bluuebunny/crossref_metadata_2025 huggingface dataset:
A generic formation mechanism of ultralight dark matter solar halos
Authors: Budker Dmitry , Eby Joshua , Gorghetto Marco , Jiang Minyuan , Perez Gilad
Published: December 2023

As-yet undiscovered light bosons may constitute all or part of the dark matter (DM) of our Universe, and are expected to have (weak) self-interactions. We show that the quartic self-interactions generically induce the capture of dark matter from the surrounding halo by external gravitational potentials such as those of stars, including the Sun. This leads to the subsequent formation of dark matter bound states supported by such external potentials, resembling gravitational atoms (e.g. a solar halo around our own Sun).
Their growth is governed by the ratio ξ
foc ≡ λdB/R
⋆ between the de Broglie wavelength of the incoming DM waves, λdB, and the radius of the ground state R
⋆.
For ξ
foc ≲ 1, the gravitational atom grows to an (underdense) steady state that balances the capture of particles and the inverse (stripping) process. For ξ
foc ≳ 1, a significant gravitational-focusing effect leads to exponential accumulation of mass from the galactic DM halo into the gravitational atom.
For instance, a dark matter axion with mass of the order of 10-14 eV and decay constant between 107 and 108 GeV would form a dense halo around the Sun on a timescale comparable to the lifetime of the Solar System, leading to a local DM density at the position of the Earth 𝒪(104) times larger than that expected in the standard halo model. For attractive self-interactions, after its formation, the gravitational atom is destabilized at a large density, which leads to its collapse; this is likely to be accompanied by emission of relativistic bosons (a `Bosenova').
Wave nature of Rosensweig instability
Authors: Li 李 Liu 柳 , Li 李 Decai 德才 , Qi 戚 Zhiqiang 志强 , Wang 王 Lu 璐 , Zhang 张 Zhili 志力
Published: December 2023

The explicit analytical solution of Rosensweig instability spikes’ shapes obtained by Navier–Stokes (NS) equation in diverse magnetic field H vertical to the flat free surface of ferrofluids are systematically studied experimentally and theoretically. After carefully analyzing and solving the NS equation in elliptic form, the force balanced surface equations of spikes in Rosensweig instability are expressed as cosine wave in perturbated magnetic field and hyperbolic tangent in large magnetic field, whose results both reveal the wave-like nature of Rosensweig instability. The results of hyperbolic tangent form are perfectly fitted to the experimental results in this paper, which indicates that the analytical solution is basically correct. Using the forementioned theoretical results, the total energy of the spike distribution pattern is calculated. By analyzing the energy components under different magnetic field intensities H, the hexagon–square transition of Rosensweig instability is systematically discussed and explained in an explicit way.
A run-and-tumble particle around a spherical obstacle: the steady-state distribution far-from-equilibrium
Authors: de Pirey Thibaut Arnoulx , van Wijland Frédéric
Published: December 2023

We investigate the steady-state distribution function of a run-and-tumble particle (RTP) evolving around a repulsive hard spherical obstacle. We demonstrate that the well-documented activity-induced attraction translates into a delta-peak accumulation at the obstacle’s surface accompanied by an algebraic divergence of the density profile close to the obstacle. We obtain the full form of the distribution function in the regime where the typical distance run by the particle between two consecutive tumbles is much larger than the obstacle’s size. This finding provides an expression for the low-density pair distribution function of a fluid of highly persistent hard-core RTP. It also advances an expression for the steady-state probability distribution of highly ballistic active Brownian particles and active Ornstein–Uhlenbeck particles around hard spherical obstacles.
Uniquely regular dessins with nilpotent automorphism groups of odd prime power order
Authors: Sun Lianghong , Wang Jin
Published: December 2023

If a graph is cut along each edge and can be divided into many faces, the graph has been defined to be a map when each face is homomorphic to an open disk and a bipartite map called dessin. A dessin D is regular Aut (D) if action transfer on the edge set. In particular, given a finite group G, a regular dessin is uniquely regular dessin if there is only one isomorphism class of Aut (D) are isomorphic to G. In this paper, for a nilpotent automorphism group of odd prime power order and nilpotency class four, we employ group-theoretical methods to classify these uniquely regular dessins.
Effects of microalgae and stocking density on growth and survival rate of giant clam (Tridacna squamosa Lamarck, 1819) larvae
Authors: Bay Phung , Anh Tuan Ngo , Van Minh Nguyen
Published: December 2023

The present study aimed to evaluate the impact of microalgae mixture and stocking density on growth and survival rate of giant clam (Tridacna squamosa) at the veliger stage. In the first experiment, giant clam larvae of the D-stage were reared in the conical fiberglass tanks and fed with combinations of microalgae, including Chaetoceros muelleri and Isochrysis galbana (1:1), and C. muelleri, I. galbana and Nannochloropsis oculata, (1:1:1). One group of giant clam larvae without feeding was used as a control. The experiment was lasted for 7 days, until the Pediveliger stage with six replicate tanks. In the second experiment, the larvae (1 day post hatched, DPH) were reared at densities of 3, 5, 7 and 9 larvae mL-1 (so-called D3, D5, D7 and D9, respectively) for a period of 7 days. Each density was randomly assigned to 6 replicate tanks. The larvae were fed once a day with a mixture of C. muelleri, I. galbana and N. oculata, (5,000 cells/ml each type of algae). At 4DPH, extracted zooxanthelle (Symbiodinium microadriaticum) was seeded into the giant clam larvae at the concentration of 5,000cells/ml once a day.

