Sink System Research Articles

Design of a thermoelectric cooler to control the temperature of telecom outdoor cabinet

This paper discusses the design of a thermoelectric cooler (TEC) system for controlling the temperature of telecom outdoor cabins. Traditional cooling methods, such as refrigerants, have potential negative impacts on the environment, making thermoelectric cooling systems a promising alternative due to their efficiency, environmental friendliness, and versatility. The paper reviews the current state of the art in designing thermoelectric cooler systems for absorbing heat generated from telecom electronic devices. The literature review highlights studies that have evaluated the cooling performance, energy efficiency, and cost-effectiveness of thermoelectric cooling systems for telecom electronic devices. The objective of this project is to design a TEC system that can absorb the heat generated from telecommunication cabinets. The design is generated analytically using the TE ideal equation with a heat sink or heat exchanger system. The design aims to investigate the optimum current and geometric ratio that can improve the cooling capacity of the TEC system. The paper also presents a modeling approach for thermoelectric coolers with two heat sinks. The study concludes that thermoelectric cooling systems have the potential to provide efficient and environmentally friendly cooling solutions for telecom electronic devices, and future studies should continue to investigate and optimize the design of thermoelectric cooling systems for various types of telecom electronic devices.

Research on energy transfer and vibration suppression of nonlinear energy sink with nonlinear damping

The nonlinear energy sink is a nonlinear shock absorber that provides targeted energy transfer and plays a crucial role in structural vibration suppression. In this paper, the energy transfer and dynamic characteristics of nonlinear damping nonlinear energy sink systems are analyzed. Firstly, the theoretical model of the nonlinear damping NES system is described, and secondly, the equations of the system in the free state are derived by using the complex variable average method and the multi-scale method to obtain the energy transfer efficiency equation of the system. Through the study of the slow invariant manifold and energy transfer efficiency of the system, the influence of each system parameter on the energy transfer efficiency is analyzed. Then the equations of the system under harmonic excitation are processed in the same method to obtain the boundary equations of the system, through which the saddle-node bifurcation diagram of the system is plotted to study the influence of each system parameter on the saddle-node bifurcation characteristics of the system. Finally, the slow-varying equation of the system under harmonic excitation is derived, and the influence of each system parameter on the frequency detuning parameter interval of the strongly modulated response is obtained using the phase trajectory and a one-dimensional mapping diagram of the system, and the time-mileage diagram and Poincare section are used to prove the damping effect of the strongly modulated response.

Estimation of carbon emissions in various clustered regions of China based on OCO-2 satellite XCO2 data and random forest modelling

Atmospheric carbon dioxide (CO2) stands as one of the most important greenhouse gasses, with steadily increasing concentrations attributable to human activities. In the pursuit of reaching peak carbon and carbon neutrality goals, it is essential to quantify carbon emissions and evaluate carbon reduction strategies. To establish a high-precision observation with full time series and spatial coverage, a spatio-temporal interpolation method was developed to obtain XCO2 data over mainland China at a resolution of 0.5° × 0.5° for the years 2015–2021. An east-west gradient, higher levels in the east and lower levels in the west, was observed, exhibiting a seasonal pattern of elevation in spring and reduction in summer. Subsequently, the research area is classified into seven clusters based on time-series XCO2 anomalies (ΔXCO2) and ODIAC (Open Source Data Inventory of Anthropogenic Carbon Dioxide) carbon emission data. This classification aims to emphasize the differentiation of spatial heterogeneity in carbon emissions and the results highlight that regions with high ΔXCO2 reflect higher carbon emission. Finally, the carbon emissions of each cluster were estimated by using a random forest model individually yielding an R2 of approximately 0.6. For assessing the variables influencing carbon emission predictions, the importance of each variable was calculated. Specifically, NightTime Lighting data (NTL), representing human production activities, emerged as a crucial variable influencing carbon emission predictions in most clusters. In comparison, Gross Primary Productivity (GPP) is considered a more critical variable in Southwest China (SWC), primarily owing to the intricate vegetation carbon sink system in this region. Temperature (T) emerges as a key variable influencing the estimation of carbon emissions in certain developed cities in Eastern China (EC), driven by the urban heat island effect which amplifies energy consumption, modifies land use, and impacts urban systems, influencing the spatial patterns of carbon emissions. Carbon emissions in different characteristic regions was quantified by establishing machine learning models with remote sensing data, which can provide new insights and support for refined carbon monitoring and management strategy.

