiujun , Teng Yan , Huai Yunlong , Li Meng , Liu Zhen , Huang Yong
Published: February 2022

We report the growth and characterization of InPSb/InAs superlattice (SL) materials and devices in the short-infrared wavelength range by metalorganic chemical vapor deposition (MOCVD). Good structural quality was achieved with a lattice mismatch of less than 0.09% and smooth surfaces with a roughness of only 0.304 nm. A pin homojunction photodetector with 10 monolayer (ML) InPSb/2 monolayer (ML) InAs SLs on InAs substrate was grown and fabricated. At 77 K, the device demonstrated a 100% cut-off wavelength of ∼2.6 μm, a dark current density of 8.7 × 10−10 A cm−2 at −0.1 V bias voltage, and a specific detectivity of 1.3 × 1013 cm·Hz1/2/W at 2.0 μm.
Conceptual design of the ALIANCE-T mirror experiment
Authors: Yakovlev D. , Chen Z. , Bagryansky P. , Bragin A. , Kotelnikov I. , Kuzmin E. , Prikhodko V. , Shikhovtsev I. , Usov P. , Wang Z. , Zeng Q. , Dong L. , Zhang K. , Ivanov A. , Yu J.
Published: February 2022

The paper describes the conceptual design of a small-scale experiment within the fusion neutron source project ALIANCE (Axisymmetric LInear Advanced Neutron sourCE). The experimental machine is an axially symmetric magnetic plasma trap with a high mirror ratio, which focuses on the physical and engineering problems of mirror-based gasdynamic neutron sources. The specific research topics covered include the magnetohydrodynamic (MHD) stability of plasmas with high mirror ratios, the operation of the electrodes used for plasma stabilization, and problems related to particle and energy transport. ALIANCE-T features superconducting mirror solenoids that enable it to reach mirror ratios of ∼100 and a helicon plasma source with a power of up to 25 kW installed directly in the confinement zone between the mirrors. The expected plasma parameters are estimated using a simple analytical model, which takes into account gasdynamic axial plasma losses, cross-field transport, and the interaction of the plasma with neutral gas. It is projected that the machine will simultaneously achieve a plasma density >1013 cm−3 and a temperature >10 eV in a continuous discharge lasting for 1–8 h. This paper gives a detailed description of the key machine subsystems and introduces the analytical model used for calculation of the plasma parameters.
Comparison of voltage drop in AC and DC shipboard electrical power distribution systems: A case study of 17,500 DWT tanker vessel
Authors: Kurniawan Akhmad R. , Kurniawan Adi , Sarwito Sardono , Gumilang Ahlur R.N. , Budianto Firman
Published: February 2022

The recent emergence of power electronics equipment raises the possibility of implementation of DC shipboard electrical distribution systems. Several investigations on the effectiveness of DC shipboard electrical power distribution systems have proven that it is more profitable than AC distribution systems both in technical and economical aspect. However, known investigations are still limited to the system in ship with electric propulsion, which the consumption of electric power is enormous. The current study investigates the technical performance of both distribution systems in a non-electric propulsion ship, especially in the aspect of power losses. Both of the original AC distribution systems in a 17,500 DWT tanker ship and its equal DC distribution systems are modelled in a computer simulation program. The electric power flow simulation for both models are performed with the data of electric load during operating conditions, to compare the power losses in the distribution systems. The results show that the DC distribution systems has fewer drop voltage than its AC counterpart.
Design and finite element analysis of gondola construction for multibeam echosounder (MBES) installation on RV Baruna Jaya III - BPPT
Authors: Putra Arfis Maydino Firmansyah , Fuad Nur Muhamad , Handoyo Tris
Published: February 2022

The revitalization of hydrographic equipment at the Research Vessel (RV) Baruna Jaya III has been carried out by the Technology Center for Marine Survey (BTSK) – BPPT to improve its service capabilities. A Multi-Beam Echosounder (MBES) for the deep-sea mapping up to 8000 meters depth has been chosen to replace the existing equipment which only has a mapping capability of 3000 meters depth. MBES requires a support construction mounted on the vessel hulls as its housing, considering the installation principle from both the shipowner and MBES maker. In this research, a gondola installation principle has been agreed to develop. The gondola construction has been designed in consideration of actual vessel conditions and several requirements by the MBES maker. The design construction is further analyzed using the finite element method (FEM) to ensure its strength and safety and meet Indonesian Classification Society (BKI) minimum requirements. The analysis conditions are divided into 3; hydrostatic load (A), sensors load (B), and the combination of hydrostatic and sensor load (C). The von Mises stress was obtained from finite element analysis for conditions A, B, and C, respectively, 164 MPa, 1.552 MPa, and 160.8 MPa. The analysis results in all loading conditions have met the minimum allowable stress required by Indonesia Classification Society rules, which is 180 MPa. In conclusion, the design of the gondola construction for MBES installation on RV Baruna Jaya III has good structural strength and safety, so it is feasible to use.
Fatigue Life Prediction of Mooring Line on Indonesian Tsunami Early Warning Systems (Ina-TEWS) Buoy
Authors: Priohutomo Kusnindar , Nugroho Wibowo Harso , Arianti Erdina , Priatno Dany Hendrik
Published: February 2022