The results showed that larvae fed with C. muelleri, I. galbana and N. oculata (1:1:1) obtained the largest shell length (217.5 ± 3.1 µm), specific growth rate (SGR) 7.18 ± 0.34 (mean±SD) and the survival rate (31.5% ± 1.6%) (P<0,05). In addition, rearing densities significantly affected growth in shell length, SGR and survival rate in giant clam larvae. Of which, the larvae at D3 gained the highest shell length, SGR and survival rate. Meanwhile, the larvae at D9 had the lowest shell length, SGR and survival rate. There was no significant difference in larval survival rate between D3 and D5. Therefore, it is suggested that in the hatchery giant clam larvae reared at 5 larvae mL-1 in order to improve productivity.
Examining morphological measurement relationships to differentiate between sexes in slender mudskipper Periophthalmus gracilis (Eggert, 1935)
Authors: Van Hua U , Dinh Quang Minh , Duc Nguyen Ton Huu
Published: December 2023

This study developed a new method for determining the sex of Periophthalmus gracilis (Eggert, 1935) fish using morphological measurements. This alternative method could potentially overcome the limitations of traditional methods, such as dissection, which is time-consuming, invasive, and can only be performed on dead or mature fish. The researchers collected 1,288 fish samples over 12 months from different coastal regions in the Vietnamese Mekong Delta. The fish were sexed based on their gonads and measured for various morphological aspects, including total length, standard length, body height, eyeglass distance, eye diameter, mouth width, and head length. The researchers found that the relationship between total length and eye distance was the most effective in distinguishing between male and female fish. Males significantly increased eye distance than females, making it a vital measurement for sex determination. The combination of eye distance, body height, and mouth width could also be used to determine the sample collection time, whether during the wet or dry season. The study highlights the importance of using non-invasive and suitable ways to determine fish sex. The alternative method can potentially help reduce the number of fish used in traditional ways, ultimately aiding in conserving fish populations. Additionally, this study provides essential information for fishery management, as it can help estimate population sizes and sex ratios, leading to more effective and sustainable management strategies.
Enzyme-assisted extraction and properties of collagen from Basa fish (Pangasius bocourti) skin
Authors: Tran Quyen T. H. , Nguyen Tang V. , Nguyen Hoa V. , Dang Thanh T. , Phan Thinh V. , Nguyen Cuc T. K.
Published: December 2023

Type I collagen is a fibrillar structure collagen, which plays an important role as the essential structural composition and mechanical scaffold of several tissues. The aim of the study was to determine the properties of type I collagen extracted from Basa fish skin using acetic acid as the extraction solvent with the assistance of pepsin. The collagen extraction yield was 520.5 mg/g of fresh fish skin on the basis of lyophilized dry weight. The denaturation temperature (Td) of collagen was 34.8 °C by measuring its viscosity. The identity and purity of collagen protein were examined by ultraviolet-visible spectroscopy (UV-Vis) at 230 nm. Based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), the molecular weight (Mw) of collagen α1, α2, and β subunits were approximately 130, 118, and above 200 kDa, respectively. By high performance liquid chromatography (HPLC), 17 proteinogenic amino acids were found in the collagen sample, in which the hydroxyproline content was 68.3 mg/g. The scanning electron microscope (SEM) images confirmed the fibril structure of collagen. Fourier transform infrared spectroscopy (FTIR) spectrum indicated characteristic bands according to the presence of amide A, B, I, II, and III bonds in collagen chemical structure. Therefore, purified collagen obtained from this study can be further used in various fields of application.
Investigation of environmental factors on the resistance characteristic: Study case of the designed patrol boat hull
Authors: Yusfianda A R , Prabowo A R , Do Q T , Adiputra R , Putranto T , Bae D M
Published: December 2023

The increase in world oil prices has led to high operational costs in the maritime sector. In this regard, it is necessary to increase efficiency in the use of fuel in the maritime transportation security sector. Resistance on the ship’s hull affects efficiency and fuel consumption. In previous studies, there have been analyses on internal factors of the ship’s hull, such as appendages, which can affect the resistance value of the ship’s hull. However, examination of the external factors, e.g., the condition of the waters during operations of patrol boats, is still scant. This study conducts a series of analyses of the influence of environmental factors on the hull resistance values, such as water density and wind speed, with five different conditions. The results of this study are expected to be a reliable reference in predicting hull performance under different environments, especially in an attempt to reduce fuel consumption due to resistance.
Analysis of the internal-design factor to the patrol boat: A study of hull resistance using Savitsky and Holtrop approaches
Authors: Lutfi M A , Prabowo A R , Do Q T , Muttaqie T , Cho J H
Published: December 2023

