bluuebunny/crossref_metadata_2025 huggingface dataset:
A simplified control parameter optimisation method of the hybrid modular multilevel converter in the medium‐voltage DC distribution network for improved stability under a weak AC system
Authors: Xu Jin , Xiao Qian , Jia Hongjie , Mu Yunfei , Jin Yu , Lu Wenbiao , Ma Shiqian
Published: April 2024

To improve the stability of the hybrid modular multilevel converter (MMC), a simplified dominant mode‐based control parameter optimisation method of the hybrid MMC system is proposed. Firstly, in the medium‐voltage DC distribution network, the small‐signal model of the hybrid MMC is established. Secondly, the influence of a weak AC system on stability is analysed through eigenvalue analysis. Finally, a simplified objective function is designed for eigenvalues of the dominant mode by considering only real parts, and improved small‐signal stability can be achieved by control parameters optimisation. The proposed method optimises all control parameters at the same time, which further reduces the number of algorithm iterations. Simulation results show that by the proposed control parameter optimisation method, the hybrid MMC has better transient performance and reduced disturbance under SCR variation, indicating a significantly improved system stability, and the dynamic response time can be reduced.
Enhancing tunnel stability in the Himalayas: Empirical design support through numerical modelling
Authors: Abbas Naeem , Li Kegang , Emad Muhammad Zaka , Fissha Yewuhalashet , Ali Mujahid , Ghribi Wade , Gamil Yaser , Ikeda Hajime
Published: April 2024

This study focuses on assessing the effectiveness of an empirically recommended support design through numerical modelling. Numerical techniques are utilized to accurately evaluate tunnel stability under various geological conditions. Numerical analysis is conducted on two different rock types along the tunnel route, employing the recommended support design based on the existing rock mass rating (RMR) and Q‐system. Furthermore, support recommendations are made using the modified RMR and Q‐system, considering the impact of stress. The numerical analysis indicates that the support recommended by the existing RMR may not substantially impact the total displacement and vertical stresses around the tunnel crown in the “Fair” to “Poor” rock mass of the study area. However, extending the bolt length by modifying the RMR to incorporate stress effects results in a reduction of total displacement and vertical stresses, ultimately achieving a stable level. These results underline the importance of considering stress effects and utilizing modified support designs to enhance tunnel stability.
Evaluation of low‐grade waste heat resources in coking and sintering processes of Chinese iron and steel enterprises
Authors: Kang Zhen , Su Fuyong , Ni Peiwei
Published: April 2024

The amount of waste heat resources produced by iron and steel industry is huge and various. Due to the lack of consideration of the lowest discharge temperature of the low‐grade waste heat and the difficulty in recycling, the classification of these resources is still ambiguous, which makes the total amount of this kind of resource is huge, but few has been effectively recycled. The industry standard of China “Detection and evaluation method for low grade waste heat from the process of iron and steel enterprises” (YB/T 4786‐2019), classifies the low‐grade waste heat resources by energy level analysis. Based on the field investigation and on‐site tests of coking and sintering process in Baosteel, the low‐grade waste heat resources are analyzed and evaluated by employing this industry standard. The category distribution and total quality of low‐grade waste heat resources are obtained. It is proved that the standard is accurate for the classification of low‐grade waste heat resources and precise for the range division. The implementation of it is of practical significance to solve the problems such as the assessment of total waste heat etc.
Observations on kopyor coconut (Cocos nucifera var. Kopyor) characteristics during distribution
Authors: Faramitha Yora , Dimawarnita Firda , Sinta Masna Maya , Saptari Rizka Tamania , Riyadi Imron , Sumaryono
Published: April 2024

Kopyor coconut (Cocos nucifera var. Kopyor), a native Indonesian coconut, differs from common coconuts because it has brittle flesh (endosperm) due to a natural genetic mutation. Kopyor coconut seedlings have been successfully cultivated from the tissue culture technique, which can produce kopyor above 99%. Nowadays, the demand for kopyor continues to increase. The cultivation of kopyor is centralized in several locations in Indonesia. Hence, the time of kopyor distribution to consumers is crucial in the kopyor business. This study evaluated changes in the characteristics of whole fruit and peeled kopyor coconuts during distribution. The observations included quality attributes (appearance, aroma, texture, and taste), physical observations (pH and water content), and microbial observations using the total plate count method. Whole kopyor showed better quality attributes than peeled kopyor. Peeled kopyor coconut flesh began to change color to yellowish-white, mushy, and had a rancid smell and a sour taste in the second week, while whole fruit kopyor in the fourth week. In conclusion, the distribution of peeled kopyor should be carried out in less than two weeks, or even sooner, while whole fruit kopyor can be distributed for up to two weeks without altering the characteristic taste of kopyor.
Potential development of non-timber forest products in the Sapat Village Forest Indragiri Hilir Regency
Authors: Sribudiani Evi , Daulay Muhammad Haidar , Andriani Yulia , Suhada Nur , Pebriandi  , Fahrorrozi Muhammad Ikhsan
Published: April 2024

