检索结果-南通市图书馆

Evaluation and management of the child with hypothyroidism

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Pediatrics 2019年第2期15卷 124-134页

作者： alexander k.C.Leung alexander A.C.Leung Department of Pediatrics The University of Calgaryand The Alberta Children's Hospital#200233-16th Avenue NWCalgaryAB T2M 0H5Canada Department of Medicine The University of CalgaryCalgaryABCanada

Background Thyroid hormones are critical for early neurocognitive development as well as growth and development throughout *** recognition and treatment of hypothyroidism is,therefore,of utmost importance to optimize physical and neurodevelopmental *** sources A PubMed search was completed in Clinical Queries using the key terms 'hypothyroidism'.Results Hypothyroidism may be present at birth (congenital hypothyroidism) or develop later in life (acquired hypothyroidism).Thyroid dysgenesis and dyshormonogenesis account for approximately 85% and 15% of permanent cases of congenital primary hypothyroidism,*** than 95% of infants with congenital hypothyroidism have few,if any,clinical manifestations of *** screening programs allow early detection of congenital *** developed countries,Hashimoto thyroiditis is the most common cause of goiter and acquired hypothyroidism in children and ***,iodine deficiency associated with goiter is the most common cause of *** hypothyroidism is uncommon and may be associated with other congenital syndromes and deficiencies of other pituitary *** of the clinical features would allow prompt diagnosis and institution of *** To optimize neurocognitive outcome in infants with congenital hypothyroidism,treatment with levothyroxine should be started as soon as possible,preferably within the first 2 weeks of *** with acquired hypothyroidism should also be treated early to ensure normal growth and development as well as cognitive *** target is to keep serum TSH < 5 mIU/L and to maintain serum free T4 or total T4 within the upper half of the age-specific reference range,with elimination of all symptoms and signs of hypothyroidism.

关键词： Dysgenesis Dyshormonogenesis Hashimoto thyroiditis Hypothyroidism Iodine deficiency Levothyroxine Mental retardation Stunted growth

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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%. Additiona

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

The long and the short of it： new insights on sperm length help demystify the complexities of sexual selection

在线全文

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2016年第6期18卷 902-903页

作者： alexander k Hill Dan TA Eisenberg Department of Anthropology University of Washington Seattle WA 98195 USA

Human sperm are approximately 6000th of a centimeter long, a smallfraction of a man＇s total body length. By contrast, fruit fly （Drosophila spp.） sperm can reach nearly 6 cm, roughly twenty times the total length of their bodies. This dramatic variation in male reproductive biology is explored in a recent paper from the journal Nature.

关键词： @@

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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 *** 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

Dextran-modified iron oxide nanoparticles

在线全文

学校读者我要写书评

暂无评论

China Particuology 2007年第1期5卷 162-168页

作者： Jií Hradil alexander Pisarev Michal Babi Daniel Hork Institute of Macromolecular Chemistry Academy of Sciences of the Czech Republic Heyrovsky Sq. 2 162 06 Prague Czech Republic

Dextran-modified iron oxide nanoparticles were prepared by precipitation of Fe（Ⅱ） and Fe（Ⅲ） salts with ammonium hydroxide by two methods. Iron oxide was precipitated either in the presence of dextran solution, or the dextran solution was added after precipitation. In the second method, the iron oxide particle size and size distribution could be controlled depending on the concentration of dextran in the solution. The nanoparticles were characterized by size-exclusion chromatography, transmission electron microscopy and dynamic light scattering. Optimal conditions for preparation of stable iron oxide colloid particles were determined, The dextran/iron oxide ratio 0-0,16 used in precipitation of iron salts can be recommended for synthesis of nanoparticles suitable for biomedical applications, as the colloid does not contain excess dextran and does not coagulate.

