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We report the analysis of radio soundings launched at our permanent measurement site in North-western Germany. The data of potential temperature and wind speed are used to derive vertical profiles of the gradient Richardson number 𝑅𝑖𝑔 in the free troposphere, and subsequently, the strength of optical turbulence 𝐶𝑛 2. These values are compared to a numerical framework, which derives 𝐶𝑛 2 from mesoscale weather prediction data by two schemes based on the gradient Richardson number and Monin-Obukhov similarity theory, respectively.

Our aim is to characterize the optical turbulence over the urban areas. Since it is difficult to measure 𝐶2/𝑛 (see PDF) continuously over an urban area, we explore the possibility of using a mesoscale weather prediction model to predict 𝐶2/𝑛 (see PDF) over the urban area. To this end, the output of the Weather Research and Forecast model (WRF) was coupled with a micrometeorological parametrization, which allowed calculation of 𝐶2/𝑛 (see PDF) at each numerical grid point in the surface layer. Numerical results are compared to data of path-averaged measurements of optical turbulence performed with a large aperture scintillometer (BLS900) over the city of Ettlingen (southwestern Germany) during two time periods in Spring and Summer 2013. Effects of the heat island effect are revealed by high turbulence values, observed at night-time.

Atmospheric turbulence impacts on the propagation of electro-optical radiation. Typical manifestations of optical turbulence are scintillation (intensity fluctuations), beam wander and (for laser systems) reduction of beam quality. For longer propagation channels, it is important to characterize the vertical and horizontal distribution (inhomogeneity) of the optical turbulence. In the framework of the First European South African Transmission ExpeRiment (FESTER) optical turbulence was measured between June 2015 and February 2016 on a 2 km over-water link over False Bay. The link ran from the Institute of Maritime Technology (IMT) in Simons Town to the lighthouse at Roman Rock Island. Three Boundary layer scintillometers (BLS900) allowed assessing the vertical distribution of optical turbulence at three different heights between 5 and 12 m above the water surface. The expected decrease of Cn 2 with height is not always found. These results are analyzed in terms of the meteorological scenarios, and a comparison is made with a fourth optical link providing optical turbulence data over a 8.7 km path from IMT to Kalk Bay, roughly 36° to the north of the three 2 km paths. The results are related to the inhomogeneous meteorological conditions over the Bay as assessed with the numerical weather prediction tool, the Weather Forecast and Research model WRF. © Copyright 2017 SPIE. The Society of Photo-Optical Instrumentation Engineers (SPIE)

A field trial was performed in the arid scrub area of White Sands, NM /USA in October 2017 investigating the atmospheric influence on imaging and sensor performance. In this paper we focus on the strength of optical turbulence. Optical turbulence is described by the structure function parameter of the refractive index Cn 2. It is responsible for beam wander, blurring. and scintillation. "Ground truth" measurements of optical turbulence were carried out using a Boundary Layer Scintillometer . The measurements were taken along an optical path of 3.64 km and a height of 1.5 m. Additionally, height dependency of Cn 2 is explored in the surface layer using 4 ultrasonic anemometers at discrete heights between 1 and 10 m. Power spectra of temperature were determined from time series of the ultrasonic anemometer data, which were inspected for the height dependency of spectral characteristics. The effect of the arid scrubs area on the applicability of Kolmogorov turbulence was investigated and discussed in this paper. © 2018 SPIE.

This paper reviews three phenomena that affect the propagation of electro-optical radiation through the atmosphere: absorption and scattering, refraction and turbulence. The net effect on imaging or laser systems is a net reduction of the effective range, or a degradation of the information contained in the electro-optical radiation. Recent advances in techniques to assess the concentration and composition of atmospheric aerosols, and to assess the strength of optical turbulence are discussed in more detail. © 2017 SPIE. The Society of Photo-Optical Instrumentation Engineers (SPIE)

