20 research outputs found
CONTEXTUALISING URBAN ENGINEERING EDUCATION FOR FUTURE CITIES
While rapidity in service activities have strengthened the role of urban areas as engines of economic growth, high population density and increased industrialization, has brought needless social and environmental complaints in cities. This phenomenon necessitates a change in societal attitude in f avor of the creation of responsible living conditions, which demands requisite skills and knowledge that would shape the cities. Thus, this paper explores the adequacy of current urban engineering education in terms of the knowledge, skills and competencie s required to plan and develop future cities. The paper examines how âwicked problemsâ that marginalize effective sustainable city planning can be addressed through astute understanding of social and environmental challenges, urban governance systems and s takeholder involvement. Based on current education system, initial findings suggest that competencies in urban planning will not necessarily enable students to address challenges related to the development of smart and sustainable cities. Rather, engineeri ng, science and social knowledge, which would engender the ability to predict future social dynamics, should enable graduates to become active drivers of sustainable and livable cities 
CONTEXTUALISING URBAN ENGINEERING EDUCATION FOR FUTURE CITIES
Published ArticleWhile rapidity in service activities have strengthened the role of urban areas as engines
of economic growth, high population density and increased industrialization, has
brought needless social and environmental complaints in cities. This phenomenon
necessitates a change in societal attitude in favor of the creation of responsible living
conditions, which demands requisite skills and knowledge that would shape the cities.
Thus, this paper explores the adequacy of current urban engineering education in terms
of the knowledge, skills and competencies required to plan and develop future cities.
The paper examines how âwicked problemsâ that marginalize effective sustainable
city planning can be addressed through astute understanding of social and
environmental challenges, urban governance systems and stakeholder involvement.
Based on current education system, initial findings suggest that competencies in urban
planning will not necessarily enable students to address challenges related to the
development of smart and sustainable cities. Rather, engineering, science and social
knowledge, which would engender the ability to predict future social dynamics, should
enable graduates to become active drivers of sustainable and livable cities
Magnetic Proximity Effect in YBaâCuâOâ/La<sub>2/3</sub>Ca<sub>1/3</sub>MnOâ and YBaâCuâOâ/LaMnOââ Superlattices
Using neutron reflectometry and resonant x-ray techniques we studied the magnetic proximity effect (MPE) in superlattices composed of superconducting YBaâCuâOâ and ferromagnetic-metallic La0.67Ca0.33MnOâ or ferromagnetic-insulating LaMnOââ. We find that the MPE strongly depends on the electronic state of the manganite layers, being pronounced for the ferromagnetic-metallic La0.67Ca0.33MnOâ and almost absent for ferromagnetic-insulating LaMnOââ. We also detail the change of the magnetic depth profile due to the MPE and provide evidence for its intrinsic nature
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Abstract
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and lowâmiddle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of âsingle-useâ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for lowâmiddle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both highâ and lowâmiddleâincome countries
Synthesis and uses of macrobicyclic cryptands: from complexation of transition metal ions to molecular devices
Syntheses of a number of cryptands having heteroditopic as well as heterotritopic receptor sites have been achieved using alkali metal ions as templates. Some of the cryptands can be synthesized on a multi-gram scale without using any templating metal ions at low temperature (278 K). Each of these cryptands readily forms inclusion complexes with transition metal ions. These cryptands exhibit interesting properties and can further accomodate small anions inside the cavity. Further, upon suitable derivatization, some of the cryptands can behave as amphiphiles and form Langmuir-Blodgett films very readily. When derivatized with 9-methylanthracene, some of the cryptands show interesting fluorescence properties and can be of use as molecular photonic devices
Correlation of dielectric, electrical and magnetic properties near the magnetic phase transition temperature of cobalt zinc ferrite
Multiferroic composite structures, i.e., composites of magnetostrictive and piezoelectric materials can be envisioned towards the goal of achieving strong room-temperature ME coupling for real practical device applications. Magnetic materials with high magnetostriction, high NĂ©el temperature (TN), high resistivity and large magnetization are required to observe high ME coupling in composite structures. In continuation to our investigations for suitable magnetic candidate for multiferroic composite structures, we have studied the crystal structure, dielectric, transport, and magnetic properties of Co0.65Zn0.35Fe2O4 (CZFO). Rietveld refinement of X-ray diffraction patterns confirms the phase purity with cubic crystal structure with (Fd3m) space group; however, we have found a surprisingly large magnto-dielectric anomaly at the Neel temperature, unexpected for a cubic structure. The presence of mixed valences of Fe+2/Fe+3 cations is probed by X-ray photon spectroscopy (XPS), which support the catonic ordering-mediated large dielectric response. Large dielectric permittivity dispersion with a broad anomaly is observed in the vicinity of the magnetic phase transition temperature (TN) of CZFO suggest the strong correlation between dielectric and magnetic properties. The ferromagnetic-paramagnetic phase transition of CZFO has been found ~640 K, which is well above room temperature. CZFO exhibits low loss tangent, high dielectric constant and large magnetization with soft magnetic behavior above room temperature. We describe the possible potential candidates for multiferroic composite structures as well as for multifunctional and spintronics device applications
