20 research outputs found
Carbon nanotube-guided thermopower waves
No full textThermopower waves are a new concept for the direct conversion of chemical to electrical energy. A nanowire with large axial thermal diffusivity can accelerate a self-propagating reaction wave using a fuel coated along its length. The reaction wave drives electrical carriers in a thermopower wave, creating a high-power pulse of as much as 7 kW/kg in experiments using carbon nanotubes. We review nanomaterials designed to overcome limitations of thermoelectricity and explore the emerging scientific and practical outlook for devices using thermopower waves
Rational design of soft mechanical metamaterials: Independent tailoring of elastic properties with randomness
No full textThe elastic properties of mechanical metamaterials are direct functions of their topological designs. Rational design approaches based on computational models could, therefore, be used to devise topological designs that result in the desired properties. It is of particular importance to independently tailor the elastic modulus and Poisson's ratio of metamaterials. Here, we present patterned randomness as a strategy for independent tailoring of both properties. Soft mechanical metamaterials incorporating various types of patterned randomness were fabricated using an indirect additive manufacturing technique and mechanically tested. Computational models were also developed to predict the topology-property relationship in a wide range of proposed topologies. The results of this study show that patterned randomness allows for independent tailoring of the elastic properties and covering a broad area of the elastic modulus-Poisson's ratio plane. The uniform and homogenous topologies constitute the boundaries of the covered area, while topological designs with patterned randomness fill the enclosed area
Shape-matching soft mechanical metamaterials
No full textArchitectured materials with rationally designed geometries could be used to create mechanical metamaterials with unprecedented or rare properties and functionalities. Here, we introduce "shape-matching" metamaterials where the geometry of cellular structures comprising auxetic and conventional unit cells is designed so as to achieve a pre-defined shape upon deformation. We used computational models to forward-map the space of planar shapes to the space of geometrical designs. The validity of the underlying computational models was first demonstrated by comparing their predictions with experimental observations on specimens fabricated with indirect additive manufacturing. The forward-maps were then used to devise the geometry of cellular structures that approximate the arbitrary shapes described by random Fourier's series. Finally, we show that the presented metamaterials could match the contours of three real objects including a scapula model, a pumpkin, and a Delft Blue pottery piece. Shape-matching materials have potential applications in soft robotics and wearable (medical) devices.Biomaterials & Tissue Biomechanic
Evaluation of four oral fluid devices (dds, drugtest 5000, drugwipe 5+ and rapidstat) for on-site monitoring drugged driving in comparison with UHPLC-MS/MS analysis
No full textNew Italian legislation on driving under the influence of drugs considers oral fluid (OF) as a possible
alternative drug testing matrix. On this basis, the present research was carried out to evaluate the
applicability of four commercial on-site OF drug screening devices, namely DDS1, Drugtest 50001,
Drugwipe 5+1 and RapidSTAT1, in a real operative context.
Preliminarily trained police officers tested randomly stopped drivers with two different kits side-by-
side during roadside patrols. A central laboratory confirmed on-site kits’ results by UHPLC–MS/MS
analysis of the saliva specimen remaining after the screening analysis. 1025 drivers were submitted to
the OF tests: 11.6% were positive for cocaine and metabolites, 11.1% for THC, 6% for amphetamines and
amphetamine-type designer drugs and 2.3% for ketamine.
