Direct Source Research Articles

As the U.S. is Derisking from China, Other Foreign U.S. Suppliers Are Relying More on Chinese Imports

China's share of U.S. goods imports has fallen significantly since 2017 following the U.S.-China tariff hikes and other geopolitical tensions. Even though the U.S. has reduced its direct sourcing from China, other foreign suppliers of U.S. imported goods have increased their reliance on imports from China.

Life cycle assesment on water treatment: Case study in Cau Do water treatment plant – Da Nang city - VietNam

Abstract Production, transportation, use, and disposal consumes resources, energy, and chemicals and causes emissions and waste, contributing to various impacts on the environment, such as heat, global warming, and acidification. Applying the Life Cycle Assessment (LCA) method can identify environmental impacts, to have solutions to control energy use and reduce waste. Research applied at Cau Do water supply plant - Da Nang city with an exploitation flow of 290,000 m3/day shows the results that the plant’s water treatment system has impacts within the allowable limits for with the geological environment in the area, but exploitation requires strict assessment to prevent possible unusual impacts. Assess the environmental impact of using electricity and chemicals in the system by estimating CO2 emissions from the electricity and chemical production process, which indirectly contribute to global warming. Direct sources of greenhouse gases come from the treatment of sludge and wastewater. The impacts discussed in this study are Global Warming, Acidification, depletion of fossil resources and Water Consumption. The amount of electricity consumed at Cau Do plant in 2018 was 16,742,752 kWh/year. The results of the analysis using the Life Cycle Assessment (LCA) method, show that the largest impact on the environment is Water Consumption 1.101 m3/m3 clean water, followed by Global Warming 0.158 kg CO2 eq/m3 Acidification 1.06 × 10−3 kg SO2 eq/m3.

Community Empowerment in the Development of Bayan Tourism Villages in North Lombok District

Community empowerment is an important aspect in developing tourist villages. This is because the development of tourist villages uses a lot of resources owned by the community. The community has an important role in supporting the success of tourism village development so that powerless communities need to be empowered to create independence and economic prosperity for the community. This type of research is qualitative research using data collection techniques, namely interviews, documentation, observation, focus group discussions and literature studies. Interviews are a data collection method with both direct and indirect data sources. This study examines tourism potential, the role of the community and how to empower the community. Data sources were obtained from the head of Bayan Village, the head of the tourism awareness group, traditional leaders of Bayan Village and the community in Bayan Village to serve as sources. The village can be used as a tourist attraction so that it can invite tourists to come to the Bayan Tourism Village. The existence of this tourist village can increase income opportunities for the community and reduce unemployment. Empowerment is carried out by providing training to the Bayan village community about tourism so that they can take advantage of the opportunities that exist in the Bayan tourist village and can create their own employment opportunities. Having a tourist village can empower the community in Bayan Village, North Lombok Regency.

Wind Source Localization System Based on a Palm-Sized Quadcopter

In this study, we implemented a compact wind direction sensor on a palm-sized quadcopter to achieve wind source localization (WSL). We designed an anemotaxis algorithm based on the sensor data and experimentally validated its efficacy. Anemotaxis refers to the strategy of moving upwind based on information on the wind direction, which is essential for tracing odors propagating through the air. Despite the limited research on quadcopter systems achieving WSL directly through environmental wind measurement sensors, debate remains regarding the relationship between sensor placement and the anemotaxis algorithm. Therefore, we experimentally investigated the placement of a wind direction sensor capable of estimating wind source direction even when propellers are rotating. Our findings demonstrated that placing the sensor 50 mm away from the enclosure of the quadcopter allowed accurate wind direction measurement without being affected by wake disturbances. Additionally, we constructed an anemotaxis algorithm based on wind direction and speed data, which we integrated into the quadcopter system. We confirmed the ability of the quadcopter to execute anemotaxis behavior and achieve WSL irrespective of environmental wind strength through wind source localization experiments.

