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Development of a Long-Term Operational Optimization model for a Building Energy System Supplied by a Geothermal Field

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Journal of Thermal Science 2022年第5期31卷 1293-1301页

作者： KÜmPEL alexander STOFFEL Phillip mÜLLER Dirk RWTH Aachen University E.ON Energy Research CenterInstitute for Energy Efficient Buildings and Indoor ClimateAachen 52074Germany

In order to reduce energy consumption and CO_(2) emissions in the building sector, more and more renewable energy sources are integrated into energy systems. Especially geothermal fields combined with heat pumps are able to supply buildings with heat and cold at low carbon emissions. However, using geothermal fields as heat and cold source influences the ground temperature. Consequently, the ground temperature can change dramatically over a building’s lifetime, leading to less efficient operation of the energy system. Therefore, a sustainable operation is required to ensure the long-term efficiency of geothermal fields. In this paper, we develop an optimization model to derive operating strategies for an efficient long-term operation of a building energy system coupled to a geothermal field. The investigated energy system is the main building of the E.ON Energy Research Center in Aachen, Germany, which includes a heat pump, two boilers, a combined heat, and power unit, a glycol cooler, and a geothermal field with 41 probes. For each component, we develop energy-based sub-models, which are connected to form the overall system. The geothermal field is modeled by using a g-functions approach as well as a simplified resistance-capacitance approach. To achieve short computing times and realize an optimization horizon of several years, the optimization problem is formulated as mixed-integer linear programming(mILP). The developed model is optimized regarding two different objectives: the minimization of energy costs and the minimization of long-term temperature changes in the ground. Conclusions for an efficient and sustainable operation of the field, especially for the cooling supply, can be derived from the optimization results. It is shown that a state of equilibrium should be aimed to achieve an energy-efficient operation, in which the temperature of the field is close to the initial ground temperature.

关键词： geothermal energy building energy systems operational optimization long-term operation

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mtDNA mutations and aging--not a closed case after all?

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Signal Transduction and Targeted Therapy 2021年第3期6卷 555-556页

作者： alexander m.Wolf Laboratory for morphological and Biomolecular Imaging Faculty of MedicineNippon Medical SchoolTokyoJapan

In a recent paper in Nature Cancer,Smith et al.demonstrate that mitochondrial DNA(mtDNA)mutations can confer a growth advantage to intestinal tumors by remodeling cell metabolism,particularly toward elevated de novo serine synthesis.1 For the reasons outlined below,in the past decade,the field of mtDNA biology has experienced a relative loss of relevance.The findings of Smith et al.breathe welcome new life into the complex field of mtDNA contributions to aging and cancer.

关键词： al. metabolism elevated

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Cloud-Based Optimal Control of Individual Borehole Heat Exchangers in a Geothermal Field

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Journal of Thermal Science 2022年第5期31卷 1253-1265页

作者： STOFFEL Phillip KÜmPEL alexander mÜLLER Dirk RWTH Aachen University E.ON Energy Research CenterInstitute for Energy Efficient Buildings and Indoor Climate52074 AachenGermany

Integrating renewable energy sources is a crucial component in reducing CO_(2) emissions in the building sector. In particular, shallow geothermal energy is expected to play a significant role in the regenerative energy supply of buildings. An effective control strategy for the geothermal field is crucial to reduce the overall energy consumption. This paper analyzes the benefits of controlling an existing field’s individual borehole heat exchangers(BHE) using nonlinear model predictive control(NmPC) and moving horizon estimation. The considered geothermal field consists of 41 BHEs and is used for heating and cooling. Each BHE is equipped with temperature sensors for in-and outflow and has individually controllable valves, while a central hydraulic pump feeds all BHEs. The sensor measurements are accessed through a cloud platform, enabling also set point writing for the pump speed and the valve positions. To control the BHEs individually, we propose a two-stage process. In the calibration stage, a moving horizon estimator estimates the actual borehole and ground temperatures for each BHE. In the second stage, first, a nonlinear model predictive controller optimizes the number of active BHEs necessary to meet the buildings’ energy demand. With the estimated ground temperatures as a basis, it is determined which BHEs shall be(de)-activated. The active BHEs are fed with a fixed volume flow of 24 L/min to ensure turbulent heat transfer. To reduce the power usage of the pumps, an optimal control problem based on a simple hydraulic model of the geothermal field is used. The methodology is analyzed through simulations first and then validated experimentally. The results show that half or more of the BHEs could be deactivated most of the time, leading to 67% savings in electricity consumption by the hydraulic pump. The experimental validation confirms the high energy saving potential of the proposed methodology, reducing the consumption of electrical energy by 71%. Additionally, the deactivated BHEs regenerate faster and

