Initial Beam Test Results from a Silicon-Strip Detector with VLSI Readout

Silicon detectors with 256 strips, having a pitch of 25 ?m, and connected to two 128 channel NMOS VLSI chips each (Microplex), have been tested in relativistic charged particle beams at CERN and at the Stanford Linear Accelerator Center. The readout chips have an input channel pitch of 47.5 ?m and a single multiplexed output which provides voltages proportional to the integrated charge from each strip. The most probable signal height from minimum ionizing tracks was 15 times the rms noise in any single channel. Two-track traversals with a separation of 100 ?m were cleanly resolved.     

Relative importance of informational units and their role in long-term recall by closed-head-injured patients and control groups.

Applied qualitative analysis to the information recalled by control Ss and closed-head-injured (CHI) patients. The Logical Memory subtest of the Wechsler Memory Scale (WMS) was administered to 40 CHI and 40 control Ss. Recall was tested immediately after administration, 40 min later, and 24 hrs later. The analysis took into account the importance of recalled information as determined by a prior rating according to 3 levels of importance. Results suggest that CHI patients have difficulty selectively retrieving the most important information after a long delay. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ion sensitive field effect transistor modelling for multidomain simulation purposes

The proper design and simulation of modern electronic microsystems oriented towards environment monitoring requires accurate models of various ambient sensors. In particular, this paper presents a comprehensive model of an ion sensitive field effect transistor (ISFET). The model can be employed straightforwardly for simulations at device, circuit or system level.First, the model was validated with electrical measurements and simulations of real structures performed for different ion concentration and temperature values. Then, the ISFET sensor model was employed for mixed-signal simulations in VHDL-AMS, when the analysis of a microsystem consisting of the ISFET sensor and a sigma-delta analogue-to-digital converter was carried out. Additionally, the presence of other ions than hydrogen in the measured solution was also taken into account in the simulations.     

The combustion products of polymeric materials. III: GC–MS Analysis of the combustion products of polyethylene,polypropylene, polystyrene and polyamide

A series of gas chromatographic–mass spectrometric analyses was carried out on polyethylene, polypropylene, polystyrene and polyamide in CAB 4.5 and CAB 650 chambers in the flaming and non-flaming combustion mode. The combustion products formed were identified and used to characterize the combustion process in both chambers; procedures were selected for testing polymeric materials for the dangerous effects of their combustion products.     

Allocation of bandwidth and storage

We consider two allocation problems in this paper, namely, allocation of bandwidth and storage. In these problems, we face a number of independent requests, respectively, for reservation of bandwidth of a communication channel of fixed capacity and for storage of items into a space of fixed size. In both problems, a request is characterized by: (i) its required period of allocation; (ii) its required bandwidth (item width, respectively)and (iii)the profit of accepting the request. The problem is to decide which requests to accept so as to maximize the total profit. These problems in general are NP-hard. In this paper we provide polynomial-time algorithms for solving various special cases, and develop polynomial-time approximation algorithms for very general NP-hard cases with good performance guarantees.     

Surface chemistry of SnO2 nanowires on Ag-catalyst-covered Si substrate studied using XPS and TDS methods

In this paper we investigate the surface chemistry, including surface contaminations, of SnO₂ nanowires deposited on Ag-covered Si substrate by vapor phase deposition (VPD), thanks to x-ray photoelectron spectroscopy (XPS) in combination with thermal desorption spectroscopy (TDS). Air-exposed SnO₂ nanowires are slightly non-stoichiometric, and a huge amount of C contaminations is observed at their surface. After the thermal physical desorption (TPD) process, SnO₂ nanowires become almost stoichiometric without any surface C contaminations. This is probably related to the fact that C contaminations, as well as residual gases from air, are weakly bounded to the crystalline SnO₂ nanowires and can be easily removed from their surface. The obtained results gave us insight on the interpretation of the aging effect of SnO₂ nanowires that is of great importance for their potential application in the development of novel chemical nanosensor devices.     

Validation and modification of modeling thermally activated building systems (TABS) using EnergyPlus

EnergyPlus (EP) integrates a low temperature radiant system module to evaluate thermal performance of radiant systems such as thermally activated building systems (TABS), but the assumptions in this module neglect thermal resistance of the pipe and thermal resistance between the pipe exterior surface and the pipe level, which may result in the inaccurate evaluation of TABS in terms of surface temperature and surface heat flow. In this paper, in order to validate this module used in EP, steady and transient heat transfer processes of TABS in buildings were studied by analytical solution, two-dimensional numerical simulation and EP simulation. The comparison shows that the assumptions indeed result in a largely overestimated cooling and heating capacity of TABS. In order to improve this radiant module, a simple solution of introducing a no mass material layer with the neglected thermal resistances to both sides of the pipe level was proposed. With this method, the results of mean surface temperature and mean heat flow show good agreement with that from analytical solution as well as numerical simulation. Furthermore, the results of the simulation coupling the modified module with room systems show very small deviation from the results found in the literature. In addition, the application of the modified module in a hollow core concrete deck structure with TABS was investigated.     

Assessing cellular toxicities in fibroblasts upon exposure to lipid-based nanoparticles: a high content analysis approach

Lipid-based nanoparticles (LNPs) are widely used for the delivery of drugs and nucleic acids. Although most of them are considered safe, there is confusing evidence in the literature regarding their potential cellular toxicities. Moreover, little is known about the recovery process cells undergo after a cytotoxic insult. We have previously studied the systemic effects of common LNPs with different surface charge (cationic, anionic, neutral) and revealed that positively charged LNPs ((+)LNPs) activate pro-inflammatory cytokines and induce interferon response by acting as an agonist of Toll-like receptor 4 on immune cells. In this study, we focused on the response of human fibroblasts exposed to LNPs and their cellular recovery process. To this end, we used image-based high content analysis (HCA). Using this strategy, we were able to show simultaneously, in several intracellular parameters, that fibroblasts can recover from the cytotoxic effects of (+)LNPs. The use of HCA opens new avenues in understanding cellular response and nanotoxicity and may become a valuable tool for screening safe materials for drug delivery and tissue engineering.     

Tight and uniform layer of covalently bound aminoethylophenyl groups perpendicular to gold surface for attachment of biomolecules

Strongly adhered layers of the compound with the primary amino group directed toward the solution were obtained at the gold surface by chronoamperometric electroreduction of 4-aminoethylobenzenodiazonium salt (AEBD) in acetonitrile solution at appropriately selected potential. The used techniques (EQCM, AFM, EIS, PM, IRRAS) showed that the nature and thickness of formed aminoethylophenyl layer strongly depend on the potential applied to the electrode. Electroreduction of AEBD salt at a potential more negative than -0.6 V (vs Ag/AgCl) leads to about monolayer on the gold surface. Additionally, such a layer was very tight and uniform. The electrochemical measurements indicate that the efficient and precise attachment of biomolecules to the aminoethylophenyl layer is only possible when this layer is formed at appropriate potential. This was shown for ss- and dsDNA.