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Investigation of particle-wall interaction in a pseudo-2D fluidized bed using CFD-DEM simulations

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Particuology 2016年第2期14卷 10-22页

作者： Tingwen Li Yongmin Zhang fernando Hernandez-Jimenez National Energy Technology Laboratory Morgantown WV26507 USA AECOM Morgantown WV 26507 USA State Key Laboratory of Heavy Oil Processing China University of Petroleum Beijing 102249 China Universidad Carlos III of Madrid Department of Thermal and Fluid Engineering Av. de la Universidad 30 28911 Leganes Madrid Spain

We report on discrete element method simulations of a pseudo-two-dimensional （pseudo-2D） fluidized bed to investigate particle-wall interactions. Detailed information on macroscopic flow field variables, including solids pressure, granular temperature, and normal and tangential wall stresses are analyzed. The normal wall stress differs from the solids pressure because of the strong anisotropic flow behavior in the pseudo-2D system. A simple linear relationship exists between normal wall stress and solids pressure. In addition, an effective friction coefficient can be derived to characterize particle-wall flow interaction after evaluating the normal and tangential wall stresses. The effects of inter-particle and particle-wall friction coefficients are evaluated. Strong anisotropic flow behavior in the pseudo-2D system needs to be considered to validate the two-fluid model where the boundary condition is usually developed based on an isotropic assumption. The conclusion has been confirmed by simulation with different particle stiffnesses. Assumptions in the newly developed model for 2D simulation are further examined against the discrete element method simulation.

关键词： Gas-solid tlow Fluidized bed Computational fluid dynamics Discrete element method Particle-wall interaction Two-dimensional flow

Nitrogen addition delays the emergence of an aridity-induced threshold for plant biomass

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National Science Review 2023年第11期10卷 148-159页

作者： Hailing Li César Terrer Miguel Berdugo fernando T.Maestre Zaichun Zhu Josep Pe?uelas Kailiang Yu Lin Luo Jie-Yu Gong Jian-Sheng Ye State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems College of EcologyLanzhou University Department of Civil and Environmental Engineering Massachusetts Institute of Technology Instituto Multidisciplinar para el Estudio del Medio“Ramón Margalef ”Universidad de Alicante Institut de Biologia Evolutiva(CSIC-UPF) Departamento de Ecología Universidad de Alicante School of Urban Planning and Design Peking University Shenzhen Graduate SchoolPeking University CSIC Global Ecology Unit CREAF-CSIC-UAB CREAF Cerdanyola del Vallès High Meadows Environmental Institute Princeton University

Crossing certain aridity thresholds in global drylands can lead to abrupt decays of ecosystem attributes such as plant productivity, potentially causing land degradation and desertification. It is largely unknown,however, whether these thresholds can be altered by other key global change drivers known to affect the water-use efficiency and productivity of vegetation, such as elevated CO2and nitrogen(N). Using >5000 empirical measurements of plant biomass, we showed that crossing an aridity(1–precipitation/potential evapotranspiration) threshold of ～0.50, which marks the transition from dry sub-humid to semi-arid climates, led to abrupt declines in aboveground biomass(AGB) and progressive increases in root:shoot ratios, thus importantly affecting carbon stocks and their distribution. N addition significantly increased AGB and delayed the emergence of its aridity threshold from 0.49 to 0.55(P < 0.05). By coupling remote sensing estimates of leaf area index with simulations from multiple models, we found that CO2enrichment did not alter the observed aridity threshold. By 2100, and under the RCP 8.5 scenario, we forecast a 0.3% net increase in the global land area exceeding the aridity threshold detected under a scenario that includes N deposition, in comparison to a 2.9% net increase if the N effect is not considered. Our study thus indicates that N addition could mitigate to a great extent the negative impact of increasing aridity on plant biomass in drylands. These findings are critical for improving forecasts of abrupt vegetation changes in response to ongoing global environmental change.