The issue with sea transportation is the high operational costs due to fuel consumption. Ship resistance generated by the shape of the ship hull is one factor that affects efficiency. Internal factors that affect the hull’s resistance include the frontal area, appendage area, and appendage factor. In previous studies, research has been conducted on the effect of adding appendages to the hull and hull design variations on resistance. However, research on the influence of internal factors, e.g., rudder surface area and frontal area of the bow on hull resistance of monohull-type ships still need to be done. In this study, the effect of the type of internal factor is to be by considering the calculation of the hull resistance using the Savitsky method and Holtrop formula. Several hull designs with variations on adding the applied appendages are proposed to be the subjects of this study. The effect of the internal factors on the hull performance, i.e., resistance, is quantified to conclude the parameter which provides the highest effect.
Numerical study on cavitation reduction using PressurePores technology
Authors: Mai Linh Hoang Thi , Danh Bui Thanh , Hai Ha Nguyen Thi
Published: December 2023

The requirements in marine propeller design are rising in quantity and quality in recent decades. Besides hydrodynamic performance demand, the targets in reducing propeller cavitation and its side effects need to be considered such as underwater radiated noise and pressure pulses, to ensure comfort requirements and environmental regulations. Using numerical simulation, the present paper investigates the reduction of propeller tip vortex cavitation (TVC) as well as the effects on its performance by employing PressurePores technology. This study uses the Potsdam Propeller Test Case (PPTC) model with commercial code STAR CCM+. The CFD results are compared with the test results in the cavitation tunnel to validate the reliability of numerical simulation. In addition, cavitation mitigation of the propeller is estimated and an obtained average performance degradation is only 2% for different cases, in terms of pore diameters and drilling methods (cylindrical pore and conus pore). This research also provides the changes in pressure distribution, turbulent viscosity, and vorticity around the propeller to clarify the reason for cavitation reduction together with the hydrodynamic efficiency degradation of the propeller.
Ultimate strength of aged ships under hull structure’s imperfections
Authors: Tuyen Vu Van
Published: December 2023

Ship hull structures, particularly those with extended service life, contain various imperfections, including initial deformities, residual stresses, and corrosion-induced degradation. Such variables critically influence the structural integrity of the hull girder. Consequently, comprehending the residual strength capacity of the hull girder is paramount for guaranteeing the vessel’s operational safety and dependability, especially under severe loading scenarios. The existing methods to determine the hull girder’s ultimate bending moment either ignore imperfections or consider imperfections such as initial deformations or residual stresses but with the assumption of a fixed level. In the current study, the stress distribution method and incremental-iterative method are used; and solutions are proposed to cover factors such as initial deformations, residual stresses, and corrosion. A single skin bulk carrier, 56,000 DWT of deadweight, is employed as the demonstrative example. Eleven cases of imperfections are suggested, and the variations of ultimate bending moment for hogging and sagging conditions under the effect of uncertainties are analyzed and evaluated. The results of the current study are offered and discussed. Several concluding remarks are also presented.
Investigation of wave effects on motion of an unmanned surface vehicle at various scales
Authors: Nguyen Tien Thua , Pham Quoc Thai , Phan Thanh Long
Published: December 2023

Motion characteristics of unmanned surface vehicle are mainly affected by sea wave during its operation. This paper shows the numerical results of the unmanned surface ship at various scales in irregular waves based on the boundary element method. The effects of different sea states on each scaled model in a head sea, bow quartering sea, and beam sea are analyzed to predict the safety region of the ship motion. The significant amplitudes of ship motion are obtained from the ship motion responses in regular waves. Steady wave drift forces in the cases of bow oblique sea are calculated to find the impact of second-order waves on the models. It is proved that the motion of model C is remarkable in the narrow frequency domain from 0.2 to 1.4 rad/s but the ship responses of model A are considerable in the range of frequency of 0.2 to 2.5 rad/s. The significant amplitude of surge and pitch motion reaches the peak values in head sea conditions while the peak values of yaw motion are in the oblique sea of 120 degrees. The left motion is maximum in head sea condition.
Dynamic impact response and residual strength of container ship under dropped object
Authors: Nguyen Huy Vu , Do Quang Thang
Published: December 2023

