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11.
Efadul Huq 《Planning Theory & Practice》2020,21(3):351-370
ABSTRACT This paper is in conversation with two important bodies of literature: one on informal settlements (informal and insurgent grassroots practices) and another on camps (spatial practices and governance of refugees). Reading inhabitants’ experiences in Korail, an informal settlement in Dhaka, Bangladesh, through the literature grounded in the experiences of refugees, we seek to contribute to the relational theorization of informal settlements and camps as an expanding and overlapping reality in the era of intensified global displacements. Weaving back and forth between the camp literature and Korail’s reality, we bring to light the comparable spatial practices and governance of the so-called citizens and the so-called stateless. We present the insights we gain from this analytical conversation under three organizing themes: experiential to highlight the precarious relationship of the two groups to citizenship and place, what we call a state of “citizenship in wait” and “in-situ displacement”; institutional to highlight the humanitarian matrices of care that provide governmental structures in both contexts; and micropolitical, to characterize dwellers’ contestations with state and humanitarian governance that constitute the processes of life-making in informal settlements, much as in the camps. Conceptually the paper lends a forceful voice to the mounting critiques of the state-centered canon in planning theories and the needed Southern turn in planning theorization. Politically, it lends a hand to the efforts of activists working to overcome exclusions and erasures that are endemic to the politics of citizenship, that pit refugees against the poor, and to gesture toward forging solidarities for a humane urbanism. 相似文献
12.
Tahmida N. Huq Lana C. Lee Lissa Eyre Weiwei Li Robert A. Jagt Chaewon Kim Sarah Fearn Vincenzo Pecunia Felix Deschler Judith L. MacManus‐Driscoll Robert L. Z. Hoye 《Advanced functional materials》2020,30(13)
In the search for nontoxic alternatives to lead‐halide perovskites, bismuth oxyiodide (BiOI) has emerged as a promising contender. BiOI is air‐stable for over three months, demonstrates promising early‐stage photovoltaic performance and, importantly, is predicted from calculations to tolerate vacancy and antisite defects. Here, whether BiOI tolerates point defects is experimentally investigated. BiOI thin films are annealed at a low temperature of 100 °C under vacuum (25 Pa absolute pressure). There is a relative reduction in the surface atomic fraction of iodine by over 40%, reduction in the surface bismuth fraction by over 5%, and an increase in the surface oxygen fraction by over 45%. Unexpectedly, the Bi 4f7/2 core level position, Fermi level position, and valence band density of states of BiOI are not significantly changed. Further, the charge‐carrier lifetime, photoluminescence intensity, and the performance of the vacuum‐annealed BiOI films in solar cells remain unchanged. The results show BiOI to be electronically and optoelectronically robust to percent‐level changes in surface composition. However, from photoinduced current transient spectroscopy measurements, it is found that the as‐grown BiOI films have deep traps located ≈0.3 and 0.6 eV from the band edge. These traps limit the charge‐carrier lifetimes of BiOI, and future improvements in the performance of BiOI photovoltaics will need to focus on identifying their origin. Nevertheless, these deep traps are three to four orders of magnitude less concentrated than the surface point defects induced through vacuum annealing. The charge‐carrier lifetimes of the BiOI films are also orders of magnitude longer than if these surface defects were recombination active. This work therefore shows BiOI to be robust against processing conditions that lead to percent‐level iodine‐, bismuth‐, and oxygen‐related surface defects. This will simplify and reduce the cost of fabricating BiOI‐based electronic devices, and stands in contrast to the defect‐sensitivity of traditional covalent semiconductors. 相似文献
13.
Synthetic Control of Kinetic Reaction Pathway and Cationic Ordering in High‐Ni Layered Oxide Cathodes
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Dawei Wang Ronghui Kou Yang Ren Cheng‐Jun Sun Hu Zhao Ming‐Jian Zhang Yan Li Ashifia Huq J. Y. Peter Ko Feng Pan Yang‐Kook Sun Yong Yang Khalil Amine Jianming Bai Zonghai Chen Feng Wang 《Advanced materials (Deerfield Beach, Fla.)》2017,29(39)
Nickel‐rich layered transition metal oxides, LiNi1?x (MnCo)x O2 (1?x ≥ 0.5), are appealing candidates for cathodes in next‐generation lithium‐ion batteries (LIBs) for electric vehicles and other large‐scale applications, due to their high capacity and low cost. However, synthetic control of the structural ordering in such a complex quaternary system has been a great challenge, especially in the presence of high Ni content. Herein, synthesis reactions for preparing layered LiNi0.7Mn0.15Co0.15O2 (NMC71515) by solid‐state methods are investigated through a combination of time‐resolved in situ high‐energy X‐ray diffraction and absorption spectroscopy measurements. The real‐time observation reveals a strong temperature dependence of the kinetics of cationic ordering in NMC71515 as a result of thermal‐driven oxidation of transition metals and lithium/oxygen loss that concomitantly occur during heat treatment. Through synthetic control of the kinetic reaction pathway, a layered NMC71515 with low cationic disordering and a high reversible capacity is prepared in air. The findings may help to pave the way for designing high‐Ni layered oxide cathodes for LIBs. 相似文献
14.
