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Stability Analysis of DC Microgrid Clusters Based on Step-by-step System Matrix Building Algorithm

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Journal of Modern power Systems and Clean Energy 2024年第3期12卷 900-912页

作者： K.Jithin N.Mayadevi R.Hari Kumar V.p.Mini the Department of Electrical Engineering College of Engineering TrivandrumAPJ Abdul Kalam Technological University(APJAKTU)ThiruvananthapuramIndia

DC microgrids(DCMGs)are made up of a network of sources and loads that are connected by a number of power electronic converters(pECs).The increase in the number of these pECs instigates major concerns in system *** interconnecting the microgrids to form a cluster,the system stability must be *** paper proposes a novel stepby-step system matrix building(SMB)algorithm to update the system matrix of an existing DCMG cluster when a new microgrid is added to the cluster through a distribution *** stability of the individual DCMGs and the DCMG cluster is analyzed using the eigenvalue ***,the particle swarm optimization(pSo)algorithm is used to retune the controller gains if the newly formed cluster is not *** simulation of the DCMG cluster is carried out in MATLAB/Simulink environment to test the proposed *** results are also validated using the op4510 real-time simulator(RTS).

关键词： Converter DC microgrid cluster eigenvalue interconnection particle swarm optimization system stability system matrix

Flame Structure of Methane and Kerosene Combustion with a Compact Concave Flame-Holder using the LES-pdf Method

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Journal of Thermal Science 2024年第1期33卷 222-234页

作者： WANG Fang WANG Yunfan WEI Guanyi LIU Denghuan JIN Jie JoNES p.William School of Energy and power Engineering Beihang UniversityBeijingBeijing 100191China Department of Mechanical Engineering Imperial College LondonLondon SW72AZUK

Compact flame-holders for afterburners are an increasing requirement for modern aero ***,flame-holder design is non-trivial since high inlet temperatures,velocities,and elaborate structures induce complex turbulence,combustion,and spray coupling in modern *** this work,the LES-pdf and stochastic fields-Lagrangian particle spray methods are used to investigate methane and aviation kerosene combustion structures formed by new-type concave *** flow pattern,combustion mode,and flame structure of gaseous and liquid fuel around a concave flame-holder are analyzed,discussed,and compared with experimental *** reveal that the flame stability of a concave flame-holder is better than that of the non-concave ***,when using liquid fuel,the concave flame-holder forms a stable and compact *** results suggest concave flame-holders are a promising design for compact afterburners.

关键词： concave structure flame-holder LES-pdf spray combustion flame structure AECSC

Sedimentary records of contaminant inputs in Frobisher Bay,Nunavut

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Environmental Science and Ecotechnology 2024年第2期18卷 28-42页

作者： Meaghan C.Bartley Tommy Tremblay Amila o.De Silva CMichelle Kamula Stephen Ciastek Zou Zou A.Kuzyk Centre for Earth observation Science Clayton H.Riddell Faculty of EnvironmentEarth and ResourcesUniversity of ManitobaWinnipegManitobaR3T 2N2Canada Department of Environment and Geography Clayton H.Riddell Faculty of EnvironmentEarth and ResourcesUniversity of ManitobaWinnipegManitobaR3T 2N2Canada Canada-Nunavut Geoscience office IqaluitNunavutX0A 0H0Canada Environment and Climate Change Canada BurlingtonOntarioL7S 1A1Canada Department of Earth Sciences Clayton H.Riddell Faculty of EnvironmentEarth and ResourcesUniversity of ManitobaWinnipegManitobaR3T 2N2Canada

Contaminants,such as polychlorinated biphenyls(pCBs),polycyclic aromatic hydrocarbons(pAHs),heavy metals,and per and polyfluoroalkyl substances(pFASs),primarily reach the Arctic through long-range atmospheric and oceanic ***,local sources within the Arctic also contribute to the levels observed in the environment,including legacy sources and new sources that arise from activities associated with increasing commercial and industrial *** City of Iqaluit in Frobisher Bay,Nunavut(Canada),has seen rapid population growth and associated development during recent decades yet remains a site of interest for ocean protection,where Inuit continue to harvest country *** the present study,seven dated marine sediment cores collected in Koojesse Inlet near Iqaluit,and from sites in inner and outer Frobisher Bay,respectively,were analyzed for total mercury(THg),major and trace elements,pAHs,pCBs,and *** sedimentary record in Koojesse Inlet shows a period of Aroclor 1260-like pCB input concurrent with military site presence in the 1950e60s,followed by decades of input of pyrogenic pAHs,averaging about ten times background ***-surface sediments in Koojesse Inlet also show evidence of transient local-source inputs of THg and pFASs,and recycling or continued slow release of pCBs from legacy land-based *** in pFAS congener composition clearly distinguish the local sources from long-range *** Koojesse Inlet but still in inner Frobisher Bay,9.2 km from Iqaluit,sediments showed evidence of both local source(pCB)and longrange *** outer Frobisher Bay,an up-core increase in THg and pFASs in sediments may be explained by ongoing inputs of these contaminants from long-range *** context for ocean protection and country food harvesting in this region of the Arctic clearly involves both local sources and long-range transport,with past human activities leaving a long legacy insofar as levels of persistent o

