检索结果-南通市图书馆

j.urnal of Power and Energy Engineering 2024年第8期12卷 20-29页

作者： Saeed j. Almalowi Mechanical & Manufacturing Engineering Department Jubail Industrial College The Royal Commission for Jubail and Yanbu Jubail Saudi Arabia

The experimental and analytical investigation was conducted on a solar-powered single-effect distillation (SED). The evaporator was designed to be an electrical evaporator as opposed to the steam evaporator that existed previously. Using sun-tracking solar panels, the electrical evaporator in the designed distillation unit was powered by solar energy. Approximately 20 kWh was utilized by the small-scale distillation apparatus. This type of design is mobile, so remote areas and countries with fragile economies can utilize it on a small or large scale. Utilizing the principles of energy and mass conservation, the amount of distillate water and power required for a single unit was determined, at the low salinity (2200 PPM) with fixed boiling point temperature (Tb = 75˚C), the unit performance is approx. 98.4%. The experimental results and those derived from a mathematical model were compared, and both showed strong accord. Using engineering equation solver (EES) software, a computer program was developed for this research scenario.

关键词： Distillation Single Effect Solar Potable Salt

Fresnel Equations Derived Using a Non-Local Hidden-Variable Particle Theory

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

j.urnal of Modern Physics 2024年第6期15卷 950-984页

作者： Dirk j. Pons Department of Mechanical Engineering University of Canterbury Christchurch New Zealand

Problem: The Fresnel equations describe the proportions of reflected and transmitted light from a surface, and are conventionally derived from wave theory continuum mechanics. Particle-based derivations of the Fresnel equations appear not to exist. Approach: The obj.ctive of this work was to derive the basic optical laws from first principles from a particle basis. The particle model used was the Cordus theory, a type of non-local hidden-variable (NLHV) theory that predicts specific substructures to the photon and other particles. Findings: The theory explains the origin of the orthogonal electrostatic and magnetic fields, and re-derives the refraction and reflection laws including Snell’s law and critical angle, and the Fresnel equations for s and p-polarisation. These formulations are identical to those produced by electromagnetic wave theory. Contribution: The work provides a comprehensive derivation and physical explanation of the basic optical laws, which appears not to have previously been shown from a particle basis. Implications: The primary implications are for suggesting routes for the theoretical advancement of fundamental physics. The Cordus NLHV particle theory explains optical phenomena, yet it also explains other physical phenomena including some otherwise only accessible through quantum mechanics (such as the electron spin g-factor) and general relativity (including the Lorentz and relativistic Doppler). It also provides solutions for phenomena of unknown causation, such as asymmetrical baryogenesis, unification of the interactions, and reasons for nuclide stability/instability. Consequently, the implication is that NLHV theories have the potential to represent a deeper physics that may underpin and unify quantum mechanics, general relativity, and wave theory.

关键词： Wave-Particle Duality Optical Law Fresnel Equation Non-Local Hidden-Variable

Mass-Based Environmental Factor and Energy Assessment of Microwave-Assisted Synthesized Transition Metal Nanostructures

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

American j.urnal of Analytical Chemistry 2024年第6期15卷 201-218页

作者： Victor j. Law School of Mechanical and Materials Engineering University College Dublin Dublin Ireland

This paper describes mass-based energy phase-space proj.ction of microwave-assisted synthesis of transition metals (zinc oxide, palladium, silver, platinum, and gold) nanostructures. The proj.ction uses process energy budget (measured in kj. on the horizontal axes and process density (measured in kj.−1) on the vertical axes. These two axes allow both mass usage efficiency (Environmental-Factor) and energy efficiency to be evaluated for a range of microwave applicator and metal synthesis. The metrics are allied to the: second, sixth and eleventh principle of the twelve principle of Green Chemistry. This analytical approach to microwave synthesis (widely considered as a useful Green Chemistry energy source) allows a quantified dynamic environmental quotient to be given to renewable plant-based biomass associated with the reduction of the metal precursors. Thus allowing a degree of quantification of claimed “eco-friendly” and “sustainable” synthesis with regard to waste production and energy usage.

关键词： Microwave-Assisted Synthesis Transition Metals Nanostructures Allometry Scaling Power-Law Signature Green Chemistry

Where Is Phase Velocity in Minkowski Space?

