The Effect of Brackish Water Extraction on the Brackish Upconing Below the Horstermeer Polder: Creating a 3D Regional Variable-Density Groundwater Model using MODFLOW 6 and FloPy

Extensive usage of vital freshwater is highly undesirable in the current era of climate change and population growth. However, the 6 millionm3/y of brackish seepage that occurs in the deep Horstermeer Polder, located in between the cities of Amsterdam and Hilversumin the Netherlands, is mitigated by using up to 207 millionm3/y of freshwater....

Control of interpenetration of copper-based MOFs on supported surfaces by electrochemical synthesis

A study of a copper-based metal–organic framework (MOF) synthesized by an electrochemical route is presented. Morphological and adsorption properties of the MOF synthesized as bulk powder and on supported copper surfaces were investigated. Differences in these properties and structural refinement studies indicate that when 4,4?,4??-s-triazine-2...

Preliminary trajectory design for a solar polar observatory using SEP and multiple gravity assists

Satellite solar observatories have always been of central importance to heliophysics; while there have been numerous such missions, the solar poles have been extremely under-observed. This paper proposes to use low-thrust as well as multiple gravity assists to reach the enormous energies required obtain high heliocentric inclinations. Two novel...

Preliminary design of a crewed Mars flyby Solar Electric Propulsion mission

The goal of this thesis research has been the improvement of a validated, robust low-thrust optimization tool for interplanetary trajectory design, written during the author's internship. This improved tool has then been applied to design crewed Martian flyby missions. Such a mission is a crucial step within the flexible path scenario for human...

Controlled amino-functionalization by electrochemical reduction of bromo and nitro azobenzene layers bound to Si(111) surfaces

4-Nitrobenzenediazonium (4-NBD) and 4-bromobenzenediazonium (4-BBD) salts were grafted electrochemically onto H-terminated, p-doped silicon (Si) surfaces. Atomic force microscopy (AFM) and ellipsometry experiments clearly showed layer thicknesses of 2–7 nm, which indicate multilayer formation. Decreasing the diazonium salt concentration and the...

Protein detection on biotin-derivatized polyallylamine by optical microring resonators

Silicon optical microring resonators (MRRs) are sensitive devices that can be used for biosensing. We present a novel biosensing platform based on the application of polyelectrolyte (PE) layers on such MRRs. The top PE layer was covalently labeled with biotin to ensure binding sites for antibodies via a streptavidin-biotin binding scheme....

Influence of Conductivity and Dielectric Constant of Water–Dioxane Mixtures on the Electrical Response of SiNW-Based FETs

In this study, we report on the electrical response of top-down, p-type silicon nanowire field-effect transistors exposed to water and mixtures of water and dioxane. First, the capacitive coupling of the back gate and the liquid gate via an Ag/AgCl electrode were compared in water. It was found that for liquid gating smaller potentials are...

Silicon nanowire-based devices for gas-phase sensing

Since their introduction in 2001, SiNW-based sensor devices have attracted considerable interest as a general platform for ultra-sensitive, electrical detection of biological and chemical species. Most studies focus on detecting, sensing and monitoring analytes in aqueous solution, but the number of studies on sensing gases and vapors using SiNW...

Hydrogen termination of CVD diamond films by high-temperature annealing at atmospheric pressure

A high-temperature procedure to hydrogenate diamond films using molecular hydrogen at atmospheric pressure was explored. Undoped and doped chemical vapour deposited (CVD) polycrystalline diamond films were treated according to our annealing method using a H2 gas flow down to ?50 ml/min (STP) at ?850?°C. The films were extensively evaluated by...

Current-induced nanogap formation and graphitization in boron-doped diamond films

A high-current annealing technique is used to fabricate nanogaps and hybrid diamond/graphite structures in boron-doped nanocrystalline diamond films. Nanometer-sized gaps down to ?1?nm are produced using a feedback-controlled current annealing procedure. The nanogaps are characterized using scanning electron microscopy and electronic transport...

Silicon nanoparticles produced by spark discharge

On the example of silicon, the production of nanoparticles using spark discharge is shown to be feasible for semiconductors. The discharge circuit is modelled as a damped oscillator circuit. This analysis reveals that the electrode resistance should be kept low enough to limit energy loss by Joule heating and to enable effective nanoparticle...

Reaction-diffusion analysis for one-step plasma etching and bonding of microfluidic devices

A self-similar reaction front develops in reactive ion etching when the ions penetrate channels of shallow height h. This relates to the patterning of microchannels using a single-step etching and bonding, as described by Rhee et al. [Lab Chip 5, 102 (2005)] . Experimentally, we report that the front location scales as xf ? ht1/2 and the width...

Data structure, method and system for address lookup

Method and computer system for constructing a decision tree for use in address lookup of a requested address in an address space. The address space is arranged as a set of basic address ranges. Each basic address range is defined by a lower and an upper bound address, and an address in the address space is represented by a predetermined number...

Electrochemical determination of hydrogen peroxide using Rhodobacter capsulatus cytochrome c peroxidase at a gold electrode

We describe the redox behaviour of horse heart cytochrome c (HHC) and Rhodobacter capsulatus cytochrome c peroxidase (RcCCP) at a gold electrode modified with 4,4?-bipyridyl. RcCCP shows no additional oxidation or reduction peaks compared to the electrochemistry of only HHC, which indicates that it most likely binds to HHC and results in a...

Service port for Beira harbour, Mozambique

This study for a service port in Beira Harbour can be divided into three different parts. These parts will be discussed below in the sequence in which they have been carried out. The first part consists of the preparations for the journey to Beira and the actual site investigation. In Beira a site investigation had been carried out to obtain all...