Correlation of dielectric, electrical and magnetic properties near the magnetic phase transition temperature of cobalt zinc ferrite
Multiferroic composite structures, i.e., composites of magnetostrictive and piezoelectric materials can be envisioned towards the goal of achieving strong room-temperature ME coupling for real practical device applications. Magnetic materials with high magnetostriction, high NĂ©el temperature (TN), high resistivity and large magnetization are required to observe high ME coupling in composite structures. In continuation to our investigations for suitable magnetic candidate for multiferroic composite structures, we have studied the crystal structure, dielectric, transport, and magnetic properties of Co0.65Zn0.35Fe2O4 (CZFO). Rietveld refinement of X-ray diffraction patterns confirms the phase purity with cubic crystal structure with (Fd3m) space group; however, we have found a surprisingly large magnto-dielectric anomaly at the Neel temperature, unexpected for a cubic structure. The presence of mixed valences of Fe+2/Fe+3 cations is probed by X-ray photon spectroscopy (XPS), which support the catonic ordering-mediated large dielectric response. Large dielectric permittivity dispersion with a broad anomaly is observed in the vicinity of the magnetic phase transition temperature (TN) of CZFO suggest the strong correlation between dielectric and magnetic properties. The ferromagnetic-paramagnetic phase transition of CZFO has been found ~640 K, which is well above room temperature. CZFO exhibits low loss tangent, high dielectric constant and large magnetization with soft magnetic behavior above room temperature. We describe the possible potential candidates for multiferroic composite structures as well as for multifunctional and spintronics device applications
Structural, microstructural and magneto-electric properties of single-phase BiFeO3 nanoceramics prepared by auto-combustion method
Polycrystalline nano BiFeO3 powders were synthesized by auto-combustion method using urea as fuel and metal nitrates (Fe(NO3)(3).9H(2)O, Bi(NO3)(3)-5H(2)O) as oxidizers. In order to optimize the single-phase synthesis condition of BiFeO3, different fuel to oxidizer ratios have been investigated. The preliminary structural investigation using X-ray diffraction shows the samples were of single phase and crystallize in rhombohedral structure (R3c). The ferroelectric and antiferromagnetic ordering temperatures of BiFeO3 were found to be 832 degrees C and 364 degrees C respectively, from differential thermal analysis. The temperature dependent dielectric study shows an anomaly around 215 degrees C which corresponds to magneto-electric coupling in the material. Field-emission scanning electron micrographs show effect of fuel to oxidizer ratio on grain size evolution. The ferroelectric hysteresis loops for all the samples were measured at a frequency of 100 Hz confirming the ferroelectric nature. An evidence of magneto-electric coupling was also observed at room temperature from magneto-capacitance measurements. (C) 2013 Elsevier B.V. All rights reserved
Consequence of Presence and Absence of ÏâClouds at Strategic Locations of Designed Binuclear Pd(II) Complexes on Packing: Self-Assembly of Self-Assembly by Intermolecular Locking and Packing
Self-assembled binuclear coordination cages of general
formula
[Pd<sub>2</sub>(NâN)<sub>2</sub>(<b>L</b>)<sub>2</sub>]Â(X)<sub>4</sub>, <b>1a/b</b>â<b>4a/b</b> are
prepared by the combination of <i>N</i>,<i>N</i>âČ-bisÂ(<i>m</i>-pyridyl)Âurea, <b>L</b>, with
a variety of <i>cis</i>-protected palladiumÂ(II) components,
PdÂ(NâN)Â(X)<sub>2</sub>. The <i>cis</i>-protecting
units âNâNâ employed for the synthesis of <b>1</b>â<b>4</b> are ethylenediamine (en), tetramethylethylenediamine
(tmeda), 2,2âČ-bipyridine (bpy), and 1,10-phenanthroline (phen),
respectively. The term âXâ stands for nitrate and perchlorate
for <b>a</b> and <b>b</b>, respectively. The assemblies
are characterized by NMR and electrospray ionization mass spectrometry
(ESI-MS) techniques, and in some cases (i.e., <b>1a</b>,<b> 2b</b>,<b> 3b</b>,<b> 4a</b>, and <b>4b</b>) the structures are confirmed by single crystal X-ray diffraction.
The conformations of bound <b>L</b> in the crystal structures
of all the PdÂ(II) complexes are found to be <i>syn-syn</i>. The influence of the presence and absence of Ï cloud at the <i>cis-</i>protecting units on the crystal packing has been studied
in detail. In the packing of [Pd<sub>2</sub>(phen)<sub>2</sub><b>L</b><sub>2</sub>]Â(NO<sub>3</sub>)<sub>4</sub>, <b>4a</b>, one unit of [Pd<sub>2</sub>(phen)<sub>2</sub><b>L</b><sub>2</sub>]<sup>4+</sup> is associated with two other units by ÏâÏ
stacking interactions thus giving a one-dimensional growth as envisioned
on the basis of a design principle. In the case of [Pd<sub>2</sub>(en)<sub>2</sub>(<b>L)</b><sub>2</sub>]Â(NO<sub>3</sub>)<sub>4</sub>, <b>1a</b>, and [Pd<sub>2</sub>(tmeda)<sub>2</sub>(<b>L</b>)<sub>2</sub>]Â(ClO<sub>4</sub>)<sub>4</sub>, <b>2b</b>, such packing is not observed due to the absence of Ï-cloud
at the strategic locations, instead notable H-bonding interactions
are seen. However, [Pd<sub>2</sub>(bpy)<sub>2</sub>(<b>L</b>)<sub>2</sub>]Â(ClO<sub>4</sub>)<sub>4</sub>, <b>3b</b>, displays
a ÏâÏ interactions using only two units of [Pd<sub>2</sub>(bpy)<sub>2</sub>(<b>L</b>)<sub>2</sub>]<sup>4+</sup>(ClO<sub>4</sub>)<sup>â</sup>