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

j.urnal of Modern Physics 2024年第10期15卷 1555-1566页

作者： Antony j. Bourdillon Ultra-High Resolution Lithography San Jose CA USA

In the special theory of relativity, massive particles can travel at neither the speed of light c nor faster. Meanwhile, since the photon was quantized, many have thought of it as a point particle. How pointed? The idea could be a mathematical device or physical simplification. By contrast, the preceding notion of wave-group duality has two velocities: a group velocity vg and a phase velocity vp. In light vp = vg = c;but it follows from special relativity that, in massive particles, vp > c. The phase velocity is the product of the two best measured variables, and so their product constitutes internal motion that travels, verifiably, faster than light. How does vp then appear in Minkowski space? For light, the spatio-temporal Lorentz invariant metric is s2=c2t2−x2−y2−z2, the same in whatever frame it is viewed. The space is divided into 3 parts: firstly a cone, symmetric about the vertical axis ct > 0 that represents the world line of a stationary particle while the conical surface at s = 0 represents the locus for light rays that travel at the speed of light c. Since no real thing travels faster than the speed of light c, the surface is also a horizon for what can be seen by an observer starting from the origin at time t = 0. Secondly, an inverted cone represents, equivalently, time past. Thirdly, outside the cones, inaccessible space. The phase velocity vp, group velocity vg and speed of light are all equal in free space, vp = vg = c, constant. By contrast, for particles, where causality is due to particle interactions having rest mass mo > 0, we have to employ the Klein-Gordon equation with s2=c2t2−x2−y2−z2+mo2c2. Now special relativity requires a complication: *** = c2 where vg c and therefore vp > c. In the volume outside the cones, causality due to light interactions cannot extend beyond the cones. However, since vp > c and even vp >> c when wavelength λ is long, extreme phase velocities are then limited in their causal effects by the particle uncertainty σ,

关键词： Event Horizon Scattering Range Wave Packet Phase Velocity Group Velocity Dispersion Dynamics Quantum Physics

j.vian Planet Influence on the Forcing of Sunspot Cycles

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World j.urnal of Condensed Matter Physics 2024年第1期14卷 1-9页

作者： Fred j. Cadieu Physics Department Queens College of CUNY New York USA

The history of our solar system has been greatly influenced by the fact that there is a large gas giant planet, j.piter that has a nearly circular orbit. This has allowed relics of the early solar system formation to still be observable today. Since j.piter orbits the Sun with a period of approximately 12 years, it has always been thought that this could be connected to the nearly 11-year periodic peak in the number of sunspots observed. In this paper, the Sun and planets are considered to be moving about a center of mass point as the different planets orbit the Sun. This is the action of gravity that holds the solar system together. The center of mass for the j.piter-Sun system actually lies outside the Sun. The four gas giant planets dominate such effects and the four gas giant j.vian planets can be proj.cted together to determine an effective distance from the Sun’s center. Taken together these effects do seem to function as a sunspot forcing factor with a periodicity very close to 11 years. These predictions are made without consideration of any details of what is happening in the interior of the Sun. From these estimates, sunspot cycle 25 will be expected to peak in about September-October of 2025. Sunspot cycle 26 should peak in the year March of 2037.

关键词： Sun Cycles Solar System Formation j.piter

Adaptive Random Effects/Coefficients Modeling

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open j.urnal of Statistics 2024年第2期14卷 179-206页

作者： George j. Knafl School of Nursing University of North Carolina at Chapel Hill Chapel Hill USA

