- document
-
Berkel, S. L. van (author), Maestrini, A. (author), Jung-Kubiak, C. (author), Bosma, S. (author), Alonso Del Pino, M. (author), Hayton, D. (author), Kooi, Jacob (author), Siles, J. V. (author), Llombart, Nuria (author), Mehdi, I. (author), Chattopadhyay, G. (author)Terahertz heterodyne spectrometer instruments have been traditionally limited to a single pixel or a handful of pixels due to integration and assembly constraints and a limited availability of local oscillator (LO) power. As a solution we propose a novel silicon-micromachined planar and modular packaging strategy, that will allow for a dense...conference paper 2023
- document
-
Zhang, Zheng (author), Santangelo, Diana L. (author), ten Brink, Gert (author), Kooi, Bart J. (author), Moulijn, J.A. (author), Melián-Cabrera, Ignacio (author)The authors regret that the original graphical abstract contained an error by accident. In particular, the values of the OH density for the calcined SBA-15 and solvent-&-Fenton-treated SBA-15 were swapped. These values contradict the main message of the study. The values contained in the paper are however correct. In summary, the paper's...journal article 2022
- document
-
Microstructure, precipitate and property evolution in cold-rolled Ti-V high strength low alloy steelZhang, Xukai (author), Ioannidou, C. (author), ten Brink, Gert H. (author), Navarro Lopez, A. (author), Wormann, Jan (author), Campaniello, Jean (author), Dalgliesh, Robert M. (author), van Well, A.A. (author), Offerman, S.E. (author), Kranendonk, Winfried (author), Kooi, Bart J. (author)A cold-rolled Ti-V high strength low alloy (HSLA) steel was isothermally annealed at 650 °C and 700 °C for different times. A unique combination of techniques including visible light microscopy (VLM), transmission electron microscopy (TEM), matrix dissolution, small angle neutron scattering (SANS) and hardness measurement has been employed to...journal article 2020
- document
-
Visser, P.W. (author), Kooi, Henk (author), Bense, Victor (author), Boerma, Emiel (author)Subsurface temperatures are substantially higher in urban areas than in surrounding rural environments; the result is a subsurface urban heat island (SUHI). SUHIs and their drivers have received attention in studies world-wide. In this study, a well-constrained data set of subsurface temperatures from Amsterdam, The Netherlands, is presented....journal article 2020
- document
-
Baldi, Andrea (author), Mooij, L.P.A. (author), Palmisano, V (author), Schreuders, H. (author), Krishnan, Gopi (author), Kooi, Bart J. (author), Dam, B. (author), Griessen, Ronald (author)Magnesium thin films covered with a layer of Pd absorb hydrogen at much higher pressures than bulk Mg. Such an effect was originally explained as a consequence of elastic clamping on Mg by the capping Pd layer. An alternative interpretation later suggested that the pressure increase could originate from simple alloying between Mg and Pd. Here...journal article 2018
- document
-
Kumar, Anil (author), Vermeulen, P. (author), Kooi, Bart J. (author), Rao, Jiancun (author), van Eijck, L. (author), Schwarzmüller, Stefan (author), Oeckler, Oliver (author), Blake, Graeme R. (author)The alloys (GeTe)<sub>x</sub>(AgSbTe<sub>2</sub>)<sub>100-x</sub>, commonly known as TAGS-x, are among the best performing p-type thermoelectric materials for the composition range 80 ≤ x ≤ 90 and in the temperature range 200-500 °C. They adopt a rhombohedrally distorted rocksalt structure at room temperature and are reported to undergo a...journal article 2017
- document
-
Hayton, D.J. (author), Gao, J.R. (author), Kooi, J.W. (author), Ren, Y. (author), Zhang, W. (author), De Lange, G. (author)We report on a method to stabilize a hot electron bolometer (HEB) mixer at 2.5 THz. The technique utilizes feedback control of the local oscillator (LO) laser power by means of a swing-arm actuator placed in the optical beam path. We demonstrate that this technique yields a factor of 50 improvement in the spectroscopic Allan variance time which...journal article 2012
- document
-
