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891.
This article examines some techno-political aspects of the early years of electrification in British-ruled 1920s Palestine. It emphasizes the importance of local technical, topographical and hydrological forms of knowledge for understanding the dynamics of electrification. Situating the analysis in a general colonial context of electrification, the study shows that British colonial rulers lagged behind both German firms and local entrepreneurs in understanding the specific conditions pertaining to electrification in Palestine. Subsequently, the study shows that the British had limited control of the actual electrification process and its declared/professed developmental purposes, thereby complicating assumptions about electrification as a tool of the Empire/tool of empire. Finding some similarities between the cases of electrifying Palestine and India, the article’s findings may shed further light on the importance of micro-politics of knowledge for understanding the trajectory of electrification in the colonies. 相似文献
892.
In the academic debate on infrastructures in the Global South, there is a broad consensus that (post)colonial legacies present a major challenge for a transition towards more inclusive, sustainable and adapted modes of providing services. Yet, relatively little is known about the emergence and evolution of infrastructures in former colonies. Until a decade ago, most historical studies followed Daniel Headrick’s (1981) “tools of empire” thesis, painting—with broad brush strokes—a picture of infrastructures as instruments for advancing the colonial project of exploitation and subordination of non-European peoples and environments. This paper explores new research perspectives beyond this straightforward, ‘diffusionist’ perspective on technology transfer. In order to do so, it presents and discusses more recent studies which focus on interactive transfer processes as well as mechanisms of appropriation, and which increasingly combine approaches from imperial history, environmental history, and history of technology.There is much to gain from unpacking the changing motives and ideologies behind technology transfer; tracing the often contested and negotiated flows of ideas, technologies and knowledge within multilayered global networks; investigating the manifold ways in which infrastructures reflected and (re)produced colonial spaces and identities; critically reflecting on the utility of large (socio)technical systems (LTS) for the Global South; and approaching infrastructures in the (post)colonial world through entangled histories of technology and the environment. Following David Arnold’s (2005) plea for a “more interactive, culturally-nuanced, multi-sited debate” on technology in the non-Western world, the paper offers fresh insights for a broader debate about how infrastructures work within specific parameters of time, place and culture. 相似文献
893.
894.
UJJAL?KUMAR?SUREmail author ABHIJIT?SAHA APARNA?DATTA BALAPRASAD?ANKAMWAR FARAH?SURTI SANNAK?DUTTA?ROY DEBASISH?ROY 《Bulletin of Materials Science》2016,39(1):159-165
A stable aqueous dispersion (5 mg ml?1) of graphene was synthesized by a simple protocol based on three-step reduction of graphene oxide (GO) dispersion synthesized using the modified version of Hummers and Offeman method. Reduction of GO was carried out using sodium borohydride, hydrazine hydrate and dimethyl hydrazine as reducing agents. The chemically synthesized graphene was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–visible absorption spectroscopy, Fourier transform infrared (FTIR) and Raman spectroscopy, thermogravimetric analysis (TGA), optical microscopy. The stability of aqueous dispersions of graphene was confirmed through zeta potential measurements and the negative zeta potentials of 55–60 mV were obtained indicating the high stability of aqueous graphene dispersions. 相似文献
895.
After deposition of NiAlOx thin films on stainless-steel substrates by the spray pyrolysis technique, various properties of the films were investigated using Fourier transform infrared spectroscopy, UV–visible reflectance spectrophotometry, energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Optical quantities were determined using reflectance spectra in the relevant spectrum region. At first the optimal substrate temperature was selected and then different nickel to aluminium ratios were examined to find the efficient solar absorber. The SEM revealed changes in morphology due to different molar ratios. The XRD of the selected sample showed a mixture of nickel and nickel oxide phases with the strong presence of substrate peaks and without the presence of alumina phase while in the EDX test the peaks corresponding to O, Al and Ni appeared. Long-term thermal stability study was performed by means of performance criterion concept. 相似文献
896.
