bluuebunny/crossref_metadata_2025 huggingface dataset:
Vertical distribution of bacteria populations at the finfish marine culture in North Bali Coast, Indonesia
Authors: Mahardika Ketut , Mastuti Indah , Septory Reagan , Nasukha Afifah
Published: November 2023

One of the indicators of aquatic biology is the bacterial population. This study was conducted to determine the vertical distribution of bacterial populations in coastal waters at the marine fish farming in North Bali. Three locations of water samples in depths of 5, 10, 20, and 30 m samples were determined. They are shoreline near the hatcheries at Penyabangan and Gerokgak and water near the net cages at Pegametan Sumberkima. Three replications of the sample collection were done in the surface, middle, and bottom at each sampling point. Samples were collected monthly during the two seasonal transitions from April to June and August to October. The distribution of bacteria was determined by the culture-dependent method (CDM) by measuring the number of bacteria based on bacterial cultivability on agar media. The results showed a lower bacterial population (101-102 cfu/mL) was observed in August. An even distribution of total bacteria (103 cfu/mL) was seen at Pegametan Bay. Higher Vibrio spp. was found at a depth of 10 m than 20 and 30 m. While Pegametan Bay station had the highest Vibrio spp. number. Halotolerant bacteria tend to increase to 5 x 102 cfu/mL from April to June at a depth of 5.
Application of kajarula technology to the productivity of seaweed Kappaphycus striatus at Tablolong Beach, West Kupang, East Nusa Tenggara
Authors: Pratiwi Rifqah , Kusuma Ni Putu Dian , Serihollo Lukas G.G. , Amalo Pieter , Suhono Lego , Kartika I. Wayan Darya
Published: November 2023

Seaweed Kappaphycus striatus is a potential marine biological resource in Indonesia, but the cultivation uses still the conventional method (long line). The decline in production yields is affected by environmental disturbances, such as pest attacks and release due to strong currents and waves, which are also not environmentally friendly. Therefore, it is necessary to develop new cultivation methods to increase seaweed productivity. This study aims to analyze the productivity of seaweed using Kajarula (Kantong Jaring Rumput Laut, also known as seaweed net bag) technology at Tablolong Beach, West Kupang, East Nusa Tenggara. The research design used for observation data was randomized pretest-posttest Control Group Design. Next, this research is a case study that includes interviews, observations, and following the process of production of seaweed using Kajarula technology. The production performance of seaweed cultivated for 42 days resulted in biomass production of 7.54 ± 0.27 kg/units with an average relative growth of 153.41 ± 10.97 %/day, a growth rate of 239.32 ± 21.95 g/day, and a total harvest of 5.82 – 7.45 kg/units. The water quality conditions in these waters are within the optimal range to support seaweed growth. The productivity of seaweed cultivation using Kajarula technology shows optimal growth and yields.
The influence of water turbidity on the spawning success of giant gourami Osphronemus goramy Lacepède, 1801
Authors: Sularto  , Listiyowati Nunuk , Gunadi Bambang
Published: November 2023

The natural spawning of gourami (Osphronemus goramy Lac.) is influenced by various factors, including both intrinsic fish factors and external conditions like water quality, which significantly affect the spawning process's success. This study aimed to investigate how water turbidity affected the spawning process of gourami. Six ponds measuring 200 m2, classified into three categories based on turbidity levels (A. <100 NTU, B. 100 – 200 NTU, and C. >200 NTU), were monitored. Each category was replicated twice under Randomized Block Design. Parameters like spawning frequency, egg quantity, and quality were considered. The results indicated that ponds with a turbidity level of <100 NTU (with a brightness of 40-80 cm) yielded better results compared to those with 100 - 200 NTU turbidity levels (brightness of 20 - 40 cm). Conversely, ponds with >200 NTU turbidity level (brightness 10 cm) showed no signs of brood spawning. The result showed that Spawning Frequency was 83.33% (A), 61.90% (B), and 0% (C), Fecundity was 2975 eggs (A), 2795 eggs (B), and 0 egg (C), and Fertilization Rate 84.29% (A), 78.02 (B) and 0% (C). Hence, successful spawning of gourami requires water with turbidity levels below 200 NTU.
Exploring the potential ofSonneratia albaleaf boiling extract as a natural preventive measure against causing white spot syndrome virus in tiger shrimp fingerlings
Authors: Nurhidayah  , Muliani  , Susianingsih Endang , Kadriah Ince Ayu Khairana
Published: November 2023

The possibility of mass mortality in farmed shrimp populations is a risk posed by WSSV. Vaccines and chemical drugs have been created to stop WSSV infection, but they can be harmful to the environment and human health. Therefore, natural prevention options are needed. 1% boiled S. alba extract was used in this study to test the technique of immersing tiger shrimp fry at different times before WSSV infection. The study was designed in RAL with eight treatments and three repetitions: These were A) 12-hour immersion; B) 24 hours; C) 36 hours; D) 48 hours; E) 60 hours; F) 72 hours; G) WSSV infection without soakingS. albaand H) without WSSV infection andS. albaextract. Treatment C had the best survival rate (85%) while the positive control had the lowest percentage (43.33%). Tiger prawns can increase resistance to WSSV infection by soaking them in 1% extract of boiled S. alba leaves. Water quality parameters were also measured, and the experimental results showed no significant changes. According to the results, immersion of tiger shrimp fry in 1% boiled S. alba extract for 36 hours was the most efficient way to increase fry survival from WSSV infection.
Integration of forestry management tasks at the forestry level
Authors: Mavzovin Vladimir , Klevanskiy Nikolay , Shakirzyanov Dmitry , Miroshikhina Ekaterina , Yumagulova Venera
Published: November 2023

