Density Analysis Research Articles

Spatial Analysis of Maritime Disasters in the Philippines: Distribution Patterns and Identification of High-Risk Areas

Maritime accidents frequently occur in the Philippine archipelagic waters, often resulting in significant loss of life. These incidents highlight the urgent need for improvements in the country’s maritime safety systems. By utilising accident data from the Philippine Coast Guard and the GISIS IMO databases, spatial analytical approaches were employed to determine incident distribution patterns and resulted in an overall depiction of the likelihood component of risk across the country’s territorial waters. Kernel density and hotspot analysis revealed areas where incidents were concentrated and where statistically significant hotspots occurred. The Maxent tool was used to develop risk likelihood models for the incident locations using environmental rasters representing wind speed, significant wave height, depth, surface current, land distance and port distance. Model performance metrics including the AUC, TSS and Kappa were used to compare the two datasets and provide confidence on model robustness. Variable contribution figures showed that land distance is the most influential variable, with the majority of high-risk areas predominantly located near population centres. The resulting maps provide an intuitive and informative depiction of the characteristic patterns of maritime accidents in the country, identify areas of high risk requiring immediate attention and offer valuable insights to support strategies for improving and enhancing the country’s maritime safety.

T4 Phage Displaying Dual Antigen Clusters Against H3N2 Influenza Virus Infection

Background: The current H3N2 influenza subunit vaccine exhibits weak immunogenicity, which limits its effectiveness in preventing and controlling influenza virus infections. Methods: In this study, we aimed to develop a T4 phage-based nanovaccine designed to enhance the immunogenicity of two antigens by displaying the HA1 and M2e antigens of the H3N2 influenza virus on each phage nanoparticle. Specifically, we fused the Soc protein with the HA1 antigen and the Hoc protein with the M2e antigen, assembling them onto a T4 phage that lacks Soc and Hoc proteins (Soc−Hoc−T4), thereby constructing a nanovaccine that concurrently presents both HA1 and M2e antigens. Results: The analysis of the optical density of the target protein bands indicated that each particle could display approximately 179 HA1 and 68 M2e antigen molecules. Additionally, animal experiments demonstrated that this nanoparticle vaccine displaying dual antigen clusters induced a stronger specific immune response, higher antibody titers, a more balanced Th1/Th2 immune response, and enhanced CD4+ and CD8+ T cell effects compared to immunization with HA1 and M2e antigen molecules alone. Importantly, mice immunized with the T4 phage displaying dual antigen clusters achieved full protection (100% protection) against the H3N2 influenza virus, highlighting its robust protective efficacy. Conclusions: In summary, our findings indicate that particles based on a T4 phage displaying antigen clusters exhibit ideal immunogenicity and protective effects, providing a promising strategy for the development of subunit vaccines against various viruses beyond influenza.

ρ meson transverse momentum-dependent parton distributions

In this paper, the light-front wave functions (LFWFs) of the ρ meson are evaluated in the framework of the Nambu–Jona-Lasinio model using the proper time regularization scheme. The transverse momentum-dependent parton distributions (TMDs) of the ρ meson are derived from the overlap representations of the LFWFs. We investigate the k⊥-weighted moments and the x-dependent average transverse momentum ⟨k⊥n(x)⟩α of ρ meson TMDs. The ⟨k⊥n(x)⟩α shows the typical transverse momenta of quark TMDs in our model. Our findings indicate that the average transverse momenta of ⟨k⊥(x)⟩α fall within the range of [0.3, 0.45] GeV, while ⟨k⊥2(x)⟩α are in the region of [0.15, 0.30] GeV2. Our TMDs and parton distribution functions (PDFs) exhibit excellent adherence to positive constraints. The investigation of spin densities within the ρ meson in transverse momentum space reveals axially symmetric distributions for quarks and targets polarized in either the longitudinal or transverse direction. Conversely, unpolarized symmetric distributions occur when the quark is longitudinally polarized and the target is transversely polarized, while exhibiting dipolar distortions in the opposite scenario. A comparison between TMDs from LFWFs and those from a covariant approach demonstrates that TMDs from LFWFs more effectively satisfy positive constraints than their counterparts from the covariant approach. Furthermore, the x-moments of ρ meson PDFs indicate that ⟨x⟩gL is larger using LFWFs than with the covariant approach. Additionally, analysis of quark spin densities within the ρ meson reveals that ρ↑↓kx,ky=f-gL-13fLL yields a negative result using the covariant approach, whereas ρ↑↓kx,ky derived from LFWFs produces a positive outcome.