Non-Timber Forest Products (NTFPs) are an important source of livelihood and forest sustainability. Village Forest (VF) is a social forestry program that can help to promote NTFP development. This study aimed to assess the potential and strategies for NTFP product development in Sapat VF, Indragiri Hilir Regency, Riau Province, Indonesia. Data were collected using observation, interviews, and literature review. Snowball sampling was used to select informants. SWOT analysis was used to assess the potential for NTFP product development. The results showed that Sapat VF has a high potential for NTFP product development, with a variety of NTFPs such as mangrove crabs, lokan, shrimp, nipah, mangrove fruit, nyirih fruit, and jeruju leaves. The community has a positive attitude towards protecting Sapat VF, as evidenced by their membership in the Supervisory Community Group (SCG). An aggressive strategy was used to develop NTFP products, which is a favorable situation because it has opportunities and strengths that can be exploited.
The influence of bird pest attack on rice damage and production in Kuantan Singingi
Authors: Seprido  , Andriani Desta , Heriansyah Febra , Alatas Andi
Published: April 2024

Birds pest in rice field activities are one of the important pest that attack. It has even caused 161,4 ha of crop loss and 124.05 ha of heavy damage in Riau. This neet to be handled and managed properly. This study was initiated by identifying the types and effects of bird pest attacks on the damage and productionof rice crops in Kuantan Singingi. This study was used a survey method by making plots (10x10 m), bird pests species and populations by using a point transect. Observations were carried out in the morning, afternoon and evening. Bird species identification refers to the MacKinnon Bird Guide in Sumatera, Jawa, and Bali. Diversity of birds pest was calculated by the Shannon-Wienner index, species richness by margaleft index, and species dominance by the Simpson index. This study were observed 1.045 birds attack of paddy field. Koto Kari site was observed 479 individual, 332 individu in Kampung Baru, and 214 in Sangau Lonchura striata was observed as many as 635 individuals. Species diversity index was 0.667, species richness index 0.288, density 0.616 and dominance value 0.527. the highest frequency of bird pest visit was in Koto Kari sithe which was 42 times while based on the species was Lonchura striata71 times with an attack time in the morning of 83 times. The highest damage to panicles by bird pest was caused by Lonchura maja at 46.09% but the highest loss of rice wight was caused by Lonchura striata.
Potential development of mangosteen (Garcinia mangostana L.) through optimizing land use in Pati, Central Java, Indonesia
Authors: Susila Arif , Cempaka Intan Gilang , Beti Jajuk Aneka , Malik Afrizal , Haskarini Dyah , Winarni Endah , Hindarwati Yulis
Published: April 2024

Preservation of local genetic resources through exploration and conservation along with inventory and characterization are efforts to maintain food resources. Optimizing land use is very potential in the development of local genetic resources. Objective of the research was to characterize local mangosteen from Pati and to optimize the land use. The primary data was derived from the mangosteen characterization results. Information for the secondary data was derived from various sources relevant to the research. The data includes: land potential, climatology, and agroecosystems. Characterization was conducted on a cultivar of Gunungsari mangosteen as the parent plant used in this research. Format of the mangosteen description has been arranged in the form of standard blanks. Results of the research showed that the public yards are potential to develop local mangosteen of Gunungsari. Morphological characters of the Gunungsari mangosteen are red petals (44 A Red Group), circular shape p-1, average weight of the fruit ranges 119.22 g-180.53 g, yellowish white aril (NN 155 A yellowish white) and the taste is sweet and slightly sour. The specific characteristics of Gunungsari mangosteen are soft seeds, the aril tastes sweet and slightly sour, fine fibrous textures, delicate aroma, and high production. The residents’ yards in Gunungsari Village are potential for the development of local fruits commodities especially mangosteen. In order to keep up the local genetic resources and to increase the economic value, Gunungsari mangosteen must be registered immediately to acquire the Certificate of Registration of Plant Varieties.
Determinants on Successful Investment of Venture Capitalist
Authors: Gui Tianyu
Published: April 2024

Venture capital (VC) has transcended its Silicon Valley origins to become a global force shaping the innovation and economic landscape. It is imperative to recognize the critical role of VC and improve its success rate. Employing the “jockey-horse-meadow” model, this paper identifies three crucial determinants influencing VC success: the entrepreneurial team, strategic approach and business model, and the market context. Delving into specific sub-points, the paper underscores the unique significance of each determinant, substantiating their pivotal roles in shaping VC outcomes. This research not only contributes insights into the success dynamics of VCs but also serves as a valuable reference for startups seeking financing and development. Additionally, it offers guidance to investors navigating the selection process, aiding them in identifying startups with genuine potential for impactful investment. By shedding light on these fundamental factors, this paper enriches the discourse surrounding VC success, fostering a more informed and strategic approach in the dynamic world of venture capital.
Comparison and Analysis of Sustainable Development between China and America
Authors: Huang Rui
Published: April 2024