The article is devoted to the problems of forestry management. Integration of control tasks is proposed on the basis of a single database containing geometric, cartographic and taxation information. The integrated information system is focused on meeting the needs of forestry management at the forestry level. The system must have a user interface with tools for using forest resources. The functional model of the integrated system project is represented by diagrams of different levels and made it possible to identify the main approaches to creating the system. Functional modeling also showed the need to develop and include editors of forest plot boundaries into the proposed integrated system with the ability to visualize them; a layout of the proposed integrated system. To edit the boundary vertices of forest taxation units, a hierarchical decomposition has been proposed, which consists of sequential fragmentation of large areas into smaller areas.
Effectiveness of mineral fertilizers in cultivation of maize for grain under conditions of the Central Chernozem region
Authors: Malysheva Ekaterina , Nikitina Oksana , Chaplygina Marina , Dolgopolova Natalya , Fomicheva Liliya
Published: November 2023

The work is devoted to the actual topic related to the quality nutrition of corn grain. depending on the applied mineral fertilizers. Currently. the issue of increasing corn grain yield and its quality is particularly acute due to the increase in the number of farm animals and poultry. Increase in corn grain yield is currently impossible without the use of scientifically based technologies of its cultivation. Properly selected hybrid for the terrain and the use of rational doses of fertilizers together give good results of yield of this crop. Corn is such a crop that responds well to the use of various fertilizers. thereby increasing yield growth. The article considers the effectiveness of mineral fertilizers in the cultivation of maize for grain in the conditions of the Central Chernozem region.
Determination of the maximum droplet diameter during centrifugal extraction, soil analysis, contamination and waste disposal
Authors: Ponikarov Sergey I. , Ponikarov Artem S.
Published: November 2023

The prospects of the research are determined by the high potential for solving current problems related to environmental problems. Extraction allows not only the purification of chemical production waste, but also the analysis of elements distributed in the soil, which is especially important for migrating contaminants, and contaminants obtained from chemical, paint and varnish and agricultural waste. Examples of such waste are metals and their compounds, fertilizers and pesticides, and radioactive waste. These contaminants enter the human body through food chains, producing toxic, carcinogenic, and mutagenic effects. This approach has several directions that allow us to solve the problem comprehensively. In the first direction of our research, we will consider how this mathematical model can be applied in waste treatment technologies. In the second direction, we will pay attention to soil analysis. In the third research direction, we will focus on optimizing extraction and waste disposal technologies. This paper considers a mathematical model that describes the formation of the shape of droplets when moving in a field of centrifugal forces. When liquid droplets move within liquid or gaseous media, the surface of these droplets undergoes deformation, which can lead to their destruction and the formation of smaller droplets.
Monitoring the effectiveness of organizational and technological complexes of enterprises for the processing and disposal of solid waste
Authors: Kovalev Igor , Kovalev Dmitry , Tueva Evgenia , Podoplelova Valerya , Borovinsky Dmitry , Efa Svetlana
Published: November 2023

The features, requirements and architecture of the monitoring subsystem of automated management systems for solid waste processing and disposal enterprises are discussed in the article. The article proposes system architecture for the efficiency monitoring subsystem, which is implemented in the structure of the organizational and technological complex of enterprises for the processing and disposal of solid waste. This subsystem collects data on the operation of production and its management system and analyzes it in order to summarize it into specified aggregate indicators. It should be noted that the performance monitoring subsystem also implies automation of both information collection and issuance of recommendations in the event of a decrease in efficiency. This allows for the issuance of acceptable recommendations to significantly free up the time resources of the decision maker.
Wireless automated environmental monitoring system
Authors: Yumalin Timur , Salikhov Timur , Gaskarova Alina
Published: November 2023

Advancements in compact integrated circuit fabrication have allowed the amalgamation of wireless transceivers, signal processing, and sensors into a unified unit. This breakthrough enables seamless interaction with the physical realm, with applications spanning security, production oversight, and environmental monitoring. Herein, we investigate the design nuances of a distributed sensor network, where each node operates under energy and communication constraints. The integration of existing wireless technologies, computational capabilities, and organic polymers into a new breed of intelligent devices stands as a pivotal aspect. Within this article, we scrutinize the deployment of a wireless sensor network utilizing the Bluetooth Low Energy protocol. Leveraging organic polymers as a sensing stratum enhances energy efficiency and selective sensitivity in monitoring applications. Notably, the expeditious and cost-effective production of electronics rooted in organic polymers constitutes a substantial advantage. Flexible organic electronics, hinging on the semiconductor and flexible traits of organic materials, represent a foundational element of our technology. We delve into key performance prerequisites for operational devices, along with accomplishments and technical hurdles in the realm of designing and fabricating next-generation devices, targeting the optimization of products.
Automated skills control of food production specialists using a training system
Authors: Polevshchikov S. Ivan , Kravchenko Rostislav A.
Published: November 2023

