Kooperativer Bibliotheksverbund

Berlin Brandenburg

and
and

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
Language
Year
  • 1
    Language: English
    In: Plant and Soil, 2013, Vol.369(1), pp.25-27
    Description: Introduction: In a recent paper, Warren et al. (2013) illustrated the potential of neutron radiography to visualize water dynamics in soil and plants. Methods: After injection of deuterated water (D sub(2)O) in soil, the authors could monitor the changes of D sub(2)O concentration in roots. Results: Based on the radiographs, the authors concluded that D sub(2)O was transported from roots growing in a wet soil region to roots in a dry region, proving hydraulic redistribution between roots. However, this interpretation depends on the correct estimation of D sub(2)O concentration in soil. Conclusions: The experiments of Warren et al. (2013) could also be explained by diffusion of D sub(2)O from soil to roots, without hydraulic redistribution within the root system.
    Keywords: Deuterated water ; Hydraulic redistribution ; Neutron radiography ; Root water uptake
    ISSN: 0032-079X
    E-ISSN: 1573-5036
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Language: English
    In: Qualitative health research, November 2018, Vol.28(13), pp.2094-2101
    Description: Generalizability in qualitative research has been a controversial topic given that interpretivist scholars have resisted the dominant role and mandate of the positivist tradition within social sciences. Aiming to find universal laws, the positivist paradigm has made generalizability a crucial criterion for evaluating the rigor of quantitative research. This positivist echo has led generalizability to acquire a quantitative meaning, inappropriate for describing qualitative studies. The purpose of qualitative research has, thus, been directed toward providing in-depth explanations and meanings rather than generalizing findings. Through a critical review of empirical and theoretical studies, this commentary seeks to show that in qualitative domains, generalizability is possible provided that, first, generalizability is the main objective of the study; second, due precautions concerning the philosophy and terminology selected are taken. Hence, this commentary contributes to the literature on qualitative research by making suggestions for more consistent and unanimous procedures to adopt in qualitative inquiries.
    Keywords: Critical Review ; Positivist and Interpretivist Tradition ; Probabilistic Generalizability ; Qualitative and Quantitative Research ; the UK ; Theoretical Generalizability ; Transferability ; Generalization (Psychology) ; Qualitative Research ; Social Sciences -- Methods
    ISSN: 1049-7323
    E-ISSN: 15527557
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Language: English
    In: Electrochimica Acta, Dec 1, 2013, Vol.112, p.950(7)
    Description: To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.electacta.2013.03.093 Byline: Marco Carminati, Giorgio Ferrari, Davide Bianchi, Marco Sampietro Abstract: The direct tracking of the potential-induced modulation of the double layer capacitance (100mV bias steps resulting in 1.2fF variations) of Pt nanoelectrodes (100nm diameter) in physiological solution with sub-fF resolution and 10ms response time is reported. This result is an example of the enhanced performance achieved thanks to an integrated CMOS current preamplifier used as an add-on for standard bench-top electrochemical instrumentation. The chip provides a current amplification of 10.sup.3 over the wide frequency range DC-2MHz and can be placed at the input of a current-to-voltage converter to reach higher gains. Thanks to its millimetric size it drastically reduces the input stray capacitance of the connection cables to the electrode, offering superior noise performance such as 0.55fA (rms) current resolution with 1Hz bandwidth demonstrated in the detection of 1.5fA current steps. The improvement in performance of state-of-art commercial potentiostats is also reported: the largest measurable impedance is increased by two orders of magnitude (up to 100GI[c] with only 10mV applied and 0.125s averaging time) and the impedance noise in time tracking is reduced 35 times. This module has been developed for nano-electrochemical and bio-sensing applications but can be profitably used in all the situations in which few electrons are exchanged at the interface, either since the electrode area is nanometric or since the concentration of the redox species is extremely low. Author Affiliation: Dipartimento di Elettronica e Informazione, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy Article History: Received 3 January 2013; Revised 14 March 2013; Accepted 14 March 2013
    Keywords: Electrochemistry -- Electric Properties ; Electrochemical Reactions -- Electric Properties ; Complementary Metal Oxide Semiconductors -- Electric Properties
    ISSN: 0013-4686
    Source: Cengage Learning, Inc.