Evaluation of carbon sink and photovoltaic system carbon reduction along roadside space

As China's photovoltaic (PV) sector experiences rapid growth, the availability of land resources has become a pivotal policy focus, driving the need for comprehensive research and strategic planning for roadside PV initiatives. Utilizing a fuzzy multi-criteria decision-making approach, combined with GIS spatial analysis and a modular design framework, our study quantitatively compared the carbon reduction capabilities of PV systems against the carbon sequestration potential of various vegetative arrangements along the roadside space. The roadside space analysis modular considers a range of factors including topography, meteorology, and construction costs. We examined the spatial distribution of suitability for PV installation and vegetation establishment along the provincial expressway network in China. The results revealed that Inner Mongolia stood out as the frontrunner in carbon reduction potential within high-suitability zones for PV construction, achieving an impressive 4.845 million tons of carbon reduction—nearly four times greater than that of Shaanxi Province. In contrast, the carbon sequestration attributed to vegetation greening in areas less suited for PV development revealed a higher propensity in the southeastern provinces. Guangdong led the charge with an impressive annual carbon sequestration of 2.89 million tons. This was closely followed by Yunnan, Sichuan, Hebei, Guizhou, and Henan, each achieving carbon sequestration amounts exceeding 2 million tons. These results offer valuable quantitative support and practical recommendations for achieving low-carbon objectives in the construction of China's expressways.

Multi-objective optimization research on nonlinear energy sink system of finite-length beam on elastic medium

Multi-objective optimization research on nonlinear energy sink system of finite-length beam on elastic medium

Quantitative Analysis of Agricultural Carbon Emissions and Absorption from Agricultural Land Resources in Shaanxi Province from 2010 to 2022

Agriculture is not only a significant source of greenhouse gas emissions but also a vast carbon sink system. Achieving the “dual carbon” goals—carbon peaking and carbon neutrality—is a major strategic objective for China in the near future. This study focuses on agricultural data from 2010 to 2022 in Shaanxi Province. It begins by analyzing the current economic and environmental conditions of the province and its resource endowment. This study then quantitatively assesses carbon absorption, carbon emissions, and the net carbon sink in agriculture over this period. Additionally, a vector autoregression (VAR) model is used to empirically analyze the relationship between agricultural carbon emissions and their influencing factors in Shaanxi Province. Key findings include the following: (1) From 2010 to 2022, the total carbon emissions from agriculture in Shaanxi Province were controlled to around 3 million tons, showing an overall trend of “growth-slow decline” with fluctuations. The carbon emissions from fertilizer application accounted for approximately 60% of the total carbon emissions from agriculture in Shaanxi Province, with a total volume ranging from 1.623 to 2.164 million tons. The total carbon absorption from agriculture in Shaanxi Province showed an increasing trend with fluctuations year by year from 2010 to 2022, with an average annual increase of 1.367%. (2) Fertilizers, pesticides, agricultural films, and agricultural diesel are the primary contributors to agricultural carbon emissions. (3) Results from the Johansen cointegration test reveal a long-term equilibrium relationship between agricultural carbon emissions in Shaanxi Province and influencing factors such as fertilizers and pesticides in the short term. The contributions of fertilizers, pesticides, agricultural films, and agricultural diesel to agricultural carbon emissions are 1.351%, 1.888%, 10.663%, and 0.258%, respectively. (4) The long-term contributions of fertilizers and pesticides to agricultural carbon emissions initially increased before undergoing a gradual attenuation, with average attenuation rates of 1.351% and 1.888%, respectively.