The article is devoted to the development of information technologies for monitoring knowledge and skills in the training of engineering specialists in the field of food production. A methodology for monitoring the initial skills of these specialists has been developed based on a training and teaching subsystem. The technique consists of automatically generating and evaluating practical tasks using mathematical models of objects of professional activity. The use of an automated information system in the educational process, which includes implementing the specified training and education subsystem functions, will allow to reduce the teacher’s time for preparing and checking assignments; increase the accuracy of assessment of assignments during control, reduce the subjectivity of assessment (compared to checking an assignment by a teacher); reduce the time a student waits for an assessment. The considered methodology will be implemented in the form of automated information system software modules for monitoring knowledge and skills during the training of specialists. The automated information system prototype is currently used at ROSBIOTECH and MSUTU n.a. K.G. Razumovsky when training students in areas of training in the field of automation, informatization, robotization of technological and business processes.
Formation of land use system in Uzbekistan: Past and today
Authors: Kazakov Aziz , Khasanov Islom , Maxmadiyev Dostonjon , Xakberdiyev Muzaffar , Akbarkhonov Saidburkhon
Published: November 2023

Terminology of land management issue has accepted differently in every country. The article depicted the formation of land-use systems in Uzbekistan starting from 8th century till nowadays. Research has stricted with current Uzbekistan territorial boundary and its predescent states of government. Research shows how land use and landowning has changed in Arab invasion, in Temurid system, in Khanate, Soviet and independence period. The article discussed how land use terminology changed through different land policy existence in times. Land-use planning has been discussed for every period and differences. How political changes altered the land-use system in a particular period of time, based on interests of head of empires influenced on planning system, from primitive to complex land use, how the land-use system has shaped of traditions of local people have been elaborated. Land relations after gaining independence have been thoroughly studied and showed pros and cons of formation of land use in nearly last 30 years.
Improving the assessment of agricultural land reclamation condition using GIS based on the interdependence of the factors impact
Authors: Goibberdiev Sunnatilla , Ikromkhodjaev Gulomkhodja , Tajekeev Ziynatdin , Ismailov Timur , Mukhtorov Uzbekkhon , Aslanov Ilhomjon
Published: November 2023

Land used for agriculture is critical in Uzbekistan and throughout the world. Land reclamation is assessed using a variety of traditional approaches. The creation of land reclamation assessment methods is becoming more common as a result of the usage of modern geoinformation technologies and their better methodology. The levels of mineralization in the groundwater level, as well as NDVI and NDSI analysis, were determined for the three months of 2020 and 2021 - April, July, and November - in the irrigated lands of the Yuqiri chirchik, Urtachirchik, and Quyichirchik districts of the Tashkent region, which were used as the research object. These data were reclassified in ArcGIS software, and fields were defined by values. Their correlation was determined based on the results provided above. It was determined that plant vegetation is dependent on the salinity and mineralization of seepage waters, i.e., a decrease in seepage water mineralization and a drop in salinity are directly associated to an increase in plant vegetation, and vice versa.
Field monitoring application based on video surveillance: Evaluation of system performance
Authors: Usmanova N.B. , Mirzayev D.A. , Ergashev F.A. , Yunusova D.A.
Published: November 2023

The article discusses the importance of a developed telecommunications infrastructure for the economic development of the state, as well as the role of IP video surveillance systems in integrated security systems. The issue raised is the integration of video surveillance with various technical systems, ensuring not only the notorious safety of agricultural production, but also helping to solve problems that are far from security. The authors paid attention to the characteristics of the IP camera traffic, examined the flow parameters, collected statistics and determined the average delay and packet transit time. Based on the data obtained, the authors developed a simulation model of an IP video surveillance system, which can be used to determine the optimal parameters of switching equipment for the system. This allows solving the problem of choosing network equipment at the design stage and reduces the likelihood of system failure at the implementation stage.
La brucellose du bouquetin des Alpes
Authors: Lambert Sébastien , Thébault Anne , Anselme-Martin Stéphane , Calenge Clément , Dunoyer Charlotte , Freddi Luca , Garin-Bastuji Bruno , Guyonnaud Benoit , Hars Jean , Marchand Pascal , Payne Ariane , Petit Élodie , Ponsart Claire , Quéméré Erwan , Toïgo Carole , van de Wiele Anne , Rossi Sophie , Gilot-Fromont Emmanuelle
Published: November 2023

La brucellose à Brucella melitensis touche les ruminants domestiques et sauvages, ainsi que d’autres mammifères, dont les humains. Bien que la France soit officiellement indemne depuis 2005, deux cas humains reportés en Haute-Savoie en 2012 ont conduit à la découverte de l’infection dans un élevage bovin et chez les bouquetins des Alpes (Capra ibex) du massif du Bargy. Nous présentons dans cette synthèse les principales découvertes de ces dix dernières années sur le système brucellose-bouquetins. Nous discuterons également de l’apport de la recherche et de l’expertise sur l’évaluation de l’efficacité des mesures de gestion sanitaire mises en place dans le massif du Bargy pour lutter contre la brucellose.
Synthetic Access to 1,3-Butadiynes via Electro-redox Cuprous-Catalyzed Dehydrogenative Csp–Csp Homocoupling of Terminal Acetylenes
Authors: Kathiresan Murugavel , Praveen Chandrasekar , Krishnan Murugan
Published: November 2023