Electro-optical and laser systems are presently deployed in naval operations around the world. The performance of these systems is negatively affected by optical turbulence in the atmosphere, quantified by the parameter Cn 2. The strength of the integrated optical turbulence Cn 2 was investigated for several coastal locations in different climatic conditions: False Bay (South Africa), the Baltic Sea (Bay of Eckernförde, Germany), the Mediterranean Sea (Crete, Greece), the Gulf of Mexico (Dauphin Island, Alabama, US), and the Arabian Gulf. The over-water, near-surface turbulence was characterized along paths that typically spanned 1.5 - 8.7 km using large aperture scintillometers. The dependency of Cn 2 on the air-sea surface temperature difference and wind speed is discussed, and the results for the five geographic regions are compared and discussed in terms of environmental conditions and climate. © Copyright 2017 SPIE. The Society of Photo-Optical Instrumentation Engineers (SPIE)

A transmission experiment has been performed over an optical path of 1.53 km at a rural test site in Meppen, Northwest Germany. Direct transmission measurements were made by a 7-wavelength transmissometer. Transmission was further estimated from the average voltage received by a BLS2000 scintillometer, and evaluated with Mie theory from in-situ aerosol measurements near the optical path. Furthermore, the transmission was modeled with MODTRAN, driven with local meteorology, visibility and the rural aerosol model. For a central wavelength of 0.88μm, the transmissometer, the BLS200 and MODTRAN agree well. Remaining differences may be due to water transmission and continuum around 0.95μ;m that is picked up by the transmissometer and not by the narrow-banded BLS2000 and MODTRAN calculations. When MODTRAN is run without an aerosol model, or when this model is driven by a "default" visibility, the overlap with the measurements is extremely poor. © 2016 SPIE. The Society of Photo-Optical Instrumentation Engineers (SPIE)

The First European South African Experiment (FESTER) was conducted over about a 10 month period at the Institute of Maritime Technology (IMT) in False Bay, South Africa. One of the important goals was to validate atmospheric refraction and turbulence models. To achieve this goal it was required to measure the vertical profile of meteorological parameters and compare this to model predictions. A special helium kite balloon (Helikite) was used as lifting device for weather and temperature sensors to obtain a measured vertical air profile. This measurement was conducted in the middle of the atmospheric path for the principal electro-optic transmission link monitoring equipment (i.e. scintillometer and multi-spectral radiometer-transmissometer system). First results will focus on the vertical air temperature profile shape as function of general environmental conditions and the comparison to model predictions. © 2016 SPIE. The Society of Photo-Optical Instrumentation Engineers (SPIE)

Optical turbulence for over-water conditions was investigated in a long-term experiment over False Bay near Cape Town, South Africa. A sonic anemometer and two boundary-layer scintillometers were deployed to access in-situ turbulence as well as the integrated turbulence over two 1.8 and 8.7 km paths. Statistical analysis reveals spatial temporal variations of the turbulence conditions over False Bay, which might be related to differences in the atmospheric conditions and/or the surface (water) temperatures. An analysis in terms of mechanical and thermal forcing reveals that the latter factor is more dominant in determining the turbulence strength. © 2016 SPIE. The Society of Photo-Optical Instrumentation Engineers (SPIE)

We fabricated arrays of cantilever sensors suspended deep inside fluid wells. To eliminate critical alignment and assembling steps during encapsulation of the cantilevers, these 3-D MEMS devices are realized in a single-side, single-wafer process by employing photolithography on bulk micromachined substrates. Silicon nitride cantilevers with varying geometries are suspended up to [email protected] below the wafer surface, and a structured gold layer is patterned on top. After calibrating the cantilevers in an optical lever setup, the formation of a DNA monolayer on the cantilever surface is detected.

Summary Objective Delirium is a frequent and serious problem in the Intensive Care Unit (ICU). Several international guidelines recommend daily monitoring for ICU-delirium. The purpose of this article is to give an up-to-date overview of the current status of monitoring and treatment of ICU-delirium in the Netherlands. Design Nation-wide, telephone-based questionnaire survey. Participants Head nurse of all ICUs and a random sample of intensivists. Results Only 14% (n = 14) of all Dutch ICUs (n = 103) monitored for ICU-delirium. Of these, only half (7%) used a tool that is validated in ICU patients. In 31% of Dutch ICUs, a protocol was used to treat ICU-delirium. Responses were obtained from 100% of ICUs. Conclusion Despite an international guideline, not more than 7% of ICUs in our study routinely evaluated the presence of delirium with a validated instrument. Fewer than one-third of Dutch ICUs use a protocol to treat ICU-delirium.