关键词： Arctic sediments Mercury polycyclic aromatic hydrocarbons(pAHs) polychlorinated biphenyls(pCBs) per and polyfluoroalkyl substances(pFASs) persistent organic pollutants(pops)

Technological advancements in millet dehulling and polishing process: An insight into pretreatment methods, machineries and impact on nutritional quality

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Grain & oil Science and Technology 2024年第3期7卷 186-195页

作者： Shagolshem Mukta Singh Jayasree Joshi T p.Srinivasa Rao Agricultural and Food Engineering Department Indian Institute of Technology KharagpurKharagpurWest Bengal 721302India

Millets are widely recognized for their nutritional significance;however, the methods employed for their processing are currently lacking. This article primarily focuses on the advanced technologies and progressions in millet dehulling and polishing. These technologies operate based on the fundamental principles of compression-shearing, abrasion-friction, and centrifugal-impact forces. processing of millets can be challenging because of the physical characteristics and tight attachment of hull and bran to the endosperm. However, several dehullers have been designed to solve this problem for different kinds of millets. In addition, the nutritional and anti-nutritional characteristics undergo alterations due to both dehulling and polishing processes. These alterations are thoroughly examined and discussed in this article. Specifically, anti-nutrients such as tannins and phytate are predominantly found in the outer pericarp of the grain and experience a reduction after undergoing dehulling and polishing. The nutritional properties are also subjected to a reduction;however, this reduction can be mitigated by subjecting the grains to certain pretreatments before dehulling and polishing. These treatments serve to enhance dehulling efficiency and nutrient digestibility while simultaneously reducing the presence of anti-nutrients. Novel thermal and non-thermal methodologies such as microwave, hydrothermal, high-pressure processing, and ohmic heating can be employed for processing millets, thereby diminishing the loss of nutrients. Additional research can be carried out to investigate their impact on the dehulling and polishing of millets.

关键词： Millets Dehulling polishing pretreatment Novel thermal and non-thermal techniques

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Assisted-Living Home

英语世界 2024年第6期 127-128页

作者： John o'Reilly

In the future those who are taking care of old or sick people may get help from the house *** the last few years, new technology, such as the Internet, Wi-Fi and flat TV screens, has changed our homes and the way we live. Now, another technology revolution is happening. A new project at the University of Hertfordshire wants to create a home that supervises people living in it who are weak or elderly.

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Efficient people Detection with Infrared Images

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Journal of Computer and Communications 2024年第4期12卷 31-39页

作者： Maria da Conceição proença Marine and Environmental Sciences Centre & ARNET Aquatic Research Infrastructure Network Associated Laboratory Department of Physics Faculty of Sciences University of Lisbon Lisbon Portugal

This work focuses on the problem of monitoring the coastline, which in portugal’s case means monitoring 3007 kilometers, including 1793 maritime borders with the Atlantic ocean to the south and west. The human burden on the coast becomes a problem, both because erosion makes the cliffs unstable and because pollution increases, making the fragile dune ecosystem difficult to preserve. It is becoming necessary to increase the control of access to beaches, even if it is not a popular measure for internal and external tourism. The methodology described can also be used to monitor maritime borders. The use of images acquired in the infrared range guarantees active surveillance both day and night, the main objective being to mimic the infrared cameras already installed in some critical areas along the coastline. Using a series of infrared photographs taken at low angles with a modified camera and appropriate filter, a recent deep learning algorithm with the right training can simultaneously detect and count whole people at close range and people almost completely submerged in the water, including partially visible targets, achieving a performance with F1 score of 0.945, with 97% of targets correctly identified. This implementation is possible with ordinary laptop computers and could contribute to more frequent and more extensive coverage in beach/border surveillance, using infrared cameras at regular intervals. It can be partially automated to send alerts to the authorities and/or the nearest lifeguards, thus increasing monitoring without relying on human resources.