Structure and dynamics of piperidinium based amino acid ionic liquids: a computational investigation.

There has been growing interest in amino acid ionic liquids because of their low-cost synthesis and superior biodegradability and biocompatibility compared to traditional ionic liquids. In this study, we have investigated the structure and dynamics of three ionic liquids consisting of N-butyl N-methyl piperidinium[Pip] cation with amino acid (lysine [Lys], histidine [His], and arginine [Arg]) anions. The radial distribution functions, the spatial distribution functions, and the coordination numbers have been used to analyze the structure in the bulk phase. The time-correlation functions for hydrogen bonds, ion pairs, and ion cage formation have been calculated to analyze the dynamic properties. The hydrogen bonds found between the ion pairs are mostly electrostatically dominant with moderate to weaker strengths. The [Pip][His] system showed the strongest interaction energy between the ion pairs, while the [Pip][Lys] system demonstrated faster dynamics consistent with its higher diffusion and ion conductivity. The density functional theory at M06-2X/6-311 + + G(d,p) level was employed for geometry optimization and wave function calculations. The theory of atoms-in-molecule was used for the topological analysis of electron density. The classical molecular dynamics simulations with OPLS-AA force field were employed to study the dynamics of the systems.

First-Principles Study on the Mechanical Properties of Ni3Sn4-Based Intermetallic Compounds with Ce Doping

Ni3Sn4 intermetallic compound (IMC) is a critical material in modern electronic packaging and soldering technology. Although Ni3Sn4 enhances the strength of solder joints, its brittleness and anisotropy make it prone to crack formation under mechanical stress, such as thermal cycling or vibration. To improve the plasticity of Ni3Sn4 and mitigate its anisotropy, this study employs first-principles calculations to investigate the mechanical properties and electronic structure of the doped compounds Cex Ni3−xSn4 (x = 0, 0.5, 1, 1.5, 2) by adding the rare earth element Ce. The results indicate that the structure Ce0.5 Ni2.5Sn4 has a lower formation enthalpy (Hf) compared to other doped structures, suggesting enhanced stability. It was found that all structures exhibit improved plasticity with Ce doping, while the Ce0.5 Ni2.5Sn4 structure shows relatively minor changes in hardness (H) and elastic modulus, along with the lowest anisotropy value (AU). Analysis of the total density of states (TDOS) and partial density of states (PDOS) reveals that the electronic properties are primarily influenced by the Ni-d and Ce-f orbitals. At the Fermi level, all Cex Ni3−xSn4 (x = 0, 0.5, 1, 1.5, 2) structures exhibit metallic characteristics and distinct electrical conductivity. Notably, the TDOS value at the Fermi level for Ce0.5 Ni2.5Sn4 lies between those of Ni3Sn4 and other doped structures, indicating good metallicity and conductivity, as well as relative stability. Further PDOS analysis suggests that Ce doping enhances the plasticity of Ni3Sn4. This study provides valuable insights for the further application of rare earth elements in electronic packaging materials.

Gafchromic Films as a Complementary In-field Dosimetric Tool to Monitor Low Photon Radiation Doses (≤50 mSv).

