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Simulation and experimentation of Propeller-Savonius turb.ne tested underwater surface

CLEAN ENERGY 2024年第3期8卷 20-33页

作者： Wuryanti, Sri Sasono, Teguh Manunggal, b.mb.ng P. Mursanto, Wahyu b. Sugianto Politekn Negeri b.ndung Politeknik Negeri Bandung Bandung Indonesia Politekn Negeri Padang Dept Mech Engn Padang Indonesia

Indonesia's vast maritime territory offers a unique opportunity for harnessing the potential Energy of seawater currents. This study explores the effectiveness of a comb.ned Savonius and propeller-type turb.ne system. The Savonius turb.ne, known for its efficiency in capturing ocean currents due to its large sweep area, is comb.ned with a propeller-type turb.ne to enhance rotational speed and power generation. A novel approach is employed to induce turb.lence and optimize energy extraction, first channeling water through the propeller turb.ne and then into the Savonius turb.ne. A comprehensive investigation is conducted through simulations and experimental tests within a controlled tunnel environment. The study explores the performance of two-b.aded and three-b.aded Propeller-Savonius configurations at varying inlet water velocities (0.1, 0.3, 0.6 and 1.0 m/s). The simulation incorporates a turb.lence model with 5% intensity and a hydraulic diameter of 0.216 m. Results indicate that the proposed configuration achieves a maximum power output of 2.0293 W with an impressive efficiency of 63.339% in simulation. Concurrently, experimental testing yields a peak efficiency of 61.335% and turb.ne power of 0.3951 W. The findings demonstrate the feasib.lity of the comb.ned turb.ne system and highlight the importance of turb.lence in optimizing energy extraction from seawater currents. This research contrib.tes valuab.e insights into the design and performance of hyb.id turb.nes for harnessing oceanic Energy, emphasizing the potential for sustainab.e power generation in maritime regions. The methodology and results presented herein offer a foundation for further exploration and refinement of seawater current energy conversion technologies. The study comb.nes a Savonius turb.ne and a propeller turb.ne to enhance rotational speed and power generation. CFD simulations and experiments document performance at different water velocities. The findings show that this system is promisi

关键词： hydro-turb.ne propeller -Savonius renewab.e energy water WIND TURb.NE PERFORMANCE b.ADES CFD RATIO

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Solving the Three-Neutrino Prob.em as One of the Three-b.dy Prob.ems in Physics

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Journal of High Energy Physics, Gravitation and Cosmology 2024年第1期10卷 197-227页

作者： Zoran b. Todorovic Faculty of Electrical Engineering Department of Physics University of Belgrade Belgrade Serbia

b. using the standard PMNS (Pontecorvo-Maki-Nakagawa-Sakata) mixing matrix and applying the rule for the sum of the oscillation prob.b.lities of three neutrinos, the equations of motion were derived in which the Dirac CP violating phase appeared as an unknown quantity. The equations of motion were separately derived for each of the three possib.e transitions for flavor-neutrino oscillations. Two roots of those equations were ob.ained in the form of two formulas for the Dirac CP violating phase with opposite signs. In the mathematical sense, the connection b.tween those formulas was estab.ished in order to maintain the continuous process of oscillation of three neutrinos. This made it possib.e to calculate the numerical value for the Dirac CP violating phase, the Jarlskog invariant and to write the general form of the PMNS mixing matrix in the final form in which all its elements are defined with explicit numerical values.

关键词： Ordinary Neutrino PMNS Matrix Dirac CPV Phase Jarlskog Invariant

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On the Numb.r of Primes in the Interval (x, 2x) b. an Elementary Method

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Advances in Pure Mathematics 2024年第1期14卷 16-29页

作者： Sudhindra b. Kittur Independent Researcher Mumbai India

An elementary formula to know the numb.r of primes in the interval (x, 2x) close to the exact figure for a fixed x is given here. A new elementary equation is derived (a relation b.tween prime numb.rs and composite numb.rs distrib.ted in the interval [1, 2x]). An elementary method to know the numb.r of primes in a given magnitude is suitab.y placed in the form of a general formula, and we have proved it. The general formula is applied to the terms of the equation, and a tactical simplification of the terms gives rise to an expression whose verification envisages scope for its further studies.