In recent years, sustainable development has been widely discussed. This article primarily explores the reasons behind the necessity for sustainable development. The inevitable environmental degradation resulting from rapid economic development is a crucial factor. Economic development is closely tied to the demand for energy, and sustainable development reduces environmental pollution and alleviates energy shortages. The environmental benefits brought about by sustainable development, in turn, positively impact economic growth. Therefore, sustainable development is indispensable. The strategic approaches to sustainable development in China and the United States differ due to their respective national conditions. This article also delves into the disparities in the sustainable development strategies between China and the U.S. China’s sustainable development leans towards technological advancement, energy conservation, and environmental protection, while the U.S. prioritizes addressing social inequality. Post-COVID-19 pandemic, the sustainable development strategies of China and the U.S. have become increasingly apparent. The article explores what sustainable development strategies China and the U.S. have chosen post-pandemic to swiftly recover their economies. It also analyzes the characteristics of social inequality in China and the U.S., noting that China’s economic inequality is regional, whereas the economic inequality in the U.S. stems from differences in educational attainment. The article further proposes solutions for these economic inequalities. In sustainable development strategies, despite differing national conditions, addressing economic inequality is a crucial component. China requires balancing the allocation of resources across its regions, while the U.S. needs to alleviate wealth disparities resulting from educational differences and address the issue of higher education accessibility.
Game-Theoretic Analysis of Live-Streaming E-Commerce on TikTok
Authors: Li Zhifei , Lin Xinyue
Published: April 2024

This paper analyzes the application of game theory in live streaming sales from three models: prisoner’s dilemma, British auction, and Nash equilibrium. Firstly, using the prisoner’s dilemma to analyze cooperation and competition in live streaming sales, using charts to analyze that competition appears to be the optimal strategy, but cooperation is more common. In the process of signing contracts with internet celebrities, the company also used English auctions for analysis. During the bidding process, it is necessary to avoid the curse of the winner, maintain fairness in competition, and reduce the minimum bidding increment. Finally, the application of Nash equilibrium was explored to find the balance of interests between sellers and buyers, while meeting their expectations. Overall, this research provides valuable insights into strategic decision-making in e-commerce, enhancing understanding of the interplay between influencers and brands and guiding them towards mutually beneficial outcomes in the evolving market of live-streaming commerce.
The collapse of Kyoto Protocol: An analysis based on Game Theory
Authors: Peng Ziyu
Published: April 2024

Everyone is a stakeholder in environmental issues. Contemporarily, climate change is incrementally imposing threats to human development, making multilateral cooperation necessary to minimise the impacts of climate-related risks. The Kyoto Protocol was a significant internationally binding agreement that aimed to reduce greenhouse gases emissions, whereas its signatories failed to achieve its target to a large extent. This paper analyzes the reason behind the failure of the Kyoto Protocol through a game-theoretic literature. The main factors that contributed to the collapse of the Kyoto Protocol include the complex nature of the environmental issue and strategic interest in the treaty ratification procedure. The global environment is defined as a public good, therefore, each country has a free-rider incentive to take advantage of others’ actions in pollution reduction, which is analyzed through a single prisoners’ dilemma game. When such a game is extended to a repeated prisoners’ dilemma game with an infinite horizon, there is a possibility that nations adopt a cooperative strategy in the long run. Simultaneously, the ultimatum game provides a representation of the treaty negotiation and ratification process, highlighting the importance of fairness and reciprocity of the treaty for its signatories. Potential solutions include trade sanctions, tax on exports, and the measure of cumulative emission has been evaluated at the end of the paper.
Supraorbital Keyhole Approach: Opening of the Frontal Sinus and Cerebrospinal Fluid Rhinorrhea
Authors: Mehrotra Anant , Das Kuntal Kanti , Rangari Kamlesh , Kanjilal Soumen , Tataskar Pooja , Verma Pawan Kumar , Bhaisora Kamlesh S. , Jaiswal Awadhesh , Kumar Raj
Published: April 2024

Introduction: The supraorbital keyhole approach (SOKHA) has been a less invasive alternative for anterior and middle skull base lesions. We aimed to review our data and understand the advantages and limitations of the approach.

Methods: We analyzed our data and reviewed 89 consecutive cases who underwent the SOKHA. We included the clinico-radiological parameters, pathology, use of endoscope, complications, etc. for analysis.

Results: A total of 47 patients were of aneurysm with a total of 48 aneurysms (39 were ruptured and 9 were unruptured) and Acomm artery aneurysm was the most common site. Meningiomas were the second most common pathology encountered (n = 29). Tuberculum sella meningioma being the most common type of meningiomas operated through this approach. Gross total resection was done in all except two cases in which a small part of the tumor was left behind as the tumor was adhered to blood vessels. Among the remaining cases, craniopharyngiomas (n = 7), optic pathway gliomas (n = 2), hypothalamic hamartomas (n = 2), dermoid (n = 1), and arteriovenous malformation (n = 1) were the other pathologies operated upon. Eight patients had opening of the frontal sinus. Four patients had wound bulge and one patient had cerebrospinal fluid (CSF) rhinorrhea. All these cases were managed conservatively.

