Cost-effective fabrication of nanoscale electrode memristors with reproducible electrical response

Accepted versio

A SiGe HEMT Mixer IC with Low Conversion Loss

The authors present the first SiGe HEMT mixer integrated circuit. The active mixer stage, operating up to 10GHz RF, has been designed and realized using a 0.1µ µµ µm gate length transistor technology. The design is based on a new large-signal simulation model developed for the SiGe HEMT. Good agreement between simulation and measurement is reached. The mixer exhibits 4.0dB and 4.7dB conversion loss when down-converting 3.0GHz and 6.0GHz signals, respectively, to an intermediate frequency of 500MHz using high-side injection of 5dBm local oscillator power. Conversion loss is less than 8dB for RF frequencies up to 10GHz with a mixer linearity of –8.8dBm input related 1dB compression point

Average drift mobility and apparent sheet-electron density profiles in strained-Si-SiGe buried-channel depletion-mode n-MOSFETs

Published versio

SiGe HMOSFET monolithic inverting current mirror

Accepted versio

Analogue micropower FET techniques review

A detailed introduction to published analogue circuit design techniques using Si and Si/SiGe FET devices for very low-power applications is presented in this review. The topics discussed include sub-threshold operation in FET devices, micro-current mirrors and cascode techniques, voltage level-shifting and class-AB operation, the bulk-drive approach, the floating-gate method, micropower transconductance-capacitance and log-domain filters and strained-channel FET technologies

SiGe HMODFET "KAIST" micropower model and amplifier realization

Published versio

Predicting the safety and efficacy of butter therapy to raise tumour pHe: an integrative modelling study

Background: Clinical positron emission tomography imaging has demonstrated the vast majority of human cancers exhibit significantly increased glucose metabolism when compared with adjacent normal tissue, resulting in an acidic tumour microenvironment. Recent studies demonstrated reducing this acidity through systemic buffers significantly inhibits development and growth of metastases in mouse xenografts.\ud \ud Methods: We apply and extend a previously developed mathematical model of blood and tumour buffering to examine the impact of oral administration of bicarbonate buffer in mice, and the potential impact in humans. We recapitulate the experimentally observed tumour pHe effect of buffer therapy, testing a model prediction in vivo in mice. We parameterise the model to humans to determine the translational safety and efficacy, and predict patient subgroups who could have enhanced treatment response, and the most promising combination or alternative buffer therapies.\ud \ud Results: The model predicts a previously unseen potentially dangerous elevation in blood pHe resulting from bicarbonate therapy in mice, which is confirmed by our in vivo experiments. Simulations predict limited efficacy of bicarbonate, especially in humans with more aggressive cancers. We predict buffer therapy would be most effectual: in elderly patients or individuals with renal impairments; in combination with proton production inhibitors (such as dichloroacetate), renal glomular filtration rate inhibitors (such as non-steroidal anti-inflammatory drugs and angiotensin-converting enzyme inhibitors), or with an alternative buffer reagent possessing an optimal pK of 7.1–7.2.\ud \ud Conclusion: Our mathematical model confirms bicarbonate acts as an effective agent to raise tumour pHe, but potentially induces metabolic alkalosis at the high doses necessary for tumour pHe normalisation. We predict use in elderly patients or in combination with proton production inhibitors or buffers with a pK of 7.1–7.2 is most promising

Interband transitions in InxGa1-xAs/In0.52Al0.48As single quantum wells studied by room-temperature modulation spectroscopy

Room-temperature phototransmittance and electrotransmittance of single quantum wells of InxGa1-xAs with In0.52Al0.48As barriers have been used to study the excitonic interband transitions between the confined conduction- and valence-band states. Peak assignment has been confirmed by photocurrent spectroscopy. The lattice-matched (x=0.53) and strained (x=0.6) structures were considered for two different well widths of 50 and 250 Å. Transition energies and broadening parameters were measured from the spectra of the wide well samples and studied as a function of the principal quantum number. Reasonably good agreement between theory and experiment has been achieved by using published values of the electronic band-structure parameters. An observed monotonic increase of the linewidth with the quantum number has been associated with the presence of well-width fluctuations due to rough interfaces

Monolithic micropower amplifier using SiGe n-MODFET device

Accepted versio