The First European South African Experiment (FESTER) was conducted over about a 10 month period at the Institute of Maritime Technology (IMT) in False Bay, South Africa. One of the important goals was the establishment of the air-sea temperature difference (ASTD) homogeneity along the main propagation link atmospheric path since it is a basic assumption for most of the atmospheric turbulence models (caused by refractive index variations). The ASTD was measured from a small scientific work boat (called Sea Lab) moving along a straight in- and outbound track along the main propagation link path. The air temperature on-board was measured using standard weather sensors, while the sea surface temperature was measured using a long wavelength infrared radiometer, which was compared to the bulk sea temperature half a meter below the sea surface. This was obtained by an under water temperature sensor mounted on a â€surfboard' that was towed alongside Sea Lab. Vertical water temperature profiles were also measured along the main propagation path in order to determine the depth of the surface mixed layer and thermocline using a Conductivity Temperature Depth profiler (CTD). First results investigated the ASTD variation along the horizontal line-of-sight path used by the principal electro-optic transmission link monitoring equipment (i.e. scintillometer and multi-spectral radiometer-transmissometer system). © 2016 SPIE. The Society of Photo-Optical Instrumentation Engineers (SPIE)

A long term field trial called FESTER (First European South African Transmission Experiment) has been conducted by an international collaboration of research organizations during the course of almost one year at False Bay, South Africa. Main objectives of the experiment are a better insight into atmospherical effects on propagation of optical radiation, a deeper understanding of the effects of (marine) aerosols on transmission, and the connection of the mentioned effects to the general meteorological and oceanographic conditions/parameters. Modelling of wakes and possible infrared-radar synergy effects are further points of interest. The duration of one year ensures the coverage of most of the relevant meteorological conditions during the different seasons. While some measurements have been performed by permanent installations, others have been performed during intensive observation periods (IOP). These IOPs took place every two to three months to ensure seasonal changes. The IOPs lasted two weeks. We will give an overview of the general layout of the experiment and report on first results. An outlook on the planned analysis of the acquired data, which includes linkage to the Weather Research and Forecasting model (WRF), will be given. © 2016 SPIE. The Society of Photo-Optical Instrumentation Engineers (SPIE)

The experiment FESTER (First European South African Transmission ExpeRiment) took place in 2015 to investigate the atmospheric influence on electro-optical systems performance across False Bay / South Africa on a long term basis. Several permanent stations for monitoring electro-optical propagation and atmospheric parameters were set up around the Bay. Additional intensive observation periods (IOPs) allowed for boat runs to assess the inhomogeneous atmospheric propagation conditions over water. In this paper we focus on the distribution of optical turbulence over the Bay. The different impact of water masses originating from the Indian Ocean and the Benguela current on the development of optical turbulence is discussed. The seasonal behavior of optical turbulence is presented and its effect on electro-optical system performance examined. © 2016 SPIE. The Society of Photo-Optical Instrumentation Engineers (SPIE)

A method is described to integrate particle filters inside a silicon wafer by creating pores in a recessed membrane. The filters are created in either a silicon or a silicon nitride membrane located 100@mm below the wafer surface. The fabrication process involves anisotropic etching of front- and back-side of a (100) silicon wafer, deposition of a silicon nitride layer, spraycoating of photoresist and reactive ion etching of the pores. The filters may serve as a well or reaction chamber at the same time. We have patterned pore diameters in the 10-50@mm range in 100@mm recessed membranes that are suitable for application in stacked systems such as in an integrated inkjet nozzle.