Conclusion: SOKHA is an excellent approach for anterior cranial fossa lesions especially with properly chosen cases. Incidence of CSF leak in our study is 1.1% and majority can be managed by placement of lumbar drain. Intraoperative obliteration of the frontal sinus can reduce the risk of postoperative CSF leak. A large frontal sinus needs not be a contraindication for SOKHA.
Clinical Outcomes of Salvage Microsurgical Resection after Radiation Therapy for Sporadic Vestibular Schwannomas
Authors: Moshtaghi Omid , Barba Patrick , Dixon Peter , Ren Yin , Schwartz Marc , Friedman Rick
Published: April 2024

Background The purpose of this study was to evaluate clinical outcomes after salvage microsurgery for vestibular schwannoma (VS) treated initially with modern radiotherapy techniques as compared to those treated with primary microsurgical resection.

Methods Patients who underwent microsurgical resection of sporadic VS undergoing a translabyrinthine approach at a single academic skull base tertiary referral center were included. Baseline and postoperative dynamic gait index, functional gait assessment, House–Brackmann facial nerve grading, and completeness of resection were prospectively recorded.

Results Of the 265 patients reviewed, 21 (7.9%) patients underwent prior radiation. Median age of the cohort was 55 years (interquartile range: 51–63). The likelihood of achieving a gross total resection was significantly lower for radiated as compared to nonradiated patients (odds ratio: 0.18, 95% confidence interval: 0.05–0.53, p = 0.004) when controlling for tumor size. Radiated patients had better postoperative facial nerve function on the first postoperative day, but this difference was not significant at long-term follow-up. Radiated patients had lower preoperative postural stability scores than nonradiated patients on FGA (26 vs. 23, p = 0.035). Postoperatively, radiated patients had comparable outcomes compared to nonradiated patients when controlling for age and tumor size.

Conclusions Compared to patients with VS treated with surgery alone, previously radiated patients are less likely to achieve gross total resection in the salvage setting. Radiated patients scored better on facial nerve outcomes compared to nonradiated patients in the initial postoperative period but demonstrated similar long-term outcomes.
An agent-based evolutionary system model of the transformation from building material industry (BMI) to green intelligent BMI under supply chain management
Authors: Yin Shi , Zhao Yudan
Published: April 2024

The building materials industry ranks first in terms of carbon emissions and energy consumption within the industrial sector. To achieve the goal of reducing carbon emissions, the development of the green intelligent building materials (GIBMs) industry has become a strategic priority and major demand for the country. Government support plays a vital role in promoting the growth of the GIBMs industry. This paper utilizes evolutionary game theory and Matlab software to analyze the impact of government regulations on the development of the GIBMs industry. The research findings indicate the following. i) Appropriate government control over building materials enterprises is beneficial for the advancement of the GIBMs industry. A balance is necessary, as both excessive control and weak control hinder the industry’s development. ii) Increased financial assistance from the government to enterprises producing GIBMs has a positive influence. This support enables building materials enterprises to overcome technical barriers, drive technological innovation, and encourage construction developers to actively purchase these materials. iii) Stronger government punishment for pollutant emissions by building materials enterprises serves as a catalyst for the production of GIBMs. Stricter penalties motivate these enterprises to adopt more environmentally friendly practices. iv) Moderate to strong government investment in infrastructure has a significant impact. It prompts construction developers to actively choose and purchase GIBMs. In response to government regulations and market demand, building materials enterprises are inclined to produce these environmentally friendly materials. This study emphasizes the importance of government regulations and support in promoting the growth of the GIBMs industry. By implementing appropriate control measures, providing financial assistance, imposing punishments for pollution, and investing in infrastructure, the government can effectively encourage the development of the GIBMs industry. These measures contribute to achieving the double carbon goals and fostering a more sustainable built environment.
The virtual staining method by quantitative phase imaging for label free lymphocytes based on self-supervised iteration cycle-consistent adversarial networks
Authors: Zhang Lu , Li Shengjie , Wang Huijun , Jia Xinhu , Guo Bohuan , Yang Zewen , Fan Chen , Zhao Hong , Zhao Zixin , Zhang Zhenxi , Yuan Li
Published: April 2024

Quantitative phase imaging (QPI) provides 3D structural and morphological information for label free living cells. Unfortunately, this quantitative phase information cannot meet doctors’ diagnostic requirements of the clinical “gold standard,” which displays stained cells’ pathological states based on 2D color features. To make QPI results satisfy the clinical “gold standard,” the virtual staining method by QPI for label free lymphocytes based on self-supervised iteration Cycle-Consistent Adversarial Networks (CycleGANs) is proposed herein. The 3D phase information of QPI is, therefore, trained and transferred to a kind of 2D “virtual staining” image that is well in agreement with “gold standard” results. To solve the problem that unstained QPI and stained “gold standard” results cannot be obtained for the same label free living cell, the self-supervised iteration for the CycleGAN deep learning algorithm is designed to obtain a trained stained result as the ground truth for error evaluation. The structural similarity index of our virtual staining experimental results for 8756 lymphocytes is 0.86. Lymphocytes’ area errors after converting to 2D virtual stained results from 3D phase information are less than 3.59%. The mean error of the nuclear to cytoplasmic ratio is 2.69%, and the color deviation from the “gold standard” is less than 6.67%.
Challenges for density functional theory in simulating metal–metal singlet bonding: A case study of dimerized VO2
Authors: Zhang Yubo , Ke Da , Wu Junxiong , Zhang Chutong , Hou Lin , Lin Baichen , Chen Zuhuang , Perdew John P. , Sun Jianwei
Published: April 2024

