Investigation of the MOST channel conductance in weak inversion

The drain-source conductance of several MOS transistors has been studied as a function of the silicon surface-potential ψs in the weak and intermediate inversion region, under the condition of quasi-thermal equilibrium at room temperature. The silicon surface conductance per square ifG(in□ has been measured to vary exponentially with qψs/kT in weak inversion for excess minority carrier densities extending over the range 105-1011 cm−2. The exponential behaviour of G□ vs. qψs/kT appeared to be insensitive for the presence of interface states, when distributed around peak values as large (As) 6 × 1011/cm2 eV at ≈ 200 meV energy distance from midgap.\ud \ud Garrett and Brattain predicted theoretically that the excess minority carrier surface charge for weak inversion should also be an exponential function of qψs/kT, we conclude that the minority carrier mobility remains constant over the entire weak inversion region.\ud \ud A refined version of the low frequency CV method the so-called ‘split’ CV method has been introduced, which allows a simple determination of the charge trapped in interface states in weak and intermediate inversion as well as a determination of the bulk dope density

Simulation of Future Land Use for Water Management - Assessing the suitability of scenario-based modelling

The problem of water shortage is increasingly getting attention within the field of water management, even in the wet Netherlands. Clean ground and surface water may become too scarce to allow for sustainable use for various functions. In order to assess the magnitude of this problem a water shortage study has been started in the Netherlands, in which the impact of land use change is an important issue. Land use models can help translate hypotheses regarding future spatial developments into maps of a possible future. These scenarios can then be used in spatial planning processes. Future land use is greatly influenced by current land use, autonomous socio-economic developments, current policy and in the long term climate changes and other changes in the physical environment. By developing scenarios that are clearly different from each other, especially on the factors that influence the problem of water shortage, divergent images of the future have been generated for 2030. In this way, a first impression has been developed for the bandwidth in which future developments can occur. The goal of this paper is to evaluate whether we are able to generate new, spatially diverse scenario’s based on existing material within a very short time period.

Two-lead multiplex system for sensor array applications

We present a multiplex system that creates the opportunity to use only two wires in sensor array applications, with arbitrary inter-sensor distances. The utility of this principle is shown by the realization of a CMOS prototype of this multiplexer

Soiling and other optical losses in solar-tracking PV plants in Navarra

Field data of soiling energy losses on PV plants are scarce. Furthermore, since dirt type and accumulation vary with the location characteristics (climate, surroundings, etc.), the available data on optical losses are, necessarily, site dependent. This paper presents field measurements of dirt energy losses (dust) and irradiance incidence angle losses along 2005 on a solar-tracking PV plant located south of Navarre (Spain). The paper proposes a method to calculate these losses based on the difference between irradiance measured by calibrated cells on several trackers of the PV plant and irradiance calculated from measurements by two pyranometers (one of them incorporating a shadow ring) regularly cleaned. The equivalent optical energy losses of an installation incorporating fixed horizontal modules at the same location have been calculated as well. The effect of dirt on both types of installations will accordingly be compared

A well-characterised peak identification list of MALDI MS profile peaks for human blood serum

MALDI MS profiling, using easily available body fluids such as blood serum, has attracted considerable interest for its potential in clinical applications. Despite the numerous reports on MALDI MS profiling of human serum, there is only scarce information on the identity of the species making up these profiles, particularly in the mass range of larger peptides. Here, we provide a list of more than 90 entries of MALDI MS profile peak identities up to 10 kDa obtained from human blood serum. Various modifications such as phosphorylation were detected among the peptide identifications. The overlap with the few other MALDI MS peak lists published so far was found to be limited and hence our list significantly extends the number of identified peaks commonly found in MALDI MS profiling of human blood serum

Cities are hot

Cities are great places to live in, as is extensively documented in urban economic literature. They offer employment, interaction opportunities and plenty of amenities. Their agglomeration benefits, for example, translate into higher labour productivity and higher wages and thus continue to attract more inhabitants every year. Yet, cities are not the most healthy places to live in

Interface studies of the MOS-structure by transfer-admittance measurements

The transfer-admittance of n- and p-channel MOS transistors has been measured under the condition of a uniform channel. These MOS transistors all showed a measurable “slow interface state drift” <0·1–0·2 V. The transfer-susceptance has been found to show a significant peak value in moderate inversion. Over the entire moderate and strong inversion region the transfer-susceptance remains constant as a function of the measurement frequency ω between 1·6 Hz and 2 × 104 Hz, while the transfer-conductance varies almost like ln ω. Furthermore the transfer-susceptance shows a linear relationship with the variation of the transfer-conductance per frequency decade. The paper shows that these phenomena can be well explained by assuming a tunneling of channel charge carriers into electron states in the oxide. Also the temperature behaviour of the transfer-admittance does not seem to be in conflict with this tunnel model. More than the CV measuring method the measurement of the transfer-admittance allows an investigation of the interaction between mobile inversion layer charge carriers, and interface states in the condition of moderate inversion (5 × 1010-5 × 1011 electrons cm−2). The measuring method might therefore find application in the investigation of charge trapping in CCD devices. As a pertinent result the density of oxide states having time constants between 6 × 10−1 sec and 1·6 × 10−5 sec appears to increase to values of about 1011 per cm2V as the interface state energy approaches the conduction and valence band edge energies within a distance of 70 meV

The impact of urban resurgence on public green space

Cities are great places for interaction and innovation that continue to attract new waves of migrants. This is reflected in the resurgence of most cities in Europe since the turn of the century. Their current popularity may, however, threaten their livability as house prices are soaring, city tourism results in overcrowding, congestion limits accessibility and green space is lost to urban development