关键词： geothermal energy moving horizon estimation model predictive control operation optimization optimal control

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CXCR4 signaling in central nervous system regeneration: friend or foe?

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Neural Regeneration Research 2022年第7期17卷 1481-1483页

作者： Daniel Terheyden-Keighley alexander m.Hilla Dietmar Fischer Department of Cell Physiology Ruhr University of BochumUniversitätsstraβe 15044780 BochumGermany

The knockout of the chemokine C-X-C motif chemokine receptor 4(CXCR4)in growthstimulated retinal ganglion cells(RGCs)has a multiplicative effect on optic nerve regeneration.C-X-C motif chemokine ligand 12(CXCL12),the ... 详细信息

关键词： CXCL12 CXCR4 system

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Evaluation of the function of a luciferase-like monooxygenase homologue in 4,4´-dithiodibutyric acid catabolism in Rhodococcus erythropolis mI2

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Systems microbiology and Biomanufacturing 2022年第3期2卷 523-532页

作者： m.Venkateswar Reddy alexander Steinbüchel Institut für molekulare mikrobiologie und Biotechnologie Westfälische Wilhelms-Universität Münster48149 MünsterGermany Center for Biotechnology and Interdisciplinary Studies Rensselaer Polytechnic Institute1108th StreetTroyNY 12180USA Environmental Sciences Department King Abdulaziz UniversityJeddahSaudi Arabia

The bacterium Rhodococcus erythropolis mI2 uses 4,4´-dithiodibutyric acid(DTDB)as carbon source to synthesize polythioesters(PTE).The first step for the production of PTE using DTDB is catalyzed by an NADH:flavin oxidoreductase(nox)as it was previously shown in our laboratory,and the second step is catabolized by a putative luciferase-like monooxygenase(Llm).In the current study,experiments were carried out to identify the function of Llm.Hence,the llm gene,which encodes for the Llm protein,was amplified from the genomic DNA of mI2 using polymerase chain reaction and expressed in Escherichia coli BL21 cells.Protein purification was done using His Spin Trap affinity columns.Enzyme assay was carried out using the purified protein and p-coumaric acid as substrate giving a specific activity of 1.6 U/mg protein for the purified Llm.The responsible gene(llm)was deleted in the genome of mI2,and a single deletion mutant was subsequently generated.Finally,growth of the wild-type strain(mI2)and the mutant strain(mI2Δllm)were compared using DTDB or succinate as carbon sources.Whereas the wild type was successfully grown with DTDB or succinate,the llm-negative mutant exhibited low grow with DTDB although it grows very well with succinate.