VO2 is renowned for its electric transition from an insulating monoclinic (M1) phase, characterized by V–V dimerized structures, to a metallic rutile (R) phase above 340 K. This transition is accompanied by a magnetic change: the M1 phase exhibits a non-magnetic spin-singlet state, while the R phase exhibits a state with local magnetic moments. Simultaneous simulation of the structural, electric, and magnetic properties of this compound is of fundamental importance, but the M1 phase alone has posed a significant challenge to the density functional theory (DFT). In this study, we show none of the commonly used DFT functionals, including those combined with on-site Hubbard U to treat 3d electrons better, can accurately predict the V–V dimer length. The spin-restricted method tends to overestimate the strength of the V–V bonds, resulting in a small V–V bond length. Conversely, the spin-symmetry-breaking method exhibits the opposite trends. Each of these two bond-calculation methods underscores one of the two contentious mechanisms, i.e., Peierls lattice distortion or Mott localization due to electron–electron repulsion, involved in the metal–insulator transition in VO2. To elucidate the challenges encountered in DFT, we also employ an effective Hamiltonian that integrates one-dimensional magnetic sites, thereby revealing the inherent difficulties linked with the DFT computations.
Dynamical modulation of hypersynchronous seizure onset with transcranial magneto-acoustic stimulation in a hippocampal computational model
Authors: Ma Zhiyuan , Xu Yuejuan , Baier Gerold , Liu Youjun , Li Bao , Zhang Liyuan
Published: April 2024

Hypersynchronous (HYP) seizure onset is one of the frequently observed seizure-onset patterns in temporal lobe epileptic animals and patients, often accompanied by hippocampal sclerosis. However, the exact mechanisms and ion dynamics of the transition to HYP seizures remain unclear. Transcranial magneto-acoustic stimulation (TMAS) has recently been proposed as a novel non-invasive brain therapy method to modulate neurological disorders. Therefore, we propose a biophysical computational hippocampal network model to explore the evolution of HYP seizure caused by changes in crucial physiological parameters and design an effective TMAS strategy to modulate HYP seizure onset. We find that the cooperative effects of abnormal glial uptake strength of potassium and excessive bath potassium concentration could produce multiple discharge patterns and result in transitions from the normal state to the HYP seizure state and ultimately to the depolarization block state. Moreover, we find that the pyramidal neuron and the PV+ interneuron in HYP seizure-onset state exhibit saddle-node-on-invariant-circle/saddle homoclinic (SH) and saddle-node/SH at onset/offset bifurcation pairs, respectively. Furthermore, the response of neuronal activities to TMAS of different ultrasonic waveforms revealed that lower sine wave stimulation can increase the latency of HYP seizures and even completely suppress seizures. More importantly, we propose an ultrasonic parameter area that not only effectively regulates epileptic rhythms but also is within the safety limits of ultrasound neuromodulation therapy. Our results may offer a more comprehensive understanding of the mechanisms of HYP seizure and provide a theoretical basis for the application of TMAS in treating specific types of seizures.
A study on the reduction of microstructural non-uniformity in Ni-multilayer ceramic capacitors via repeated highly accelerated life tests and analyses of degraded local areas
Authors: Nagayoshi Maiko , Sakata Ryosuke
Published: April 2024

The degree of microstructural non-uniformity and the lifetime extension of multilayer ceramic capacitors (MLCCs) were evaluated by repeating the fabrication of “prebreakdown” MLCCs through highly accelerated life tests (HALTs), the removal of the insulation resistance-degraded layer, and the reformation of the terminal electrode. The total mean time to failure (MTTF) tended to extend and converge as HALTs were repeated. Microstructural analysis in the degraded local area revealed a clear correlation between the shorter lifetime and the minimum number of grains per unit dielectric layer. After HALTs were repeated, the number of grains came close to and converged as much as undegraded areas over a longer lifetime. These results imply that degradation occurs in order from the greatest degree of microstructural non-uniformity and that the weakest-link model can be understood by treating the lifetime as MTTF.
Advances in functionalized annihilators to extend triplet–triplet annihilation upconversion performances
Authors: Lin Wen-Yue , Huang Zhi , Huang Ling , Han Gang
Published: April 2024