Mastering high‐density optical disks, like the Blu‐ray™ disk, requires new equipment design. Active magnetic bearing technology seem well suitable for this purpose, but challenges arise in obtaining the required extreme accuracy. Creating a very low mechanical coupling between the system and the external world is the potential solution to this challenge pursued in this paper. Design considerations on actuators, amplifiers, sensors and overall design are discussed and the system performance is predicted using an error‐budgeting estimation. This prediction indicates the feasibility of the concept, while the first prototype has been assembled and is being tested.

Delirium is a common disorder in intensive care unit (ICU) patients. It is unclear whether ICU environment affects delirium. We investigated the influence of ICU environment on the number of days with delirium during ICU admission. In this prospective before–after study, ICU delirium was compared between a conventional ICU with wards and a single-room ICU with, among others, improved daylight exposure. We included patients admitted for more than 24 h between March and June 2009 (ICU with wards) or between June and September 2010 (single-room ICU). Patients who remained unresponsive throughout ICU admission were excluded. The presence of delirium in the preceding 24 h was assessed daily with the confusion assessment method for the ICU (CAM-ICU) by research physicians combined with evaluation of medical and nursing charts. The number of days with delirium was investigated with Poisson regression analysis. We included 55 patients (449 observation days) in the ICU with wards and 75 patients (468 observation days) in the single-room ICU. After adjusting for confounding, the number of days with delirium decreased by 0.4 days (95 % confidence interval 0.1–0.7) in the single-room ICU (p = 0.005). The incidence of delirium during ICU stay was similar in the ICU with wards (51 %) and in the single-room ICU (45 %, p = 0.53). This study is the first to show that ICU environment may influence the course of delirium in ICU patients.

Item does not contain fulltext RATIONALE: Delirium is often unrecognized in ICU patients and associated with poor outcome. Screening for ICU delirium is recommended by several medical organizations to improve early diagnosis and treatment. The Confusion Assessment Method for the ICU (CAM-ICU) has high sensitivity and specificity for delirium when administered by research nurses. However, test characteristics of the CAM-ICU as performed in routine practice are unclear. OBJECTIVES: To investigate the diagnostic value of the CAM-ICU in daily practice. METHODS: Teams of three delirium experts including psychiatrists, geriatricians, and neurologists visited 10 ICUs twice. Based on cognitive examination, inspection of medical files, and Diagnostic and Statistic Manual of Mental Disorders, 4th edition, Text Revision criteria for delirium, the expert teams classified patients as awake and not delirious, delirious, or comatose. This served as a gold standard to which the CAM-ICU as performed by the bedside ICU-nurses was compared. Assessors were unaware of each other's conclusions. MEASUREMENTS AND MAIN RESULTS: Fifteen delirium experts assessed 282 patients of whom 101 (36%) were comatose and excluded. In the remaining 181 (64%) patients, the CAM-ICU had a sensitivity of 47% (95% confidence interval [CI], 35%-58%); specificity of 98% (95% CI, 93%-100%); positive predictive value of 95% (95% CI, 80%-99%); and negative predictive value of 72% (95% CI, 64%-79%). The positive likelihood ratio was 24.7 (95% CI, 6.1-100) and the negative likelihood ratio was 0.5 (95% CI, 0.4-0.8). CONCLUSIONS: Specificity of the CAM-ICU as performed in routine practice seems to be high but sensitivity is low. This hampers early detection of delirium by the CAM-ICU.

