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1.
Nanotechnology ; 32(10): 105204, 2020 Dec 17.
Article in English | MEDLINE | ID: mdl-33331296

ABSTRACT

This work reports the design, manufacturing and numerical simulation approach of a 6-pixel (4.5 mm2/pixel) electroluminescent quantum dot light emitting device (QLED) based on CuInS2/ZnS quantum dots as an active layer. The QLED device was fabricated using a conventional multi-layer thin film deposition. In addition, the electrical I-V curves were measured for each pixel independently, observing how the fabrication process and layer thickness have an influence in the shape of the plot. This experimental device, enabled us to create a computational model for the QLED based on the Transfer Hamiltonian approach to calculate the current density J (mA cm-2), the band diagram of the system, and the accumulated charge distribution. Besides, it is worth highlighting that the simulator allows the possibility to study the influence of different parameters of the QLED structure like the junction capacitance between the distinct multilayer set. Specifically, we found that the Anode-HIL interface capacitance has a greater influence in the I-V curve. This junction capacitance plays an important role in the current density increase and the QLED turn-on value when a forward voltage is applied to the device. The simulation enabled that influence could be controlled by the selection of the optimal thickness and transport layers during the experimental fabrication process. This work is remarkable since it achieves to fit simulation and experiment results in an accurate way for electroluminescent QLED devices; particularly the simulation of the device current, which is critical when designing the automotive electronics to control these new nanotechnology lighting devices in the future.

2.
Nanoscale Adv ; 1(1): 71-75, 2019 Jan 15.
Article in English | MEDLINE | ID: mdl-36132451

ABSTRACT

Biomineralisation peptides that facilitate the one-pot synthesis of gold nanoparticles (AuNPs) with selected optical properties, were screened using a coherent peptide-spotted array consisting of a AuNP binding peptide library. As the biomineralised AuNPs were captured on each peptide spot, analysis of the images provided information on their collective optical properties.

3.
Nanoscale ; 8(22): 11738-47, 2016 Jun 02.
Article in English | MEDLINE | ID: mdl-27221982

ABSTRACT

Patterned thin-films of magnetic nanoparticles (MNPs) can be used to make: surfaces for manipulating and sorting cells, sensors, 2D spin-ices and high-density data storage devices. Conventional manufacture of patterned magnetic thin-films is not environmentally friendly because it uses high temperatures (hundreds of degrees Celsius) and high vacuum, which requires expensive specialised equipment. To tackle these issues, we have taken inspiration from nature to create environmentally friendly patterns of ferromagnetic CoPt using a biotemplating peptide under mild conditions and simple apparatus. Nano-patterning via interference lithography (IL) and micro-patterning using micro-contact printing (µCP) were used to create a peptide resistant mask onto a gold surface under ambient conditions. We redesigned a biotemplating peptide (CGSGKTHEIHSPLLHK) to self-assemble onto gold surfaces, and mineralised the patterns with CoPt at 18 °C in water. Ferromagnetic CoPt is biotemplated by the immobilised peptides, and the patterned MNPs maintain stable magnetic domains. This bioinspired study offers an ecological route towards developing biotemplated magnetic thin-films for use in applications such as sensing, cell manipulation and data storage.


Subject(s)
Magnetics , Nanoparticles/chemistry , Peptides/chemistry , Gold , Immobilized Proteins/chemistry , Surface Properties
4.
J Contam Hydrol ; 171: 66-80, 2014 Dec 15.
Article in English | MEDLINE | ID: mdl-25461888

ABSTRACT

A preliminary trial of a cross-injection system (CIS) was designed to stimulate in situ denitrification in an aquifer servicing an urban community in southern Ontario. It was hypothesized that this remedial strategy could be used to reduce groundwater nitrate in the aquifer such that it could remain in use as a municipal supply until the beneficial effects of local reduced nutrient loadings lead to long-term water quality improvement at the wellfield. The CIS application involved injecting a carbon source (acetate) into the subsurface using an injection-extraction well pair positioned perpendicular to the regional flow direction, up-gradient of the water supply wells, with the objective of stimulating native denitrifying bacteria. The pilot remedial strategy was targeted in a high nitrate flux zone within an aerobic and heterogeneous section of the glacial sand and gravel aquifer. Acetate injections were performed at intervals ranging from daily to bi-daily. The carbon additions led to general declines in dissolved oxygen concentrations; decreases in nitrate concentration were localized in aquifer layers where velocities were estimated to be less than 0.5m/day. NO3-(15)N and NO3-(18)O isotope data indicated the nitrate losses were due to denitrification. Relatively little nitrate was removed from groundwater in the more permeable strata, where velocities were estimated to be on the order of 18 m/day or greater. Overall, about 11 percent of the nitrate mass passing through the treatment zone was removed. This work demonstrates that stimulating in situ denitrification in an aerobic, highly conductive aquifer is challenging but achievable. Further work is needed to increase rates of denitrification in the most permeable units of the aquifer.


Subject(s)
Acetates/metabolism , Denitrification , Drinking Water/microbiology , Nitrates/metabolism , Water Pollutants, Chemical/metabolism , Water Purification/methods , Water Supply/analysis , Groundwater/analysis , Groundwater/microbiology , Ontario , Pilot Projects
5.
Nurse Educ Today ; 30(5): 448-52, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20556881

ABSTRACT

Student nurses in a transatlantic exchange program explored the role of registered nurses in five countries' public health systems. The Ottawa Charter provided a framework for students to examine the nurse's responsibilities in public health. Students took practice placements in geographically rural a reason another continent and explored inequalities in health care. If nurses are to understand their role in the health care system then they must be taught the scope of their practice including their role in health promotion,public health practice and community development. For this project nursing instructors developed an assignment relevant to the aims and suitable for students in all five nursing programs. Only three of 48 students offered an assignment which focused on building healthy public policy. Nurse educators need to explore this further to ensure nurses of the future are aware of their role and responsibilities in this area and have skills to work effectively to influence and build healthy policy. The international student exchange supported the students' developing understanding of the breadth of initiatives around the globe where nurses are actively engaged in addressing inequalities of health. Findings from an analysis of their assignments are presented in this evaluative report.