This study elucidated the radiation response characteristics of a Gafchromic radiochromic film subjected to low photon doses of ≤50 mSv, which corresponds to the annual whole body effective dose limit for radiation workers in Canada. Radiochromic films are investigated for possible use as a complementary tool for the Canadian Armed Forces that can be worn in addition to their existing personal dosimetry to quickly assess personal radiation dose received from radiological hazards without reliance on electronics. The films were exposed to varying photon energies emanating from x-ray generators and radioisotopes, specifically cesium-137, cobalt-60, and americium-241. The resultant radiation-induced film darkening was quantitatively assessed employing three analytical methodologies: net optical density analysis, UV/Visible spectroscopic analysis, and Fourier Transform Infrared spectroscopic analysis. Ideally, a film dosimeter necessitates a pronounced chromatic alteration and the capability to accurately quantify doses ≤50 mSv where net optical density analysis was identified as the optimal modality for interpreting the film darkening into a dose approximation. This new approach established a lower detection threshold of 7.6 mSv for the films when exposed to cesium-137 radiation. Notably, the film exhibited a linear dose response relationship in terms of net optical density; however, a photon energy-dependent variability was observed within the 0-100 mSv dose range. In conclusion, these Gafchromic radiochromic films present a promising candidate for military dosimetry applications. They offer a real-time, visual dose response that can be discerned by military personnel or analyzed using mobile spectroscopic instrumentation. Moreover, these films demonstrate proficiency in the accurate quantification of photon doses ≤50 mSv. Future investigations will evaluate the film's performance under heterogeneous and indeterminate radiation environments, as well as the impact of environmental conditions on the film's performance.

Ultrafast Dynamics of Diketopyrrolopyrrole Dimers.

Diketopyrrolopyrroles (DPPs) have attracted attention for their potential applications in organic photovoltaics due to their tunable optical properties and charge-carrier mobilities. In this study, we investigate the excited-state dynamics of a DPP dimer using time-dependent density functional theory (TDDFT) and nonadiabatic molecular dynamics simulations. Our results reveal a near-barrierless hydrogen migration state intersection that facilitates ultrafast internal conversion with a lifetime of about 400 fs, leading to fluorescence quenching. Electronic density analysis along the relaxation pathway confirms a hydrogen atom transfer mechanism. These findings highlight the critical role of state intersections in the photophysical properties of DPP dimers, providing new insights for the design of functionalized DPP systems aimed at suppressing nonradiative decay for enhanced performance in photovoltaic applications.

DHCT-GAN: Improving EEG Signal Quality with a Dual-Branch Hybrid CNN-Transformer Network.

Electroencephalogram (EEG) signals are important bioelectrical signals widely used in brain activity studies, cognitive mechanism research, and the diagnosis and treatment of neurological disorders. However, EEG signals are often influenced by various physiological artifacts, which can significantly affect data analysis and diagnosis. Recently, deep learning-based EEG denoising methods have exhibited unique advantages over traditional methods. Most existing methods mainly focus on identifying the characteristics of clean EEG signals to facilitate artifact removal; however, the potential to integrate cross-disciplinary knowledge, such as insights from artifact research, remains an area that requires further exploration. In this study, we developed DHCT-GAN, a new EEG denoising model, using a dual-branch hybrid network architecture. This model independently learns features from both clean EEG signals and artifact signals, then fuses this information through an adaptive gating network to generate denoised EEG signals that accurately preserve EEG signal features while effectively removing artifacts. We evaluated DHCT-GAN's performance through waveform analysis, power spectral density (PSD) analysis, and six performance metrics. The results demonstrate that DHCT-GAN significantly outperforms recent state-of-the-art networks in removing various artifacts. Furthermore, ablation experiments revealed that the hybrid model surpasses single-branch models in artifact removal, underscoring the crucial role of artifact knowledge constraints in improving denoising effectiveness.