A novel approach to understanding the genesis and distribution of widespread reservoirs at the basin edge: A case study of gas-bearing sandstone in the Sangonghe Formation, Junggar Basin, Western China

A 20 m thick sandstone drilled in the second member of the Sangonghe Formation in the Qianshao area of the Junggar Basin has been identified to be a high-quality gas-bearing reservoir. However, recent missions reveal an uncertainty in reservoir distribution and bring high risk to the subsequent gas development, although the gas-bearing reservoir has been encountered by several drillings and proved to be widespread. To investigate the accurate distribution and reveal the evolution of the reservoir, we reconstruct the stratigraphic framework and depositional stages by a high-revolution sequence stratigraphic method, effectively identify the gas-bearing reservoir by seismic attributes refusion and seismic stratigraphic slices, and finally map the distribution strata distribution at different stages. The results indicate that the landward onlap phenomenon in the seismic data indicates a retrogradational stratigraphic structure during the water level rise rather than the equal-thickness stratigraphic pattern under stable water conditions. According to the retrogradational stratigraphic structure, the real driver for the widespread characteristic of a gas-bearing reservoir is the backward staggered movement of multistage sand bodies during the transgressive process rather than single-stage deposition. The fusion of seismic acoustic impedance and main frequency attributes provides an effective survey to identify the accurate distribution of the reservoir, by which interpretation of a stratigraphic slice along the vertical centerline of the reservoir extracted from the multiattribute fusion survey can present the distribution and evolution of the three stages on only one map. Achieved by an appropriate interpretation on the map, two sandy debris flow bodies are identified as being deposited at the bottom successively during the first two transgressive stages. They are completely staggered in the source direction with a clear boundary between well Qs9 and Qs7. Subsequently, the subsequent rise of the water level led to the deposition of a large-scale multibranch shallow-water delta, which exhibits the characteristics of multistage, multisource, and multibranch. The results not only advance our comprehension of widespread sand bodies but also furnish fundamental insights for the development of lithologic condensate gas reservoirs in the Qianshao area.

Audio Pre-Processing and Beamforming Implementation on Embedded Systems

Since the invention of the microphone by Barina in 1876, there have been numerous applications of audio processing, such as phonographs, broadcasting stations, and public address systems, which merely capture and amplify sound and play it back. Nowadays, audio processing involves analysis and noise-filtering techniques. There are various methods for noise filtering, each employing unique algorithms, but they all require two or more microphones for signal processing and analysis. For instance, on mobile phones, two microphones located in different positions are utilized for active noise cancellation (one for primary audio capture and the other for capturing ambient noise). However, a drawback is that when the sound source is distant, it may lead to poor audio capture. To capture sound from distant sources, alternative methods, like blind signal separation and beamforming, are necessary. This paper proposes employing a beamforming algorithm with two microphones to enhance speech and implementing this algorithm on an embedded system. However, prior to beamforming, it is imperative to accurately detect the direction of the sound source to process and analyze the audio from that direction.

A source-directivity impact assessment for an angle-error model used to compute free-field sound power over a cylindrical enveloping surface

An angle-error model was previously shown to accurately predict the necessary sound power correction term for omnidirectional sources using only a few readily-obtainable inputs related to the geometry of the source and the enveloping measurement surface. This paper assesses the validity of that predictive regression equation when the omnidirectional assumption is removed, and the effects of a directional source are examined through modeled analysis and empirical study. The modeling work modified the initial ray-tracing model used to incorporate source directivity. The empirical aspect of this paper compares the modeled angle error to that of a directional speaker source over a range of positions using a cylindrical measurement surface in accordance with ISO 3744 and ISO 7779. The corrected sound power levels were compared to the measured sound power levels of the source per ISO 3741 direct and comparison methods.

Ionic Lignin Polymers for Controlled CO2 Capture, Release, and Conversion into High-Value Chemicals.