关键词： Deletion mutant monooxygenase Polythioesters Protein purification Rhodococcus erythropolis mI2 4,4´-Dithiodibutyric acid(DTDB)

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Recent advances in nanoparticle generation in liquids by lasers:Revealing formation mechanisms and tailoring properties

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Science China(Physics,mechanics & Astronomy) 2022年第7期65卷 115-117页

作者： alexander V.Bulgakov Nadezhda m.Bulgakova HiLASE Centre Institute of Physics of the Czech Academy of SciencesDolni Brezany 25241Czech Republic S.S.Kutateladze Institute of Thermophysics of the Siberian Branch of the Russian Academy of Sciences Novosibirsk 630090Russia

When Fojtik and Henglein [1] submitted in 1992 the first scientific paper on generation of nanoparticles(NPs) by laser ablation in liquids, the authors probably could not realize how it will revolutionize the nanoparticle science and technology. In 2017, marking a quarter century of this pioneering study, Amendola and Barcikowski [2] pointed out that the simple and bright idea of Henglein and Fojtik was an inspiration to hundreds of scientists worldwide over 25 years and opened a way to use lasers in synthesis of colloids.

关键词： liquids hundreds generation

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Assessing the performance of different outcomes for tumor growth studies with animal models

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Animal models and Experimental medicine 2022年第3期5卷 248-257页

作者： Luke W.Patten Patrick Blatchford matthew Strand alexander m.Kaizer Department of Biostatistics and Informatics University of ColoradoAuroraColoradoUSA

The consistency of reporting results for patient-derived xenograft(PDX) studies is an area of concern. The PDX method commonly starts by implanting a derivative of a human tumor into a mouse, then comparing the tumor growth under different treatment conditions. Currently, a wide array of statistical methods(e.g., t-test, regression, chi-squared test) are used to analyze these data, which ultimately depend on the outcome chosen(e.g., tumor volume, relative growth, categorical growth). In this simulation study, we provide empirical evidence for the outcome selection process by comparing the performance of both commonly used outcomes and novel variations of common outcomes used in PDX studies. Data were simulated to mimic tumor growth under multiple scenarios, then each outcome of interest was evaluated for 10?000 iterations. Comparisons between different outcomes were made with respect to average bias, variance, type-1 error, and power. A total of 18 continuous, categorical, and time-to-event outcomes were evaluated, with ultimately 2 outcomes outperforming the others: final tumor volume and change in tumor volume from baseline.Notably, the novel variations of the tumor growth inhibition index(TGII)— a commonly used outcome in PDX studies— was found to perform poorly in several scenarios with inflated type-1 error rates and a relatively large bias. Finally, all outcomes of interest were applied to a real-world dataset.

关键词： mouse model oncology outcome selection patient-derived xenograft(PDX) statistical analysis TGII translational science

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Veterans utilizing a federally qualified health center: a clinical snapshot

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military medical Research 2023年第1期10卷 134-136页

作者： Thad E.Abrams Bruce alexander Antonio Flores m.Bryant Howren VHA Office of Rural Health Veterans Rural Health Resource CenterIowa CityIA 52246USA Carver College of medicine The University of IowaIowa CityIA 52242USA Center for Access Delivery Research and Evaluation(CADRE) VA Iowa City Healthcare SystemIowa CityIA 52246USA Community Health Centers of Southeastern Iowa West BurlingtonIA 52655USA Department of Behavioral Sciences and Social medicine College of MedicineFlorida State UniversityTallahasseeFL 32306USA Florida Blue Center for Rural Health Research and Policy College of MedicineFlorida State UniversityTallahasseeFL 32306USA

Dear Editor,Te Veterans Health Administration(VHA)provides healthcare for over 9 million enrolled veterans with approximately 2.7 million of those residing in rural areas[1].Te mISSION Act of 2018 emphasizes VHA collaboration with Federally Qualifed Healthcare Centers(FQHC)to serve rural residing veterans and nearly all existing collaborations involve arrangement of payment for community-based care by VHA to FQHCs.Unfortunately,there is a paucity of descriptive clinical data on existing cross-system collaborations which may help characterize these veterans and aid understanding of conditions for which they may receive treatment across systems.Such data has implications for workforce training,development,and resource allocation[2].Te objective of this report is to describe diferent clinical profles between two mutually exclusive samples:veterans engaged in FQHC only use,and VHA-enrolled veterans engaged in dual VHA and FQHC use.