Artificial Intelligence in the Prediction of Stone-Free Status in Urinary Stone Disease Treated with Extracorporeal Shockwave Lithotripsy: A Systematic Review

Background Urolithiasis is one of the most common urological diseases worldwide. One of the most common therapy, extracorporeal shock wave lithotripsy (ESWL), has a high failure rate. The failure rate can be significantly reduced by identifying the candidates most likely to benefit from ESWL, for example, by using machine learning (ML) algorithms. Decision tree analysis (DTA), artificial neural networks (ANN), and random forests (RF) represent a few of the machine learning approaches employed to forecast the stone-free outcome following ESWL. Methods 219 studies were searched through six electronic databases (CENTRAL, MEDLINE, EMBASE, EBSCO, Proquest, SCOPUS). We employed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines and adhered to the Standards for Reporting Diagnostic Accuracy Studies (STARD). To evaluate the potential bias in all the studies, we utilized the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. Results 41,484 patients from 11 studies were included. The ML models highlight varying levels of diagnostic precision, with sensitivity spanning from 35-96%, and specificity ranging from 63-98.4%, and area under the curve falling between 0.49-0.96. It is shown in this study that the accuracy of RF and DTA in predicting stone-free status is superior than ANN. Conclusion ML is a comparable predictive method to statistical analysis in predicting stone-free status. Random forest method and DTA are superior MLs compared to ANN. Stone size, density, and 3D texture analysis are the most important variables to be considered in the ML models and should be included in the models to ensure accuracy of stone-free status prediction.

Relational Analysis of User Density, Number of Train Services and Population around Rail Stations on Local Railways in Japan

Relational Analysis of User Density, Number of Train Services and Population around Rail Stations on Local Railways in Japan

GPR time-energy density analysis with complex wavelets for concrete data analysis

GPR time-energy density analysis with complex wavelets for concrete data analysis

Doubly σ- and π-aromatic planar pentacoordinate boron polyanions.

Ten planar pentacoordinate boron (ppB) systems are reported, each featuring a pentagonal ring composed of tetrels, pnictogens, or their combination around boron. These structures exhibit double aromaticity (σ and π), consistent with Hückel's 4n+2 rule, as confirmed by magnetically induced current density analysis.

Organic fluorine mediated intermolecular interactions: insights from experimental and theoretical charge density analyses

The attractive nature of type II C–F⋯F–C interaction has been established using experimental and theoretical modelling of electron densities using multipole modelling of high-resolution X-ray diffraction data and theoretical structure factors.

영산강 상류지역의 정치체 형성과 백제 군현

The upper Yeongsan River area has a basin topography, so it is effective for archaeological analysis. In this area, Bronze Age dwellings and tombs are investigated, but the distribution density of remains is not very high. The sites rapidly increased from around the 3rd century and gradually spread throughout the upper Yeongsan River area. The Three Kingdoms Period's tombs are overwhelmingly concentrated in the Yeongsan River Mainstream area, while the dolmen is relatively abundant in the Jeungamcheon and Oryecheon areas. It is highly likely that the population group of the Bronze Age continued to the Three Kingdoms Period as the distribution area of the dolmens and the tombs overlap in the Jeungamcheon area. However, it is thought that a new population group was introduced during the Three Kingdoms period because there are not many dolmens in the rest of the region and it is also different from the distribution area of the ancient tombs. Baekje is known to have installed Chujahye County, Yulji County, and Gulji County in the upper Yeongsan River areas. According to the results of the analysis of the distribution density and tombs of the Bronze Age and Three Kingdims period's, Gulji-hyeon(county) is thought to have been located in Goseo and Changpyeong, and the center of Yulji County is thought to have been between the location of Geumseong and the northeast of Downtown Damyang. And it is estimated that the center of Chujahye County was the site of Taemok-ri, Damyang. Therefore, if there was a small state of Mahan in the upper Yeongsan River areas, it is likely to have been located in the Taemok-ri site, in the mainstream of the Yeongsan River, and Baekje would have established Chujahye county based on this area. It is understood that after reunification, Silla moved the center of Chujahye to the current Downtown Damyang area and changed its name to Chuseong.

