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Analyzing the Interplay of Sintering Conditions on Microstructure and Hardness in Indirect Additive Manufacturing of 17-4PH Stainless Steel

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Acta Metallurgica Sinica(English Letters) 2024年第9期37卷 1611-1620页

作者： Erika Lannunziata mohammad Hossein Mosallanejad Manuela Galati Gabriele Piscopo Abdollah Saboori Integrated Additive Manufacturing Center Department of Management and Production EngineeringPolitecnico di TorinoCorso Duca Degli Abruzzi 2410129TurinItaly

Indirect additive manufacturing(AM)methods have recently attracted attention from researchers thanks to their great potential for cheap,straightforward,and small-scale production of metallic *** diffusion additive manufacturing(ADAM),a variant of indirect AM methods,is a layer-wise indirect AM process recently developed based on fused deposition modeling and metal injection ***,there is still limited knowledge of the process conditions and material properties fabricated through this process,where sintering plays a crucial role in the final consolidation of ***,this research,for the first time,systematically investigates the impact of various sintering conditions on the shrinkage,relative density,microstructure,and hardness of the 17-4PH ADAM *** this reason,as-washed samples were sintered under different time-temperature *** sample density was evaluated using Archimedes,computed tomography,and image analysis *** outcomes revealed that sintering variables significantly impacted the density of brown 17-4PH Stainless Steel *** results indicated more than 99% relative densities,higher than the value reported by Markforged Inc.(~96%).Based on parallel porosities observed in the computed tomography results,it can be suggested that by modifying the infill pattern during printing,it would be possible to increase the final relative *** microhardness of the sintered samples in this study was higher than that of the standard sample provided by Markforged *** at 1330℃ for 4 h increased the density of the printed sample without compromising its mechanical *** to X-ray diffraction analysis,the standard sample provided by Markforged ***“1330℃—4 h”one had similar stable phases,although copper-rich intermetallics were more abundant in the microstructure of reference *** study is expected to facilitate the adoption of indirect metal AM methods by different sector

关键词： Indirect additive manufacturing Atomic diffusion additive manufacturing 17-4PH stainless steel Computed tomography Sintering

Stratigraphy of the Alveolina elliptica group from the Middle Eocene of Iran:Calibration with calcareous nannofossils biozones and description of Alveolina ozcani n. sp.

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Journal of Palaeogeography 2024年第1期13卷 54-79页

作者： Mehdi Hadi Lorenzo Consorti Ali Bahrami mohammad Parandavar Saeed Khorramdel Department of Geology Faculty of SciencesUniversity of IsfahanIsfahanIran Institute of Marine Sciences(ISMAR-CNR) Area Science ParkBasovizza34149 TriesteItaly National Iranian Oil Company Exploration DirectorateSheikh Bahaei SquareTehranIran Department of Geology Faculty of ScienceFerdowsi University of MashhadMashhadIran

Precise taxonomy and the chronostratigraphic calibration of the Middle Eocene Alveolina from Central Iran is here undertaken from the Chah-Talkh section of the southern Sabzevar region(Central Iran). We have identified Alveolina kieli, Alveolina stercusmuris and Alveolina nuttalli along with the new species Alveolina ozcani n. sp. that we include into the Alveolina elliptica group. We have also found Nummulites uroniensis, Nummulites obesus and Nummulites cf. verneuili and associated calcareous nannofossils that look reliable to make thoughtful correlations with the Shallow Benthic Zones(SBZ). The foraminiferal biostratigraphy suggests an assignment to the upper part of the lower Lutetian-lower part of the middle Lutetian,SBZ13(Middle Eocene), further strengthened through the identification of the calcareous nannofossil NP14b-NP15b or CNE8-CNE10 biozones, providing a solid correlation with the global stratigraphic standards.

关键词： Alveolina Calcareous nannofossil Central neo-tethys Central Iran Middle Eocene Biostratigraphy

Post processing of additive manufactured Mg alloys:Current status,challenges,and opportunities

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Journal of Magnesium and Alloys 2024年第4期12卷 1283-1310页

作者： Nooruddin Ansari Fatima Ghassan Alabtah mohammad I.Albakri Marwan Khraisheh Mechanical Engineering Program Texas A&M University at QatarP.O.Box 23874DohaQatar

Magnesium(Mg)and its alloys are emerging as a structural material for the aerospace,automobile,and electronics industries,driven by the imperative of weight *** are also drawing notable attention in the medical industries owing to their biodegradability and a lower elastic modulus comparable to *** ability to manufacture near-net shape products featuring intricate geometries has sparked huge interest in additive manufacturing(AM)of Mg alloys,reflecting a transformation in the manufacturing ***,AM of Mg alloys presents more formidable challenges due to inherent properties,particularly susceptibility to oxidation,gas trapping,high thermal expansion coefficient,and low solidification *** leads to defects such as porosity,lack of fusion,cracking,delamination,residual stresses,and inhomogeneity,ultimately influencing the mechanical,corrosion,and surface properties of AM Mg *** address these issues,post-processing of AM Mg alloys are often needed to make them suitable for *** present article reviews all post-processing techniques adapted for AM Mg alloys to date,including heat treatment,hot isostatic pressing,friction stir processing,and surface *** utilization of these methods within the hybrid AM process,employing interlayer post-processing,is also *** post-processing conditions are reported,and their influence on the microstructure,mechanical,and corrosion properties are ***,future prospects and research directions are proposed.