关键词： Veterans Federally qualified healthcare centers Healthcare utilization Dual use mental health

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On the Analytical models of Protoplanetary Formation in Extrasolar Systems

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Space(Science & Technology) 2022年第1期2022卷 422-440页

作者： alexander m.Krot Laboratory of Self-Organization System modeling United Institute of Informatics ProblemsNational Academy of Sciences of Belarus6Surganov Str.220012 MinskBelarus

In this work,we consider a statistical theory for a cosmogonical body formation(so-called spheroidal body)to develop the analytical models of protoplanetary formation in extrasolar systems.Within the framework of this theory,the models and evolution equations of the statistical mechanics have been proposed,while the well-known problem of gravitational condensation of infinite distributed cosmic substances has been solved.This paper derives the general equation of distribution of the specific angular momentum of forming protoplanets since the specific angular momentums(for particles or planetesimals)are averaged during a conglomeration process(under a planetary embryo formation).As a result,a new law for planetary distances(which generalizes Schmidt’s law)is derived theoretically.This paper develops also an alternative thermal emission of particles model of the formation of protoplanets in extrasolar systems.Within the framework of this model,the equation for the thermal distribution function of the specific angular momentums of particles moving in elliptical orbits in the gravitational field is derived.According to this thermal escape model,only 0.8%of the total number of particles in the solar system composing the protoplanetary cloud has angular momentum 15.6 times higher than the angular momentum of the remaining 99%of particles.This conclusion agrees completely with the known fact of a nonuniform distribution of the angular momentums in our solar system noted by ter Haar.As pointed out here,the exponential laws of planetary distances occur in some extrasolar systems.

关键词： momentum angular equation

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Hip hemi-arthroplasty for neck of femur fracture:What is the current evidence?

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World Journal of Orthopedics 2018年第11期9卷 235-244页

作者： Greg AJ Robertson alexander m Wood Edinburgh Orthopaedic Trauma Unit Royal Infirmary of Edinburgh Orthopaedic Department Leeds General Infirmary

This editorial reviews and summarises the current evidence(meta-analyses and Cochrane reviews) relating to the use of hip hemi-arthroplasty for neck of femur fractures. Regarding the optimal surgical approach,two recent meta-analyses have found that posterior approaches are associated with: higher rates of dislocation compared to lateral and anterior approaches; and higher rates of re-operation compared to lateral approaches. Posterior approaches should therefore be avoided when performing hip hemi-arthroplasty procedures. Assessing the optimal prosthesis head component,three recent meta-analyses and one Cochrane review have found that while unipolar hemiarthroplasty can be associated with increased rates of acetabular erosion at short-term follow-up(up to 1 year),there is no significant difference between the unipolar hemi-arthroplasty and bipolar hemi-arthroplasty for surgical outcome,complication profile,functional outcome and acetabular erosion rates at longer-term follow-up(2 to 4 years). With bipolar hemi-arthroplasty being the more expensive prosthesis,unipolar hemi-arthroplasty is the recommended option. With regards to the optimal femoral stem insertion technique,three recent metaanalyses and one Cochrane Review have found that,while cemented hip hemi-arthroplasties are associated with a longer operative time compared to uncemented Hip Hemi-arthroplasties,cemented prostheses have lower rates of implant-related complications(particularly peri-prosthetic femoral fracture) and improved postoperative outcome regarding residual thigh pain and mobility. With no significant difference found between the two techniques for medical complications and mortality,cemented hip hemi-arthroplasty would appear to be the superior technique. On the topic of wound closure,one recent meta-analysis has found that,while staples can result in a quicker closure time,there is no significant difference in post-operative infections rates or wound healing outcomes when comparing staples to sutures. Therefore,either suture or staple w

关键词： Hemi-arthroplasty Prosthesis Stem Head Hip Femoral Neck Fracture Cement

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