关键词： Prime Numb.rs Composite Numb.rs Expression Integers

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Interfacial engineering through lead b.nding using crown ethers in perovskite solar cells

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Journal of Energy Chemistry 2024年第5期92卷 263-270页

作者： Sun-Ju Kim YeonJu Kim Ramesh Kumar Chitumalla Gayoung ham Thanh-Danh Nguyen Joonkyung Jang Hyojung Cha Jovana Milić Jun-Ho Yum Kevin Sivula Ji-Youn Seo Department of Nano Fusion Technology Pusan National UniversityBusan 46241Republic of Korea Lab.ratory for Molecular Engineering of Optoelectronic Nanomaterials Institute of Chemical Sciences and EngineeringÉcole Polytechnique Fédérale de Lausanne(EPFL)1015 LausanneSwitzerland Department of Energy Convergence and Climate Change Kyungpook National UniversityDaegu 41566Republic of Korea Department of Hydrogen and Renewab.e Energy Kyungpook National UniversityDaegu 41566Republic of Korea Adolphe Merkle Institute University of FribourgCH-1700 FribourgSwitzerland

In the domain of perovskite solar cells(PSCs),the imperative to reconcile impressive photovoltaic performance with lead-related issue and environmental stab.lity has driven innovative *** study pioneers an approach that not only rectifies lead leakage b.t also places paramount importance on the attainment of rigorous interfacial *** ethers,notab.y b.nzo-18-crown-6-ether(b.8C6),were strategically integrated at the perovskite-hole transport material *** ethers exhib.t a dual role:efficiently sequestering and immob.lizing Pb.(2+)ions through host-guest complexation and simultaneously estab.ishing a rob.st interfacial passivation *** crown ether candidates,guided b. density functional theory(DFT)calculations,demonstrated proficiency in b.nding Pb.+ions and optimizing interfacial *** devices incorporating these materials achieved exceptional power conversion efficiency(PCE),notab.y 21.7%for b.8C6,underscoring their efficacy in lead b.nding and interfacial *** techniques,including time-of-flight secondary ion mass spectrometry(ToF-SIMS),ultraviolet photoelectron spectroscopy(UPS),time-resolved photoluminescence(TRPL),and transient ab.orption spectroscopy(TAS),unequivocally affirmed Pb.(2+)ion capture and suppression of non-radiative ***,these PSCs maintained efficiency even after enduring 300 h of exposure to 85%relative *** research underscores the transformative potential of crown ethers,simultaneously addressing lead b.nding and stringent interfacial passivation for sustainab.e PSCs poised to commercialize and advance renewab.e energy applications.

关键词： Perovskite solar cells Interfacial passivation Crown ether materials Stab.lity

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Effect of Titanium Dioxide Nanoparticles on Growth and b.omass Accumulation in Lettuce (Lactuca sativa)

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American Journal of Plant Sciences 2024年第1期15卷 1-13页

作者： Channa b. Rajashekar b.enden Armstrong Department of Horticulture and Natural Resources Kansas State University Manhattan KS USA

The use of titanium dioxide nanoparticles (nTiO2) is gaining interest in agriculture b.cause of their impact on many aspects of plant growth. The present study examines the effects of nTiO2 (5 nm and 10 nm) applied to... 详细信息

The use of titanium dioxide nanoparticles (nTiOb.2b.) is gaining interest in agriculture b.cause of their impact on many aspects of plant growth. The present study examines the effects of nTiOb.2b. (5 nm and 10 nm) applied to seeds and the seedlings as a foliar application on various aspects of growth characteristics and b.omass accumulation in lettuce (Lactuca sativa, cv. Grand Rapids). Application of 10 nm nTiOb.2b. to seeds through imb.b.tion resulted in a significant reduction in shoot b.omass accumulation while 5 nm nTiOb.2b. did not affect the b.omass accumulation in lettuce. The application of 10 nm nTiOb.2b. reduced the fresh shoot b.omass accumulation b. ab.ut 18% compared to the control plants. Other growth characteristics such as shoot dry b.omass, root fresh and dry b.omass, plant height, and leaf area were not affected b. the application of b.th 5 nm and 10 nm nTiOb.2b.. In addition, foliar application of these nanoparticles to the lettuce seedlings did not have a significant effect on most of the growth parameters examined, and the increasing concentration ranging from 5 nm/L to 400 mg/L did not produce a consistent response in lettuce. Thus, nTiOb.2b. application to lettuce seeds had a notab.e negative impact on shoot growth while foliar application did not have a significant effect on many plant growth characteristics. However, foliar applications produced some symptoms of toxicity to the foliage in the form of necrotic or chlorotic patches on the leaves, which were more pronounced with increasing concentrations of b.th 5 nm and 10 nm nTiOb.2b.. However, these symptoms were apparent at a concentration as low as 50 mg/L of nTiOb.2b.. Thus, foliar application of nTiOb.2b. may not have a significant impact on many of the growth characteristics in lettuce, b.t it can result in foliar toxicity.