Provenance Analysis of the Northern Offshore Mud Area of the Shandong Peninsula, China, Spanning the Last 2000 Years

The mud area in the northern offshore of the Shandong Peninsula constitutes a dynamic source–sink system in China’s continental shelf and is a hotspot for research. However, the provenance of the sediments remains controversial, and the depositional environment is not yet fully understood. This paper performed accelerator mass spectrometry 14C dating, grain-size analysis, clay mineralogic analysis, and geochemical analysis of the ZZ04 sediment core. The results showed that this core primarily comprises silt and clay, reflecting weak sedimentary hydrodynamic conditions and stable deposition. The clay mineral assemblage—illite, smectite, chlorite, and kaolinite—indicates strong physical weathering. The provenance of the mud area was mainly from the Yellow River, Shandong Peninsula rivers, and Yangtze River, highlighting its multi-source characteristics. The smectite/(illite + chlorite) ratio in the ZZ04 core serves as a mineralogical indicator of the East Asian summer monsoon (EASM). Eight significant East Asian winter monsoon (EAWM) intensifications were identified, correlating with global cooling events similar to those at 1.89, 1.4, 1.03, and 0.62 thousand years ago. During the EAWM period, the coastal current and the Yellow Sea warm current play crucial roles in the transportation of matter and heat flux in the mud area. In contrast, during the EASM period, the sediments are predominantly sourced from the Shandong Peninsula rivers, contributing terrigenous materials shaped by chemical weathering.

Controlled Substance Liquid Waste Management Systems As Potential Reservoirs for Nosocomial Infection in a Pediatric Hospital.

The purpose of this study was to determine if controlled substance waste management systems (CSWMS) demonstrate microbial growth, and therefore present a potential infection risk to pediatric hospital patients. Twenty CSWMS, either Smart Sink or Pharma Lock systems, located in patient care areas were sampled. Twelve were located in critical care areas. Cultures were obtained by swabbing the drain grate with a sterile swab. Swabs were then transported to the microbiology lab for culture. Each sample was labeled with the location of the CSWMS and each system was photographed. Of the CSWMS sampled, 50% demonstrated bacterial or fungal growth with a total of 15 microorganisms isolated, including 3 systems with Micrococcus luteus, 2 with Aspergillus species, and 2 with -Bacillus cereus. Nine of the 15 microorganisms isolated were from systems in the pediatric intensive care unit (PICU) followed by 2 microorganisms in the neonatal intensive care unit (NICU). Of the 12 systems sampled in critical care areas, 8 (66%) had positive cultures. Of the 10 systems which demonstrated growth, 9 were Pharma Lock and 1 was Smart Sink. Controlled substance waste management systems harbor potential pathogens and may serve as reservoirs of infectious agents in pediatric hospitals. Microbial growth was identified in more than half of sampled CSWMS located in critical care areas, where the most vulnerable patients are located. Based on this study, a cleaning procedure for CSWMS should be implemented. Further investigation on the relationship between CSWMS and nosocomial infections is warranted.

Research on Dynamics Characteristics of Grounded Damping Nonlinear Energy Sink

The nonlinear energy sink (NES) system mainly dissipates energy through damping elements, and changing the position of the damping element will also change the performance of the NES. In this paper, a grounded damping NES is proposed by grounding the damping element of the traditional cubic stiffness NES. The complex dynamics of this two-degree-of-freedom system are investigated. The slow-varying equations of the system under 1:1 internal resonance are derived by using the complexification-averaging (C×A) method, based on which the influence of the primary structure’s damping on a bifurcation is analyzed. The conditions for the existence of strongly modulated response (SMR) are studied, and the accuracy of the results is verified using the slow invariant manifold (SIM), Poincare mapping, and time-history diagrams. This provides a means of verifying the analytical findings. The vibration suppression effects of the grounded damping NES, as compared to the cubic stiffness NES, are thoroughly studied under both pulse and harmonic excitations. The results indicate that the main structure damping affects the stability of the system and the occurrence of the SMR. Most previous studies of the NESs have overlooked the effect of main structure damping, which may influence the selection of structural parameters. Moreover, under relatively large pulse or harmonic excitations, the vibration suppression effectiveness of the grounded damping NES surpasses that of traditional cubic stiffness NES. This finding has important practical significance for improving the vibration suppression effect and robustness of the NES, and provides a reference for the structural design of the NES.