The sensitivities of the kits were 81% (RapidSTAT1), 82% (DDS1), 90% (Drugwipe 5+1) and 97%
(Drugtest 50001) for cocaine and 38% (DDS1), 47% (Drugwipe 5+1), 72% (RapidSTAT1) and 92%
(Drugtest 50001) for THC. Drugtest 5000 was the only kit showing an acceptable sensitivity for on-site
application. Only Drugtest 50001 and RapidSTAT1 could be evaluated for amphetamines and
methamphetamines: Drugtest 50001 showed a sensitivity of 100% in the case of amphetamines and 86%
for methamphetamines, while RapidSTAT1 90% and 76% respectively. Nowadays, ketamine is not
included in the target analytes of any on-site devices, but it was systematically included in the UHPLC–
MS/MS confirmatory analysis. To ensure adequate reliability, MS confirmation of on-site OF screening
tests is anyway always necessary, due to the presence of a significant number of false positive results
even when using the commercial kit with the best performance
Ion beam analysis (IBA) and instrumental neutron activation analysis (INAA) for forensic characterisation of authentic Viagra® and of sildenafil-based illegal products
No full textIllegal trafficking of pharmaceutical products by criminal organisations is a global threat for public health. Drugs for erectile dysfunction such as phosphodiesterase type 5 inhibitors are the most commonly counterfeited medicines in Europe. The search of possible toxic chemical substances in seized products is needed to provide early warning for public health. Furthermore, the elemental profile of the seized products can be useful in criminal investigations. For the first time an ion beam analysis (IBA) procedure to characterise authentic Viagra® tablets and sildenafil-based illegal products is described. Moreover, results are compared with the ones obtained by instrumental neutron activation analysis (INAA) on authentic Viagra® tablets in two reactors. IBA results showed that a combination of particle-induced X-ray emission (PIXE) and secondary ion mass spectrometry using primary ions with energies in the range of several MeV (MeV-SIMS) is a powerful tool to characterise different products in a straightforward manner, allowing discrimination between legal and illegal products. INAA allowed accurate elemental quantification and also showed a great potential for the future implementation of an inter-laboratory classification system.Accepted Author ManuscriptRID/TS/Technici Poo
The Wisconsin drinking culture: perceptions and drinking patterns of high school students
No full textIncludes bibliographical references
THE DEVELOPMENT OF ATTITUDES TOWARDS AUTHORITY IN CHILDREN
No full textThis study is concerned with the way in which school
CHILDREN ACQUIRE FEELINGS FOR THE PRIME MINISTER OF CANADA AND THE
policeman. There are four main objectives to this research project.
The first aspect is concerned with the child’s evaluation of each
authority. This is essentially a mapping operation in which the
CHILD EVALUATES THE PRIME MINISTER AND THE POLICEMAN AGAINST A
BACKDROP OF ’MOST OTHER MEN*. THE OBJECTIVE OF THIS STUDY IS AN
EXAMINATION OF THE INFLUENCE OF AGE, SEX, POLITICAL PARTY AFFILIATION
AND SOCIAL CLASS UPON THE APPRAISAL OF POLITICAL AUTHORITY. THE
THIRD OBJECTIVE IS CONCERNED TO PROVIDE A COMPARISON OF THIS
Canadian data with recent published American data. The saliency
OF the national leaders in the two countries can be determined
FROM THE STUDENT’S EVALUATIONS. THE ITEMS HAVE BEEN SELECTED TO
PROVIDE COMPARABILITY BETWEEN CANADIAN AND AMERICAN DATA. THE FINAL
OBJECTIVE INVOLVES AN EVALUATION OF EFFICACY OF THE THEORIES WHICH
PURPORT TO ACCOUNT FOR THE CHILD’S PERCEPTION OF POLITICAL
AUTHORITY.
Chapter one outlines the objectives of this study and provides
A REV 1 EV/ OF THE RECENT LITERATURE.
Chapter two is concerned with the child’s knowledge of the
Prime Minister’s name and political party affiliation. Age, sex,
POLITICAL PARTY PREFERENCE AND SOCIAL CLASS ARE EXAMINED TO DETERMINE
THE INFLUENCE OF THESE GROUPINGS UPON THE CHILD’S LEVEL OFPOLITICAL KNOWLEDGE.
Chapters three through seven are concerned with the child’s
FEELINGS FOR AUTHORITY. THE CHILD WILL BE PROVIDED WITH FIVE
DIMENSIONS ON WHICH TO EXPRESS HIS FEELINGS FOR AUTHORITY. THESE
DIMENSIONS HAVE BEEN ARRANGED FROM THE MOST PERSONAL FEATURES OF
LIKING AND PERCEPTIONS OF BENEVOLENCE TO THE MORE INSTITUTIONAL
ASPECTS OF POLITICAL AUTHORITY HAVING TO DO WITH POWER AND LEADERSHIP. Chapter three is concerned with the child’s liking for
AUTHORITY, CHAPTER FOUR WITH THE CHILD’S PERCEPTION OF BENEVOLENCE,
Chapter five with authority dependability, Chapter six with power
PERCEPTIONS AND CHAPTER SEVEN WITH THE EVALUATION OF THE LEADERSHIP
ABILITIES OF THE PRIME MINISTER AND POLICEMAN.