关键词： Beach overload people Counting Border Control people Detection Deep Learning Methods Remote Surveillance

Forgiveness and Chronic pain: A Cohort Study

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pain Studies and Treatment 2024年第2期12卷 13-20页

作者： Sheena o’Beirne Dominic Harmon Medical School University of Limerick Limerick Ireland

Background: Chronic pain is a major public health issue. It is a complex condition comprising biological, social and psychological elements, which can be challenging to manage. Forgiveness is a recognised effective intervention in various health conditions. Research has shown promising results using forgiveness as an intervention in the management of pain. This study aims to examine the relationship between forgiveness and other variables in patients suffering from chronic pain in the setting of a chronic pain clinic. Methods: Institutional ethical approval was granted for this study. patients attending a chronic pain clinic for the first time were invited to complete a questionnaire comprising a brief socio-demographic survey and questionnaires including the Heartland Forgiveness Scale, Hospital Anxiety and Depression Scale, pain and Anxiety Symptoms Scale and perceived Injustice. Results: 104 adult patients were included. The mean age was 59 years. Back pain was the most common chronic pain presentation. The Heartland Forgiveness Scale (HFS) was found to have a good internal consistency among the Irish population. This study found that 55% of patients attending the pain clinic were not forgiving. Negative correlations were identified between forgiveness and pain, and forgiveness and injustice. Conclusion: The majority of patients attending a chronic pain clinic were not forgiving as measured on the HFS. There was a negative correlation between forgiveness and pain. The results have shown that forgiveness could be beneficial as a therapeutic intervention among patients attending a chronic pain clinic.

关键词： Forgiveness Chronic pain Associations

Actively tunable sandwich acoustic metamaterials with magnetorheological elastomers

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Applied Mathematics and Mechanics(English Edition) 2024年第11期45卷 1875-1898页

作者： Jinhui LIU Yu XUE Zhihong GAo A.o.KRUSHYNSKA Jinqiang LI College of Aerospace and Civil Engineering Harbin Engineering University Engineering and Technology Institute of Groningen (ENTEG) University of Groningen

Sandwich structures are widespread in engineering applications because of their advantageous mechanical properties. Recently, their acoustic performance has also been improved to enable attenuation of low-frequency vibrations induced by noisy environments. Here, we propose a new design of sandwich plates(Sps) featuring a metamaterial core with an actively tunable low-frequency bandgap. The core contains magnetorheological elastomer(MRE) resonators which are arranged periodically and enable controlling wave attenuation by an external magnetic field. We analytically estimate the sound transmission loss(STL) of the plate using the space harmonic expansion method. The low frequency sound insulation performance is also analyzed by the equivalent dynamic density method, and the accuracy of the obtained results is verified by finite-element simulations. our results demonstrate that the STL of the proposed plate is enhanced compared with a typical Sp analog, and the induced bandgap can be effectively tuned to desired frequencies. This study further advances the field of actively controlled acoustic metamaterials, and paves the way to their practical applications.

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Art and construction related qualities of 14th‒15th century monuments in a rural landscape on the western coast of Türkiye

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Frontiers of Architectural Research 2024年第4期13卷 712-728页

作者： Mine Hamamcıoğlu-Turan Engin Aktaș Özge Deniz Toköz Faculty of Architecture İzmir Institute of TechnologyİzmirTürkiye Faculty of Engineering İzmir Institute of TechnologyİzmirTürkiye

This study aims to contribute to the understanding of the evolution of art and construction in the early settlements established by Turkish communities on the far west Asian coast by focusing on two developed examples in Urla *** surveying and evaluation techniques of architectural restoration and civil engineering were *** findings include the understanding of the hierarchy of rural settlements in the studied landscape:old C¸esme the most developed village of peninsula in the 16th *** was positioned along a valley in distance to coast,but in control of harbor that played significant role in commerce between Europe and *** mosque and tomb,dated to late 14th e early 15th centuries,used to crown *** minaret tower of mosque,domed tomb tower on a cubical base and squinch in the transition zone of mosque are evidences for Central Asian *** of local lime stone,re-usage of andesite blocks,framing of the stone blocks with bricks,and pendentive in tomb refer to Roman-Byzantine *** study presents the development of Turkish art and construction on the far west Asian coast in the 14th‒15th *** will be a guide for related conservation management in similar contexts.

关键词： Mosque Tomb Central Asia Western Anatolia Mediterranean Conservation