关键词： Magnesium alloy Additive manufacturing Post-processing Heat treatment HIP

Artificial ground freezing of underground mines in cold regions using thermosyphons with air insulation

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International Journal of Mining Science and Technology 2024年第5期34卷 643-654页

作者： Ahmad F.Zueter mohammad Zolfagharroshan Navid Bahrani Agus P.Sasmito Department of Civil and Resource Engineering Dalhousie UniversityHalifax B3H4R2Canada Department of Mining Engineering McGill UniversityMontreal H3A0E8Canada

Current practice of underground artificial ground freezing(AGF)typically involves huge refrigeration systems of large economic and environmental *** this study,a novel AGF technique is proposed deploying available cold wind in cold *** is achieved by a static heat transfer device called thermosyphon equipped with an air insulation layer.A refrigeration unit can be optionally integrated to meet additional cooling *** introduction of air insulation isolates the thermosyphon from ground zones where freezing is not needed,resulting in:(1)steering the cooling resources(cold wind or refrigeration)towards zones of interest;and(2)minimizing refrigeration *** design is demonstrated using well-validated mathematical models from our previous work based on two-phase enthalpy method of the ground coupled with a thermal resistance network for the *** Canadian mines are considered:the Cigar Lake Mine and the Giant *** results show that our proposed design can speed the freezing time by 30%at the Giant Mine and by two months at the Cigar Lake ***,a cooling load of 2.4 GWh can be saved at the Cigar Lake ***,this study provides mining practitioners with sustainable solutions of underground AGF.

关键词： Artificial ground freezing Underground mining Sustainable mining Thermosyphon Air insulation Cold regions

Q-learning based control for energy management of series-parallel hybrid vehicles with balanced fuel consumption and battery life

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能源与人工智能(英文) 2023年第1期11卷 118-128页

作者： Saeid Ahmadian mohammad Tahmasbi reza abedi Department of Mechanical Engineering Sharif University of TechnologyTehranIran Department of Electrical and Computer Engineering Concordia UniversityMontrealQCCanada Department of Mechanical Engineering K.N.Toosi University of TechnologyTehranIran

The present study investigates an energy management strategy based on reinforcement learning for seriesparallel hybrid vehicles. Hybrid electric vehicles allow using more advanced power management policies because of their complexity of power management. Towards this feature, a Q-Learning algorithm is proposed to design an energy management strategy. Compared to previous studies, an online reward function is defined to optimize fuel consumption and battery life cycle. Moreover, in the provided method, prior knowledge of the cycle and exact modeling of the vehicle are not required. The introduced strategy is simulated for four driving cycles in MATLAB software linked with ADVISOR. The simulation results show that in the HWFET cycle, the fuel consumption decreases by 1.25 %, and battery life increases by 65% compared to the rule-based method implemented in ADVISOR. Also, the results for the other driving cycles confirm the self-improvement property. In addition, it has been depicted that in the case of change in the driving cycle, the method performance has been maintained and gained better performance than the rule-based controller.

关键词： Hybrid electric vehicles Series-parallel configuration Power management policy Reinforcement learning Q-Learning

Using X Social Networks (formerly Twitter) and web news mining to predict the measles outbreak

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Asian Pacific Journal of Tropical Medicine 2024年第4期17卷 188-190页

作者： Kia Jahanbin mohammad Jokar Vahid Rahmanian Department of Computer Engineering Yazd University YazdIran Faculty of Veterinary Medicine Karaj BranchIslamic Azad UniversityKarajIran Department of Public Health Torbat Jam Faculty of Medical SciencesTorbat JamIran

Measles,an infectious disease caused by the measles virus,remains a significant public health concern worldwide due to its highly contagious nature and potential for severe complications[1].In addition to symptoms such as high fever,cough,Koplik spots,and rash,measles can lead to serious complications including pneumonia and myocarditis,particularly in vulnerable populations such as young children[1,2].