关键词： aboveground biomass root:shoot ratios elevated CO2 nitrogen fertilization ecosystem threshold

Peri-implant femoral fractures:Challenges,outcomes,and proposal of a treatment algorithm

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Chinese Journal of Traumatology 2023年第4期26卷 211-216页

作者： fernando Bidolegui Sebastian Pereira Mateo Alzate Munera German Garabano Cesar A.Pesciallo Robinson Esteves Pires Vincenzo Giordano Orthopaedics and Trauma Surgery Department Sirio Libanes HospitalBuenos AiresArgentina Orthopaedics and Trauma Surgery Department British Hospital of Buenos AiresBuenos AiresArgentina Department of the Locomotor Apparatus Federal University of Minas GeraisBelo HorizonteBrazil Orthopedics and Traumatology Prof.Nova Monteiro Hospital Municipal Miguel CoutoRio de JaneiroBrazil

Purpose:Non-prosthetic peri-implant fractures are challenging *** factors must be care-fully evaluated for an adequate therapeutic strategy,such as the state of bone healing,the type of implant,the time and performed personnel of previous surgery,and the stability of *** aim of this study is to propose a rationale for the ***:The peri-implant femoral fractures(PIFFs)system,a therapeutic algorithm was developed for the management of all patients presenting a subtype A PIFF,based on the type of the original implant(***-medulllary),implant length and fracture *** adequacy and reliability of the proposed algorithm and the fracture healing process were assessed at the last clinical follow-up using the Parker mobility score and radiological assessment,*** addition,all complications were *** variables were expressed as mean and standard deviation,or median and range according to their *** variables were expressed as frequency and ***:This is a retrospective case series of 33 PIFFs,and the mean post-operative Parker mobility score was(5.60±2.54)*** patients(15.1%)achieved complete mobility without aids(9 points)and 1(3.0%)patient was not able to *** other patients(6.1%)were non-ambulatory prior to *** mean follow-up was(21.51±9.12)months(range 6-48 months).There were 7(21.2%)complications equally distributed between patients managed either with nailing or *** were no cases of nonunion or mechanical failure of the original ***:The proposed treatment algorithm shows adequate,reliable and straightforward to assist the orthopaedic trauma surgeon on the difficult decision-making process regarding the management of PIFF occurring in previously healed *** addition,it may become a useful tool to optimize the use of the classification,thus potentially improving the outcomes and minimizing complications.

关键词： Peri-implant femoral fracture Peri-osteosynthesis fracture Femurfracture Treatment algorithm

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Controls of fracturing on porosity in pre-salt carbonate reservoirs

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能源地球科学(英文) 2023年第2期4卷 49-61页

作者： Wagner Moreira Lupinacci Tuany Younis Abdul Fatah Maria Cordeiro do Carmo Antonio fernando Menezes Freire Luiz Antonio Pierantoni Gamboa Exploratory Interpretation and Reservoir Characterization Group(GIECAR) Department of Geology and GeophysicsUniversidade Federal FluminenseNiteróiRio de Janeiro24210346Brazil National Institute of Science and Technology of Petroleum Geophysics(INCT-GP/CNPQ) NiteróiRio de Janeiro24210346Brazil

This work aims to improve the understanding of how fracture zones affect carbonate reservoir properties based on observations of a pre-salt well located in the Santos Basin,*** identification of fracture zones allowed for the observation of a relationship between the occurrence of rock fractures and the silicification,as the latter plays an important role in determining porosity(higher silica content may increase brittleness of the rocks therefore increasing the likelihood of creating fractures zones and fractures may be filled up reducing the total porosity).To support the proposed observation,an integrated study was conducted using borehole imaging,spectroscopy logs,and sidewall core *** porosities were defined using nuclear magnetic resonance log analysis,alongside sidewall core samples,and thin *** integration of rock samples and well data with seismic analysis was performed to analyze the presence of a regional fault system that could explain high fracture densities as well as observed silica content *** results show how different types of cement filling up the formation pores affect fracture densities and total ***,it was possible to infer that the amount of silica content observed in well logs and thin sections relates to hydrothermal fluids reaching out the reservoir through regional fault systems detected in the seismic ***,this paper supports the comprehension of how diagenetic processes can significantly affect the properties of presalt reservoirs.

关键词： Fracture Porosity Pre-salt carbonatereservoir Santos Basin

Liver volumetric and anatomic assessment in living donor liver transplantation: The role of modern imaging and artificial intelligence

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World Journal of Transplantation 2023年第6期13卷 290-298页

作者： Mayara Machry Luis fernando Ferreira Angelica Maria Lucchese Antonio Nocchi Kalil Flavia Heinz Feier Department of Hepato-Biliary-Pancreatic Surgery and Liver Transplantation Irmandade Santa Casa de Misericórdia de Porto AlegrePorto Alegre 90020-090Brazil Postgraduation Program in Medicine:Hepatology Federal University of Health Sciences of Porto AlegrePorto Alegre 90050-170Brazil