This study aims to present numerical investigations on container ships’ residual longitudinal ultimate strength subjected to dropped container collisions. First, the commercial software ABAQUS was applied. The accuracy and reliability of the proposed numerical analyses were established by comparing the numerical results with the experimental results. Next, parametric studies were carried out on actual container ships to assess the degree of loss of the ship’s longitudinal strength in two dangerous situations a ship sagging and hogging. The effects of parameters including drop heigh and impact angles on the ultimate longitudinal strength of the ship have been investigated. The results present in this study can be applied to predict the residual longitudinal strength of dropped container collisions on a container ship. It is also useful for the initial design stage of ship structures in case of collision incidents.
Numerical Investigation on the Motion of a High-Speed Planning Hull in Calm Water Condition using RANSE Method
Authors: Ha Tran Viet , Tu Tran Ngoc , Ngoc Pham Minh
Published: December 2023

Planing hulls were commonly used in both civilian and military situations. The prediction of the motion of the planing hull was complicated due to the trim angle and sinkage oscillations caused by the lift variations and complex hydrodynamic interactions at high speeds. To evaluated the motion of the planing hull, it was essential to analyse the hydrodynamic performance of the planing hull at high speed. This paper presented a CFD method for calculating the hydrodynamics of a planing hull in calm water conditions at different Froude numbers. The numerical method was based on the Reynolds-averaged Navier-Stokes equation (RANSE). The volume of fluid (VOF) and two degrees of freedom equations were utilized. An efficient procedure was introduced to solve numerical divergence in numerical simulations. Resistances of the planing hull in numerical results were compared with experimental results to verified and validated the used RANSE method.
Numerical Investigation on the Influence of Ship Hull Form Modification on Resistance of the 4600DWT Cargo Ship Using RANSE Method
Authors: Ngoc Vu Minh , Hai Ha Nguyen Thi , Ngoc Pham Minh , Tung Dam Van , Hao Nguyen Huy , Tu Tran Ngoc
Published: December 2023

Optimization of ship hull form in the ship design process aims to reduce ship resistance, which is crucial for economic efficiency and meets the International Maritime Organization (IMO) requirement for emission reduction and energy saving. This paper investigates the impact of the longitudinal centre of buoyancy (LCB) position on the resistance of a cargo ship 4600DWT using the RANSE (Reynolds – averaged Navier – Stokes equation) method. The ship hull form was modified using the Lackenby method. The obtained numerical results indicate that the LCB position significantly affects ship resistance. The physical phenomenon of the change in ship resistance is also explained through the analysis of the differences in the flow field around the ship’s hull form with modified LCB positions.
Numerical Simulation Flow Around The 4600DWT Cargo Ship in Calm Water Condition Using RANSE Method
Authors: Ngoc Vu Minh , Hai Ha Nguyen Thi , Ngoc Pham Minh , Tung Dam Van , Hao Nguyen Huy , Tu Tran Ngoc
Published: December 2023

Information about the flow field around the ship may enable the designers to improve ship hull form concerning ship hydrodynamics. The flow around the ship can be obtained through model tests in towing tank and simulations. However, the experimental method provides the most reliable data about flow around the ship, but this method is too expensive and time-consuming. Currently, the RANSE (Reynolds – averaged Navier – Stokes equation) method has been widely employed in predicting the ship resistance and flow around the ship in the ship design process due to it provides relatively accurate results, savings in time and money compared to the experimental method. Therefore, this paper deals with the numerical results of the study flow around the 4600DWT cargo ship, which operate on Vietnam’s river-sea routes in calm water condition at different ship speeds using the RANSE method. The effect of ship speed on ship resistance components, wave pattern, wave profile along the ship, distribution of dynamic pressure, and wall shear stress on the ship’s hull surface and nominal wake field are presented and analysed in the paper.
Assessment of predicting temperature distribution of friction stir welded AA6061 induced by pin profiles for developing sustainable industry
Authors: Tien Dat Tra Ngoc , Duong Hao Dinh , Hoa Vu Cong , Tran Tra Hung
Published: December 2023

Nowadays, the aspects of energy and environmental pollution have been becoming a big challenge in developing sustainable industries. Using green technology is considered as priority solution for any manufacturing process. Friction stir welding (FSW) is invented as green technology applied widely in many field industries. To evaluate its applicability, this study focused on the prediction of temperature distribution of FSWed AA6061 induced by various pin profiles. Research efforts are being made to gain a better understanding of FSW process, to explore different tool configurations, and their influence on the heat generation. The numerical model was developed in Abaqus software, utilizing the coupled Eulerian Lagrangian method, the Johnson-Cook material model, and the mass scaling technique. The model’s accuracy is verified by comparing its simulated temperature values with experimental data in Stir zone (SZ) and Heat-affected zone (HAZ). The numerical results show the high correlation with the experimental study, with the deviation around 10%. It is shown that tool pin profiles with the combination of thread and flat features generated the highest temperature.
A Numerical Simulation and Multi-objective Optimization for the Plastic Injection Molding of a Centrifugal Pump Casing
Authors: Nguyen Huu-That , Nguyen Minh-Quan
Published: December 2023