Herein, we disclose the oxidative homocoupling of terminal alkynes under electrochemically generated cuprous catalysis. The scope of this protocol was established by preparing an array of structurally and electronically different 1,3-butadiyne derivatives. Good synthetic yields, functional group tolerance, oxidant-free conditions, and no cross-selectivity are some of the intrinsic advantages of this methodology. The developed chemistry features the electro-redox formation of copper acetylide, an intermediate appropriate for the Csp–Csp coupling step. The chemical state of copper in the acetylide intermediate was found to be Cu(I), as confirmed by click trapping experiments, cyclic voltammetry, EPR spectroscopy, and XPS. A competition reaction to determine the reactivity of electronically dissimilar acetylenes revealed that the product ratio is rather dependent on the electronic nature of the alkynyl substituents. To highlight the synthetic value of the products, selected diynes were subjected to chemical diversification.
Antegrade Continence Enema Alone for the Management of Functional Constipation and Segmental Colonic Dysmotility (ACE-FC): A Pediatric Colorectal and Pelvic Learning Consortium Study
Authors: Ahmad Hira , Smith Caitlin , Witte Amanda , Lewis Katelyn , Reeder Ron William , Garza Jose , Zobell Sarah , Hoff Kathleen , Durham Megan , Calkins Casey , Rollins Michael D. , Ambartsumyan Lusine , Rentea Rebecca Maria , Yacob Desale , Lorenzo Carlo Di , Levitt Marc A. , Wood Richard J.
Published: November 2023

Objective The purpose of the study was to determine if antegrade continence enema (ACE) alone is an effective treatment for patients with severe functional constipation and segmental colonic dysmotility.

Methods A retrospective study of patients with functional constipation and segmental colonic dysmotility who underwent ACE as their initial means of management. Data was collected from six participating sites in the Pediatric Colorectal and Pelvic Learning Consortium. Patients who had a colonic resection at the same time as an ACE or previously were excluded from analysis. Only patients who were 21 years old or younger and had at least 1-year follow-up after ACE were included. All patients had segmental colonic dysmotility documented by colonic manometry. Patient characteristics including preoperative colonic and anorectal manometry were summarized, and associations with colonic resection following ACE were evaluated using Fisher's exact test and Wilcoxon rank-sum test. p-Values of less than 0.05 were considered significant. Statistical analyses and summaries were performed using SAS version 9.4 (SAS Institute Inc., Cary, North Carolina, United States).

Results A total of 104 patients from 6 institutions were included in the study with an even gender distribution (males n = 50, 48.1%) and a median age of 9.6 years (interquartile range 7.4, 12.8). At 1-year follow-up, 96 patients (92%) were successfully managed with ACE alone and 8 patients (7%) underwent subsequent colonic resection for persistent symptoms. Behavioral disorder, type of bowel management, and the need for botulinum toxin administered to the anal sphincters was not associated with the need for subsequent colonic resection. On anorectal manometry, lack of pelvic floor dyssynergia was significantly associated with the need for subsequent colonic resection; 3/8, 37.5% without pelvic dyssynergia versus 1/8, 12.5% (p = 0.023) with pelvic dyssynergia underwent subsequent colonic resection.

Conclusion In patients with severe functional constipation and documented segmental colonic dysmotility, ACE alone is an effective treatment modality at 1-year follow-up. Patients without pelvic floor dyssynergia on anorectal manometry are more likely to receive colonic resection after ACE. The vast majority of such patients can avoid a colonic resection.
Students' Perception of a Virtual Dissection Laboratory in Undergraduate Anatomy and Physiology of Speech and Hearing: A Focus Group Study
Authors: Bush Erin J. , Jones Erika , Dietz Richelle , Kotlarek Katelyn J.
Published: November 2023

Hands-on laboratory experience that allows for manipulation of realistic and relevant materials in course curricula has been shown to improve students' learning, understanding, and critical thinking skills. The purpose of this study was to gain insight into the experiences of students who engaged in laboratory coursework using a virtual dissection (VD) table as part of an undergraduate course in anatomy and physiology of speech and hearing. Undergraduate students enrolled in an anatomy and physiology of speech and hearing course at a single university for the fall 2021 semester consented to participate. Nine students, divided into two focus groups, were encouraged to describe their experiences and perspectives about the VD table and corresponding laboratory assignments. Following verbatim transcription of the data, the authors conducted a thematic analysis. Five themes emerged from the body of data: (1) using the VD table, (2) completing the VD lab assignments, (3) preparation for laboratory sessions, (4) suggested modifications, and (5) enriched learning. Students believed using the VD table aided in a better understanding of course material than traditional methods. Moreover, they surmised that this method of learning, particularly for speech-language pathologists, may be superior to learning through models and cadavers.
An image mosaic technique with non-overlapping regions based on microscopic vision in precision assembly
Authors: Li Yawei , Wang Xiaodong , Wang Tao , Luo Yi
Published: November 2023