Ina-Buoy Gen 3.1 is one of the application of the program that has been developed by BPPT (Agency for the Assessment and Application of Technology) in order to reduce the risk of a tsunami disaster in Indonesia. This Indonesian Buoy for Tsunami Early Warning System (INATEWS - Buoy) consists of a tsunami buoy, an ocean bottom unit (OBU), a satellite and a ground station. This paper discuss about calculation of fatigue life due to wave loads for the mooring line that used to hold the buoy position in the sea. A taut mooring system is applied to the buoy until sinker at seabed. Calculation of operational tension at mooring line obtained using numerical simulation fully licensed software Orcaflex ver 11 owned by Centre Technology for Maritime Industrial Engineering (PTRIM), BPPT with wave input of Hs=2.5m and Tp=10.5sec. The depth of sea is varied at 2088m (Sunda Strait), 3563m (Cilacap Sea) and 4082m (Bali Strait). By knowing those tension forces, stress at time history on the mooring line can be obtained. This stress time history is then applied to Palmgren – Miner formula that based on SN-Curve of the mooring line material to predict the life of the mooring line. By applying a safety factor of 2.5 it is found that the fatigue life of the mooring line at water depth of 2088m in Sunda Strait is 6,9 years, then, at water depth of 3563 m in Cilacap Sea is 15,8 years, finally at water depth of 4082 m in Bali Strait is 10 years.
The development of internet-of-things (IoT)-based safety monitoring system in north sea madura
Authors: Maulidi A , Irmiyana T , Ilman A F , Annafiyah  , Kuzzairi
Published: February 2022

Internet of Things (IoT) is a concept where an object has the ability to transfer data over a network without requiring human-to-human or human-to-computer interaction, used in the navigation and monitoring systems for ships safety. This monitoring system receives data from the AIS Transceiver, the equipment installed, and integrated with the ship’s network infrastructure. The equipment transmits signatures tracking the ships sailing and going ashore as the AIS Receiverreceives them. By the increasing number of ships transporting fuels and natural gas from mine-producing areas in the north sea Madura, passenger and cargo ships heading to Surabaya port. The development of an IoT-based monitoring system is prominent, it will ease to monitor the movements of ships. It may also become the basis for further developing ships monitoring systems to improve safety operating in the north sea Madura. In the initial system design, the system can transmit and receive static data, such as ships’ID and names. Then it can transmit and receive dynamic data, such as the ships’ geographical coordinate, to identify marine traffic around the areas. Later, this system could be developed so that it not only collects data but also proceeds the data to analyze the ships condition.
Structural Analysis of Floating Net Cage Bracket in Current and Wave
Authors: Syalsabila F , Prastianto R W , Hadiwidodo Y S , Adaalah A H , Syarifudin M R
Published: February 2022

Aquaculture becomes an important industry and associates with many targets of sustainable development goals. As the aquaculture industries go forward offshore, the design of the floating net cage must be able to withstand extreme sea conditions. One of the vulnerable parts of floating net cage is the floater, especially at the bracket. There is load transfer in the bracket from net drag force, mooring tension, and horizontal force of the wave. Thus, this study aims to analyze the bracket under current and wave using the finite element method. Hydrodynamic force is based on the Morison formula. The numerical model was validated with the data obtained from corresponding experimental and numerical tests. On the basis, using the environmental condition in Pangandaran, Indonesia, the structure is simulated globally to obtain the deformation and tension. The simulations of the fish cage consist of single and double pipes. Then, the bracket at the floater will be analyzed locally to get the deformation and stress distribution. The maximum stress occurs at the connection between the horizontal and outer pipe of the bracket.
Strength Analysis of Offshore Aquaculture Net Structure Under Wave and Current Loads
Authors: Syarifudin M R , Prastianto R W , Hadiwidodo Y S , Adaalah A H , Syalsabila F
Published: February 2022