The shortage of deceased donor organs has prompted the development of alternative liver grafts for ***-donor liver transplantation(LDLT)has emerged as a viable option,expanding the donor pool and enabling timely transplantation with favorable graft function and improved long-term *** accurate evaluation of the donor liver’s volumetry(LV)and anatomical study is crucial to ensure adequate future liver remnant,graft volume and precise liver ***,ensuring donor safety and an appropriate graftto-recipient weight *** LV(MLV)using computed tomography has traditionally been considered the gold standard for assessing liver ***,the method has been limited by cost,subjectivity,and *** LV techniques employing advanced segmentation algorithms offer improved reproducibility,reduced variability,and enhanced efficiency compared to manual ***,the accuracy of automated LV requires further *** study provides a comprehensive review of traditional and emerging LV methods,including semi-automated image processing,automated LV techniques,and machine learning-based ***,the study discusses the respective strengths and weaknesses of each of the aforementioned *** use of artificial intelligence(AI)technologies,including machine learning and deep learning,is expected to become a routine part of surgical planning in the near *** implementation of AI is expected to enable faster and more accurate image study interpretations,improve workflow efficiency,and enhance the safety,speed,and cost-effectiveness of the *** preoperative assessment of the liver plays a crucial role in ensuring safe donor selection and improved outcomes in *** has inherent limitations that have led to the adoption of semi-automated and automated software ***,AI has tremendous potential for LV and segmentation;however,its widespread use is hindered

关键词： Liver transplantation Living-donor Diagnostic imaging Artificial intelligence Machine learning Deep learning

Pan-retinal ganglion cell markers in mice, rats, and rhesus macaques

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Zoological Research 2023年第1期44卷 226-248页

作者： Francisco M.Nadal-Nicolás Caridad Galindo-Romero fernando Lucas-Ruiz Nicholas Marsh-Amstrong Wei Li Manuel Vidal-Sanz Marta Agudo-Barriuso Grupo de Oftalmología Experimental Instituto Murciano de Investigación Biosanitaria Pascual Parrilla(IMIB)Murcia 30120Spain Dpto.Oftalmología Facultad de MedicinaUniversidad de MurciaMurcia 30120Spain Retinal Neurophysiology Section National Eye InstituteNational Institutes of HealthBethesdaMaryland 20892-2510USA Department of Ophthalmology and Vision Science University of CaliforniaDavisCA 95817USA

Univocal identification of retinal ganglion cells(RGCs) is an essential prerequisite for studying their degeneration and neuroprotection. Before the advent of phenotypic markers, RGCs were normally identified using retrograde tracing of retinorecipient areas. This is an invasive technique, and its use is precluded in higher mammals such as monkeys. In the past decade, several RGC markers have been described. Here, we reviewed and analyzed the specificity of nine markers used to identify all or most RGCs, i.e., pan-RGC markers, in rats, mice, and macaques. The best markers in the three species in terms of specificity, proportion of RGCs labeled, and indicators of viability were BRN3A, expressed by vision-forming RGCs, and RBPMS, expressed by vision-and non-vision-forming RGCs. NEUN, often used to identify RGCs, was expressed by non-RGCs in the ganglion cell layer, and therefore was not RGC-specific. γ-SYN, TUJ1, and NF-L labeled the RGC axons, which impaired the detection of their somas in the central retina but would be good for studying RGC morphology. In rats, TUJ1 and NF-L were also expressed by non-RGCs. BM88, ERRβ,and PGP9.5 are rarely used as markers, but they identified most RGCs in the rats and macaques and ERRβ in mice. However, PGP9.5 was also expressed by non-RGCs in rats and macaques and BM88 and ERRβ were not suitable markers of viability.

关键词： RGC Optic nerve crush BM88 BRN3A Estrogen-related receptorβ ERRβ NEUN Neurofilament-L PGP9.5 RBPMS γ-SYN βIII-tubulin TUJ1

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Differences in standing balance between patients with diplegic and hemiplegic cerebral palsy

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Neural Regeneration Research 2013年第26期8卷 2478-2483页

作者： Valeska Gatica Rojas Guillermo Méndez Rebolledo Eduardo Guzman Muoz Natalia Ibarra Cortés Caterine berrios Gaete Carlos Manterola Delgado Laboratory of Human Motor Control Faculty of Health Sciences University of Talca Laboratory of Human Motor Control School of Kinesiology Faculty of Health Sciences University of Talca School of Kinesiology University Santo Tomas Student School of Kinesiology Faculty of Health Sciences University of Talca Program in Medical Sciences University of the Frontera