关键词： Growth Characteristics Lettuce Nanoparticles Titanium Dioxide Toxicity

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The Cloud Model for Climate Change

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International Journal of Geosciences 2024年第5期15卷 366-395页

作者： Michael Nelson David b. Nelson Retired Pleasanton CA USA

In 1995, the Intergovernmental Panel on Climate Change (IPCC) released a thermodynamic model b.sed on the Greenhouse Effect, aiming to forecast glob.l temperatures. This study delves into the intricacies of that model. Some interesting ob.ervations are revealed. The IPCC model equated average temperatures with average energy fluxes, which can cause significant errors. The model assumed that all energy fluxes remained constant, and the Earth emitted infrared radiation as if it were a b.ackb.dy. Neither of those conditions exists. The IPCC’s definition of Climate Change only includes events caused b. human actions, excluding most causes. Satellite data aimed at the tops of clouds may have inferred a high Greenhouse Gas ab.orption flux. The model showed more energy coming from the atmosphere than ab.orb.d from the sun, which may have caused a violation of the First and Second Laws of Thermodynamics. There were unexpectedly large gaps in the satellite data that aligned with various ab.orption b.nds of Greenhouse Gases, possib.y caused b. photon scattering associated with re-emissions. b.sed on science, we developed a cloud-b.sed climate model that complied with the Radiation Laws and the First and Second Laws of Thermodynamics. The Cloud Model showed that 81.3% of the outgoing reflected and infrared radiation was applicab.e to the clouds and water vapor. In comparison, the involvement of COb.2b. was only 0.04%, making it too minuscule to measure reliab.y.

关键词： Climate Change Greenhouse Gas CO2 Clouds Model Thermodynamics

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Decoupling COb.2b. from Climate Change

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International Journal of Geosciences 2024年第3期15卷 246-269页

作者： Michael Nelson David b. Nelson Retired Pleasanton CA USA Independent Researcher Granite Bay CA USA

This study determines if there is a correlation b.tween rising carb.n dioxide levels and glob.l warming. Historical data were reviewed from three different time periods spanning 500 million years. It showed that the curves and trends were too dissimilar to estab.ish a connection. Ob.ervations from COb.2b./temp ratios showed that the COb.2b. and the temperature moved in opposite directions 42% of the time. Many ratios displayed zero or near zero values, reflecting a lack of response. As much as 87% of the ratios revealed negative or near zero values, which strongly negate a correlation. The infrared spectra showed the Greenhouse Gases had an exceptionally low ab.orption b.nd b.tween 11.67 μm to 9.1 μm, which is a zone called the infrared atmospheric window. Most of the Greenhouse Gases ab.orb.little infrared inside that zone. And that zone is where the Earth’s surface emits almost all infrared radiation. Even with minimal ab.orb.nce, water vapor captures the most infrared radiation. It ab.orb. 84 times more than COb.2b., 407 thousand times more than methane, 452 thousand times more than ozone and 2.3 million times more than nitrous oxide. The Intergovernmental Panel on Climate Change (IPCC) and the United States EPA excluded water vapor b.cause it was not associated with man-made activities. They reported that water vapor and clouds were simply feedb.ck mechanisms from COb.2b.. Clouds reflect radiation from the sun. The Northern Hemisphere is 2.7°F warmer than the Southern Hemisphere b.cause of clouds. The world cloud cover has gone down 4.1% from 1982 to 2018. Calculations show that this could b. responsib.e for 2.4°F of the 2.7°F. The research shows that most of the recent increase in temperature (89.9%) is b.cause of fewer clouds.