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Language: English
    In: Science (New York, N.Y.), 10 November 2017, Vol.358(6364), pp.765-768
    Description: The microstructure of a medium strongly influences how light propagates through it. The amount of disorder it contains determines whether the medium is transparent or opaque. Theory predicts that exciting such a medium homogeneously and isotropically makes some of its optical properties depend only on the medium's outer geometry. Here, we report an optical experiment demonstrating that the mean path length of light is invariant with respect to the microstructure of the medium it scatters through. Using colloidal solutions with varying concentration and particle size, the invariance of the mean path length is observed over nearly two orders of magnitude in scattering strength. Our results can be extended to a wide range of systems-however ordered, correlated, or disordered-and apply to all wave-scattering problems.
    Keywords: Optical Properties ; Invariance ; Optical Properties ; Scattering ; Light ; Acoustics ; Matter Waves ; Microstructure ; Acoustics ; Acoustics ; Optical Properties;
    ISSN: 00368075
    E-ISSN: 1095-9203
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Language: English
    In: Physical Review B, 4/2011, Vol.83(16)
    Keywords: Physics;
    ISSN: 1098-0121
    E-ISSN: 1550-235X
    Source: American Physical Society (APS) (via CrossRef)
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Language: English
    In: Journal of Applied Physics, June 15, 2010, Vol.107(12), p.124519-1-124519-7
    Description: A theoretical investigation of the physics involved in spectromicroscopy technique, called photothermal induced resonance (PTIR), is described and used to measure the local infrared absorption spectrum of a sample shined with a tunable infrared laser pulse. The analytical method has complemented the results and has validated the PTIR method as a method of choice for infrared spectroscopy of nanoscopic samples, getting around optical artifacts like reflectance perturbation.
    Keywords: Atomic Force Microscopy -- Usage ; Infrared Spectroscopy -- Innovations ; Laser Ablation -- Usage ; Nanotechnology -- Research
    ISSN: 0021-8979
    E-ISSN: 10897550
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Language: English
    In: American Journal of Obstetrics and Gynecology, June 2011, Vol.204(6), pp.565.e1-565.e2
    Description: To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ajog.2011.01.067 Byline: Massimo Origoni, Guia Carminati, Massimo Candiani Author Affiliation: Department of Gynecology and Obstetrics, Vita-Salute San Raffaele University School of Medicine at San Raffaele Scientific Institute, Milan, Italy Article Note: (footnote) Cite this article as: Origoni M, Carminati G, Candiani M. An oral component: vaginal lesions were associated with gingival symptoms. Am J Obstet Gynecol 2011;204:565.e1-2.
    Keywords: Medicine
    ISSN: 0002-9378
    E-ISSN: 1097-6868
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Language: English
    In: The Journal of the Acoustical Society of America, 04/2011, Vol.129(4), pp.2545-2545
    Description: In this work, the radiation of pulsed acoustic waves by an acoustic monopole is theoretically studied based on energy consideration. Specifically, the instantaneous acoustic intensity and the instantaneous acoustic energy contained in a spherically symmetrical pulsed radiated field are calculated. In the case of a subwavelength‐sized acoustic monopole, it is shown that the radiation of a given amount of energy involves energy exchanges between the field and the source that are much larger than the radiated energy. It is also shown that even after the source has been turned off, the instantaneous acoustic intensity may be directed inwards, although the field cannot exchange energy with the source anymore. By time‐reversing the radiated field, we demonstrate that subwavelength refocusing requires a subwavelength energy exchanger, which is not only needed to absorb the incoming energy as well‐known, but importantly also to transiently provide energy to the field before reabsorbing it. In other words, we demonstrate in a homogeneous medium that the acoustic sink needed to perform subwavelength time‐reversal must transiently be an active source of energy.