Ab-initio insights into the mechanical, phonon, bonding, electronic, optical and thermal properties of hexagonal W2N3 for prospective applications

We thoroughly investigated the structural, mechanical, electronic, vibrational, optical, thermodynamic, and a number of thermophysical properties of W2N3 compound through first-principles calculations using the DFT based formalism. The calculated structural parameters show very good agreement with the available theoretical and experimental results. The mechanical and dynamical stabilities of this compound have been investigated theoretically from the elastic constants and phonon dispersion curves. The Pugh's and Poisson's ratios of W2N3 are located quite close to the brittle/ductile borderline. W2N3 is elastically anisotropic. The calculated electronic band structure and density of states reveal that W2N3 is conducting in nature. The Fermi surface topology has also been explored. The analysis of charge density distribution map shows that W atoms have comparatively high electron density around compared to the N atoms. Presence of covalent bondings between W–N, W–W, and N–N atoms are anticipated. High melting temperature and high phonon thermal conductivity of W2N3 imply that the compound has potential to be used as a heat sink system. The optical characteristics show anisotropy. The compound can be used in optoelectronic devices due to its high absorption coefficient and low reflectivity in the visible to ultraviolet spectrum. Furthermore, the quasi-harmonic Debye model is used to examine temperature and pressure dependent thermal characteristics of W2N3 for the first time.

Research Progress in Reducing Pollution and Sequestration of Carbon by Carbon Neutral Plants

Under the dual constraints of economic development and ecological carrying capacity, it is necessary to explore more technical means to achieve carbon neutrality and peak in China. Plants are important carriers of terrestrial and marine carbon sink systems, whereas phytoremediation is also a scientific method to remedy environmental pollution. However, the current studies mostly focus on the single aspect of plant carbon sequestration (including both the reduction of pollutant concentrations in environmental media and degradation of pollutants) or plant pollution reduction, without considering the dual benefits of plant pollution reduction and carbon sequestration. In order to explore the carbon neutral effect of plants, we focused on the pollution reduction and carbon sequestration effect of carbon neutral plants and its progress and evaluated the pollution reduction and carbon sequestration potential of carbon neutral plants and other organisms (such as animals and soil microorganisms) and environmental functional materials. The mechanisms underlying the synergistic coupling of carbon neutral plants and animals, microorganisms, and environmental functional materials and ecosystems in reducing pollution and carbon sequestration were also explored. Finally, we proposed constructive prospects for future research on the effects of carbon neutral plants on pollution reduction and carbon sink.

On formation, annihilation, and evolution of potential wells, and nonlinear phenomena of multi-magnet energy sink system.

This paper investigates the formation, annihilation, and evolution mechanisms of potential energy wells in nonlinear energy sink systems. The nonlinear energy sink system is composed of multiple inner and outer magnets. Two multi-magnet energy sink (MES) architectures are designed: a single-magnet vibrator and a double-magnet vibrator. Multi-stable (bi-, tri-, quad-, penta-, hexa-, and hepta-stable) mechanisms are elaborated by the Poincaré section and bifurcation diagram concerning the magnet length, the link length, and the MES configuration. The results show that the change in the internal structural parameters of the MES system will generate different types of bifurcations (i.e., saddle-node, subcritical, and super pitchfork bifurcations) and phase trajectories and have rich nonlinear response behaviors in the low frequency and wide frequency range, which can be used for damping and vibration reduction of engineering structures, vibration control, and energy source of the microgrid.

Late Quaternary marine transgressions off the Shandong Peninsula inferred from paleosalinity indicators: Implications for Holocene mud wedge formation

Mud depocenters play an important role in the sediment source–sink system of marginal seas; however, the factors controlling the formation of mud deposits are not well understood. This study focused on Core LHSD-1, which is located on the southern margin of the Shandong Peninsula mud wedge in the northwestern part of the South Yellow Sea. Elemental ratios, such as the C/S ratio (the mass ratio of total organic carbon and total sulfur) and Sr/Ba ratio, were used to track the changes in paleosalinity during the late Quaternary and to investigate the mechanisms that influenced the formation of the mud wedge off the Shandong Peninsula. Our results indicate that Core LHSD-1 likely recorded two transgression events, corresponding to MIS3 and MIS1. Following sea-level rise after the Last Glacial Maximum (LGM), transgressive deposition began in the study area at approximately 11.5 kyr BP. During the early Holocene, fluctuating water salinity was recorded by Sr/Ba ratios, which became stable at approximately 6.8 kyr BP when the sea level reached its highstand. At the same time, the modern current system was established, and a significant amount of terrestrial material, such as refractory organic carbon and iron, has been transported to the study area by enhanced coastal currents, which was documented by elevated C/S ratios (C/S > 2.8) in mud sediments. Our findings indicate that marine transgressions controlled the initial development of the mud depocenter and that the establishment of the modern ocean current system promoted the rapid deposition of mud sediments, which corresponded to the growth of global mud depocenters.