Adaptive fractional polynomial modeling of general correlated outcomes is formulated to address nonlinearity in means, variances/dispersions, and correlations. Means and variances/dispersions are modeled using generalized linear models in fixed effects/coefficients. Correlations are modeled using random effects/coefficients. Nonlinearity is addressed using power transforms of primary (untransformed) predictors. Parameter estimation is based on extended linear mixed modeling generalizing both generalized estimating equations and linear mixed modeling. Models are evaluated using likelihood cross-validation (LCV) scores and are generated adaptively using a heuristic search controlled by LCV scores. Cases covered include linear, Poisson, logistic, exponential, and discrete regression of correlated continuous, count/rate, dichotomous, positive continuous, and discrete numeric outcomes treated as normally, Poisson, Bernoulli, exponentially, and discrete numerically distributed, respectively. Example analyses are also generated for these five cases to compare adaptive random effects/coefficients modeling of correlated outcomes to previously developed adaptive modeling based on directly specified covariance structures. Adaptive random effects/coefficients modeling substantially outperforms direct covariance modeling in the linear, exponential, and discrete regression example analyses. It generates equivalent results in the logistic regression example analyses and it is substantially outperformed in the Poisson regression case. Random effects/coefficients modeling of correlated outcomes can provide substantial improvements in model selection compared to directly specified covariance modeling. However, directly specified covariance modeling can generate competitive or substantially better results in some cases while usually requiring less computation time.

关键词： Adaptive Regression Correlated Outcomes Extended Linear Mixed Modeling Fractional Polynomials Likelihood Cross-Validation Random Effects/Coefficients

Artificial-intelligent-powered safety and efficiency improvement for controlling and scheduling in integrated railway systems

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

High-speed Railway 2024年第3期2卷 172-179页

作者： Liu j. Liu G. Wang Y. Zhang W. Beij.ng National Railway Research & Design Institute of Signal & Communication Group Co. Ltd Beijing 100070 China Engineering Research Center of Railway Industry of Intelligent and Autonomous Train Control Beijing 100070 China

The multi-mode integrated railway system, anchored by the high-speed railway, caters to the diverse travel requirements both within and between cities, offering safe, comfortable, punctual, and eco-friendly transportation services. With the expansion of the railway networks, enhancing the efficiency and safety of the comprehensive system has become a crucial issue in the advanced development of railway transportation. In light of the prevailing application of artificial intelligence technologies within railway systems, this study leverages large model technology characterized by robust learning capabilities, efficient associative abilities, and linkage analysis to propose an Artificial-intelligent (AI)-powered railway control and dispatching system. This system is elaborately designed with four core functions, including global optimum unattended dispatching, synergetic transportation in multiple modes, high-speed automatic control, and precise maintenance decision and execution. The deployment pathway and essential tasks of the system are further delineated, alongside the challenges and obstacles encountered. The AI-powered system promises a significant enhancement in the operational efficiency and safety of the composite railway system, ensuring a more effective alignment between transportation services and passenger demands. © 2024 Beij.ng j.aotong University

关键词： Artificial intelligence High-speed railway Large-scale mode, system framework Multi-mode railway system Safety and efficiency improvement

Meticulously engineered three-dimensional-printed scaffold with microarchitecture and controlled peptide release for enhanced bone regeneration

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Biomaterials Translational 2024年第1期5卷 69-83页

作者： Yang j. Fatima K. Zhou X. He C. Shanghai Engineering Research Center of Nano-Biomaterials and Regenerative Medicine College of Biological Science and Medical Engineering Donghua University Shanghai China

The repair of large load-bearing bone defects requires superior mechanical strength, a feat that a single hydrogel scaffold cannot achieve. The obj.ctive is to seamlessly integrate optimal microarchitecture, mechanical robustness, vascularisation, and osteoinductive biological responses to effectively address these critical load-bearing bone defects. To confront this challenge, three-dimensional (3D) printing technology was employed to prepare a polycaprolactone (PCL)-based integrated scaffold. Within the voids of 3D printed PCL scaffold, a methacrylate gelatin (GelMA)/methacrylated silk fibroin (SFMA) composite hydrogel incorporated with parathyroid hormone (PTH) peptide-loaded mesoporous silica nanoparticles (PTH@MSNs) was embedded, evolving into a porous PTH@MSNs/GelMA/SFMA/PCL (PM@GS/PCL) scaffold. The feasibility of fabricating this functional scaffold with a customised hierarchical structure was confirmed through meticulous chemical and physical characterisation. Compression testing unveiled an impressive modulus of 17.81 ± 0.83 MPa for the composite scaffold. Additionally, in vitro angiogenesis potential of PM@GS/ PCL scaffold was evaluated through Transwell and tube formation assays using human umbilical vein endothelium, revealing the superior cell migration and tube network formation. The alizarin red and alkaline phosphatase staining assays using bone marrow-derived mesenchymal stem cells clearly illustrated robust osteogenic differentiation properties within this scaffold. Furthermore, the bone repair potential of the scaffold was investigated on a rat femoral defect model using micro-computed tomography and histological examination, demonstrating enhanced osteogenic and angiogenic performance. This study presents a promising strategy for fabricating a microenvironment-matched composite scaffold for bone tissue engineering, providing a potential solution for effective bone defect repair. © 2024, Chinese Medical Multimedia Press Co Ltd. All rights reserve