Investigation of Microstructure and Mechanical Properties in Hybrid Composites Produced with Fe3O4/nanographene Additives to Al7020 Alloy by Powder Metallurgy Method via Mechanical Alloying

The objective of this work is to enhance the microstructural and mechanical characteristics of Aluminium (Al) 7020 alloys, which are receiving growing application in the aerospace sector. The mechanical properties of Al 7XXX series alloys are at high levels compared to other Al alloys. However, the need for Metal Matrix Composites (MMC) is increasing day by day to increase the mechanical properties to the desired levels. Powder metallurgy is one of the advanced production techniques for MCCs. It is known that microstructural and mechanical properties are improved by mechanically alloying (MA) and homogeneous mixing of powders in the structure. Investigated were the effects of various mechanical alloying durations (1, 2, 4, and 8 hours) on the mechanical and microstructural characteristics of composites formed by reinforcing nanographene at 0.25% with 10% Fe3O4 fixed in Al7020 alloy. Density, XRD and SEM analyses were performed on all composite samples for characterization purposes. After that, the mechanical characteristics of the hybrid composite samples were determined by accurate hardness and tensile testing methods. The sample who received mechanical alloying for 8 hours achieved the highest tensile strength of 335 MPa.

Comparisons and Analyses of Thermospheric Mass Densities Derived from Global Navigation Satellite System–Precise Orbit Determination and an Ionization Gauge–Orbital Neutral Atmospheric Detector Onboard a Spherical Satellite at 520 km Altitude

Comparisons and Analyses of Thermospheric Mass Densities Derived from Global Navigation Satellite System–Precise Orbit Determination and an Ionization Gauge–Orbital Neutral Atmospheric Detector Onboard a Spherical Satellite at 520 km Altitude

Dynamically switchable multifunctional device for terahertz application using vanadium dioxide and graphene-based metasurface

Abstract In this article, a dynamically switchable and multifunctional metasurface is realized using a combination of vanadium dioxide (VO2) and graphene-based structures. The device can be tuned using the temperature transition property of vanadium dioxide from a wideband linear-to-circular polarization converter (LTCPC) to a wideband linear-to-linear cross polarization converter (LTLPC) and a dual-band absorber. The unit cell is designed with a gold-backed lossy-silicon dioxide (SiO2) substrate with a permittivity of 3.9, and the top metasurface layer is designed with a graphene-based dual triangle loaded split ring (DTLSR) and two stripes of vanadium oxide to cover the split partially. The proposed device can be used as a wideband LTCPC at normal temperature (298 K) from 1.43 THz to 2.85 THz, i.e., 66.35% fractional bandwidth (FBW). At temperatures greater than 341 K, VO2 exhibits metallic properties, and the structure functions as LTLPC from 1.82 THz to 3.31 THz (PCR ≥ 80%), i.e., 58.08 % FBW and maximum polarization conversion ratio (PCR) reported as high as 99.65 %. Furthermore, at this metallic condition, two absorption peaks are obtained at 1.22 THz and 3.30 THz with absorptivity of 93.5% and 100%, respectively. The device offers incident angle invariability up to 40° for LTCPC and up to 50° for LTLPC operation. Further insight into the mechanism of operation is developed using the surface current density and electric field distribution analysis. The advantage of the proposed metasurface over other similar structures is assessed with respect to multifunctional behavior, bandwidth, and stability under oblique incidence.