Plastic pumps are used to efficiently move liquids within aquaculture systems and seafood processing facilities. Commonly, the centrifugal pump casing is fabricated by plastic injection molding technology. In the plastic injection molding process, the control parameters are essential to the success of plastic molding product fabrication. This study aims to optimize process parameters for the quality of centrifugal pump casing during plastic injection molding using a combination of response surface methodology (RSM) and the NSGA-II method. Firstly, the L27 orthogonal array design of the experiment method is used, which has four input variables, including plastic temperature, mold temperature, cooling time, and injection time (filling time and packing time). The output responses of the injection molding process to be evaluated are the warpage and shrinkage deformation of the molded product. After obtaining data, the RSM model is applied to describe the relationship between the input and output variables. Finally, multi-objective optimization uses the NSGA-II method for the best product quality. The results show that the optimized parameters for injection molding of the centrifugal pump casing are a plastic temperature of 200°C, mold temperature of 65°C, cooling time of 25s, and injection time of 10s with warpage of 0.868 mm, and shrinkage of 10.104mm.
Investigation on microplastics in some bivalves at Binh Dien Market in Hochiminh City, Vietnam
Authors: Dao Thanh-Son , Lai Dang-Minh-Tri , Nguyen Quoc-Hung , Pham Anh-Duc , La Xuan-Thao , Tran Anh-Tu , Bui Xuan-Thanh
Published: December 2023

Microplastics (MPs) and their risk to living things and human health have been attained a lot of attention worldwide. Reports on the MPs in mollusks used as seafood are being increased in all continents. However, the information is limited in Vietnam. This study aimed to identify the quantitative presence of MPs in three bivalves (Anadara granosa, Meretrix lyrata, and Ensidens sp.) in Hochiminh City which are popularly used as daily seafood by local residents. Samples of the bivalves were bought biweekly from the wholesale market Binh Dien, Hochiminh City, from February to April 2022. All three bivalve species were found with fiber MPs in their tissues. The concentrations of MPs (mean ± standard deviation) were 8.9 ± 5.4 items/individual (idv), and 4.2 ± 3.2 items/gram wet weight (g ww) in the A. granosa; 6.4 ± 2.6 items/idv, and 1.1 ± 0.4 items/g ww in the M. lyrata; and 5.9 ± 2.8 items/idv, and 0.7 ± 0.3 items/g ww in the Ensidens sp. The shorter length the fiber MPs were, the higher concentration they were, in the samples. Eight different colors of MPs in the bivalves were observed including blue, black, red, yellow, green, white, pink and grey in which the blue color was dominant in the samples. Chemical analysis with the fourier transform infrared microspectroscope revealed that 50% of fibers were polyethylene terephthalate (PET), polyethylene (PE) and rayon. This study firstly reported the MPs in the Ensidens sp. and the A. granosa (as items/ g ww). The total fiber intake from the three bivalve consumption was approximately 3,992 items per person per year. The presence of MPs in the bivalves used as food in Hochiminh City possesses a health risk to local people who commonly consume them as daily food. Further insight studies on the effects of MPs from food on human health in Hochiminh City are suggested.
The generation pathways of OH and H2O2 by plasma-liquid interactions
Authors: Thai Van-Phuoc , Dam Tran Ngoc , Takahashi Kazumasa , Sasaki Toru , Kikuchi Takashi
Published: December 2023

Plasma-liquid interactions (PLIs) are a rich source providing many reactive oxygen species (ROS). These ROS species, such as OH and H2O2, feature powerful oxidative properties, which are excellent utilization for bacterial killing, water treatment, and other applications. Lifetime and reaction pathways of ROS species from plasma into the bulk liquid are complex. Understanding these behaviors is essential for the applications of the ROS species. In this work, we presented two pathways for generation of OH radicals and H2O2 from the plasma into the bulk liquid. Firstly, OH radicals are mainly produced via the dissociation of water molecules by free electrons in the plasma. Generated radicals then quickly recombine into H2O2. These species with a high Henry constant easily absorb and disperse into the bulk liquid. In a second way, OH radicals and H2O2 are also generated by the reaction of O3 with H2O molecules. At first, O3 is absorbed into the bulk liquid and reacts with H2O2 molecules to generate H2O2. Next, O3 continues reacting with this generated H2O2 to produce OH radicals.
Wave dissipation by vegetation for coastal defense in the Western Mekong Delta under climate change
Authors: Thu Nguyen Ha Thi , Chinh Vu Dan
Published: December 2023

The combination of the Mekong Delta dyke-mangrove system effectively protects the hinterland against flooding and erosion in extreme conditions for decades since they could dissipate waves and currents efficiently. However, literature and satellite data indicate that severe erosion happens along the Western sea-dykes of the Ca Mau coast caused by increased intensity of storms due to climate change. State-of-the-art wave transformation models are used to predict the influences of wave propagation and wave overtopping discharge over sea dykes and/or associated with mangrove ecosystems under extreme typhoons, which cooperates with both high – frequencies (HF) and low – frequencies (LF) waves. Results confirm that the HF wave quickly dissipates in shallow water, whereas the LF wave is dominant and penetrates over a longer distance. At dyke toe, the wave height through vegetation is substantially diminished, approximately ten times less than that in the sea-dyke solely. However, the modelling wave overtopping discharge seems to be overestimated compared with the standard-based formula.
Watercraft tracking and monitoring system towards safe and resilient marine communication systems
Authors: Salido Julie Ann A. , Gelonga Rowen R. , Porcal Abraham A. , Popes Ma. Fe P. , Oquendo Miquel Von R. , Martirez Mary Ann P. , Hilario Kirk M.
Published: December 2023