Microscopic vision has been widely applied in precision assembly. To achieve sufficiently high resolution in measurements for precision assembly when the sizes of the parts involved exceed the field of view of the vision system, an image mosaic technique must be used. In this paper, a method for constructing an image mosaic with non-overlapping areas with enhanced efficiency is proposed. First, an image mosaic model for the part is created using a geometric model of the measurement system installed on a X-Y-Z precision stages with high repeatability, and a path for image acquisition is established. Second, images are captured along the same path for a specified calibration plate, and an entire image is formed based on the given model. The measurement results obtained from the specified calibration plate are utilized to identify mosaic errors and apply compensation for the part requiring measurement. Experimental results show that the maximum error is less than 4 μm for a camera with pixel equivalent 2.46 μm, thereby demonstrating the accuracy of the proposed method. This image mosaic technique with non-overlapping regions can simplify image acquisition and reduce the workload involved in constructing an image mosaic.
Osmotic swelling behavior of surface-charged ionic microgels
Authors: Alziyadi Mohammed O. , Denton Alan R.
Published: November 2023

In recent years, ionic microgels have garnered much attention due to their unique properties, especially their stimulus-sensitive swelling behavior. The tunable response of these soft, permeable, compressible, charged colloidal particles is increasingly attractive for applications in medicine and biotechnologies, such as controlled drug delivery, tissue engineering, and biosensing. The ability to model and predict variation of the osmotic pressure of a single microgel with respect to changes in particle properties and environmental conditions proves vital to such applications. In this work, we apply both nonlinear Poisson–Boltzmann theory and molecular dynamics simulation to ionic microgels (macroions) in the cell model to compute density profiles of microions (counterions, coions), single-microgel osmotic pressure, and equilibrium swelling ratios of spherical microgels whose fixed charge is confined to the macroion surface. The basis of our approach is an exact theorem that relates the electrostatic component of the osmotic pressure to the microion density profiles. Close agreement between theory and simulation serves as a consistency check to validate our approach. We predict that surface-charged microgels progressively deswell with increasing microgel concentration, starting well below close packing, and with increasing salt concentration, in qualitative agreement with experiments. Comparison with previous results for microgels with fixed charge uniformly distributed over their volume demonstrates that surface-charged microgels deswell more rapidly than volume-charged microgels. We conclude that swelling behavior of ionic microgels in solution is sensitive to the distribution of fixed charge within the polymer-network gel and strongly depends on bulk concentrations of both microgels and salt ions.
Room temperature two-dimensional electron gas scattering time, effective mass, and mobility parameters in AlxGa1−xN/GaN heterostructures (0.07 ≤ x ≤ 0.42)
Authors: Knight Sean , Richter Steffen , Papamichail Alexis , Kühne Philipp , Armakavicius Nerijus , Guo Shiqi , Persson Axel R. , Stanishev Vallery , Rindert Viktor , Persson Per O. Å. , Paskov Plamen P. , Schubert Mathias , Darakchieva Vanya
Published: November 2023

AlxGa1−xN/GaN high-electron-mobility transistor (HEMT) structures are key components in electronic devices operating at gigahertz or higher frequencies. In order to optimize such HEMT structures, understanding their electronic response at high frequencies and room temperature is required. Here, we present a study of the room temperature free charge carrier properties of the two-dimensional electron gas (2DEG) in HEMT structures with varying Al content in the AlxGa1−xN barrier layers between x=0.07 and x=0.42. We discuss and compare 2DEG sheet density, mobility, effective mass, sheet resistance, and scattering times, which are determined by theoretical calculations, contactless Hall effect, capacitance-voltage, Eddy current, and cavity-enhanced terahertz optical Hall effect (THz-OHE) measurements using a low-field permanent magnet (0.6 T). From our THz-OHE results, we observe that the measured mobility reduction from x=0.13 to x=0.42 is driven by the decrease in 2DEG scattering time, and not the change in effective mass. For x<0.42, the 2DEG effective mass is found to be larger than for electrons in bulk GaN, which in turn, contributes to a decrease in the principally achievable mobility. From our theoretical calculations, we find that values close to 0.3m0 can be explained by the combined effects of conduction band nonparabolicity, polarons, and hybridization of the electron wavefunction through penetration into the barrier layer.
A neuroevolution potential for predicting the thermal conductivity of
α
,
β
, and
ε
-Ga2O3
Authors: Sun Zhanpeng , Qi Zijun , Liang Kang , Sun Xiang , Zhang Zhaofu , Li Lijie , Wang Qijun , Zhang Guoqing , Wu Gai , Shen Wei
Published: November 2023

