A5081637581- Advanced Frequency and Time Standards
- Atomic and Subatomic Physics Research
- Cold Atom Physics and Bose-Einstein Condensates
- Electrochemical Analysis and Applications
- Gold and Silver Nanoparticles Synthesis and Applications
- Spectroscopy and Quantum Chemical Studies
- Advanced Fiber Laser Technologies
- Environmental Toxicology and Ecotoxicology
- Pesticide and Herbicide Environmental Studies
- Cardiovascular Syncope and Autonomic Disorders
- Advanced Battery Technologies Research
- Geophysics and Sensor Technology
- Advanced Battery Materials and Technologies
- Seismic Waves and Analysis
- Spectroscopy and Laser Applications
- Scientific Measurement and Uncertainty Evaluation
- Semiconductor Lasers and Optical Devices
- Fish Ecology and Management Studies
- Electrocatalysts for Energy Conversion
- Transition Metal Oxide Nanomaterials
- Adipose Tissue and Metabolism
- Advancements in Battery Materials
- Advanced biosensing and bioanalysis techniques
- Traffic and Road Safety
- Injury Epidemiology and Prevention
National Physical Laboratory
2015-2024
University of Nottingham
1999-2024
Nottingham Biomedical Research Centre
2024
Queen's Medical Centre
2024
Organisation de Coopération et de Développement Economiques
2017
Imperial College London
2008-2012
Teddington Memorial Hospital
2012
National Research Council Canada
2001-2005
Syngenta (United Kingdom)
2001
Syngenta (Switzerland)
2001
Phase compensated optical fiber links enable high accuracy atomic clocks separated by thousands of kilometers to be compared with unprecedented statistical resolution. By searching for a daily variation the frequency difference between four strontium lattice in different locations throughout Europe connected such links, we improve upon previous tests time dilation predicted special relativity. We obtain constraint on Robertson--Mansouri--Sexl parameter $|\alpha|\lesssim 1.1 \times10^{-8}$...
Optical fiber-based sensing technology can drastically improve Earth observations by enabling the use of existing submarine communication cables as seafloor sensors. Previous interferometric and polarization-based techniques demonstrated environmental over cable lengths up to 10,500 kilometers. However, measurements were limited integrated changes entire length cable. We demonstrate detection earthquakes ocean signals on individual spans between repeaters a 5860-kilometer-long transatlantic...
Abstract Ultrastable lasers are essential tools in optical frequency metrology enabling unprecedented measurement precision that impacts on fields such as atomic timekeeping, tests of fundamental physics, and geodesy. To characterise an ultrastable laser it needs to be compared with a similar performance, but suitable system may not available locally. Here, we report comparison two geographically separated lasers, over the longest ever reported metrological fibre link network, measuring 2220...
Abstract Under laboratory conditions, in water without particulate matter, pyrethroid insecticides have a high toxicity to fish and some aquatic invertebrates. The pyrethroids are of very low solubility/high lipophilicity, therefore rapidly strongly adsorbed material. In the state their bioavailability organisms is greatly reduced. Consequently, under field conditions impact these likely be much less than might predicted by acute or chronic test data. Over past 10 years large number studies...
The Raman and infrared spectra for the C4, C8, C12, C16 carboxylic acid series were obtained at liquid nitrogen temperatures, in 2900 cm−1 spectral region compared to selected branched straight chain alkane systems. For hexadecanoic acid-d3 Fermi resonance interaction between CD3 symmetric stretching mode overtone level of asymmetric deformation vibration was examined as a function physical state. In this example negative perturbation, which lower frequency component is more intense than...
We search for transient variations of the fine structure constant using data from a European network fiber-linked optical atomic clocks. By searching coherent in recorded clock frequency comparisons across network, we significantly improve constraints on constant. For example, constrain variation alpha to <5*10^-17 transients duration 10^3 s. This analysis also presents possibility dark matter, mysterious substance hypothesised explain galaxy dynamics and other astrophysical phenomena that...
Abstract We present a new framework to study the time variation of fundamental constants in model-independent way. Model independence implies more free parameters than assumed previous studies. Using data from atomic clocks based on 87 Sr, 171 Yb + and 133 Cs, we set bounds controlling fine-structure constant, α , electron-to-proton mass ratio, µ . consider variations timescales ranging minute almost day. In addition, use our results derive some tightest limits date parameter space models...
Abstract The detection of variations fundamental constants the Standard Model would provide us with compelling evidence new physics, and could lift veil on nature dark matter energy. In this work, we discuss how a network atomic molecular clocks can be used to look for such unprecedented sensitivity over wide range time scales. This is precisely goal recently launched QSNET project: A measuring stability constants. will include state-of-the-art clocks, but also develop next-generation highly...
The brains from 12 babies up to 21/2 years of age, who died after repeated non-accidental injury the head, were subjected detailed neuropathological examination. nine infants under 5 months showed contusional tears--slit like lesions in white matter surrounded by astrocytes and associated with evidence old recent haemorrhage. three over similar those seen adults closed head injury, including damage dorsolateral quadrant brain stem without axonal hemispheric damage, which may have been a...
The clinical and autopsy findings of a two half year-old infant with Toxocara sp. infection the brain granulomatous lesions in liver are reported. cause death was non-accidental injury. relationship between behavioural disorders is discussed.
Abstract We realize a two-stage, hexagonal pyramid magneto-optical trap (MOT) with strontium, and demonstrate loading of cold atoms into cavity-enhanced 1D 2D optical lattice traps, all within single compact assembly in-vacuum optics. show that the device is suitable for high-performance quantum technologies, focusing especially on its intended application as strontium clock. prepare 2 × 10 4 spin-polarized 87 Sr in 500 ms; we observe vacuum-limited lifetime 27 s; measure background DC...
OBJECTIVES To investigate the relation between local road traffic activity and occurrence, severity, persistence of wheeze in children. METHODS Data on asthma were collected a cross sectional questionnaire survey 22 968 primary school children (age 4–11) 27 826 secondary 11–16) Nottingham area. Direct measures flow made locality each combined with Local Authority data for major roads to estimate vehicle metres/day/km 2 . Assessment effects potential confounders was performed nested...
Aquatic exposure assessments for pesticides are generally based on laboratory studies performed in water alone or sediment systems. Although aquatic macrophytes, which include a variety of bryophytes, macroalgae, and angiosperms, can be significant component many ecosystems, their impact pesticide fate is not included assessments. To investigate the influence plants behavior pyrethroid insecticide lambda (lambda)-cyhalothrin, two experiments (to assess adsorption degradation) an indoor...
We develop a method of modified hyper-Ramsey spectroscopy in optical clocks, achieving complete immunity to the frequency shifts induced by probing fields themselves. Using particular pulse sequences with tailored phases, frequencies, and durations, we can derive an error signal centered exactly at unperturbed atomic resonance steep discriminant which is robust against variations probe shift. experimentally investigate scheme using magnetically-induced $^1$S$_0- ^3$P$_0$ transition...