Triplet–triplet annihilation upconversion (TTA-UC) has made major advances in many emerging fields in recent years, such as solar light harvesting, photocatalysis, biological imaging, and sensing. TTA-UC consists of photosensitizers and annihilators. In addition to acting as emitters, chemical modification of annihilators has expanded their roles to include the formation of organic gel to avoid oxygen-mediated triplet quenching, amplifying the asymmetry factor of circularly polarized luminescence, constructing an upconversion sensor as recognition units, serving as photoremovable protecting groups, and photocatalysts to realize long-wavelength light-driven organic transformations. Here, we will focus on the significant applications of functionalized annihilators other than photoluminescence, which are manifested via chemical modification with other functional units. Finally, we will elaborate on the existent issues with TTA-UC, including challenges in molecular design, material development, and emerging field applications. In accordance with our research experience, we will propose potential solutions.
Bioengineered cell-constructs using decellularized fish skin-based composite bioink for regenerating muscle tissue
Authors: Jo SeoYul , Lee Hyeongjin , Jo Yunju , Jin Eun-Ju , Kim Dongyun , Ryu Dongryeol , Kim Geun Hyung
Published: April 2024

A biocomposite for enhancing muscle tissue regeneration was introduced using decellularized fish skins. Decellularized tilapia and cod skin were explored as constituents of the composite and compared with the conventionally used decellularized extracellular matrix (dECM) derived from porcine skin tissue. As a cell-laden bioink for 3D bioprinting, the choice of tilapia skin dECM, which possesses remarkable printability, allows for precise three-dimensional (3D) structure fabrication. Meanwhile, cod skin dECM was selected as the dispersed phase for enhancing biological activities because of its omega-3 unsaturated fatty acid, which is known to promote angiogenesis and is crucial for nutrient supply during tissue regeneration and lower inflammation. Through meticulous compositional optimization of the fish skin dECMs, efficient printability and high myogenic activity of the fish skin dECM composite were attained. In vitro evaluations using adipose stem cells clearly demonstrated the support of the cell-laden composite bioink for myogenesis, as determined by various cellular activities, including myogenic genes, compared to those of the porcine-based dECM bioink. The regenerative potential of the composites was validated using an in vivo mouse model of volumetric muscle loss. Based on these results, this study provides valuable insights into the use of decellularized fish skin as composite biomaterials and demonstrates their distinct advantages in muscle tissue engineering, in terms of both printability and bioactivity induction.
Thermoelectric response of textured Sb2Te3–BiSb and Sb2Te3–Bi2Te3 thin film junctions
Authors: Nepal Rajeev , Bajracharya Prabesh , Kumar Ravinder , Kolagani Rajeswari , Budhani Ramesh C.
Published: April 2024

Surface mounted thin film thermoelectric (TE) devices for localized cooling, power generation, and sensing are topics of immense current interest. Here, we establish the superior TE performance of thin film junctions made of topological insulators (TIs) Bi85Sb15 (BiSb) and Sb2Te3 by comparing their performance with those of Bi2Te3 and Sb2Te3. Thin films of these TIs were first evaluated for their carrier concentration, Hall mobility, resistivity, and thermopower. The Seebeck coefficient of BiSb, Sb2Te3, and Bi2Te3 measured against copper at ambient temperature is −100, +160, and −70 (±10) μV/K, while their power factors are 0.5, 0.5, and 0.45 (±0.05) 10−3 W m−1 K−2, respectively. Single TE junctions of BiSb–Sb2Te3 and Bi2Te3–Sb2Te3 yield a response of 272 and 240 (±10) μV/K, respectively. This comparative study shows that BiSb is a superior n-type counter electrode for Sb2Te3 compared to the n-type Bi2Te3. Moreover, Bi2Te3 is prone to tellurium antisite disorder, which affects its TE properties significantly.
Intrinsic resonance in gyrotron using non-resonant RF structure
Authors: Yang Tien-Fu , Yao Hsin-Yu , Chen Shih-Hung , Chang Tsun-Hsu
Published: April 2024

Gyromonotrons are typically believed to rely on the convective interaction between the co-propagating beam and wave, with the extended energy-exchanging process stemming from the external feedback. However, numerous studies focusing on both transverse electric (TE) mode and transverse magnetic (TM) mode gyrotrons have consistently shown that beam–wave interactions in weak-feedback systems or even in uniform tubes without any structural feedback can yield a theoretical beam efficiency of more than 30% with major forward-wave output during near-cutoff operation, which is the typical operating condition for gyromonotrons. These intriguing findings raise questions about the actual feedback mechanism of gyromonotrons. In this article, comparative studies on the linear and nonlinear behaviors of uniform-tube gyrotron are investigated. The forward and backward waves are observed to co-generate and exhibit similar characteristics of ultra-slow group velocity under near-cutoff operation. This situation allows the as-generated forward wave to modulate the fresh beam, establishing a new backward-wave-like internal feedback loop. Additionally, the quasi-degenerate nature of the bi-directional propagating waves ensures their intrinsic in-phase relationship. The consequent constructive interference enables the uniform tube to function as a high-Q resonator. These findings are found to be independent of the choices of TE or TM modes, providing valuable insights into the underlying interaction mechanism of gyrotron devices.
Shape-memory microfluidic chips for fluid and droplet manipulation
Authors: Ye Wen-Qi , Zhang Wei , Xu Zhang-Run
Published: April 2024