In this research, Sea-condition Emergency Alert and Warning Apparatus for Vessel Safety (SEAWAVES) is a watercraft tracking and monitoring system developed and deployed to monitor watercraft and sea conditions to provide a safer and more resilient marine communication system. The proposed method puts together an application of contemporary technology using the fused location provider Application Programming Interface (API) to retrieve the device’s current location. In addition to managing the underlying location technologies, like Global Positioning System (GPS) and Wi-Fi, the fused location provider offers a straightforward API that you may use to specify the desired level of service. The work includes calibrating the compass, GPS, and Global System for Mobile Communication (GSM) for watercraft tracking and monitoring using Android sensors of mobile phones. The GPS provides the present site of the watercraft; General packet radio service (GPRS) sends the tracking information to the server and thus an alert message generated is transmitted to the registered monitoring systems. This scheme is deployed in the watercraft to monitor location and sea conditions, which are to be determined on the web page and supervised in real-time. Hence, if the watercraft is at a critical level, alert messages will be sent to the monitoring system, and the registered mobile phone number of the watercraft. Also a warning display and sound are produced by the device. The SEAWAVES tracking and monitoring system could be recommended for use onboard a watercraft throughout the country for effective management and monitoring of the performance of such watercraft, and low-cost instrumentation as a stand-alone system through modern technologies.
Energy absorption capacity under tensile and compressive loads of auxetic metamaterial structures
Authors: Nhat Nguyen Minh Phuc , Vu Cong Hoa , Nguyen Minh Ngoc
Published: December 2023

An auxetic metamaterial is a mechanical metamaterial with a negative Poisson’s ratio. When compressed or stretched in one direction, it contracts or expands in a perpendicular direction. This review paper focuses on the energy absorption of auxetic metamaterial structures and their applications. Starting with the original structure proposed by D. Han et al., another structural model with heuristically enhanced ribs is proposed to suit the structure’s anisotropy, reduce mass, and increase energy absorption. An extension to this is the newly designed MH-1 model, which is lightweight compared to commonly reported auxetic forms. Numerical results show that MH-1 has the best specific energy absorption and exhibits an obvious auxetic effect under tension, with symmetrical and stable deformation modes. Auxetic metamaterials are also progressively finding applications in the biomedical field. One of the most promising applications of auxetic is in the development of new and improved prosthetics and implants.
Review of the corrosion behaviour in tannic-acid coated magnesium implants
Authors: Asawan Esa Lahan , Sihombing Jackson , Nurrochman Andrieanto , Prajatelistia Ekavianty
Published: December 2023

Magnesium is a bio-degradable material used for bone implants because of its similar mechanical properties to bones. However, magnesium has a high corrosion rate, resulting in an implant’s degradation before the bone is fully healed. Thus, researches are conducted to study ways to improve the corrosion resistance of magnesium. Coating is one of the methods to hinder the corrosion rate of magnesium. There are two types of coatings: organic and inorganic. Organic coatings are preferable due to their non-toxicity and good biocompatibility. Tannic acid (TA) is an organic coating with a strong bond with magnesium due to its many hydroxyl groups. Besides bonding with the substrate material, tannic acid can also bind with other compounds or elements to improve the performance of the coating layer. This review evaluated several types of TA-based coatings on magnesium alloys used in orthopaedic implants and the fabrication processes affecting the structural integrity of the coating. The strategies for using TA-compound combination for corrosion mitigation with ease of fabrication process were also highlighted. This review is expected to provide some insight on the challenges and future directions of TA-based magnesium coatings for orthopaedic applications.
Recent advances in nano/micro systems for improved circulation stability, enhanced tumor targeting, penetration, and intracellular drug delivery: a review
Authors: Chan Wei-Jen , Li Huatian
Published: December 2023

In recent years, nanoparticles (NPs) have been extensively developed as drug carriers to overcome the limitations of cancer therapeutics. However, there are several biological barriers to nanomedicines, which include the lack of stability in circulation, limited target specificity, low penetration into tumors and insufficient cellular uptake, restricting the active targeting toward tumors of nanomedicines. To address these challenges, a variety of promising strategies were developed recently, as they can be designed to improve NP accumulation and penetration in tumor tissues, circulation stability, tumor targeting, and intracellular uptake. In this Review, we summarized nanomaterials developed in recent three years that could be utilized to improve drug delivery for cancer treatments.
Feel warm then do well: understanding how green human resources management improves employee extra-role green behavior and person-organization fit
Authors: Wang Xinnan , Jin Jiafei , YahiaMarzouk Yasmine
Published: December 2023