Zhonghe Bi Juan Peña-Martínez Jung-Hyun Kim Craig A. Bridges Ashfia Huq Jason P. Hodges M. Parans Paranthaman 《International Journal of Hydrogen Energy》2012
The sintering properties, crystal structure and electrical conductivity of La1−xCaxNbO4−δ (x = 0, 0.005, 0.01, 0.015, 0.02 and 0.025), prepared by a solid-state reaction, have been investigated using powder X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS), and electrochemical impedance spectroscopy (EIS). In 2.5% Ca-doped samples, a small amount of impurities Ca2Nb2O7 were observed from the XRD patterns. Impedance spectra show that the grain boundary resistance increases with increasing Ca content, while the bulk resistance remains essentially constant below 550 °C. Despite the higher degree of grain growth observed for higher Ca doping levels, the total conductivity of the La1−xCaxNbO4−δ series decreases with increasing Ca content from 0.5 to 2.0 mol%. The activation energy for the total conductivity decreases with increasing Ca content from 0.71 eV (x = 0) to 0.54 eV (x = 0.01) for the high temperature tetragonal phase, then it increases to 0.60 eV for x = 0.02. For the monoclinic phase, the activation energy exhibits similar trend except La0.995Ca0.005NbO4−δ shows the lowest value of 1.26 eV. The Ca and Nb content present at the grain boundaries for La0.99Ca0.01NbO4−δ are much higher than that on the grain surface, as determined from the EDS analysis. These results imply that the solubility of CaO in LaNbO4 is in the range from 0.5 to 1.0 mol%. By increasing the sintering temperature from 1500 °C to 1550 °C, the proton conductivity of the Ca-doped LaNbO4 was improved with enlarged grain size due to a reduction in the resistive grain boundary contribution. 相似文献
15.
This study addresses the extension of the “procedural justice” model for understanding public cooperation with law enforcement to new policing contexts and new minority populations. The study draws on four recent surveys of public reactions to policing against crime or against terrorism across different populations to examine whether the changing purpose of policing, or changes in the communities targeted for heightened policing, have an effect on how cooperative behaviors are elicited. This paper presents evidence that procedural justice mechanisms are robust across a variety of contexts and populations in the United States. Three issues in particular are addressed. First, whether the procedural justice model applies across policing functions and policed populations. Second, whether the perception that another group is the target of disproportionate policing efforts has any effect on the cooperation behavior of a non-targeted population. And third, whether people attend to different aspects of policing behavior if their community is targeted for heightened policing attention. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
16.
Tanzina Huq Avik Khan Nazia Noor M. Saha Mubarak A. Khan 《Polymer-Plastics Technology and Engineering》2013,52(4):407-413
The aim of the research was to study the effect of LLDPE incorporation in the jute fiber-reinforced PET composites (50% fiber by wt). The effect of LLDPE incorporation into PET was investigated by measuring the mechanical properties of the LLDPE blended jute fiber-reinforced PET composites. LLDPE was blended (20-80% by wt) with PET and the thin films were made by compression molding. Water uptake of the composites was also investigated. Degradation of all the composites was carried out in soil medium. 相似文献
17.
18.
Fletcher J.R. Thorpe J.R. Huq E. Mann C. Steenson D.P. Chamberlain M. 《Microwave Theory and Techniques》2004,52(10):2344-2351
The problems facing the development of klystrons for use at submillimeter wavelengths are reviewed. Analytical formulas for reentrant cavity resonance, starting conditions, output power, and oscillation buildup are presented. This paper describes methods of calculating cavity Q-factor, output coupling, focusing potentials, electron paths, and heating effects. The scaling of output power with frequency is derived. Examples of techniques that might be used to realize a working device are presented. 相似文献
19.
In January 1994 mass antibiotic prophylaxis was undertaken in the contiguous villages of Deir el-Asad and B'ine in northern Israel (combined population of 11600) in response to a prolonged outbreak of serogroup B meningococcal infection with an overall annual rate of 37.4 cases of infection per 100000 residents. The average case fatality rate in the villages was 23% compared with 11% in Israel during the same period. Neisseria meningitidis group B was identified in 9 of 13 (69%) cases. Seven of these were subtype P1.7,16. The persistence of the outbreak with its accompanying public reaction prompted the establishment of an intervention programme that included antibiotic prophylaxis for the whole community with monitoring for pharyngeal carriage of meningococci in a stratified sample of the population. The objectives were to achieve a reduction of carriage of the outbreak strain and to reduce morbidity and mortality. A total of 1036 pharyngeal swabs were taken 1 day before and 6 weeks after treatment. Antibiotic prophylaxis was administered in one dose: children under 5-years-old received ceftriaxone i.m.; all others received oral ciprofloxacin. Overall, 96% of the population received treatment. The carriage rate was 8.3% prior to treatment (three serogroup B:14:P1.7,16), and 1.3% afterwards (one serogroup B:14:P1.7,16). The intervention failed to eradicate carriage of the putative outbreak strain, or to reduce the incidence and fatality rates in the villages. The outbreak finally terminated in late 1996. Public health professionals should bear this experience in mind when faced with prolonged, localized, nonexplosive outbreaks of meningococcal disease associated with low carriage rates of the outbreak strain. 相似文献
20.