Baldi, A. (author), Pálsson, G.K. (author), Gonzalez-Silveira, M. (author), Schreuders, H. (author), Slaman, M. (author), Rector, J.H. (author), Krishnan, G. (author), Kooi, B.J. (author), Walker, G.S. (author), Fay, M.W. (author), Hjörvarsson, B. (author), Wijngaarden, R.J. (author), Dam, B. (author), Griessen, R. (author)Mg-Ti alloys have uncommon optical and hydrogen absorbing properties, originating from a “spinodal-like” microstructure with a small degree of chemical short-range order in the atomic distribution. In the present study we artificially engineer short-range order by depositing Pd-capped Mg/Ti multilayers with different periodicities....journal article 2010
- document
-
Krishnan, G. (author), Kooi, B.J. (author), Palasantzas, G. (author), Pivak, Y. (author), Dam, B. (author)In this work we present a unique transmission electron microscopy study of the thermal stability of gas phase synthesized Mg nanoparticles, which have attracted strong interest as high capacity hydrogen storage materials. Indeed, Mg nanoparticles with a MgO shell ( ? 3?nm thick) annealed at 300?°C show evaporation, void formation, and void...journal article 2010
- document
- Mena, F.P. (author), Kooi, J.W. (author), Baryshev, A.M. (author), Lodewijk, C.F.J. (author), Hesper, R. (author), Wild, W. (author), Klapwijk, T.M. (author) journal article 2008
- document
-
Eijt, S.W.H. (author), De Roode, J. (author), Schut, H. (author), Kooi, B.J. (author), De Hosson, J.T.M. (author)Coimplantation of Zn and O ions into a single crystalline MgO and subsequent thermal annealing were applied in the synthesis of ZnO nanocrystals. Electron microscopy showed that rocksalt instead of wurtzite ZnO stabilizes for relatively large nanocrystals up to ~15?nm, resulting from its small lattice mismatch with MgO of ~1.7%. The vacancies...journal article 2007
- document
-
Kooi, J.W. (author), Baselmans, J.J.A. (author), Hajenius, M. (author), Gao, J.R. (author), Klapwijk, T.M. (author), Dieleman, P. (author), Baryshev, A. (author), De Lange, G. (author)The intermediate frequency (IF) characteristics, the frequency dependent IF impedance, and the mixer conversion gain of a small area hot electron bolometer (HEB) have been measured and modeled. The device used is a twin slot antenna coupled NbN HEB mixer with a bridge area of 1×0.15??m2, and a critical temperature of 8.3?K. In the experiment the...journal article 2007
- document
-
Hajenius, M. (author), Baselmans, J.J.A. (author), Baryshev, A. (author), Gao, J.R. (author), Klapwijk, T.M. (author), Kooi, J.W. (author), Jellema, W. (author), Yang, Z.Q. (author)We present a complete experimental characterization of a quasioptical twin-slot antenna coupled small area (1.0×0.15??m2) NbN hot electron bolometer (HEB) mixer compatible with currently available solid state tunable local oscillator (LO) sources. The required LO power absorbed in the HEB is analyzed in detail and equals only 25?nW. Due to the...journal article 2006
- document
-
Kooi, J.W. (author), Baselmans, J.J.A. (author), Baryshev, A. (author), Schieder, R. (author), Hajenius, M. (author), Gao, J.R. (author), Klapwijk, T.M. (author), Voronov, B. (author), Gol'tsman, G. (author)In this paper we discuss the stability of heterodyne terahertz receivers based on small volume NbN phonon cooled hot electron bolometers (HEBs). The stability of these receivers can be broken down in two parts: the intrinsic stability of the HEB mixer and the stability of the local oscillator (LO) signal injection scheme. Measurements show that...journal article 2006
- document
- van Huis, M.A. (author), van Veen, A. (author), Schut, H. (author), Kooi, B.J. (author), De Hosson, J.Th.M. (author) journal article 2003
- document
- Kooi, B.J. (author) doctoral thesis 1995
- document
-
Kooi, J.W. (author), Sarin, S.L. (author)An experimental study was conducted to determine the effect of flow on the acoustic impedance of locally reacting perforate plate liners. Different boundary layer velocity distributions were obtained by air injection upstream of the liner. The impedance was measured in-situ with the two-microphone technique in the NLR flow duct facility. It was...report 1981
- document
-
Kooi, J.W. (author)An experiment is described in which a nominal normal shock impinges on a turbulent flat plate boundary layer. The wall pressure distribution in the interaction region was measured for Mach numbers in front of the shock of 1.40, 1.44 and 1.46. The Reynolds number based on shock position was 18 X 10(6) and based on momentum thickness at the start...report 1978
- document
- Kooi, J.W. (author) report 1975