SHADAB?DABAGH ALI?A?ATI S?K?GHOSHAL SAMAD?ZARE R?M?ROSNAN AHMED?S?JBARA ZULKAFLI?OTHAMANEmail author 《Bulletin of Materials Science》2016,39(4):1029-1037
Cu–Al substituted Co ferrite nanopowders, Co1?x Cu x Fe2?x Al x O4 (0.0 ≤ x ≤ 0.8) were synthesized by the co-precipitation method. The effect of Cu–Al substitution on the structural and magnetic properties have been investigated. X-ray diffraction (XRD) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM) and vibrating sample magnetometer (VSM) are used for studying the effect of variation in the Cu–Al substitution and its impact on particle size, magnetic properties such as M s and H c . Cu–Al substitution occurs and produce a secondary phase, α-Fe 2 O 3. The crystallite size of the powder calcined at 800 °C was in the range of 19–26 nm. The lattice parameter decreases with increasing Cu–Al content. The nanostructural features were examined by FESEM images. Infrared absorption (IR) spectra shows two vibrational bands; at around 600 (v 1) and 400 cm ?1 (v 2). They are attributed to the tetrahedral and octahedral group complexes of the spinel lattice, respectively. It was found that the physical and magnetic properties have changed with Cu–Al contents. The saturation magnetization decreases with the increase in Cu–Al substitution. The reduction of coercive force, saturation magnetization and magnetic moments are may be due to dilution of the magnetic interaction. 相似文献
897.
In this paper, device performance of graphene nanoribbon field effect transistor (GNRFET) with different doping concentrations in different parts of the channel is reported. The study is performed by using atomistic simulations based on self-consistent solution of Schrodinger’s and Poisson’s equation within the non-equilibrium Green’s function formalism. The transfer and output characteristics suggest that device performance with n-type doping in the channel is better with smaller supply voltage compared to higher supply voltage. On increasing the n-type doping concentration, we obtained better on-current and output characteristics in comparison with undoped and p-type doped channel GNRFET. Further, we introduced step-doping profile in the graphene nanoribbon (GNR) channel and found that the device gives better on-current and good saturation condition when compared to undoped or uniformly-doped channel. 相似文献
898.
PING-YING?TANGEmail author GUO-HUA?HUANG QING-LIAN?XIE JIAN-YING?LI 《Bulletin of Materials Science》2016,39(6):1411-1418
The stress–strain relationships for four different shear processes of L1 0 TiAl have been investigated from first-principles calculations, and the peak shear stresses in these slip systems were obtained. By analysing the structural unit cell, bond length and charge density, the deformation modes under shear were elaborately discussed. Both of the peak shear stresses and the charge density indicate that the ideal shear strength of L1 0 TiAl occurs in the \(\boldsymbol {\langle \! 11\bar {2} ]\{111\}}\) direction. It is shown that some bonds are enormously stretched accompanying with depletion of charge density as the strain increase. The density of states was studied in detail. It is indicated that strong hybridization exists between Ti 3 d and Al 2 p, and the structural stability would be lowered with increase of the strain. 相似文献
899.
Delay and cost overrun are common phenomena in projects worldwide. However, these are especially severe in developing countries. In India as per MOSPI report, 235 projects out of 410 were severely affected cost overrun due to certain factors. A short questionnaire was conducted with 15 prominent factors responsible for cost overrun and forwarded to 190 constructional professionals across India. Total 85 responses were received and it was analyzed using various statistical tools such as analysis of variance (ANOVA) and factor analysis tool using SPSS. In this study, top three factors affecting cost overruns were identified such as price escalation of raw material, delay in planned activity and lack of co-ordination between construction parties which could be significantly responsible for cost overnun of construction project in India. Factor analysis method was also carried out to group the factors into three components of overall questionnaire. These components, such as client control component, project management component, and contractor control component, would be useful to the various parties involved in the construction activities. This paper also provides suggestive frameworks which have been framed after discussing with large number of construction professionals or expert. 相似文献
900.
Enhancing Interfacial Bonding between Anisotropically Oriented Grains Using a Glue‐Nanofiller for Advanced Li‐Ion Battery Cathode 下载免费PDF全文