Maintaining standing postural balance is important for walking and handling abilities in patients with cerebral palsy. This study included 23 patients with cerebral palsy （seven with spastic diplegia and 16 with spastic hemiplegia）, aged from 7 to 16 years of age. Standing posture balance measurements were performed using an AMTI model OR6-7 force platform with the eyes open and closed. Patients with diplegic cerebral palsy exhibited greater center of pressure displacement areas with the eyes open and greater center of pressure sway in the medial-lateral direction with the eyes open and closed compared with hemiplegic patients, Thus, diplegic patients exhibited weaker postural balance control ability and less standing stability compared with hemiplegic cerebral palsy patients.

关键词： neural regeneration cerebral palsy postural balance postural control center of pressure children diplegia hemiplegia grants-supported paper neuroregeneration

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High resolution manometric findings in patients with Chagas' disease esophagopathy

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Asian Pacific Journal of Tropical Medicine 2012年第2期5卷 110-112页

作者： Luciana C Silva fernando PP Vicentine fernando AM Herbella Department of Surgery Escola Paulista de MedicinaFederal University of Sao PauloSao PauloBrazil

Objective:To describe high resolution manometry features of a population of symptomatic- patients with Chagas’ disease esophagopathy(CDE).Methods:Sixteen symptomatic dysphagic patients with CDE[mean age(54.81±13.43) years,10 women]were included in this *** patients underwent a high resolution ***:Mean lower esophageal sphincter(LES) extension was(3.02±1.17) cm with a mean basal pressure of(15.25±7.00) *** pressure was(14.31±9.19) *** was found in all 16 *** with minimal esophageal pressurization(type I) was present in 25%of patients and achalasia with esophageal compression(type 2) in 75%,according to the Chicago *** esophageal sphincter(UES) mean basal pressure was(97.96±54.22) mmHg with a residual pressure of(12.95±6.42) ***:Our results show that LES was hypotensive or normotensive in the majority of the *** relaxation was found in a minority of our *** was seen in 100%of *** had impaired relaxation in a significant number of patients. Further clinical study is needed to investigate whether manometric features can predict outcomes following the studies of idiopathic achalasia..

关键词： Achalasia Chagas disease High resolution manometry

Dynamics of phosphorus in sediments of a naturally acidic lake

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International Journal of Sediment Research 2013年第1期28卷 90-102页

作者： Temporetti PEDRO Snodgrass KIMBERLEY Pedrozo fernando Centro Regional Universitario Bariloche Universidad Nacional del ComahueCONICETQuintral 12508400 BarilocheArgentina Staff Environmental Engineer Water and Environmental Technologies 480 East Park StreetSuite 200 ButteMT59701MontanaEEUU INIBIOMA Centro Regional Universitario BarilocheUniversidad Nacional del ComahueCONICETQuintral 12508400 BarilocheArgentina

The mechanisms which controls the fixation and/or release of P in sediment of an extremely acidic lake（pH = 2.0 to 3.0） and its response to the influence of eutrophic urban waste water were *** results,in the chemical composition,in the mineralogy of the sediment and in the material as obtained from sediment traps,show that the lake sediments are mainly volcanic material reflecting volcanic features of the *** sedimentation rate calculated for the lake(2.5×10;mg m;day;) was higher than that observed in other similar glacial lakes in both Andean Patagonia and also elsewhere in the *** Total Phosphorus concentration in sediments was higher than figures reported by other authors for mining acid lakes,and the main fraction of P was found associated with organic *** was no control by Fe or Al on P,because both are in solution at pH < *** was concluded that changes in the natural input of nutrients（derivatives of Copahue volcano fluid,the discharge of sewage,or basin run-off） are responsible for a high concentration of SRP and N-NH;in the *** experiments showed that sediments have no ability to retain phosphorus and a continuous release of P from the sediments into the water column was *** assays where the pH was artificially increased showed that the P still remains in solution until at least pH *** was concluded that changes in the natural input of nutrients due to:1) the volcanic fluids,2) the increase in sewage charges,or 3) surface runoff upstream,maintain a high trophic state with high concentrations of dissolved P and N-NH;,although the threshold of neutral pH in the lake is *** study will enable a better understanding about of the mechanism of release/fixation of phosphorus in acidic sediments in order to assist in making decisions regarding the conservation and management of this natural environment.

关键词： Sediments Phosphorus release Acidic lake