The FATMOSE trial (FAlse-bay ATMOSpheric Experiment) running over a period from November 2009 to July 2010,was a continuation of the cooperation between TNO and IMT on atmospheric propagation and point target detection and identification in a maritime environment. Instruments were installed for measuring scintillation, blurring- and refraction effects over a 15.7 km path over sea. Simultaneously, a set of instruments was installed on a mid-path lighthouse for collecting local meteorological data, including scintillation, sea surface temperature and visibility. The measurements covered summer and winter conditions with a prevailing high wind speed from the South East, bringing in maritime air masses. The weather conditions included variations in the Air-Sea Temperature Difference (ASTD), that may affect the vertical temperature gradient in the atmospheric boundary layer, causing refraction effects in the lightpath. This was measured with a theodolite camera, providing absolute Angles of Arrival (AOA). Blur data were collected with a high resolution camera system with 10 bits dynamic range. Specially designed image analysis software allows determination of the atmospheric blur, while simultaneously providing information on the Scintillation Index (S.I.). This S.I. was also measured by using the Multiband Spectral Radiometer Transmissometer (MSRT). The ratio of the transmission levels of this instrument contains information on the size distribution of the aerosols along the path. In the paper, experimental details on the set-up and the instrumentation are given as well as the methods of analysis. Preliminary results are shown, including a comparison of measured blur and scintillation data with Cn 2 data from the scintillometer, correlation between AOA and ASTD and comparison of transmission data with data from the visibility meter. Blur and scintillation data are compared with predictions from standard turbulence model predictions, using Cn 2. In future studies the data will be used for validation of propagation models such as EOSTAR.

The FATMOSE trial (FAlse-bay ATMOSpheric Experiment) running over a period from November 2009 to July 2010, was a continuation of the cooperation between TNO and IMT on atmospheric propagation and point target detection and identification in a maritime environment. Instruments were installed for measuring scintillation, blurring- and refraction effects over a 15.7 km path over sea. Simultaneously, a set of instruments was installed on a mid-path lighthouse for collecting local meteorological data, including scintillation, sea surface temperature and visibility. The measurements covered summer and winter conditions with a prevailing high wind speed from the South East, bringing in maritime air masses. The weather conditions included variations in the Air-Sea Temperature Difference (ASTD), that may affect the vertical temperature gradient in the atmospheric boundary layer, causing refraction effects in the lightpath. This was measured with a theodolite camera, providing absolute Angles of Arrival (AOA). Blur data were collected with a high resolution camera system with 10 bits dynamic range. Specially designed image analysis software allows determination of the atmospheric blur, while simultaneously providing information on the Scintillation Index (S.I.). This S.I. was also measured by using the Multiband Spectral Radiometer Transmissometer (MSRT). The ratio of the transmission levels of this instrument contains information on the size distribution of the aerosols along the path. In the paper, experimental details on the set-up and the instrumentation are given as well as the methods of analysis. Preliminary results are shown, including a comparison of measured blur and scintillation data with Cn2 data from the scintillometer, correlation between AOA and ASTD and comparison of transmission data with data from the visibility meter. Blur and scintillation data are compared with predictions from standard turbulence model predictions, using Cn2. In future studies the data will be used for validation of propagation models such as EOSTAR.

High control performance is essential in many precision positioning applications, such as control of the vertical sample position in a atomic-force microscope (AFM). This paper investigates the impact of load flexibility on piezoelectrically actuated positioning systems in terms of control performance. The modeling method used combines modal analysis with simple transfer function manipulations, and shows, how the load dynamics may influence the control performance. The analysis is experimentally verified on a commercial AFM system.

Delirium is a frequent problem in the intensive care unit (ICU) associated with poor prognosis. Delirium in the ICU is underdiagnosed by nursing and medical staff. Several detection methods have been developed for use in ICU patients. The aim of this study was to compare the value of three detection methods (the Confusion Assessment Method for the ICU [CAM-ICU], the Intensive Care Delirium Screening Checklist [ICDSC] and the impression of the ICU physician with the diagnosis of a psychiatrist, neurologist, or geriatrician).Prospective study.During an 8-month period, 126 patients (mean age 62.4 years, sd 15.0; mean Acute Physiology and Chronic Health Evaluation II score 20.9, sd 7.5) admitted to a 32-bed mixed medical and surgical ICU were studied.The included patients were assessed independently by trained ICU nurses using either the CAM-ICU or the ICDSC. Furthermore, the ICU physician was asked whether a patient was delirious or not. A psychiatrist, geriatrician, or neurologist serving as reference rater diagnosed delirium using established criteria.The CAM-ICU showed superior sensitivity and negative predictive value (64% and 83%) compared with the ICDSC (43% and 75%). The ICDSC showed higher specificity and positive predictive value (95% and 82% vs. 88% and 72%). The sensitivity of the physicians view was only 29%.ICU physicians underdiagnose delirium in the ICU, which underlines the necessity of standard evaluation in all critically ill patients. In our mixed ICU population, the CAM-ICU had a higher sensitivity than the ICDSC.

