Increase In Growth Pressure Research Articles

A Dual Strategy in the Adaptive Reuse of Industrial Heritage Buildings: The Shanghai West Bund Waterfront Refurbishment

Waterfront intervention, as one of the post-industrial reuse paradigms, has flourished around the world and been studied as a global phenomenon. This paper investigates the application of a dual adaptive reuse strategy to industrial heritage waterfront buildings and explores its social significance. The case study is of the West Bund, a waterfront renovation in Shanghai, China. Insights are drawn from the qualitative research approach of triangulation, with evidence derived from document sources, archival records, direct participants and semi-structured interviews. This paper examines a series of galleries and landscapes created from former industrial buildings and facilities along the Huangpu River. It concludes that the West Bund exemplifies a dual strategy of adaptive reuse: art-led and landscape-led building reuse. This dual strategy can be viewed as an endeavour to balance urban gentrification and publicness in the megalopolis. It can also be argued, however, that the dual approach to adaptive reuse is unsustainable within the framework of an entrepreneurial state, and significantly so in the post-epidemic era when economic growth pressure increases. This study contributes to our understanding of the complex nature of industrial heritage in the rapidly shifting landscape of contemporary China.

Effects of growth pressure on the characteristics of the β-Ga2O3 thin films deposited on (0001) sapphire substrates

β-Ga2O3 films were grown on (0001) sapphire substrates by low-pressure MOCVD. The effects of growth pressure on the growth rate, surface morphology and optical properties of β-Ga2O3 thin films were investigated. XRD showed that the β-Ga2O3 films grown preferentially along the (-201) crystal plane family were obtained, and the increase in growth pressure led to a decrease in growth rate, consistent with the SEM results. AFM measurements indicated that the increase in growth pressure reduced the grain size and RMS roughness. Optical transmission spectroscopy demonstrated that the average transmittance of all films in the visible range exceeded 75%, and the optical bandgap at 20, 30 and 40 Torr were 4.95, 4.93 and 4.91 eV, respectively. XPS revealed that the Ga 2p peak and O 1s peak blue shift as the growth pressure. Through RT-Raman spectroscopy, the low-frequency and high-frequency Raman vibration modes of β-Ga2O3 were detected.

Gallium oxide films deposition by RF magnetron sputtering; a detailed analysis on the effects of deposition pressure and sputtering power and annealing

In this study, gallium oxide (Ga2O3) thin films were deposited on sapphire and n-Si substrates using Ga2O3 target by radio frequency magnetron sputtering (RFMS) at substrate temperature of 300 °C at variable RF power and deposition pressure. The effects of deposition pressure and growth power on crystalline structure, morphology, transmittance, refractive index and band gap energy were investigated in detail. X-ray diffraction results showed that amorphous phase was observed in all the as-deposited thin films except for the thin films grown at low growth pressure. All the films showed conversion to poly-crystal β-Ga2O3 phase after annealing process. When the deposition pressure increased from 7.5 mTorr to 12.20 mTorr, change in the 2D growth mode to 3D columnar growth mode was observed from the SEM images. Annealing clearly showed formation of larger grains for all the thin films. Lower transmission values were observed as the growth pressure increases. Annealing caused to obtain similar transmittance values for the thin films grown at different pressures. It was found that a red shift observed in the absorption edges and the energy band gap values decrease with increasing growth pressure. For as-deposited and annealing films, increasing sputtering power resulted in the increase refractive index.

Growth Control of WS2: From 2D Layer by Layer to 3D Vertical Standing Nanowalls.

Large area 2D WS2 has been grown successfully by radio frequency magnetron sputtering (RFMS) method. First, in order to investigate the pressure dependence on the grown WS2 samples, WS2 were grown at 5 different growth pressures, 5, 10, 15, 20, and 25 mTorr. It has been observed that the surface morphology changes for the samples grown at higher growth pressures, 15, 20, and 25 mTorr. Vertically standing nanowall (NW)-like structures have been formed at these relatively high growth pressures. It has also been observed that the (002) plane is highly dominant, which means layer by layer growth parallel to the substrate, for the sample grown at 20 mTorr. X-ray photoelectron spectroscopy (XPS) measurements revealed an increasing atomic percentage of the S element to W element, S/W, ratio in thin films, as the growth pressure increases. Growth dynamics of WS2 has been investigated by time-dependent-growth WS2 samples, 5, 10, 20, 40, and 80 s under 20 mTorr pressure. It has been shown by atomic force microscopy, scanning electron microscopy, and transmission electron microscopy that a highly smooth surface has been achieved in the samples grown for the duration of 5 and 10 s. Raman mapping measurements on the sample grown at 5 s have revealed large area homogeneous growth. As the growth time gets longer, the NWs emerge on the surface at some nucleation points. Only the peak that belongs to the (002) plane has been observed for samples grown at 5 and 10 s by the X-ray diffraction (XRD) measurements. XRD measurements have revealed the appearance of turbostratic peaks of (11l) and (10l) as the thickness increases. Photoluminescence measurements have indicated near-band-edge emission centered at 630 nm for only 5 and 10 s samples.