Ga2O3 is an ultrawide-bandgap semiconductor with a variety of crystal configurations, which has the potential for a variety of applications, especially in power electronics and ultraviolet optoelectronics. However, there has been no single interatomic potential reported for Ga2O3 polymorphs in terms of molecular dynamics prediction of thermal conductivity. Here, one interatomic potential has been developed based on neural networks, which has the clear advantages of consuming less computational power than density functional theory and has high accuracy in predicting the thermal conductivity of the three polymorphs of Ga2O3. Using the neuroevolution potential, the thermal conductivity values at 300 K have been predicted. Hence, the κ[average-α] was 67.2% that of β-Ga2O3, and the κ[average-ε] was only 26.4% that of β-Ga2O3. The possible reasons for the discrepancies in thermal conductivity values in various crystal types and orientations have been explored. As a result, it could be shown that the contribution of low-frequency phonons to thermal conductivity was very significant in Ga2O3, and a unit cell with low symmetry and high atomic number would negatively impact the thermal conductivity of the material. In this work, a scheme has been proposed for accurately predicting the thermal conductivity of Ga2O3 and a relatively accurate value of the thermal conductivity of ε-Ga2O3 has been achieved, which could also provide an atomic-scale perspective for the insight into the thermal conductivity differences among α, β, and ε-Ga2O3.
Dual-comb-based multi-axis time-of-flight measurement via high-efficiency optical cross-correlation in a semiconductor optical amplifier
Authors: Jang Jaeyoung , Kim Seung-Woo , Kim Young-Jin
Published: November 2023

Absolute distance measurement for multiple targets is required in industrial and scientific fields such as machine monitoring, detection of distortion in large structures, wafer alignment in semiconductor manufacturing, and the formation flying of satellites. Furthermore, the expansion of measurement channels is essential for the effective application of multi-target measurement. However, because measurement channels' expansion requires high power, it is difficult due to the low conversion efficiency of conventional systems that use a non-linear crystal for optical cross-correlation. In this study, for measurement channel expansion, time-of-flight based absolute laser ranging via high-efficiency dual-comb cross-correlation using a semiconductor optical amplifier is developed. The semiconductor optical amplifier acts as a cross-correlator, and it can produce a cross-correlation signal with a laser’s power of 50 µW because of its very high conversion efficiency. This method is suitable for expanding the measurement channels and measuring non-cooperative targets as it can detect low-power signals. The repeatability of the distance measurement is 4 µm at a single shot (37 µs) and 120 nm for 5 ms. The linearity is assessed by evaluating the R-square, which is equal to 1 within the range of significant figures. Moreover, the distance measurement of targets lying on the two axes was demonstrated to ensure the measurement channels' expansion. This measurement system has the potential to determine multiple distances, making it applicable to diverse fields such as semiconductor manufacturing, smart factories, plant engineering, and satellite formation flying.
Dual-band waveform-selective metasurfaces for reflection suppression
Authors: Takeshita Hiroki , Nita Daisuke , Cheng Yongzhi , Fathnan Ashif Aminulloh , Wakatsuchi Hiroki
Published: November 2023

In this study, we present a design method to realize waveform-selective metasurface absorbers operating in more than one frequency band, which is validated both numerically and experimentally. The waveform-selective metasurface absorbers could preferentially absorb target electromagnetic waves of the same frequency in accordance with the incident waveform, more specifically, the pulse width. Although such waveform selectivity is expected to offer additional selectivity at a fixed frequency, thus far, its operation has been limited to a single frequency band. Our design method enables waveform-selective metasurface absorbers to suppress reflection depending on the incident pulse width at two independent frequencies. Importantly, the dual-band approach is enhanced by varying the spatial ratio of unit cells assigned to the two frequencies. Thus, our study opens up possibilities for the utilization of waveform-selective metasurfaces in diverse frequency bands, providing a valuable and versatile solution to address challenges spanning various applications, such as wireless communications, sensing, and electromagnetic shielding.
Magnetic field properties in non-axisymmetric divertors
Authors: Boozer Allen H.
Published: November 2023

Stellarator power plants require a plan for the removal of the particles and the heat that are exhausted across the plasma edge. Unless a flowing liquid metal can be used to carry the helium exhaust to places where it can be removed from the plasma chamber, the particle exhaust must be magnetically diverted into pumping chambers. Studies are required to determine how magnetic features relate to the required divertor properties, how these magnetic features can be produced, and how they can be controlled. General studies are clarified and simplified by the use of the magnetic field line Hamiltonian ψp(ψ,θ,φ) and a vector x→(ψ,θ,φ) that gives the point in space associated with each point in the (ψ,θ,φ) canonical coordinates, a flux and two angles. The non-resonant Fourier terms in ψp can be removed by a canonical transformation, so only resonant Fourier terms can determine the field line properties in the plasma edge and divertor. This paper discusses the important divertor properties and explains how ψp(ψ,θ,φ) and x→(ψ,θ,φ) can be obtained numerically in a special form for any stellarator magnetic field, B→(x→). This form holds between an arbitrary magnetic surface and the chamber walls with the non-resonant terms eliminated. Studies based on variations in the terms in such derived field-line Hamiltonians can determine what magnetic features are mathematically possible and how they could be produced and controlled by the external magnetic field coils.
Flow state analysis of molten salt in shell and tube heat exchanger with perforated baffles
Authors: Xie Qiyue , Liu Yu , Liang Chao , Fu Qiang , Wang Xiaoli
Published: November 2023