Although it is an increasingly popular assumption that green human resource management (GHRM) can improve employee green behaviors, little empirical evidence has studied the link between different types (in-role and extra-role) of green behavior and how GHRM may have an impact beyond its original environmental domain. To bridge the research gap, this study develops and tests two serial mediation models of GHRM based on warm glow theory. Specifically, we propose that GHRM -as an organization management measure-will first increase employee in-role green behavior (IRGB). Then, due to employees’ perception and cognitive appraisal of organization’s GHRM policy and prosocial ‘Halo effect’ of green behavior, employees feel that they are doing the ‘right thing’, thus feel warm glow (WG) psychologically. The positive emotional experience accumulated by warm glow allows employees to obtain intrinsic rewards, resulting in green behaviors that are beyond their core task responsibilities and that can increase employee value and psychological consistency with organization. Drawing upon 301 data collected from Prolific, results support two significant serial mediation models. First, GHRM increased extra-role green behavior (ERGB) through in-role green behavior and warm glow. Second, GHRM increased person-organization fit through in-role green behavior and warm glow. Therefore, warm glow creates a spillover effect at the employee behavioral level and at the personal value level. This study contributes to existing literature by explaining how GHRM affects extra-role green behavior from a new perspective. By establishing a link between GHRM and non-green outcomes, we also expands the scope of GHRM research.
Tracking and detecting sargassum pathways across the tropical Atlantic
Authors: Fidai Y A , Dash J , Marsh R , Oxenford H A , Biermann L , Martin N , Tompkins E L
Published: December 2023

Pelagic sargassum (S fluitans and S natans) algal blooms and beach landings have become a regular occurrence in the Tropical Atlantic Basin since 2011; they have a variety of impacts on the marine ecosystem and blue economy. To reduce the impacts and enable effective management, forecasting and monitoring of the blooms are essential. Challenges associated with use of satellite imagery for sargassum detection in the Tropical Atlantic are spatial resolution and cloud cover, which is particularly dense in this region due to the inter-tropical convergence zone, tropical storms and hurricanes. Successful models of forecasting and prediction of pelagic sargassum are hindered by unreliable satellite data, uncertainty around windage and as well as growth and mortality. In the longer term, we aim to improve the forecast models of pelagic sargassum mat movements in open oceans by introducing evidence of the speed of travel, changing mat morphology, and size and health status of sargassum mats. To achieve this, we deployed eight trackers on floating sargassum mats in the Western Tropical Atlantic. In addition, we explore the coincidence of surface currents, wind stress and sea surface temperature as a parameter for growth on the tracker pathways. When used in conjunction with both remote sensing methods and climate data (wind, current and sea temperature), we find that GPS tracker data can facilitate more reliable monitoring of sargassum transport pathways, helps to overcome satellite-based challenges as well as model based uncertainties, and may improve the accuracy and general utility of sargassum early warning systems.
The relationship between determinants of husband–wife agreement and household climate change mitigation behavior
Authors: Hung Li-San , Li Yen-Wei , Bayrak Mucahid Mustafa
Published: December 2023

Reducing carbon emissions from household activities is an important element in achieving climate goals. Engagement in household climate change mitigation behaviors usually requires interaction and negotiation among household members. Congruence theory suggests that individual-determinants of climate change mitigation behavior are strongly influenced by household-level determinants, such as mutual agreement between couples, but few studies have empirically tested this hypothesis. Being a pioneer study of its kind in the field of climate change mitigation behavior, a unique dataset that contained the survey results of 152 married heterosexual couples in Taipei City, Taiwan was used to test the congruence effect on household climate change mitigation behaviors. Eight theoretical determinants of household climate change mitigation behaviors (five at individual-level and three at household-level) and the level of engagement in three household climate change mitigation behaviors were analyzed. Results from a response surface analysis suggested that none of the five individual-level determinants exhibited congruence effects, while two out of three household-level determinants exerted congruence effects on the behavior of energy-efficient appliance purchasing. In other words, based on the results of this study, married heterosexual couples having similar attitudes regarding household-level variables but not individual-level variables is a nonnegligible factor influencing engagement in household climate change mitigation behaviors that require a certain level of intrahousehold interactions.
Investigating the mechanical properties of sintered 440 C stainless steel produced by an extrusion-based 3D printer
Authors: Akhoundi Behnam , Modanloo Vahid
Published: December 2023