关键词： Iron oxide Nanoparticles Dextran Size-exclusion chromatography Particle size

Magnetic Moment Tensor Potentials for collinear spin-polarized materials reproduce different magnetic states of bcc Fe

在线全文

学校读者我要写书评

暂无评论

npj Computational Materials 2022年第1期8卷 107-112页

作者： Ivan Novikov Blazej Grabowski Fritz körmann alexander Shapeev Skolkovo Institute of Science and Technology Skolkovo Innovation CenterNobel St.3Moscow143026Russia Institute for Materials Science University of StuttgartPfaffenwaldring 5570569StuttgartGermany Computational Materials Design Max-Planck-Institut für Eisenforschung GmbHD-40237DüsseldorfGermany Materials Science and Engineering Delft University of Technology2628 CDDelftThe Netherlands

We present the magnetic Moment Tensor Potentials(mMTPs),a class of machine-learning interatomic potentials,accurately reproducing both vibrational and magnetic degrees of freedom as provided,e.g.,from first-principles *** accuracy is achieved by a two-step minimization scheme that coarse-grains the atomic and the spin *** performance of the mMTPs is demonstrated for the prototype magnetic system bcc iron,with applications to phonon calculations for different magnetic states,and molecular-dynamics simulations with fluctuating magnetic moments.

关键词： magnetic fluctuating states

Robust tracking control of a robot manipulator using a passivity-based extended-state observer approach

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

IET Cyber-Systems and Robotics 2019年第2期1卷 63-71页

作者： Mohammed Ali C.k.alexander Department of Electrical Engineering Computer Science Cleveland State UniversityClevelandOhio 44115USA

study presents a combination of the robust passivity-based controller(RPBC)and an extended state observer(ESO)for the tracking control of a three degree-of-freedom PUMA 500 robot manipulator under parameter variations and external *** dynamic model of the PUMA robot and its structural properties are *** extra state in the ESO estimates the parameter variations and external disturbances in the control *** the RPBC cancels them in the control *** stability of the proposed control system and the convergence of the observation errors are *** prove that the proposed controller is robust and tracks well under parameter variations,and external disturbances,validating the proposed control scheme.

关键词： robot state PUMA

Compact stars admitting Finch-Skea symmetry in the presence of various matter fields

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics C 2023年第1期47卷 234-251页

作者： Oleksii Sokoliuk alexander Baransky P.k.Sahoo Main Astronomical Observatory of the NAS of Ukraine(MAO NASU) Kyiv03143Ukraine Astronomical Observatory Taras Shevchenko National University of Kyiv3 Observatorna St.04053 KyivUkraine Department of Mathematics Birla Institute of Technology and Science-PilaniHyderabad CampusHyderabad-500078India

In the present study,we investigate the anisotropic stellar solutions admitting Finch-Skea symmetry(viable and non-singular metric potentials)in the presence of some exotic matter fields,such as Bose-Einstein Condensate(BEC)dark matter,the kalb-Ramond fully anisotropic rank-2 tensor field from the low-energy string theory effective action,and the gauge field imposing U(1)*** spacetime is matched with both Schwarzchild and Reissner-N?rdstrom vacuum spacetimes for BEC,kB,and gauge *** addition,we study the energy conditions,Equation of State(EoS),radial derivatives of energy density and anisotropic pressures,Tolman-OppenheimerVolkoff equilibrium condition,relativistic adiabatic index,sound speed,and surface *** of the aforementioned conditions are ***,the solutions derived in the current study lie in the physically acceptable regime.

关键词： compact stars Finch-Skea symmetry energy conditions Tolman-Oppenheimer-Volkoff equilibrium condition sound speed

The effect of self-focusing on laser space-debris cleaning

在线全文

学校读者我要写书评

暂无评论

Light(Science & Applications) 2014年第1期3卷 250-255页

作者： alexander M Rubenchik Michail P Fedoruk Sergei k Turitsyn Lawrence Livermore National Laboratory LivermoreCA 94550USA Institute of Computational Technologies Siberian Branch of the Russian Academy of SciencesNovosibirsk 630090Russia Novosibirsk State University Novosibirsk 630090Russia Aston Institute of Photonic Technologies School of Engineering and Applied ScienceAston UniversityBirmingham B47ETUK

A ground-based laser system for space-debris cleaning will use powerful laser pulses that can self-focus while propagating through the *** demonstrate that for the relevant laser parameters,this self-focusing can noticeably decrease the laser intensity on the *** show that the detrimental effect can be,to a great extent,compensated for by applying the optimal initial beam *** effect of laser elevation on the system performance is discussed.

关键词： laser self-focusing space debris