Addressing the issue of flow dead zones in molten salt heat exchangers in concentrating solar power generation systems, this study focuses on the conventional shell and tube heat exchanger using molten salt and heat transfer oil as the working medium. The flow dynamics of molten salt within the heat exchanger are analyzed. To quantify the volume fraction of the molten salt flow dead zones, the residence time distribution curve is employed. Four baffle salt flow configurations are comparatively assessed. Findings indicate that the four opening configurations effectively enhance the reduction of molten salt flow dead zones, with volume fraction reductions ranging from 57.8% to 68.21%. Notably, configuration 4 yields the most optimal results. Furthermore, molten salt flow states in varying regions were examined: the innermost flow dead zone exhibited the highest improvement, followed by the middle area, with the edge area showing the least enhancement. Additionally, the impact of the opening diameter on the flow dead zone was explored. The volume fraction of the molten salt flow dead zone diminishes as the opening diameter expands, with the rate of this change also decelerating. Given that molten salt at the opening manifests as a jet, enlarging the opening diameter lessens the pressure differential across the baffle, subsequently weakening the jet's intensity and its influence on the flow dead zone.
Polymer micro-ring modulator on silicon nitride platform
Authors: Yu Hongyan , Li Bin , Wang Lu , Qiu Feng
Published: November 2023

The development of silicon nitride (SiN) waveguide platforms has enabled the realization of photonic circuits with unprecedented performance. Despite the exciting progress, SiN suffers from intrinsic material properties that block it for high-speed electro-optic (EO) modulators. Here, we present an approach to heterogeneously integrate organic EO polymer on SiN for high-performance modulators. We utilize the high resistivity of SiN to achieving a strong overlap between the optical and electrical field. Furthermore, sol–gel SiO2 side-claddings inserted in waveguides shorten the inter-electrode distance and increase the EO activity to a much higher level. As a result, the fabricated micro-ring modulator exhibits an electrical tunability of 10 pm/V, corresponding to an in-device EO coefficient as 60 pm/V. High frequency tests in the device show a 3-dB bandwidth of 32 GHz and a data rate of 40 Gbps. The proposed approach will enable efficient mass-production of the micro-footprint modulators and promote the development of integrated SiN photonics.
Half-metallic magnetism in 2D MX2 (M = V, Cr, Mn, and Fe; X = S, Se, and Te) intercalated with 1D MX chains
Authors: Ding W. J. , Li Xin , Zhao Zhenjie , Xie Wenhui
Published: November 2023

Intercalation has attracted considerable attention due to its extensive ability to modify the electronic, optical, and magnetic properties of two-dimensional (2D) layered nanomaterials. Typically, dispersed atoms or molecules are inserted into the van der Waals gap of the 2D materials. Recently, Guo et al. experimentally reported the novel VS2–VS superlattice, where the intercalation takes the form of atomic chain arrays. In this study, we employed the first-principles calculations based on density functional theory to investigate a series of analogous 2D MX2–MX–MX2 nanomaterials, which, consisting of 2D transition metal dichalcogenide bilayers, intercalated with a one-dimensional transition metal chalcogenide MX chain array, forming a hotdog-like structure. Some of the 2D MX2–MX–MX2 are thermally and dynamically stable, suggesting their potential for experimental fabrication similar to VS2–VS–VS2. MnS2–MnS–MnS2 and MnSe2–MnSe–MnSe2 have been found to exhibit ferromagnetic half-metallic properties. In addition, VSe2–VSe–VSe2, CrS2–CrS–CrS2, and CrSe2–CrSe–CrSe2 have been found to be thermally and dynamically stable. Under appropriate external stress, doping, or bias, they could become ferromagnetic half-metals, revealing their potential for spintronic applications.
The perspective of topological photonics for on-chip terahertz modulation and sensing
Authors: Sun Yiwen , Mei Zhijie , Xu Xuejiao , Xie Qingxuan , Fan Shuting , Qian Zhengfang , Liu Xudong
Published: November 2023

Terahertz (THz) technology has seen significant advancements in the past decades, encompassing both fundamental scientific research, such as THz quantum optics, and highly applied areas like sixth-generation communications, medical imaging, and biosensing. However, the progress of on-chip THz integrated waveguides still lags behind that of THz sources and detectors. This is attributed to issues such as ohmic losses in microstrip lines, coplanar and hollow waveguides, bulky footprints, and reflection and scattering losses occurring at sharp bends or defects in conventional dielectric waveguides. Inspired by the quantum Hall effects and topological insulators in condensed matter systems, recent discoveries of topological phases of light have led to the development of topological waveguides. These waveguides exhibit remarkable phenomena, such as robust unidirectional propagation and reflectionless behavior against impurities or defects. As a result, they hold tremendous promise for THz on-chip applications. While THz photonic topological insulators (PTIs), including wave division, multiport couplers, and resonant cavities, have been demonstrated to cover a wavelength range of 800–2500 nm, research on tunable THz PTIs remains limited. In this perspective, we briefly reviewed a few examples of tunable PTIs, primarily concentrated in the infrared range. Furthermore, we proposed how these designs could benefit the development of THz on-chip PTIs. We explore the potential methods for achieving tunable THz PTIs through optical, electrical, and thermal means. Additionally, we present a design of THz PTIs for potential on-chip sensing applications. To support our speculation, several simulations were performed, providing valuable insights for future THz on-chip PTI designs.
High cryogenic ductility of the high-entropy alloy CoCrFeNiAl0.1Ti0.05 at 77 K
Authors: Jiang Mingyue , Wang Zekun , Su Haojian , Jiang Di , Huang Chuanjun , Zhou Min , Huang Rongjin , Li Laifeng
Published: November 2023