Extrusion-based 3D printing of parts is one of the simplest, cheapest, and most widely used additive manufacturing (AM) methods. The raw materials in this process are generally filaments with a constant diameter. By equipping extrusion-based 3D printers with the barrel and screw system and removing the filament manufacturing step, a wide range of materials can be 3D printed. In this research, the parts were 3D printed using a feedstock of metal powder injection molding process and with a direct granule extruder system equipped with a barrel and screw. Then, on the printed parts, debinding, sintering, and grinding processes were performed, and finally, their tensile and impact mechanical properties were evaluated. The average tensile strength and modulus are equal to 295 MPa and 85 GPa, respectively, the average of impact resistance is equal to 12.5 J and the hardness number is equal to 118 HB. In addition, by calculating the amount of porosity in the samples, the low value of the mechanical properties of the samples was justified.
Building a Child’s Trust before a Medical Procedure: A Linguistic Case Study
Authors: Depraetere Ilse , Caët Stéphanie , Debulpaep Sara , Ezzahid Siham , Janke Vikki
Published: December 2023

When a paediatrician establishes a trusting relationship with their patient, the chance of a positive outcome multiplies. A calm child, who participates fully in the communicative exchange is more receptive to the clinician’s requests and reports weaker sensations of pain. This experience stays with the child, shaping how they approach their healthcare as adults. Our qualitative case study unpacks the linguistic aspects of a 32-minute videoed and transcribed exchange between a paediatrician (co-author) and a five-year-old boy she is preparing for a risky procedure. It asks: what linguistic strategies reduce his anxiety? Non-pharmacological methods are key here, as deep sedation is problematic. Our study explains the communicative techniques that the paediatrician exploits. We identify how they function, and how seemingly disconnected strategies group naturally under a few general principles. This is important for professional development because fewer overarching principles are easier to grasp and subsequently to deploy. Our interdisciplinary approach, which relies on real data, can be replicated and expanded with healthcare professionals to enable them to act concretely on their language productions.
scATAC-seq preprocessing and imputation evaluation system for visualization, clustering and digital footprinting
Authors: Akhtyamov Pavel , Shaheen Layal , Raevskiy Mikhail , Stupnikov Alexey , Medvedeva Yulia A
Published: December 2023

Single-cell ATAC-seq (scATAC-seq) is a recently developed approach that provides means to investigate open chromatin at single cell level, to assess epigenetic regulation and transcription factors binding landscapes. The sparsity of the scATAC-seq data calls for imputation. Similarly, preprocessing (filtering) may be required to reduce computational load due to the large number of open regions. However, optimal strategies for both imputation and preprocessing have not been yet evaluated together. We present SAPIEnS (scATAC-seq Preprocessing and Imputation Evaluation System), a benchmark for scATAC-seq imputation frameworks, a combination of state-of-the-art imputation methods with commonly used preprocessing techniques. We assess different types of scATAC-seq analysis, i.e. clustering, visualization and digital genomic footprinting, and attain optimal preprocessing-imputation strategies. We discuss the benefits of the imputation framework depending on the task and the number of the dataset features (peaks). We conclude that the preprocessing with the Boruta method is beneficial for the majority of tasks, while imputation is helpful mostly for small datasets. We also implement a SAPIEnS database with pre-computed transcription factor footprints based on imputed data with their activity scores in a specific cell type. SAPIEnS is published at: https://github.com/lab-medvedeva/SAPIEnS. SAPIEnS database is available at: https://sapiensdb.com
EGR1 modulates EPHB4-induced trophoblast dysfunction in recurrent spontaneous abortion
Authors: Hua Rong , Mo Yi , Lin Xiu , Zhang Bin , He Min , Huang Chun , Huang Yujie , Li Jie , Wan Jiangfan , Qin Huamei , Xie Qinshan , Zeng Donggui , Sun Yan
Published: December 2023

Recurrent spontaneous abortion, defined as at least three unexplained abortions occurring before the 20-24 week of pregnancy, has a great impact on women’s quality of life. Ephrin receptor B4 has been associated with trophoblast function in preeclampsia. The present study aimed to verify the hypothesis that ephrin receptor B4 regulates the biological functions of trophoblasts in recurrent spontaneous abortion and to explore the upstream mechanism. Ephrin receptor B4 was overexpressed in mice with recurrent spontaneous abortion. Moreover, ephrin receptor B4 inhibited trophoblast proliferation, migration, and invasion while promoting apoptosis. Downregulation of early growth response protein 1 expression in mice with recurrent spontaneous abortion led to ephrin receptor B4 overexpression. Poor expression of WT1-associated protein in mice with recurrent spontaneous abortion reduced the modification of early growth response protein 1 mRNA methylation, resulting in decreased early growth response protein 1 mRNA stability and expression. Overexpression of WT1-associated protein reduced the incidence of recurrent spontaneous abortion in mice by controlling the phenotype of trophoblasts, which was reversed by early growth response protein 1 knockdown. All in all, our findings demonstrate that dysregulation of WT1-associated protein contributes to the instability of early growth response protein 1, thereby activating ephrin receptor B4-induced trophoblast dysfunction in recurrent spontaneous abortion. Our study provides novel insights into understanding the molecular pathogenesis of recurrent spontaneous abortion.