Effect of different migration energy for reaction atoms on growth orientation and optical absorption characteristics of cubic MgZnO thin films under different pressure by PLD method

Mg1−xZnxO thin films were deposited under different pressures during the growth process, which is modulated by different Ar/O2 flow ratio. When growth pressure increases, the growth orientation of MgZnO thin film changed from (200) to (111) because of the decrease in migration energy of reactive Mg, Zn and O atoms from MgZnO target material. The band gap of MgZnO thin films decreased when growth pressure increased from 2Pa to 6Pa, which is reason from more Zn atoms combined with O atoms in (111) orientation MgZnO crystal lattice in MgZnO thin film deposited at higher pressures. But when the growth pressure increased from 6Pa to 7Pa, the band gap value of MgZnO thin films increased because less Zn atoms than Mg atoms combined with O atoms in MgZnO crystal lattice at higher pressures with the same (111) orientation.

Effect of stimulated phase separation on properties of blue, green and monolithic white LEDs

AbstractDifferent methods of stimulation of phase separation in an InGaN QWs by technological methods and by design of structure were investigated. Effect of admixing of hydrogen during growth interruptions (GIs) after deposition of the InGaN QWs on their structural and optical properties and properties of InGaN‐based LEDs was investigated. Effect of growth pressure on the phase separation was investigated and formation of separate InGaN islands at increase in growth pressure was revealed. It was shown that the phase separation is stumulated in composite InAlN/GaN/InGaN heterostructures and formation of well isolated InGaN islands was observed. Effect of the phase separation on the properties of the blue and deep green LEDs was investigated and strong changes in the spectral position and current dependence of the quantum efficiency were revealed. It was shown that formation of the island due to the phase separation allows control position and width of the emission line and maximum in current dependence of the quantum efficiency. Monolithic white LEDs are containing in active region blue and green InGaN QWs grown with applying of the GIs and emitting in spectral range from 440 nm to 560 nm were studied. Monolithic white LEDs having optimal design of active region demonstrate CCT in the range of 9000‐12000 K and maximal external quantum efficiency up to 14 lm/W. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Structural and optical properties of silicon–germanium alloy nanoparticles

Silicon–germanium alloy nanoparticles with spherical shape have been prepared by the thermal evaporation method. The shape and structure of these dots have been studied. Transmission electron microscopy images show that the SiGe nanoparticles grown at 100 Torr may be composed of two half-moon shaped sections. Furthermore from the transmission electron diffraction patterns and Raman spectra, a change of structure from amorphous to crystalline at the 0.4 Torr growth pressure was observed. It is also found that if the growth pressure increases, the Ge composition of SiGe dots will decrease. A model is proposed to explain this phenomenon.

Adaptive changes in membrane lipids of barophilic bacteria in response to changes in growth pressure.

The lipid compositions of barophilic bacterial strains which contained docosahexaenoic acid (DHA [22:6n-3]) were examined, and the adaptive changes of these compositions were analyzed in response to growth pressure. In the facultatively barophilic strain 16C1, phosphatidylethanolamine (PE) and phosphatidylglycerol (PG) were major components which had the same fatty acid chains. However, in PE, monounsaturated fatty acids such as hexadecenoic acid were major components, and DHA accounted for only 3.7% of the total fatty acids, while in PG, DHA accounted for 29.6% of the total fatty acids. In response to an increase in growth pressure in strain 16C1, the amounts of saturated fatty acids in PE were reduced, and these decreases were mainly balanced by an increase in unsaturated fatty acids, including DHA. In PG, the decrease in saturated fatty acids was mainly balanced by an increase in DHA. Similar adaptive changes in fatty acid composition were observed in response to growth pressure in obligately barophilic strain 2D2. Furthermore, these adaptive changes in response were also observed in response to low temperature in strain 16C1. These results confirm that the general shift from saturated to unsaturated fatty acids including DHA is one of the adaptive changes in response to increases in pressure and suggest that DHA may play a role in maintaining the proper fluidity of membrane lipids under high pressure.

Structural characterization of photochemically grown silicon dioxide films by ellipsometry and infrared studies

Silicon dioxide films grown by photochemical vapor deposition at different deposition rates are investigated by ellipsometry and Fourier transform infrared measurements. Disagreement in the variation of refractive index with chamber pressure between thin and thick films is interpreted in terms of a deposition rate dependent buildup of internal stress in the film. Direct measurements of curvature show the presence of compressive stress in thick SiO2 films grown at chamber pressures ≳600 mTorr. Infrared transmission measurements also indicate a change in the structural characteristics of films (probably induced by stress), with increasing deposition rate. Molecular model calculations show a decrease in the Si—O—Si bond angle as the growth pressure increases. Ion implantation seems to release the stress in these films as evidenced by the shift observed in the stretching mode frequency. The relative concentrations of H2O, SiOH, and SiH groups in these films and the effect of annealing on the strength of these modes are also discussed. Reflection infrared measurements at 60° incidence reveal a disorder induced longitudinal-transverse optic pair at around 1200 cm−1.