In this paper, the design and realization of a magnetically levitated high speed spindle for micro machining is presented. This spindle is built to investigate various micro machining processes. The main application is milling with extremely small diameter tools. The micro milling tools have a diameter in the range of 0.1 mm. To improve the milling accuracy extremely high rotational speeds are required. The spindle presented in this research is built to reach speeds over 200,000 rpm. The spindle is equipped with two radial bearings, one axial bearing and a permanent magnet synchronous motor. The radial bearings consist of permanent magnet biased homopolar active magnetic bearings. The axial bearing consists of reluctance type actuators in a differential driving mode. The motor is a commercially available permanent magnet motor, able to reach speeds over 250,000 rpm. This spindle is part of a micro factory, which is built in this research program. The first test results are presented.

Delirium is common after cardiac surgery and may be partly related to the systemic inflammatory response triggered by the surgery and the use of cardiopulmonary bypass. We hypothesized that intraoperative administration of high-dose dexamethasone, a drug with potent anti-inflammatory effects, would reduce the incidence of delirium at any time point during the first 4 postoperative days after cardiac surgery.This was a single-center substudy within a larger, multicenter placebo-controlled randomized clinical trial, the Dexamethasone for Cardiac Surgery (DECS) trial that randomized patients ≥18 years, undergoing cardiac surgery with cardiopulmonary bypass, to receive, in a double-blind fashion, either dexamethasone 1 mg/kg or placebo at the induction of anesthesia. Over the first 4 postoperative days, we compared between groups the incidence of delirium (based on the Confusion Assessment Method adapted for the intensive care unit, or after intensive care unit discharge, by the Confusion Assessment Method, accompanied by chart review), restraint use, and administered haloperidol, benzodiazepines, and opioids. Data were analyzed according to the intention-to-treat principle. The proportion of patients with delirium in the dexamethasone versus the placebo group was compared using the odds ratio (OR) with a 95% confidence interval (CI). The proportion also was compared using logistic regression to adjust for common baseline variables that might confound the presence of delirium between the 2 groups.Of 768 eligible patients, 737 subjects (96.0%) had complete data. The incidence of delirium was similar between the dexamethasone (14.2%) and placebo (14.9%) groups (crude OR = 0.95, 95% CI, 0.63-1.43; adjusted OR = 0.85, 95% CI, 0.55-1.31). Among patients who developed delirium, the median (interquartile range) duration of delirium was similar between the dexamethasone and placebo groups (2 [1-3] vs 2 [1-2] days, respectively, P = 0.45; WMWodds 0.98, 95% CI, 0.83-1.17). Restraint use and the administration of haloperidol, benzodiazepines, and opioids were also similar between the 2 groups.The intraoperative administration of dexamethasone did not reduce the incidence or duration of delirium in the first 4 days after cardiac surgery.

The design and development of advanced and intelligent systems requires contributions from different technical disciplines. When the required cooperation is successfully achieved a whole range of competitive business options is created. Unfortunately such cooperation is not easily obtained. During the past 15 years the Philips Centre for Industrial Technology developed a strong mechatronics community. For this development the law of cooperation proved to be very suitable to guide the process. The basic aspects of this "law" are presented in combination with some of the technical results obtained during our development.

Photolithography on high topography substrates, such as the sidewalls or the bottom of cavities and trenches created by bulk micromachining, enables the design of complex three-dimensional structures. When a contact lithography system is used to pattern such substrates, local gaps exist between the mask and the substrate. In this paper we investigate the deformation of patterns as a result of these local gaps. We determine the position accuracy and the minimum size of features that can be patterned as a function of the gap distance. Deformations introduced by the optical system are quantified for a common exposure tool, and compared to pattern deformation due to variations in photoresist layer thickness. Finally, methods to improve the quality of patterns transferred through gaps up to 350 ?m are discussed