Fluid manipulation is an important foundation of microfluidic technology. Various methods and devices have been developed for fluid control, such as electrowetting-on-dielectric-based digital microfluidic platforms, microfluidic pumps, and pneumatic valves. These devices enable precise manipulation of small volumes of fluids. However, their complexity and high cost limit the commercialization and widespread adoption of microfluidic technology. Shape memory polymers as smart materials can adjust their shape in response to external stimuli. By integrating shape memory polymers into microfluidic chips, new possibilities for expanding the application areas of microfluidic technology emerge. These shape memory polymers can serve as actuators or regulators to drive or control fluid flow in microfluidic systems, offering innovative approaches for fluid manipulation. Due to their unique properties, shape memory polymers provide a new solution for the construction of intelligent and automated microfluidic systems. Shape memory microfluidic chips are expected to be one of the future directions in the development of microfluidic technology. This article offers a summary of recent research achievements in the field of shape memory microfluidic chips for fluid and droplet manipulation and provides insights into the future development direction of shape memory microfluidic devices.
Asymptotic stability of nonlinear fractional delay differential equations with
α
∈ (1, 2): An application to fractional delay neural networks
Authors: Yao Zichen , Yang Zhanwen , Fu Yongqiang
Published: April 2024

We introduce a theorem on linearized asymptotic stability for nonlinear fractional delay differential equations (FDDEs) with a Caputo order α∈(1,2), which can be directly used for fractional delay neural networks. It relies on three technical tools: a detailed root analysis for the characteristic equation, estimation for the generalized Mittag-Leffler function, and Lyapunov’s first method. We propose coefficient-type criteria to ensure the stability of linear FDDEs through a detailed root analysis for the characteristic equation obtained by the Laplace transform. Further, under the criteria, we provide a wise expression of the generalized Mittag-Leffler functions and prove their polynomial long-time decay rates. Utilizing the well-established Lyapunov’s first method, we establish that an equilibrium of a nonlinear Caputo FDDE attains asymptotically stability if its linearization system around the equilibrium solution is asymptotically stable. Finally, as a by-product of our results, we explicitly describe the asymptotic properties of fractional delay neural networks. To illustrate the effectiveness of our theoretical results, numerical simulations are also presented.
Strong Rashba effect induced by mechanical strain in the GeTe monolayer
Authors: Ju Weiwei , Li Mengjie , Chen Jing , Li Tongwei , Wang Xinxin , Kang Dawei , Li Haisheng , Zhao Bao
Published: April 2024

The GeTe monolayer possesses an AB binary buckled configuration, which can induce intrinsic Rashba spin splitting due to the existence of an internal electric field. However, the electronic structure obtained shows that these splittings are not present near the Fermi level, which makes it unsuitable for practical application. Based on first-principles calculations, we introduce strain engineering to manipulate the Rashba effect. Our results suggest that tensile strain can induce a remarkable Rashba spin splitting of valence band maximum (VBM). With a tensile strain of 10%, the Rashba coefficient can increase to ∼2 eVÅ, which is larger than most 2D Rashba materials. This is because the tensile strain converts the orbital component of the VBM from Te-px (Te-py) to Te-pz states. We propose a spin transistor based on the GeTe monolayer according to its Rashba effect and tunability under strain. Compared to conventional spin field-effect transistors, this transistor can achieve a shorter channel length at the nanometer level, which means that a chip can contain more transistors and integrate it into nanodevices with higher density.
Effect of substrate mismatch, orientation, and flexibility on heterogeneous ice nucleation
Authors: Camarillo M. , Oller-Iscar J. , M. Conde M. , Ramírez J. , Sanz E.
Published: April 2024

Heterogeneous nucleation is the main path to ice formation on Earth. The ice nucleating ability of a certain substrate is mainly determined by both molecular interactions and the structural mismatch between the ice and the substrate lattices. We focus on the latter factor using molecular simulations of the mW model. Quantifying the effect of structural mismatch alone is challenging due to its coupling with molecular interactions. To disentangle both the factors, we use a substrate composed of water molecules in such a way that any variation on the nucleation temperature can be exclusively ascribed to the structural mismatch. We find that a 1% increase in structural mismatch leads to a decrease of ∼4 K in the nucleation temperature. We also analyze the effect of orientation of the substrate with respect to the liquid. The three main ice orientations (basal, primary prism, and secondary prism) have a similar ice nucleating ability. We finally assess the effect of lattice flexibility by comparing substrates where molecules are immobile to others where a certain freedom to fluctuate around the lattice positions is allowed. Interestingly, we find that the latter type of substrate is more efficient in nucleating ice because it can adapt its structure to that of ice.
Ferroelectric Al1−xBxN–GaN heterostructures
Authors: Casamento Joseph , He Fan , Skidmore Chloe , Hayden John , Nordlander Josh , Redwing Joan M. , Trolier-McKinstry Susan , Maria Jon-Paul
Published: April 2024