In this study, an innovative and cost-effective ionic polymer for CO2 capture and utilization for the first time, using abundant and nonfood-based biomass lignin is reported. The modified ionic polymer synthesizes through the reaction of glycidyltrimethylammonium chloride with lignin under alkaline conditions to yield quaternary ammonium ionic functionality. Subsequently, the hydroxide-based pure ionic lignin polymer is employed for CO2 capture from both direct air and concentrated CO2 sources at room temperature and atmospheric pressure. Structural characterization of the polymers is accomplished through 1H, 13C, and 2D-heteronuclear single quantum coherence (HSQC)NMR, and FT-IR spectroscopy. The CO2 capture process is established through the formation of bicarbonate ions alongside the presence of CO2. The captured CO2 is precisely quantified by using inverse-gated proton decoupled 13C NMR with an internal standard (trioxane). Remarkably, the captured-CO2 amounts of ionic lignin polymer are 1.06mmol g-1 (47mg g-1) from concentrated-CO2 source and 0.60mmol g-1 (26mg g-1) from direct-air. The captured-CO2 in ionic lignin polymer is released in controlled manner and utilized in the synthesis of cyclic carbonate, showcasing the productive application of the captured carbon. Moreover, the fully controlled recovering of ionic lignin polymer achieves via repeated CO2 release ↔ CO2 capture.

Cutting–Edge Physics Driven Advancements in Medical Industry

Science contributed to technology by serving as a direct source and creation of ideas for new knowledge. Technology emerged from the application of this knowledge in terms of products, processes and services. Nowadays, due to the multidisciplinary application of physics, medical technology and radiation treatment has begun and widely accompanied within a technology based medical diagnosis and treatment due to the development of physics. In this paper a detailed description and analysis of scientific achievement and technological advancements of physics in medical industry has been clearly reviewed. The application of physics principles to medical sector has made an outstanding contribution in the diagnosis and treatment of diseases. Many extraordinary tools, those could have played a great role in diagnostic and treatment methods, have appeared as a result of physics discoveries in the last century. This description of physics applications in medical technology and principles has mainly based on comprehensive review of the literature, contributes to suggest the novel ideas used for the innovation of modern medical technologies. This journal paper anecdote the fundamental physical principles used for the innovation of these technological advances, emphasizing their applications to the practice of modern medical industry based on comprehensive review of the literature.

Carbon Dioxide Capture by Niobium Polyoxometalate Fragmentation.

High oxidation state metal cations in the form of oxides, oxoanions, or oxoperoxoanions have diverse roles in carbon dioxide removal (direct air capture and point source). Features include providing basic oxygens for chemisorption reactions, direct binding of carbonate, and catalyzing low-temperature CO2 release to regenerate capture media. Moreover, metal oxides and aqueous metal-oxo species are stable in harsh, point-source conditions. Here, we demonstrate aqueous niobium polyoxometalate (POM) carbon capture ability, specifically [Nb6O19]8-, Nb6. Upon exposure of aqueous Nb6 to CO2, Nb6 fragments and binds chemisorbed carbonate, evidenced by crystallization of Nb-carbonate POMs including [Nb22O53(CO3)16]28-and [Nb10O25(CO3)6]12-. While Rb/Cs+ counter cations yield crystal structures to understand the chemisorption processes, K+ counter cations enable higher capture efficiency (based on CO3/Nb ratio), determined by CHN analysis and thermogravimetry-mass spectrometry of the isolated solids. Sum frequency generation spectroscopy also showed higher carbon capture efficiency of the K-Nb6 solutions at the air-water interface, while small-angle X-ray scattering (SAXS) provided insights into the role of the alkalis in influencing these processes. Tetramethylammonium counter cations, like K+, demonstrate high efficiency of carbonate chemisorption at the interface, but SAXS and Raman of the bulk showed a predominance of a Nb24-POM (HxNb24O72, x ∼ 9) that does not bind carbonate. Control experiments show that carbonate detected at the interface is Nb-bound, and the Nb-carbonate species are stabilized by alkalis, demonstrating their supporting role in aqueous Nb-POM CO2 chemisorption. Of fundamental importance, this study presents rare examples of directing POM speciation with a gas, instead of liquid phase acid or base.

The effect of water mist nozzle settings on fire suppression of electric vehicles in garages

In recent years, along with the widespread use of electric vehicles (EV), EV fires have occurred frequently. However, few studies have investigated EV fires in confined spaces. To address this gap, this paper aims to explore the different aspects of fire evolution of EVs as well as examining the suppression effect of different water mist (WM) settings on these fires. Multiple simulations are carried out, using the Fire Dynamics Simulator (FDS) simulation tool, considering different numbers and working pressures of WM devices. The results highlighted that the number of WM devices had a more significant effect on the fire. Peak heat release was reduced by 17 % and peak arrival time was delayed by 26 % using 6 MPa with 3 nozzles compared to 0 nozzles. Additionally, it leads to accelerated mixing of the smoke layer with the air layer. Moreover, it was shown that the closer to the fire source in the vertical direction, the greater the degree of peak temperature decrease. In this regard, the maximum reduction in the measured temperature was around 70 %.