One of the main problems of floating net cages when operating is the escape of fish caused by breaking or tearing of the net. This is due to the influence of environmental loads that have been studied by several researchers. However, the influence of fish on net strength has not been considered. The schooling of fish in the cage can make the hydrodynamic flow change downstream of the cage. The collision of fish in groups on the net can increases 10–28% of the environmental load received by the net. Besides, fish bites on the net reduce the net cross-sectional area and lead to axial stiffness reduction. So, this study focuses on the analysis of the net strength to determine the net maximum tension, deformation, and the location of each parameter by considering the influence of fish in the net cage Simulations are conducted out using finite element method software with cage models based on physical and numerical experiments from prior studies. The results show that the net could withstand operating conditions. Meanwhile, in extreme conditions, the net could only survive in the 0° loading direction. The largest deformation reached 2.5 times the diameter of the cage. The collision of fish in groups on the net showed that the tensile force increased significantly when adding stress loading factor. While the effect of fish bites showed that the tensile force significantly decreased on all threads with a reduction in cross-sectional area.
Capacitated Vehicle Routing Problem Optimization for Bali and Nusa Tenggara Natural Gas Distribution
Authors: Prananda I M Gita , Pratiwi E , Dinariyana A A B , Artana K B
Published: February 2022

Utilization of gas as an energy source has become a principal issue in recent years. The Minister of Energy and Mineral Resources of the Republic of Indonesia have a plan to guarantee national energy security and improve the national trade balance, as well as accelerate the use of gas in the electricity sector. The Ministry of Energy and Mineral Resources issued a regulation to conduct the gasification process at 52 power plants in Indonesia through Ministerial Decree No. 13K of 2020. In this study, LNG distribution was designed using the Capacitated Vehicle Routing Problem (CVRP) method to minimize the transportation costs and optimal use of the fleet. The vehicles used have a limited capacity and can supply all demands at nine power plants in the Bali and Nusa Tenggara regions. In the distribution there is also have a Hub which purpose to reduce the distance travelled by a ship. The ships that will be used are Mini LNG-Carrier for the route from the LNG refinery to HUB, LCT ship for the route from HUB to each port near the power plant, and ISO Tank transport truck for the route from the port to the plant. The distribution uses four Vessel 1, and one LCT 300 vessel, with Hubs located in Benoa and Flores, and two Mini LNG-Carriers with a capacity of 15,600 m3 to Benoa and 10,000 m3 to Flores. The total cost for this scenario is US$ 51,398,568, with a minimum sales margin of US$ 2.5 per MMBTU.
Future perspective of the ship alternative fuels in Indonesia
Authors: Felayati F M , Semin  , Cahyono B , Prayogi U , Winarno A
Published: February 2022

Ship operation has a huge demand due to the ability to achieve a low-cost operation with big cargo density worldwide. Meanwhile, the ship fuel is the highest cost of the operational spending thus increasing the fuel consumption efficiency is required. Alternative fuels have been proposed to achieve it over decades of research. Indonesia, as a maritime country, also encourages the shipowner to accept the alternative fuel application. However, apply a new type of fuel directly to the existing ships is very complicated. This study aims to contribute the future direction with the author’s perspective of the implementation of the alternative fuel in Indonesia. Gas fuel type is chosen as the main case on this point of view. There are several gas fuels that are evaluated based on the maturity level of the research study case, such as natural gas and hydrogen. Moreover, the possibility of gas fuel type implementation in Indonesia is also studied. In the last, the future of natural gas and hydrogen fuels is discussed.
Virtual Reality Based Application for Safety Training at Shipyards
Authors: Wahidi S I , Pribadi T W , Rajasa W S , Arif M S
Published: February 2022

The implementation of safety training is conducted to provide knowledge on the importance of safety for its employees. However, the implementation of safety training requires many consumable things such as a lot of Portable Fire Extinguishers (PFE) that increase the operational cost and trigger the environmental pollution. This research aims to design a safety simulation based on VR (virtual reality) to provide an immersive experience for safety training and reduce the training costs. It was obtained that the application of VR technology requires two main devices namely HMD (Head-Mounted Display) and controller. Observations were conducted in the training of conventional safety and health at shipyards and training institutes. This research only simulates training on the use of PFE, fire drill, and risk observation on confined space from the ten topics of safety training based on observations that have been undertaken. Software such as Inventor, Microsoft Visual Studio, and Unity were used. After safety simulations was conducted, the result showed that safety training used VR can improve the work safety theory knowledge by 14.05%. Total cost of investment required for the development and equipment was IDR 24,043,667. The reduced cost of the safety training using VR was about IDR 193,889,154.88 or 68.13%.