This report demonstrates Al0.93B0.7N thin films grown epitaxially on n-type GaN (0002)/c-plane sapphire substrates by reactive magnetron sputtering at 300 °C. At 200 nm film thickness, the Al0.93B0.07N layers exhibit partially relaxed substrate-induced epitaxial strain, a 0.16° wide (0002) rocking curve, in-plane crystallographic registry, and sub-nanometer surface roughness. Electrically, the stack shows robust hysteresis over three frequency decades, a remanent polarization of ∼125 μC/cm2, a strongly frequency dependent coercive field, highly uniform dc leakage currents, and endurance >106 field cycles. This report validates possibilities for ferroelectric nitride integration into conventional III-nitride heterostructures with high crystalline fidelity, high electrical resistivity, and persistent hysteresis. Such materials are synthesizable at thermal budgets and temperatures compatible with back-end-of-the-line boundary conditions.
Theoretical and experimental study of the spanwise effect of turbulence on the aerodynamic lift on a wing with different aspect ratios
Authors: Li Ming , Yu Jianhan , Lin Zhongyu , Li Mingshui
Published: April 2024

In this paper, a combined theoretical and experimental study is carried out to investigate the spanwise effect of turbulence on the aerodynamic lift on a wing with different aspect ratios. The ratio of the mean square variance of the aerodynamic lift calculated by the commonly used strip theory and the two-wavenumber buffeting theory is analyzed comprehensively for the wings with different aspect ratios in turbulence with various integral scales. To validate the theoretical analysis and achieve a deeper understanding of the spanwise effects of turbulence, wind tunnel experiments are performed on National Advisory Committee for Aeronautics 0015 airfoils in grid-generated turbulent flows with different integral scales. The results demonstrate that it is essential to use the two-wavenumber buffeting theory to account for the spanwise effect of turbulence when calculating the aerodynamic lifts on wings with small aspect ratios, especially when in small-scale turbulence. The deviations between the equivalent two-wavenumber coherence function and the spanwise effect influence function at low reduced streamwise wavenumbers are the underlying causes for spanwise effects of turbulence. To achieve reliable wind tunnel testing results, appropriate simulations of the ratio of the turbulence integral scale to the chord are very important in the measurements of aerodynamic lifts on finite-span wing sections, especially for those with small aspect ratios.
Evolution of quantum spin sensing: From bench-scale ODMR to compact integrations
Authors: Esmaeili Shahriar , Schmalenberg Paul , Wu Songtao , Zhou Yuqing , Rodrigues Sean , Hussain Naveed , Kimura Taishi , Tadokoro Yukihiro , Higashi Shougo , Banerjee Debasish , Dede Ercan M.
Published: April 2024

This paper provides a comprehensive review of quantum spin sensing with a focus on the nitrogen vacancy (NV) center in diamond. Beginning with the discovery of optically detected magnetic resonance in NV centers, we trace the evolution of this technology and its integration with complementary metal-oxide-semiconductor technology, marking a significant advancement in measurement science. The unique optical and spin properties of NV centers, operational at room temperature and under ambient conditions, have broadened their application spectrum, notably in magnetometry for nanoscale magnetic field detection. This work describes the transition from isolated NV centers to dense ensembles, highlighting the challenges and advancements in microfabrication and nanofabrication that have facilitated the integration of these centers with photonic structures and electronic devices. The efficient readout of NV spin states and the challenges in miniaturization are addressed, showcasing the development of compact, portable quantum sensors. We also discuss the potential impact of these sensors in various domains, including vehicle sensor systems and biomedical applications, underscoring the significance of environmental influences on magnetometric readings.
Shock waves at final stages of cavity collapse in non-homogeneous liquid with divergenceless flow
Authors: Silveira F. E. M. , Camargo R. S.
Published: April 2024

We show the emergence of shock waves at the final stages of the complete collapse of a spherical cavity in a liquid with a smoothly decreasing density. The well-known Rayleigh assumption of fluid homogeneity is altered, while maintaining that of divergenceless flow. The fundamental difference between both infinite liquids is that his has an infinite mass, while ours, a finite one. Given the ease of deformation of non-homogeneous media in relation to homogeneous ones, as observed in several materials, all Rayleigh results are modified, including the cavity wall speed and acceleration, total time of complete collapse, and distribution of pressure in the infinite liquid. Rather than the homogeneous Rayleigh fluid, our non-homogeneous liquid can support a finite local sound speed. As a result, we succeed to show the emergence of shock patterns at the final stages of the cavity collapse. The analytical formulation is compared with underwater implosion and explosion experiments and simulations. Possible applications as a benchmark test for hydrocodes are briefly discussed.
Synthesizing avian dreams
Authors: Döppler Juan F. , Atencio Melina , Amador Ana , Mindlin Gabriel B.
Published: April 2024

During sleep, sporadically, it is possible to find neural patterns of activity in areas of the avian brain that are activated during the generation of the song. It has recently been found that in the vocal muscles of a sleeping bird, it is possible to detect activity patterns during these silent replays. In this work, we employ a dynamical systems model for song production in suboscine birds in order to translate the vocal muscles activity during sleep into synthetic songs. Besides allowing us to translate muscle activity into behavior, we argue that this approach poses the biomechanics as a unique window into the avian brain, with biophysical models as its probe.