Habitat complexity versus habitat heterogeneity: Invertebrates prefer macrophyte stands with intermediate biomass and high functional diversity

Abstract Aquatic macrophytes serve as shelter and a direct source of food for invertebrates, in addition to indirectly providing items such as algae, detritus, and microorganisms. Thus, aquatic macrophytes act as habitat structuring elements, requiring a distinction between habitat complexity (physical formations such as fractal dimensions, density and biomass) and habitat heterogeneity (diversity of these structures). Here we explore the effects of habitat complexity and habitat heterogeneity on the invertebrate community. We collected macrophytes and invertebrates from 28 sampling sites along a 13.7‐km stretch of the Baía River in Brazil, and examined specific groups (insects, microcrustaceans, and other invertebrates). Environmental variables in the sites were also measured. We aimed to explore the effects of habitat complexity (measured by macrophyte biomass) and habitat heterogeneity (evaluated through macrophyte functional diversity) on the richness and abundance of invertebrates. We found that overall invertebrate richness was positively influenced solely by habitat heterogeneity. For invertebrate abundance, intermediate habitat complexity had more invertebrates, while habitat heterogeneity had a positive impact. Environmental variables influenced only the abundance. For specific groups, insect richness was positively influenced by habitat heterogeneity, while insect abundance decreased with high complexity and increased with high heterogeneity. Microcrustacean abundance was positively influenced by habitat complexity. Richness and abundance of other invertebrates was positively influenced by habitat heterogeneity. Invertebrates prefer macrophyte stands with intermediate complexity and high heterogeneity. Abundance is linked to structural complexity and heterogeneity, while species richness is more strongly associated with heterogeneity. Furthermore, the impact of these factors varies among invertebrate groups. These findings emphasise the importance of integrating a broad range of metrics, such as macrophyte biomass and functional diversity, to gain a thorough understanding of invertebrate community dynamics in future studies. Additionally, our study demonstrates that preserving macrophyte stands with high heterogeneity significantly enhances the diversity of associated invertebrate species.

Vertical InGaN Light-Emitting Diode with Hybrid Distributed Bragg Reflectors.

A vertical-type InGaN light-emitting diode with a resonant cavity was demonstrated with a 9 μm aperture size and a short cavity formed by hybrid distributed Bragg reflectors (DBRs). The approach involved designing epitaxial structures and utilizing an electrochemical etching process to convert heavily doped n-type gallium nitride (n+-GaN) layers into porous GaN layers as a porous-GaN DBR structure. Thirteen pairs of the conductive porous-GaN:Si/GaN:Si DBR structure provided a vertical current path in a vertical-type light-emitting diodes (LED) structure. The LED epitaxial layers were separated from sapphire for membrane-type LED structures through a laser lift-off process. During the free-standing membrane fabrication process, the dielectric DBR deposited on ITO/p-GaN:Mg layers was inverted from top to bottom, thereby establishing the concept of higher reflectivity for the bottom DBR compared to the porous-GaN DBR. The physical cavity length was reduced from about 2.3 μm for the LED membrane to 0.74 μm for the membrane-type LED with the embedded porous-GaN DBR structure. The divergent angles and line width of EL emission light were reduced from 124°/31.7 nm to 44°/3.3 nm due to the resonant cavity effect. The membrane-type LED structures with hybrid DBRs consisted of small divergent angles, narrow line width, and vertical current injection properties that have potential for directional emission light sources and vertical-cavity surface-emitting diode laser applications.