    Keywords: Program Abstracts Of The 161st Meeting Of The Acoustical Society Of America;
    ISSN: 0001-4966
    Source: CrossRef
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Language: English
    In: Plant and Soil, 2013, Vol.367(1), pp.651-661
    Description: Issue Title: Pedogenesis, nutrient dynamics, and ecosystem development: the legacy of T.W. Walker and J.K. Syers Roots need to be in good contact with the soil to take up water and nutrients. However, when the soil dries and roots shrink, air-filled gaps form at the root-soil interface. Do gaps actually limit the root water uptake, or do they form after water flow in soil is already limiting? Four white lupins were grown in cylinders of 20 cm height and 8 cm diameter. The dynamics of root and soil structure were recorded using X-ray CT at regular intervals during one drying/wetting cycle. Tensiometers were inserted at 5 and 18 cm depth to measure soil matric potential. Transpiration rate was monitored by continuously weighing the columns and gas exchange measurements. Transpiration started to decrease at soil matric potential [psi] between -5 kPa and -10 kPa. Air-filled gaps appeared along tap roots between ψ=-10 kPa and ψ=-20 kPa. As [psi] decreased below -40 kPa, roots further shrank and gaps expanded to 0.1 to 0.35 mm. Gaps around lateral roots were smaller, but a higher resolution is required to estimate their size. Gaps formed after the transpiration rate decreased. We conclude that gaps are not the cause but a consequence of reduced water availability for lupins.[PUBLICATION ]
    Keywords: Root water uptake ; Root-soil contact ; Transpiration rate ; Root shrinkage ; X-ray CT
    ISSN: 0032-079X
    E-ISSN: 1573-5036
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Language: English
    In: Sensors & Actuators: B. Chemical, Nov, 2012, Vol.174, p.168(8)
    Description: To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.snb.2012.08.021 Byline: M. Carminati (a), M. Vergani (a), G. Ferrari (a), L. Caranzi (b), M. Caironi (b), M. Sampietro (a)(b) Keywords: Silicon biosensors; Quartz substrate; Lab-on-chip; Impedimetric biosensor; Disposable CMOS cartridge; Conductive substrate Abstract: Arrays of microelectrodes for electrochemical biosensing are commonly fabricated on standard silicon wafers. This choice positively profits from the optimized microelectronic technology, offering micrometric spatial resolution and the possibility to integrate electronic processing capabilities directly on the sensing chips. This paper analyzes the drawbacks on the accuracy and resolution in impedance detection arising when using such highly conductive substrates. To this aim, a direct experimental comparison is reported for identical 10[mu]m disk electrodes fabricated on quartz (i.e. insulating) and on the silicon dioxide grown on a silicon wafer. The paper shows how the high conductivity of the substrate in contact with the solution promotes additional stray capacitances (in our experiment 280 times larger than the expected interfacial capacitance) that (i) heavily modify the measured impedance spectrum, thus affecting the biosensor accuracy, and (ii) increase the total current noise of the detector, thus affecting the resolution in the biosensor readout. Although the spectral distortion can be minimized through proper grounding of the substrate, the presence of the stray capacitance still degrades the resolution. We also show that even in the case of a microfluidic encapsulation system coupled to the chip, stray couplings through the substrate still affect the detection. However, as silicon appears irreplaceable for smart analytical micro-systems, the paper discusses the key aspects for an optimal design of the chips in terms of metal trace area, pad size, thickness of the insulating layers and bulk resistivity. Author Affiliation: (a) Dipartimento di Elettronica e Informazione, Politecnico di Milano, P.za L. da Vinci 32, 20133 Milano, Italy (b) Center for Nanoscience and Technology @PoliMi, Istituto Italiano di Tecnologia, Via Pascoli, 70/3, 20133 Milano, Italy Article History: Received 5 June 2012; Revised 1 August 2012; Accepted 7 August 2012
    Keywords: Silicon -- Chemical Properties ; Silicon -- Analysis ; Complementary Metal Oxide Semiconductors -- Chemical Properties ; Complementary Metal Oxide Semiconductors -- Analysis ; Silicon Compounds -- Chemical Properties ; Silicon Compounds -- Analysis ; Biosensors -- Chemical Properties ; Biosensors -- Analysis ; Microfluidics -- Chemical Properties ; Microfluidics -- Analysis ; Medical Equipment -- Chemical Properties ; Medical Equipment -- Analysis
    ISSN: 0925-4005
    Source: Cengage Learning, Inc.
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. Further information can be found on the KOBV privacy pages