High-entropy alloys possess significant potential for material applications in demanding structural components subjected to extreme conditions. Through experimental investigations, we have validated that the CoCrFeNiAl0.1Ti0.05 high-entropy alloy, which was fabricated using a cold rolling and annealing process, exhibits an excellent balance of strength and ductility at 77 K. Specifically, it demonstrates a yield strength of 575 MPa, a tensile strength of 1145 MPa, and a ductility of 55%. This enhanced performance can be attributed to the altered deformation mechanism at low temperatures, leading to the multiplications of stacking faults and twins. Additionally, the introduction of small quantities of aluminum and titanium results in the formation of precipitated phases within the alloy matrix. The synergistic influence of these two factors contributes to the augmentation of cryogenic plasticity in the alloy.
Spatiotemporal dynamics of a multi-delayed prey–predator system with variable carrying capacity
Authors: Anshu  , Dubey Balram
Published: November 2023

This paper presents the temporal and spatiotemporal dynamics of a delayed prey–predator system with a variable carrying capacity. Prey and predator interact via a Holling type-II functional response. A detailed dynamical analysis, including well-posedness and the possibility of coexistence equilibria, has been performed for the temporal system. Local and global stability behavior of the co-existence equilibrium is discussed. Bistability behavior between two coexistence equilibria is demonstrated. The system undergoes a Hopf bifurcation with respect to the parameter β, which affects the carrying capacity of the prey species. The delayed system exhibits chaotic behavior. A maximal Lyapunov exponent and sensitivity analysis are done to confirm the chaotic dynamics. In the spatiotemporal system, the conditions for Turing instability are derived. Furthermore, we analyzed the Turing pattern formation for different diffusivity coefficients for a two-dimensional spatial domain. Moreover, we investigated the spatiotemporal dynamics incorporating two discrete delays. The effect of the delay parameters in the transition of the Turing patterns is depicted. Various Turing patterns, such as hot-spot, coldspot, patchy, and labyrinth, are obtained in the case of a two-dimensional spatial domain. This study shows that the parameter β and the delay parameters significantly instigate the intriguing system dynamics and provide new insights into population dynamics. Furthermore, extensive numerical simulations are carried out to validate the analytical findings. The findings in this article may help evaluate the biological revelations obtained from research on interactions between the species.
Simultaneous identification of strong and weak interactions with Pauli energy, Pauli potential, Pauli force, and Pauli charge
Authors: Zhang Wenbiao , He Xin , Li Meng , Zhang Jingwen , Zhao Dongbo , Liu Shubin , Rong Chunying
Published: November 2023

Strong and weak interatomic interactions in chemical and biological systems are ubiquitous, yet how to identify them on a unified theoretical foundation is still not well established. Recently, we proposed employing Pauli energy-based indexes, such as strong covalent interaction and bonding and noncovalent interaction indexes, in the framework of density functional theory for the purpose. In this work, we extend our previous theoretical work by directly employing Pauli energy, Pauli potential, Pauli force, and Pauli charge to simultaneously identify both strong covalent bonding and weak noncovalent interactions. Our results from this work elucidate that using their signature isosurfaces, we can identify different types of interactions, either strong or weak, including single, double, triple, and quadruple covalent bonds, ionic bond, metallic bond, hydrogen bonding, and van der Waals interaction. We also discovered strong linear correlations between Pauli energy derived quantities and different covalent bond orders. These qualitative and quantitative results from our present study solidify the viewpoint that a unified approach to simultaneously identify both strong and weak interactions is possible. In our view, this work signifies one step forward towards the goal of establishing a density-based theory of chemical reactivity in density functional theory.
A wireless passive vibration sensing method for cryogenic applications
Authors: Zhao Ziqi , Fastier-Wooller Jarred , Yamamoto Michitaka , Takamatsu Seiichi , Itoh Toshihiro
Published: November 2023

In this Letter, we developed a wireless passive vibration sensing method functional at cryogenic temperatures (−196 °C). Traditional vibration sensors are either inconvenient or complicated in cryogenic environments due to inaccessible working positions and weak low-temperature tolerances. We propose a vibration measurement method that transfers a mechanical vibration to a wirelessly obtained return loss. Passive wireless monitoring is performed using a backscattering tag antenna integrated with a tunnel magnetoresistor. We fabricate and evaluate our vibration sensor at room temperature (24 °C) and cryogenic temperature (−196 °C) to verify the proposed design. Experimental analysis identified different vibration amplitudes with sensitivities of 4.61 dB/mm at 24 °C and 1.13 dB/mm at −196 °C. Further analysis shows that the vibrational frequency can be extrapolated. Our sensor provides a low-cost, robust, wireless, and passive vibration measurement method that is desirable in cryogenic applications.