Azimuth correction for passive surface wave dispersion based on polarization analysis

SUMMARY Passive surface wave methods have found extensive application in near-surface investigation due to their benefits of low costs, non-invasiveness and high accuracy. Linear arrays are usually adopted in urban environments for their convenience and efficiency. However, the distribution of noise sources in densely populated urban areas varies rapidly in time and space, making it challenging to estimate accurate dispersion spectra using a linear array. To solve this problem, we propose a polarization analysis-based azimuthal correction method. We first obtain the azimuth of each segment by calculating the correlation coefficient of three-component ambient noise data. The normalized correlation coefficient is then applied for quality control to select reliable segments. For selected segments, the overestimated velocity caused by directional sources are corrected to obtain accurate dispersion spectra. A synthetic test is conducted to demonstrate the feasibility of our method. Compared with the dispersion spectra obtained without any correction, the dispersion spectra obtained following the suggested scheme are more consistent with the theoretical dispersion curves. Two real-world examples at crossroads show the superiority of the proposed technique in obtaining higher resolution dispersion energy and more accurate phase velocities. In addition, our approach can attenuate the artefacts and improve the dispersion measurements.

Experimental Study of Trailing-Edge Bluntness Noise Reduction by Porous Plates

The acoustic and aerodynamic fields of blunt porous plates are examined experimentally in an effort to mitigate trailing-edge bluntness noise. The plates are characterized by a single dimensionless porosity parameter identified in previous works that controls the influence of porosity on the sound field. Hot-wire anemometry interrogates the velocity field to connect turbulence details of specific regions to flow noise directivity and beamforming source maps. Porous plates are demonstrated to reduce the bluntness-induced noise by up to 17 dB and progressively suppress broadband low-frequency noise as the value of the porosity parameter increases. However, an increase in this parameter also increases the high-frequency noise created by the pores themselves. The same highly perforated plate characterized by a large value of the porosity parameter reduces the bluntness-induced vortex shedding that is present in the wake of the impermeable plate. Lastly, pore shape and positional alignment are shown to have a complex effect on the acoustic field. Among the porosity designs considered, plates with circular pores are most effective for low-frequency noise reductions but generate high-frequency noise. No meaningful difference is found between the acoustic spectra from plates of the same open-area fraction with pores aligned along or staggered about the flow direction.

Sustainable Energy Use for Mechanized Wheat Production Systems in Iraq

The utilization of agricultural machinery was fully mechanized for wheat production in Iraq. This study essentially aimed to inspect inputs – outputs energy for wheat production in Salah Al-Deen, Iraq. The data were obtained from 45 wheat farms by using face to face questionnaire method in 2022. The findings from this study were determined in five basic operations (i.e. tillage, sowing, fertilizing. spraying, and harvesting). Direct energy sources (fuel and human) accounted for about 51.39% of the total energy used in cultivation. Energy exemplified in fuel recorded the highest rate of the total expenditure of energy, with 51.09 % (6091.01MJ/ha). Farmers utilized nearly 879.11±39.77 MJ/ha of machinery energy, the highest rate of expenditure of machinery energy was in harvesting, which recorded 38.38 % (337.42 ± 23.89 MJ/ha) of the total energy of machinery used in the study. Results of analyzing the energy of fuel that farmers utilized indicated that operations of tillage were about 25.98 % (1582.29 ± 39.43 MJ/ha) of the total energy of fuel. This rate denoted the highest operation of fuel consumption. Harvesting operations followed it. These operations were implemented through the use of engines powered with diesel were about 23.43% (1427.05 ± 35.68 MJ/ha). The average energy input/output ratio was 4.40 for the wheat crop; while energy intensity was 1.79 MJ/kg for the wheat crop.

Directivity analysis and source parameter estimation: insights from the 2014 Arzew earthquake, Mw3.9, northwestern Algeria

Directivity analysis and source parameter estimation: insights from the 2014 Arzew earthquake, Mw3.9, northwestern Algeria

Comparison of kinetic energy conversion characteristics of two extreme precipitation episodes during persistent unusually heavy rainfall on 17–23 July 2021 in Henan, China