关键词： Twitter web mining

Decision Making Based on Valued Fuzzy Superhypergraphs

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Computer Modeling in Engineering & Sciences 2024年第2期138卷 1907-1923页

作者： mohammad Hamidi Florentin Smarandache Mohadeseh Taghinezhad Department of Mathematics University of Payame NoorTehran19395-4697Iran Department of Mathematics University of New MexicoGallup87301 NMUSA

This paper explores the defects in fuzzy (hyper) graphs (as complex (hyper) networks) and extends the fuzzy(hyper) graphs to fuzzy (quasi) superhypergraphs as a new *** have modeled the fuzzy superhypergraphsas complex superhypernetworks in order to make a relation between labeled objects in the form of details andgeneralities. Indeed, the structure of fuzzy (quasi) superhypergraphs collects groups of labeled objects and analyzesthem in the form of the part to part of objects, the part of objects to the whole group of objects, and the whole tothe whole group of objects at the same *** have investigated the properties of fuzzy (quasi) superhypergraphsbased on any positive real number as valued fuzzy (quasi) superhypergraphs, considering the complement of valuedfuzzy (quasi) superhypergraphs, the notation of isomorphism of valued fuzzy (quasi) superhypergraphs based onthe permutations, and we have presented the isomorphic conditions of (self complemented) valued fuzzy (quasi)superhypergraphs. The concept of impact membership value of fuzzy (quasi) superhypergraphs is introducedin this study and it is applied in designing the real problem in the real world. Finally, the problem of businesssuperhypernetworks is presented as an application of fuzzy valued quasi superhypergraphs in the real world.

关键词： (Quasi)superhypergraph valued fuzzy(quasi)superhypergraph impact membership value complex superhypernetwork

A Review of Privacy and Security of Edge Computing in Smart Healthcare Systems: Issues, Challenges, and Research Directions

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Tsinghua Science and Technology 2024年第4期29卷 1152-1180页

作者： Ahmad Alzu’bi Ala’a Alomar Shahed Alkhaza’leh Abdelrahman Abuarqoub mohammad Hammoudeh Department of Computer Science Jordan University of Science and TechnologyIrbid 22110Jordan Cardiff School of Technologies Cardiff Metropolitan UniversityCardiff CF52YBUK Department of Information and Computer Science King Fahd University of Petroleum and MineralsDhahran 31261Kingdom of Saudi Arabia

The healthcare industry is rapidly adapting to new computing environments and technologies. With academics increasingly committed to developing and enhancing healthcare solutions that combine the Internet of Things (IoT) and edge computing, there is a greater need than ever to adequately monitor the data being acquired, shared, processed, and stored. The growth of cloud, IoT, and edge computing models presents severe data privacy concerns, especially in the healthcare sector. However, rigorous research to develop appropriate data privacy solutions in the healthcare sector is still lacking. This paper discusses the current state of privacy-preservation solutions in IoT and edge healthcare applications. It identifies the common strategies often used to include privacy by the intelligent edges and technologies in healthcare systems. Furthermore, the study addresses the technical complexity, efficacy, and sustainability limits of these methods. The study also highlights the privacy issues and current research directions that have driven the IoT and edge healthcare solutions, with which more insightful future applications are encouraged.

关键词： edge computing fog computing data privacy healthcare systems intelligent edges

Robust design of sliding mode control for airship trajectory tracking with uncertainty and disturbance estimation

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Journal of Systems Engineering and Electronics 2024年第1期35卷 242-258页

作者： WASIM Muhammad ALI Ahsan CHOUDHRY mohammad Ahmad SHAIKH Inam Ul Hasan SALEEM Faisal Department of Aeronautics and Astronautics Engineering Institute of Space TechnologyIslamabad 44000Pakistan Department of Electrical Engineering University of Engineering and TechnologyTaxila 47080Pakistan Department of Measurements and Control Systems Silesian University of TechnologyGliwice 44-101Poland The Joint Doctoral School Silesian University of TechnologyGliwice 44-100Poland

The robotic airship can provide a promising aerostatic platform for many potential *** applications require a precise autonomous trajectory tracking control for *** has a nonlinear and uncertain *** is prone to wind disturbances that offer a challenge for a trajectory tracking control *** paper addresses the airship trajectory tracking problem having time varying reference path.A lumped parameter estimation approach under model uncertainties and wind disturbances is opted against distributed *** uses extended Kalman filter(EKF)for uncertainty and disturbance *** estimated parameters are used by sliding mode controller(SMC)for ultimate control of airship trajectory *** comprehensive algorithm,EKF based SMC(ESMC),is used as a robust solution to track airship *** proposed estimator provides the estimates of wind disturbances as well as model uncertainty due to the mass matrix variations and aerodynamic model *** stability and convergence of the proposed method are investigated using the Lyapunov stability *** simulation results show that the proposed method efficiently tracks the desired *** method solves the stability,convergence,and chattering problem of SMC under model uncertainties and wind disturbances.

关键词： airship chattering extended Kalman filter(EKF) model uncertainties estimation sliding mode controller(SMC)