Progress in Fast Modular Reactor Conceptual Design

The Fast Modular Reactor (FMR) is a 100-MW(thermal) gas-cooled fast reactor being developed by General Atomics Electromagnetic System with the goal of developing a FMR for flexible and dispatchable power to the U.S. electricity market in the mid-2030s. The conceptual design aims to develop and verify simplified design features. These include an inert helium gas coolant, pellet-loaded fuel rods, installations with air cooling as ultimate heat sink, and small and passive heat removal systems. The goal is to ensure the development of a safe, maintainable, cost-effective, and distributed nuclear energy-generating station. The baseline technologies selected to achieve this goal are a helium coolant that is an inert gas with no chemical reaction with structural components, not activated, single phase, enabling high-temperature operation and a high thermal efficiency Brayton cycle; conventional uranium dioxide (UO2) fuel, which is the most widely used and well-known fuel material, capable of high burnup (100 MWd/kg) and a long fuel life; and silicon carbide composite (SiGA®) cladding and internal structures that are chemically inert in the helium environment, exceptionally radiation tolerant, and being derisked by accident tolerant fuel technology development. The reactor was specifically designed with passive safety features, including high-temperature in-core materials and a reactor vessel cooling system consisting of cooling panels of naturally circulating water. The passive safety of the core was confirmed for the depressurized loss-of–forced cooling accident, which showed the peak cladding temperature at ~1600°C during the transient, which is below the current design limit of 1800°C. The conceptual design of the FMR has been conducted for the reactor system, vessel system, generator and turbomachine, instrumentation and control, residual heat removal system, plant service system, and containment, as well as pre-application licensing documents.

Appropriateness Evaluation Study of Land Reclamation of Pre-drilling Project in Southwest China Under Dual-carbon Background

Cultivated land and forest land are important carbon sink systems in the context of dual-carbon, so it is necessary to do a suitability evaluation study of pre-drilling project land reclamation to support the restoration of carbon sink function of the temporarily occupied farmland. In this paper, the suitability evaluation model of pre-drilling engineering land reclamation was established by adopting hierarchical analysis method and TOPSIS multi-attribute decision-making method, and the suitability evaluation study of pre-drilling engineering land reclamation was carried out on a drilling platform in Southwest China.

Decision-making Modeling of Brownfield Redevelopment in the Context of Dual Carbon: The Case of Brownfield in Chengdu Industrial Zone

How to effectively utilize the existing brownfield sites within the city and propose scientific and reasonable brownfield reuse methods have become the key issues to inhibit the encroachment of the city into the carbon sink system and achieve the goal of "double carbon". This paper takes an industrial area brownfield redevelopment project in Chengdu, Sichuan Province as an example, introduces the WSR theory to construct a brownfield redevelopment evaluation index system, and establishes a brownfield redevelopment second-order SEM model in combination with the SEM model, and then discusses the brownfield redevelopment plan. The results of the study show that the most suitable direction of redevelopment for this brownfield redevelopment project is public service land, and during the implementation of the project, attention should be paid to the restoration of the relevant measurement indexes in the physical dimension, and to increase the disclosure of project information and publicity.

Policy suggestions for tapping the potential of ocean carbon sinks in the context of “double carbon” goals in China

China is rich in marine resources and has excellent potential for the development of oceanic carbon sinks. Ocean carbon sinks have shown broad application prospects, but the technical system for trading has not yet been perfected, the relevant legislation has not yet been established, etc. China should actively promote scientific research on ocean carbon sinks, improve the technical system of ocean carbon sinks, establish an ocean carbon sink trading system, and develop the eco-economy of ocean carbon sinks. It should also establish a sound system of laws and regulations to explore the potential of oceanic carbon sinks and contribute to the realization of China’s dual-carbon goal.