Subject(s)
Education, Nursing/methods , Health Status Disparities , International Educational Exchange , Nurse's Role , Students, Nursing , Curriculum , Education, Nursing/trends , Faculty, Nursing , Health Policy , Health Promotion , Humans , Ontario , Public Health Nursing , Public Health Practice , Rural Health Services , Sweden
6.
Langmuir ; 24(24): 13969-76, 2008 Dec 16.
Article in English | MEDLINE | ID: mdl-19360937

ABSTRACT

The chemical modification caused by prolonged exposure to X-rays on a series of para-substituted phenyl moieties (-NO2, -CN, -CHO, -COOH, -CO2Me, and -CO2(1)Bu) at the surface of thiolate-Au self-assembled monolayers (SAMs) has been investigated by X-ray photoelectron spectroscopy (XPS). Furthermore, the influence that the phenyl group has on the chemical modification induced by the X-ray irradiation on the SAMs was investigated by comparing the XPS results obtained from irradiation on a NO2-aromatic-terminated SAM (6-(4-nitro-phenoxy)-hexane-1-thiolate (NPHT)) and NO2-aliphatic-terminated SAM (thioacetic acid S-(12-nitrododecyl) ester (TNDDE)). The NPHT and TNDDE SAMs have been shown to behave differently to X-ray exposure. The irradiation of the NPHT SAM led to the reduction of the nitro (-NO2) moiety to the amine (-NH2) moiety, as shown by the decrease in the intensity of the N 1s photoelectron peak for -NO2 (406 eV) in the XPS spectra with the concomitant increase in the N 1s photoelectron peak for -NH2 (399 eV). On the TNDDE SAM, XPS showed the -NO2 photoelectron peak again decreasing with prolonged X-ray irradiation whereas no peak was observed at 399 eV; therefore, the -NO2 moieties are selectively cleaved. No change was observed on the other functionalized monolayers apart from the -CO2(t)Bu-functionalized monolayer, where after 100 min of X-ray irradiation approximately 11% of the carbon content was lost. The S 2p and O 1s spectra remained unchanged during the irradiation suggesting the conversion of the -CO2(t)Bu to the -COOH moiety, although the conversion was not complete because the tertiary butyl moiety contributes 25% to the total carbon content of the SAM. Also, there was no evidence of the molecules desorbing from the substrate for any of the SAMs studied during the X-ray irradiation as shown by no change in the S 2p and C 1s XPS spectra taken during the X-ray irradiation.


Subject(s)
Gold/chemistry , Sulfhydryl Compounds/chemistry , X-Rays , Electrons , Molecular Structure , Photochemical Processes , Spectrophotometry
7.
Nanotechnology ; 19(8): 085201, 2008 Feb 27.
Article in English | MEDLINE | ID: mdl-21730719

ABSTRACT

We present an improved method for fabricating tungsten STM tips for measuring nanoscale objects using a multiprobe STM. The tips were prepared by a 'drop-off' technique combined with a magnetic field. For magnetic field strengths above 150 Oe the electrolyte was seen to rotate about the tungsten anode. This rotation reduced the adhesion of bubbles and led to a reduction in the cone angle of the tips produced. This property is advantageous for multiprobe measurements as it allows one to bring multiple tips into close proximity.

8.
Avian Pathol ; 15(3): 619-21, 1986.
Article in English | MEDLINE | ID: mdl-18766560

ABSTRACT

The liver of a 5-week-old turkey poult submitted for examination was found to have multiple focal lesions which contained unsporulated coccidial oocysts. These oocysts sporulated after incubation and were subsequently identified as oocysts of E. adenoeides. The source of the oocysts was not determined. This appears to be the first time a spontaneous occurrence of a species of Eimeria has been recorded in the liver of an avian host.

12.
Equine Vet J ; 8(4): 176-8, 1976 Oct.
Article in English | MEDLINE | ID: mdl-976234

ABSTRACT

A 6 month Welsh pony filly with an interventricular septal defect in conjunction with a pulmonary stenosis due to a bicuspid pulmonary valve is described. The animal had poor exercise tolerance, a loud pansystolic murmur and a precordial thrill. Blood pressure and oxygen tension values obtained during cardiac catheterization suggested the diagnosis which was confirmed at autopsy.


Subject(s)
Heart Septal Defects, Ventricular/veterinary , Horse Diseases/congenital , Pulmonary Valve Stenosis/veterinary , Pulmonary Valve/abnormalities , Animals , Female , Horses
13.
Equine Vet J ; 8(3): 128-9, 1976 Jul.
Article in English | MEDLINE | ID: mdl-954722

ABSTRACT

An 18 month Thoroughbred gelding was diagnosed on cardiac catheterization as having an interventricular septal defect. Right side cardiac blood pressures were within the normal range and confirmation of the diagnosis came from changes in the blood pO2 and pCO2 between the right atrium and right ventricle. The significance of these values is discussed.


Subject(s)
Carbon Dioxide/blood , Heart Septal Defects, Ventricular/veterinary , Horse Diseases/blood , Oxygen/blood , Animals , Heart Septal Defects, Ventricular/blood , Horses , Male
14.
J Small Anim Pract ; 17(6): 391-4, 1976 Jun.
Article in English | MEDLINE | ID: mdl-950785
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