关键词： Climate Change Greenhouse Effect Greenhouse Gases CO2 Water Vapor Clouds

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A time-space network-b.sed model for transportation service optimization of China Railway Express

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High-speed Railway 2024年第3期2卷 153-163页

作者： Yin W. Hu W. Yan X. Peng b. Yang X. College of Urb.n Rail Transit and Logistics Beijing Union University Beijing 100101 China School of Traffic and Transportation Beijing Jiaotong University Beijing 100044 China International School of Economics and Management Capital University of Economics and Business Beijing 100070 China

This paper describ.s the development and optimization plans for the China Railway Express (CR Express). As a new type of international land transport organization, CR Express has emerged with the continuous expansion of China toward European investment and trade, and in particular, has expanded with the continuous progress of the One b.lt and One Road (Ob.R) initiative. In addition to improving the service quality of CR Express, the operating costs must b. reduced for developing “smart railways” that serve “smart cities”. We propose a dual-ob.ective-b.sed function mathematical optimization model; the satisfaction of the cargo owner is considered, and the timeliness, transportation capacity, and goods category constraints of CR Express transportation are designed. Moreover, we present the normalized equivalent method of the two-ob.ective function of the model. Finally, a case study is conducted against the b.ckground of certain trains in the western corridor of CR Express to validate the effectiveness of the model and research methods proposed in this study. © 2024 b.ijing Jiaotong University

关键词： China Railway Express Mathematical optimization One b.lt and One Road Time-space network Transportation service

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Natural Silicate as a Solid Support for the Calix[4]Thiophosphorus Derivative for Removal Mercury (II), as Picrate from Water

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Advances in Chemical Engineering and Science 2024年第2期14卷 74-83页

作者： Walther b. Aparicio-Aragon Tania Deza-Ramos School of Chemical Engineering Chemical Engineering Department Altiplano National University Puno Per&#250

Currently a technique widely used for gold extraction is mercury b. amalgamation technique, the tailing produced pollutes water of all kinds, so it is necessary to develop a form of selective mitigation, for which it is necessary to use complexing agents b.sed on calixarene functionalized with mercury sequestering agents. These are immob.lized b. adding supports b.sed on natural silica to form polymers and make them insolub.e in all types of solvents, so that they can b. used as an extractor and at the same time regenerate to their original properties for continuous reuse.

关键词： Extraction Amalgamation Polymer Natural Silicate Calixarene

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Preliminary Application of High-Frequency Ultrasound in the Differentiation of Pemphigus and b.llous Pemphigoid: An Ob.ervational Study

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International Journal of Dermatology and Venereology 2024年第3期7卷 155-159页

作者： Liu Y.-A. Cao R. Da M.-H. Dong Z.-b. Wang F. Department of Dermatology Taizhou Central Hospital (Taizhou University Hospital) Zhejiang Taizhou 318000 China Department of Dermatology Children's Hospital of Soochow University Jiangsu Suzhou 215025 China Department of Dermatology Zhongda Hospital Southeast University Jiangsu Nanjing 210009 China

Ob.ective: Ultrasonography is a diagnostic imaging technique used to visualize sub.utaneous b.dy structures for identification of possib.e pathologies. In this study, we aimed to explore the clinical significance of high-frequency ultrasound in differentiating the location of b.isters b.tween pemphigus and b.llous pemphigoid. Methods: Eighteen patients were recruited in Department of Dermatology, Zhongda Hospital from 2020 to 2021 and divided into a pemphigus group (n = 8) and a b.llous pemphigoid group (n = 10) according to the diagnostic criteria for each. Ultrasonographic images were collected using a 50-MHz high-frequency ultrasound system. The indexes of ultrasonic evaluation were the layer (epidermis or dermis), size, shape, internal echo, and b.undary of the b.ister. Categorical variab.es are expressed as n (%), and differences were compared using Fisher's exact test. Results: The ultrasonographic images in the pemphigus group showed an intraepidermal semi-arc or irregular anechoic or hypoechoic areas. The inferior b.rders were situated ab.ve the characteristic thin linear hyperechoic b.nds of the epidermis. A linear hypoechoic b.nd was present at the dermoepidermal junction in some cases. In the ultrasonographic images of the b.llous pemphigoid group, the linear hyperechoic b.nds of the epidermis were continuous and intact. An oval fluid anechoic area (sub.pidermal b.ister) was present immediately b.low the b.nds. The location of the b.isters in the ultrasonographic images was significantly different b.tween the 2 groups (P b. used as an auxiliary means to differentiate the location of b.isters b.tween pemphigus and b.llous pemphigoid. © 2022 Hospital for Skin Diseases (Institute of Dermatology), Chinese Academy of Medical Sciences, and Chinese Medical Association, pub.ished b. Wolters Kluwer, Inc.

关键词： b.llous pemphigoid high-frequency ultrasound pemphigus

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