A persistent heavy rainfall event, contributed by two extreme episodes (P1 and P2), occurred in Henan province of China from 17 to 23 July 2021. An active mesoscale vortex was present in the lower troposphere, along with a shallow trough moving eastward in the upper troposphere. The budgets of rotational kinetic energy (KR) and divergent kinetic energy (KD) at distinct stages are investigated. The lower-level KR anomaly, related to the mesoscale vortex growth therein, was responsible for P1. However, the upper-troposphere KR was dominant and strong during the P2 stage, associated with an eastward-developing upper-level trough. Prior to both P1 and P2, active inner interaction between rotational and divergent winds presented, manifested as a rapid increase of KVRVD signals. KVRVD and precipitation had similar pattern distribution and consistent evolution tendency. Therefore, KVRVD might be a useful indicator for the occurrence and intensification of rainfall. Expect for two components of winds interaction, the external source feeding kinetic energy growth is also explored. For P1, APE (available potential energy)-> KD-> KR was the key path towards rotational kinetic energy, providing energy for mesoscale vortex growth in lower troposphere, which was favorable for the extreme episode of P1. Nevertheless, for P2 stage, APE acted as a direct energy source towards KR in upper troposphere, with higher efficiency (via APE-> KR) and thus stronger KR. This kind of difference in conversion path depended on the vertically-coupled degree between the lower-level mesoscale vortex and the upper-level trough, in addition to the rotational and divergent wind speed. Their tilting/upright configuration produced strong baroclinic/barotropic process, accelerating energy conversion of APE-> KD/APE-> KR via GD/GR (i.e., generating KD/KR by divergent/rotational winds crossing geopotential height contours, usually as a generator resulting from barotropic/baroclinic process). Therefore, kinetic energy budget may be a valuable tool for identifying key weather systems development and forecasting extreme rainfall episodes.

Photovoltaic Power Injection Control Based on a Virtual Synchronous Machine Strategy.

The increasing participation of photovoltaic sources in power grids presents the challenge of enhancing power quality, which is affected by the intrinsic characteristics of these sources, such as variability and lack of inertia. This power quality degradation mainly generates variations in both voltage magnitude and frequency, which are more pronounced in microgrids. In fact, the magnitude problem is particularly present in the distribution systems, where photovoltaic sources are spread along the grid. Due to the power converter's lack of inertia, frequency problems can be seen throughout the network. Grid-forming control strategies in photovoltaic systems have been proposed to address these problems, although most proposed solutions involve either a direct voltage source or energy storage systems, thereby increasing costs. In this paper, a photovoltaic injection system is designed with a virtual synchronous machine control strategy to provide voltage and frequency support to the grid. The maximum power point tracking algorithm is adapted to provide the direct voltage reference and inject active power according to the droop frequency control. The control strategy is validated through simulations and key experimental setup tests. The results demonstrate that it is possible to inject photovoltaic power and provide voltage and frequency support.

A remote sensing analysis method for soil heavy metal pollution sources at site scale considering source-sink relationships

Conventional methods for identifying soil heavy metal (HM) pollution sources are limited to area scale, failing to accurately pinpoint sources at specific sites due to the spatial heterogeneity of HMs in mining areas. Furthermore, these methods primarily focus on existing solid waste polluted dumps, defined as “direct pollution sources”, while neglecting existing HM pollution hotspots generated by historical anthropogenic activities (e.g., mineral development, industrial discharges), defined as “potential pollution sources”. Addressing this gap, a novel remote sensing analysis method is proposed to identify both direct and potential pollution sources at site scale, considering source-sink relationships. Direct pollution sources are extracted using a supervised classification algorithm on high-resolution multispectral imagery. Potential pollution sources depend on the spatial distribution of HM pollution, mapped using a machine learning model with hyperspectral imagery. Additionally, a source identification algorithm is developed for gridded pollution source analysis. Validated through a case study in a cadmium (Cd)-polluted mine area, the proposed method successfully extracted 21 solid waste polluted dumps with an overall accuracy approaching 90 % and a Kappa coefficient of 0.80. Simultaneously, 4167 HM pollution hotspots were identified, achieving optimal inversion accuracy for Cd (Rv2 = 0.91, RMSEv = 4.27, and RPDv = 3.02). Notably, the spatial distribution patterns of these identified sources exhibited a high degree of similarity. Further analysis employing the identification algorithm indicated that 3 polluted dumps and 258 pollution hotspots were pollution sources for a selected high-value point of Cd content. This innovative method provides a valuable methodological reference for precise prevention and control of soil HM pollution.