关键词： angiogenesis bone regeneration methacrylated gelatin methacrylated silk fibroin osteogenesis PTH

Mitigating Carbon Emissions:A Comprehensive Analysis of Transitioning to Hydrogen-Powered Plants in j.pan’s Energy Landscape Post-Fukushima

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Energy Engineering 2024年第5期121卷 1143-1159页

作者： Nugroho Agung Pambudi andrew Chapman Alfan Sarifudin Desita Kamila Ulfa Iksan Riva Nanda Department of Mechanical Engineering Education Universitas Sebelas MaretSukoharjo57161Indonesia International Institute for Carbon-Neutral Reserch(WPI-I2CNER) Kyushu UniversityFukuoka819-0395Japan Postgraduate of Mechanical Engineering Universitas Sebelas MaretSurakarta57126Indonesia Energy and Society Laboratory Department of Mechanical Engineering EducationUniversitas Sebelas MaretSukoharjo57161Indonesia Department of Metallurgical and Material Engineering Universitas IndonesiaDepok16424Indonesia

One of the impacts of the Fukushima disaster was the shutdown of all nuclear power plants in j.pan,reaching zero production in *** response,the country started importing more fossil energy including coal,oil,and natural gas to fill the energy ***,this led to a significant increase in carbon emissions,hindering the efforts to reduce its carbon *** the current situation,j.pan is actively working to balance its energy requirements with environmental considerations,including the utilization of hydrogen ***,this paper aims to explore the feasibility and implications of using hydrogen power plants as a means to reduce emissions,and this analysis will be conducted using the energy modeling of the MARKAL-TIMES j.pan *** hydrogen scenario(HS)is assumed with the extensive integration of hydrogen into the power generation sector,supported by a hydrogen import ***,this scenario will be compared with the Business as Usual(BAU)*** results showed that the generation capacities of the BAU and HS scenarios have significantly different primary energy *** BAU scenario is highly dependent on fossil fuels,while the HS scenario integrates hydrogen contribution along with an increase in renewable energy,reaching a peak contribution of 2,160 Pj.in *** the HS scenario,the target of reducing CO_(2) emissions by 80%is achieved through significant hydrogen *** 2050,the total CO_(2) emissions are estimated to be 939 million tons for the BAU scenario and 261 million tons for the Hydrogen *** addition,the contribution of hydrogen to electricity generation is expected to be 153 TWh,smaller than PV and wind power.

关键词： Business as usual(BAU)scenario hydrogen scenario CO_(2)emissions power generation sector

Resection and reconstruction in high-grade pancreatic head inj.ries

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World j.urnal of Gastrointestinal Surgery 2024年第5期16卷 1467-1469页

作者： j.ke Krige Eduard j.nas andrew j.hn Nicol Pradeep Harkson Navsaria HPB Surgery University of Cape Town Health Sciences FacultyCape Town 7925Western CapeSouth Africa Trauma Center Department of SurgeryGroote Schuur HospitalCape Town 7925Western CapeSouth Africa Department of Surgery Trauma CenterGroote Schuur HospCape Town 7925Western CapeSouth Africa

This study by Chui et al adds further important evidence in the treatment of highgrade pancreatic inj.ries and endorses the concept of the model of pancreatic trauma care designed to optimize treatment,minimize morbidity and enhance survival in patients with complex pancreatic *** the authors have demonstrated favorable outcomes based on their limited experience of 5 patients who underwent a pancreaticoduodenectomy(PD),including 2 patients who were“unstable”and did not have damage control surgery(DCS),we would caution against the general recommendations promoting index PD without DCS in“unstable”grade 5 pancreatic head inj.ries.

关键词： Pancreas Inj.ry Surgery Pancreaticoduodenectomy