Differential read-out architecture for CMOS ISFET microsystems

The operation of a pH (H/sup +/ ion concentration) sensitive ion-sensitive field-effect transistor (ISFET) microsystem with a sensitivity of 40-45 mV/pH is demonstrated. This system has two identical ISFETs as the inputs to a pair of ISFET operational transconductance amplifiers (IOTAs) arranged in a novel differential architecture. The IOTAs have different sized p-MOSFET load transistors that enable pH sensitive operation without any post-fabrication processing or material deposition. The CMOS ISFET chip is fabricated in an unmodified 1.5 /spl mu/m commercial process.     

Multifunctional and Stimuli‐Responsive Polydopamine Nanoparticle‐Based Platform for Targeted Antimicrobial Applications

The rising threat of antimicrobial resistance is a crisis of a global scale. If not addressed, it can lead to health care system problems worldwide. This warrants alternative therapeutic approaches whose mechanism of action starkly differs from conventional antibiotic‐based therapies. Here, a multifunctional and stimuli‐responsive (NIR laser‐activated) antimicrobial platform is engineered by combining the intrinsic photothermal capability and excellent biocompatibility of polydopamine nanoparticles (PdNPs), with the membrane targeting and lytic activities of an antimicrobial peptide (AMP). The resulting PdNP‐AMP nanosystem can specifically target and destabilize the mechanical integrity of the outer membrane of Escherichia coli, as measured using the atomic force microscope. Furthermore, the laser‐induced nano‐localized heating of PdNP—in close proximity to the already compromised bacterial envelope—induces further membrane damage. This results in a more efficient, laser‐activated, bacterial killing action of PdNP‐AMP. The antimicrobial platform developed in this work is shown to be effective against a drug‐resistant E. coli. Overall, this work highlights the advantage and strength of combining multiple and coordinated biocidal mechanisms, into one nanomaterial‐based system and its promise in treating drug‐resistant pathogens.     

Design and implementation of an industrial vector-controlled induction motor drive

Vector-controlled induction motor drives are quite popular in the industry in applications that demand high dynamic performance. This paper describes the implementation of a complete industrial vector-controlled drive for a 30 kW induction motor. The control algorithms for the drive are implemented using a TMS320F28335 Digital Signal Controller (DSC). Various monitoring and protection functions for the drive are implemented using a Cyclone IV FPGA that communicates with the DSC, and acts as the master controller for the drive. The FPGA also communicates with a Human–Machine Interface to provide a simple graphical control interface to the operator.     

Challenges and implemented technologies used in autonomous drone racing

Intelligent Service Robotics - Autonomous drone racing (ADR) is a challenge for autonomous drones to navigate a cluttered indoor environment without relying on any external sensing in which all the...     

Growth performance of rats fed raw and extruded African breadfruit‐based complementary diets: A response surface analysis

BACKGROUND: African breadfruit, from which diverse food forms are produced, is popular in most West African tropical regions. The present study is part of a larger research project aimed at developing appealing, processed, nutritious products from blends of breadfruit, corn and defatted soybean by utilising extrusion cooking using response surface analysis. The study describes the ability or otherwise of raw and extruded African breadfruit‐based diets, similar to weaning diets simulated with rats, to support growth of children and infants. RESULTS: Maximum protein efficiency and net protein ratios of 2.22 and 3.69, respectively, were obtained with rats fed diets made from 40 g 100 g^?1 African breadfruit + 5 g 100 g^?1 corn + 55 g 100 g^?1 soybean extrudates at 18 mL 100 mL^?1 feed moisture and 140 rpm screw speed. It compared favourably with a casein standard and was 54–69% and 42–55% higher than those fed raw diets. CONCLUSION: Extrusion cooking significantly improved the nutritional quality of African breadfruit–corn–defatted soybean as reflected in their protein efficiency and net protein values. The superiority in protein quality of diet 1 (containing 40 g 100 g^?1 breadfruit, 5 g 100 g^?1 corn and 55 g 100 g^?1 defatted soybean) over the other experimental diets has serious nutritional implication in dietary diversification to address protein‐energy malnutrition prevalent in Nigeria and other West African countries especially where African breadfruit is known to be highly cultivated as a food resource. Copyright © 2007 Society of Chemical Industry     

The origin of shallow n-type conductivity in boron-doped diamond with H or S co-doping: Density functional theory study

The ionization potentials and the electron affinities of doped diamond were calculated using B3LYP hybrid density functional theory and nanocrystalline cluster models, while taking into account the quantum confinement of the charge carriers. In many cases donor and acceptor levels were created in the middle of the gap between the conduction and valence bands. A possible explanation for the n-type behavior created by co-doping diamond films with boron and sulfur is given in terms of thermally activated electron donation from an SVS (V is vacancy) donor to a BB acceptor band. Both lie deep in the band gap. It is proposed that electrons in the BB acceptor band are mobile charge carriers. It is also proposed that the conversion of boron-doped diamond from p-type conductivity, with hole charge carriers in the top of the valence band, to n-type conductivity, following treatment in a deuterium plasma, may arise from formation of interstitial hydrogen donor levels and B_nH_m acceptor levels that create an acceptor band in which electrons are mobile. Again, both are deep in the band gap of pure diamond. In a prior attempt to explain this n-type behavior, BH_n defects with unrelaxed structures were proposed to be shallow donors to the diamond conduction band. This paper shows that these defects become deep donors when their structures are optimized. Finally, defects created from vacancies with 1 to 4 H in them are shown to be deep donors to the diamond conduction band.     

A MIS transistor using the nucleation surface of polycrystalline diamond

In this work, the nucleation surface of a polycrystalline diamond film was used for the first time to fabricate a MISFET structure using standard photolithographic procedures, with a channel length of 100 μm. The resulting structure works as an enhancement-type p-type MOSFET. The I_ON/I_OFF ratio is about three orders of magnitude. The saturation of the current is clearly observed, with I_DS currents of about 20 nA for V_DS of 20 V. The smoothness of the nucleation surface allows a higher control of the electrodes, as well as their size decrease. The results show that, even though in an early stage, this investigation opens the door for a new generation of devices built on free-standing diamond films.     

Study of the Fate of Lipophilic Wood Extractives During Acid Sulphite Pulping Process by Ultrasonic Solid-Liquid Extraction and Gas Chromatography Mass Spectrometry

Abstract

Lipophilic extractives in dissolving pulp are still a big concern for pulp industries due to their detrimental effect on the quality of pulp. Since lipophilic extractives remaining in pulp are trapped in low-accessible fiber structures, effective extraction methods need to be established for studying their fate in the process. A simple, ultrasonic, solid liquid extraction established in this study was found to be more effective in capturing extractive residues in all “elemental chlorine-free” bleaching stages. Its efficiency was dependent on the extraction temperature, time, and solvent composition. A linearly correlated removal pattern of sterols and unsaturated fatty acids by the bleaching sequence was observed. It was further found that the bleaching combination did not fully remove lipophilic extractives. This study suggests an opportunity to explore ultrasonication-based extraction as an effective extraction procedure prior to gas chromatography mass spectrometry analysis for monitoring extractives in pulp.