Experimental study on the bionic microchannel heat sink integrated with a piezoelectric pump

The increased integration of electronic chips and the miniaturization of electronic products significantly raise the heat generated by electronic devices. To meet the cooling requirements of highly integrated electronic devices and enhance the cooling performance of the piezo-driven cooling system, a piezo-driven microchannel liquid-cooling system for CPU chip cooling was developed. The system integrated a bionic microchannel heat sink and a piezoelectric pump with umbrella valves (PP-UV). The piezoelectric pump was used as the driving source to propel the coolant flow, and the output of the piezoelectric pump pulsated, contributing to the convective heat transfer of the fluid in the microchannel. The spider web microchannel heat sink (SWM-HS) was designed and compared with the tandem Y-shaped microchannel heat sink (T-YMHS). The performance of the piezo-driven microchannel heat sink system with different structured microchannel heat sinks was studied by combining experimentation and simulation. The results indicated that the SWM-HS cooling system exhibited better fluid transmission and cooling characteristics, along with lower input power (3.32 mW). When the drive voltage was 100 V, the output flow of the SWM-HS cooling system was 56.4 mL/min. With a thermal power consumption of 30 W, the CPU temperature remained stable at approximately 55 °C, while the total thermal resistance measured 0.183 °C/W. In comparison with T-YMHS, the internal pressure drop of the SWM-HS decreased by 20.7 %, the Nusselt number increased by 13.7 %, and it achieved a cooling efficiency of 64.48 %. The experimental results aligned well with the simulation results. This work contributes to advancing the application of piezoelectric devices in electronic cooling and enhancing the cooling efficiency of miniature cooling systems.

Evaluation of hydrological and sediment connectivity in catchments with mining activity in semiarid central Mexico

Source–sink systems in arid and semiarid regions contain low plant cover areas (inter-patches) functioning as sources of runoff, sediments, and nutrients that are retained by vegetated patches, which act as sinks. The spatial configuration of these hydrological units largely determines the connectivity network of runoff sources. At the same time, their dynamics are essential for assessing ecohydrological functionality, which mining can modify through the alteration of the system's ability to retain water and sediments, causing increased runoff and soil erosion. The objectives of this work were to: (1) identify the spatio-temporal changes in ground cover (i.e., vegetated patches and inter-patches) in two areas with mining activity: Cerro de San Pedro (1970–2015) and Villa de la Paz (1983–2014); and (2) evaluate, from an ecohydrological perspective, the changes in hydrological and sediment connectivity as the result of changes in ground cover in the two periods within each study area. Ground cover maps were obtained from aerial photographs and high-resolution WorldView 2 satellite images calibrated with 2 × 2 m plots measured in the field. For each study area, a transition matrix was used to assess spatio-temporal changes of patches and inter-patches, while hydrological and sediment connectivity were evaluated with the index of connectivity (IC). The results showed that the area with vegetated patches has decreased in Cerro de San Pedro and Villa de la Paz, leading to increased hydrological and sediment connectivity related to mining infrastructure and urbanization. The results can be used to prioritize areas for restoring ecohydrological functioning by reducing the connectivity of runoff sources.

Research on carbon-neutral calculation model of urban parks based on life-cycle assessment: a case study from Beijing, China

Abstract Urban parks are an essential component of the urban carbon sink system. Calculating a city’s overall carbon balance is significant by predicting when urban parks will achieve carbon-neutral. This research is based on the theory of life-cycle assessment and uses carbon emission factors to calculate the project’s carbon emissions. Using the established model, we calculated the urban park with a total area of 6.5 hectares in a certain city in Fangshan District, Beijing, China. The results indicate that the carbon emission intensity of the city park during the construction materials production phase is $5.97$${\mathrm{tCO}}_2\mathrm{e}/\mathrm{ha}$; during the construction phase, it is 18.947${\mathrm{tCO}}_2\mathrm{e}/\mathrm{ha}$; and during the operation phase, it is $5.97{\mathrm{tCO}}_2\mathrm{e}/\mathrm{ha}/\mathrm{Year}$. The total carbon reduction of the photovoltaic system in the first 25 years is $260.007{\mathrm{tCO}}_2/\mathrm{ha}$. Carbon sinks have a relatively minor impact on achieving carbon neutrality goals for urban parks. The case urban park will take 20–21 years to achieve the carbon-neutral target. We propose a future low-carbon strategy for urban parks through the study results. This will also contribute to developing uniform evaluation standards for carbon neutrality in urban parks.