Chapter eight concludes this study by answering questions
RAISED IN RELATION TO THE FOUR OBJECTIVES OF THE STUDY SET OUT IN
THE FIRST CHAPTER. The author is grateful for the programming assistance of Mrs
K. Strano and the cooperation extended by other members of the
McMaster data processing and computing centre. The author also
acknowledges the kind assistance provided in the early stages of
THIS STUDY BY MR. W. K. M. ARMSTRONG, SUPER 1NTENDENT.OF OAKVILLE
Public Schools, enabling this study to be carried out at short
notice. Thanks, also, to the principals of the Oakville public
schools for their wholehearted cooperation in arranging time for
the administration of the questionnaire.ThesisMaster of Arts (MA
Single-layer graphene membranes by crack-free transfer for gas mixture separation
No full text© 2018 The Author(s). The single-layer graphene film, when incorporated with molecular-sized pores, is predicted to be the ultimate membrane. However, the major bottlenecks have been the crack-free transfer of large-area graphene on a porous support, and the incorporation of molecular-sized nanopores. Herein, we report a nanoporous-carbon-assisted transfer technique, yielding a relatively large area (1 mm2), crack-free, suspended graphene film. Gas-sieving (H2/CH4 selectivity up to 25) is observed from the intrinsic defects generated during the chemical-vapor deposition of graphene. Despite the ultralow porosity of 0.025%, an attractive H2 permeance (up to 4.1 × 10-7 mol m-2 s-1 Pa-1) is observed. Finally, we report ozone functionalization-based etching and pore-modification chemistry to etch hydrogen-selective pores, and to shrink the pore-size, improving H2 permeance (up to 300%) and H2/CH4 selectivity (up to 150%). Overall, the scalable transfer, etching, and functionalization methods developed herein are expected to bring nanoporous graphene membranes a step closer to reality
Is prolonged infusion of piperacillin/tazobactam and meropenem in critically ill patients associated with improved pharmacokinetic/pharmacodynamic and patient outcomes? An observation from the Defining Antibiotic Levels in Intensive care unit patients (DALI) cohort
No full textObjectives: We utilized the database of the Defining Antibiotic Levels in Intensive care unit patients (DALI) study to statistically compare the pharmacokinetic/pharmacodynamic and clinical outcomes between prolonged- infusion and intermittent-bolus dosing of piperacillin/tazobactam and meropenem in critically ill patients using inclusion criteria similar to those used in previous prospective studies. Methods: This was a post hoc analysis of a prospective, multicentre pharmacokinetic point-prevalence study (DALI), which recruited a large cohort of critically ill patients from 68 ICUs across 10 countries. Results: Of the 211 patients receiving piperacillin/tazobactam and meropenem in the DALI study, 182 met inclusion criteria. Overall, 89.0% (162/182) of patients achieved the most conservative target of 50% fT≥MIC (time over which unbound or free drug concentration remains above the MIC). Decreasing creatinine clearance and the use of prolonged infusion significantly increased the PTA for most pharmacokinetic/pharmacodynamic targets. In the subgroup of patients who had respiratory infection, patients receiving β-lactams via prolonged infusion demonstrated significantly better 30 day survival when compared with intermittent-bolus patients [86.2% (25/29) versus 56.7% (17/30); P=0.012]. Additionally, in patients with a SOFA score of ≥ 9, administration by prolonged infusion compared with intermittent-bolus dosing demonstrated significantly better clinical cure [73.3% (11/15) versus 35.0% (7/20); P=0.035] and survival rates [73.3% (11/15) versus 25.0% (5/20); P=0.025]. Conclusions: Analysis of this large dataset has provided additional data on the niche benefits of administration of piperacillin/tazobactam and meropenem by prolonged infusion in critically ill patients, particularly for patients with respiratory infections. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved
Important influence of single neutron stripping coupling on near-barrier 8Li + 90Zr quasi-elastic scattering
No full textQuasi-elastic scattering data were obtained for the radioactive nucleus 8Li on a 90Zr target at the near-barrier energy of 18.5MeV over the angular range to 80°. They were analyzed within the coupled channels and coupled reaction channels frameworks pointing to a strong coupling effect for single neutron stripping, in contrast to 6, 7Li + 90Zr elastic scattering at similar energies, a non-trivial result linked to detailed differences in the structure of these Li isotopes. © 2015, The Author(s)