Gender-Specific effects of L-arginine supplementation on bone mineral density and trabecular bone volume in Sprague-Dawley rats; stereological study

BackgroundL-arginine (Arg) is a semi-essential amino acid that can be used as a key mediator for the release of growth hormone (GH), insulin-like growth factor-1(IGF-1), and other growth factors. In this study, we comprehensively evaluated the effect of Arg intake on bone growth and associated markers.MethodsThe study involved 24 Sprague-Dawley rats (12 males, 12 females) divided into two groups (Age = 24 days). One group received a standard diet, while the other was injected with 10 mg/kg of Arg daily for 90 days. Serum bone markers like calcium (Ca), phosphorous(P), and alkaline phosphatase (ALP) were analyzed via colorimetric assays. stereological study and bone mineral density (BMD) were conducted via dissector method and Hologic Dual-energy x-ray absorptiometry (DXA) system; respectively.ResultsBiochemical assays showed no significant differences in Ca, P, and ALP levels between groups. Male rats in the case group exhibited lower testosterone levels (p.value = 0.009). Stereological and bone mineral density (BMD) analyses revealed contrasting gender-specific outcomes. Female rats in the case group had higher BMD (p.value = 0.001), while males had lower BMD compared to controls (p.value = 0.018). Arg consumption affects trabecula volume values differently in females compared to males (p.value = 0.022). Furthermore, the study observed decreased osteocytes and osteoblasts in male case rats. The gender-based differences in BMD were attributed to Arg’s paradoxical impact on testosterone levels in males.ConclusionOverall, Arg supplementation was found to influence BMD and trabecular bone volume, with outcomes varying depending on gender. The study highlights the intricate interplay between Arg, sex hormones, and bone health, offering insights into these complex relationships.

STRUKTUR POPULASI DAN POLA DISTRIBUSI PALA (Myristica fragrans Houtt) PADA PERKEBUNAN PALA DI DUSUN MANGKOBATU BANDA NEIRA MALUKU TENGAH

Nutmeg (Myristica fragrans Houtt) is a native plant of Indonesia and endemic to the Banda Islands, Maluku. Nutmeg plantations are scattered across various locations in Banda Neira, one of which is in Mangkobatu Village. The population structure in nutmeg plantations is essential for predicting the future regeneration of trees to replace the old ones. This study aims to describe the population structure and analyze the distribution pattern of nutmeg in the plantations of Mangkobatu Village, Banda Neira, Central Maluku. The research used the quadrat method to count individual nutmeg trees for analysis of density, sex ratio, and distribution patterns. The results show that the population structure of nutmeg in the plantations of Mangkobatu Village consists of seedling stages with a density of 250 individuals/ha, sapling stages with 380 individuals/ha, pole stages with 190 individuals/ha, and mature trees with 68.75 individuals/ha. The population structure forms a bell-shaped polygon diagram. The sex ratio of nutmeg in the plantations of Mangkobatu Village is 1:27, which does not align with the recommended ratio for nutmeg plantations. The distribution pattern of nutmeg at the seedling stage is clumped (Ip = 1), while at the sapling (Ip = -0.464), pole (Ip = -0.357), and mature tree (Ip = -0.567) stages, the distribution is uniform.

Effect of rPET Content and Preform Heating/Cooling Conditions in the Stretch Blow Molding Process on Microcavitation and Solid-State Post-Condensation of vPET-rPET Blend: Part II—Statistical Analysis and Interpretation of Tests

This research explores how varying proportions of virgin polyethylene terephthalate (vPET) and recycled polyethylene terephthalate (rPET) in vPET-rPET blends, combined with preform thermal conditions during the stretch blow molding (SBM) process, influence PET bottles’ microscopic characteristics. Key metrics such as viscosity, density, crystallinity, amorphous phase relaxation, and microcavitation were assessed using response surface methodology (RSM). Statistical analysis, including Analysis of variance (ANOVA) and its power, supported the interpretation of results. The first part of the work details the experimental design and statistical methods. Positron annihilation lifetime spectroscopy (PALS) and amorphous phase density analysis revealed reduced free volume size, a substantial increase in free volume quantity, and a transformation toward ellipsoidal geometries, highlighting significant structural changes in the material. At the same time, the intrinsic viscosity (IV) and PALS studies indicate that the solid-state post-condensation effect (SSPC) is linked with microcavitation through post-condensation product diffusion. The conclusions, which resulted from the microstructure analysis, affected the material’s mechanical strength and were validated by pressure resistance tests of the bottles.