Surface morphology ofCuFeS2: The stability of the polar(112)/(112¯)surface pair

ABSTRACTHow the surface morphology of a low index crystal surface evolves under annealing below the roughening temperature is still being investigated both theoretically and experimentally. This research is needed to understand the stability of nanostructures and for the control of step array on surfaces for various technological applications.We have approached this problem from an experimental point of view by looking at the step morphology on the top of mesas patterned on Si(111) after flashing at 1200°C and annealing between 1000–1100°C. We find that after annealing, nanometer height ridges develop on the edges of the mesas except for one edge which becomes a source for steps advancing into the mesa top. The edge that does not develop a ridge is mainly determined by the initial miscut of the surface.We attempt to explain our results through step dynamics and present some applications of this phenomena in creating novel arrays of steps.

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Stability and Reactivity of [11-20] Step in Initial Stage of Epitaxial Graphene Growth on SiC(0001)

Materials Science Forum ◽

10.4028/www.scientific.net/msf.778-780.1150 ◽

2014 ◽

Vol 778-780 ◽

pp. 1150-1153

Author(s):

Hiroyuki Kageshima ◽

Hiroki Hibino ◽

Hiroshi Yamaguchi ◽

Masao Nagase

Keyword(s):

Surface Morphology ◽

First Principles ◽

Epitaxial Graphene ◽

First Principles Calculation ◽

Control Parameters ◽

Graphene Growth ◽

Initial Stage ◽

The Stability

The energetics for the Si desorption and the C adsorption at a [11-20] step on SiC(0001) surface are studied using the first-principles calculation. It is found that the [11-20] step is stable and nonreactive. The stability of the step is thought to govern the surface morphology during the graphene formation. It is shown that the Si pressure and the temperature are the control parameters for the surface morphology and the graphene quality.

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PEMANFAATAN ZEOLIT ALAM SEBAGAI MEDIA PENDUKUNG AMOBILISASI ENZIM α-AMILASE

Jurnal Riset Kimia ◽

10.25077/jrk.v5i1.188 ◽

2015 ◽

Vol 5 (1) ◽

pp. 79

Author(s):

Upita Septiani ◽

Agrina Lisma

Keyword(s):

Surface Morphology ◽

Unit Activity ◽

Incubation Time ◽

Natural Zeolite ◽

Immobilized Enzyme ◽

Natural Zeolites ◽

Optimum Temperature ◽

Optimal Activity ◽

Immobilization Enzyme ◽

The Stability

ABSTRACT The utilization of natural zeolite as supporting media of α-amylase enzyme has been done. Natural zeolite which is activated with 3M HCl can remove impurities in the surface natural zeolite, uncover and widen the pores of the zeolite and activate functional groups to interact with α-amylase enzyme in the process of immobilization enzyme process. The mass of activated natural zeolite which is used as a material immobilized to get the optimal activity of α-amylase enzyme was 0.3 gram. Based on the measurement result of optimization of α-amylase enzyme were obtained optimum temperature of 35 oC, pH 5.6 and incubation time of 35 minutes with 0.04845 units/mL of the unit activity. And for α-amylase immobilized enzyme will be stable at the optimum temperature of 50 oC, pH 5.6 and incubation time of 45 minutes with 0.030 units/mL of the unit activity. SEM-EDX pattern shows the differences in surface morphology between natural zeolite and activated natural zeolites which contain α-amylase enzyme. A mobilization technique can increase the stability utilized in a α-amylase enzyme. Keywords : Zeolite, amobilization, α-amylase enzyme

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Effect of Ammonia on CeO2 Microspheres Prepared by Internal Gelation Process

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.281.9 ◽

2018 ◽

Vol 281 ◽

pp. 9-14

Author(s):

Xue Qiang Ding ◽

Jing Tao Ma ◽

Xing Yu Zhao ◽

Shao Chang Hao ◽

Chang Sheng Deng ◽

...

Keyword(s):

Grain Size ◽

Surface Morphology ◽

Cerium Dioxide ◽

Smooth Surface ◽

Molar Ratio ◽

Internal Gelation ◽

Compact Structure ◽

Gelation Process ◽

The Stability

The internal gelation process was used to prepare cerium dioxide microspheres. The effect of ammonia on the stability of the precursor solutions was investigated with the NH3∙H2O/Ce (NH4)2(NO3)6 molar ratio from 0 to 1.25. The surface morphology and microstructure of the sintered CeO2 microspheres were analyzed. With the increase of NH3∙H2O/Ce (NH4)2(NO3)6 molar ratio, the solutions became more unstable, which indicated that their gelation was initiated. When the NH3∙H2O/Ce (NH4)2(NO3)6 ratio varied from 0 to 0.75, the surface of the microspheres became rougher and grain size became larger. Further increase in the NH3∙H2O/Ce (NH4)2(NO3)6 ratios to 1 and 1.25 led to CeO2 microspheres with smooth surface and compact structure.

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Effect of Preparation-Induced Surface Morphology on the Stability of H-Terminated Si(111) and Si(100) Surfaces

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.92.179 ◽

2003 ◽

Vol 92 ◽

pp. 179-182 ◽

Cited By ~ 5

Author(s):

Heike Angermann ◽

W. Henrion ◽

M. Rebien ◽

A. Röseler

Keyword(s):

Surface Morphology ◽

The Stability

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Vacancies in solids and the stability of surface morphology

Nature ◽

10.1038/35088026 ◽

2001 ◽

Vol 412 (6847) ◽

pp. 622-625 ◽

Cited By ~ 91

Author(s):

K. F. McCarty ◽

J. A. Nobel ◽

N. C. Bartelt

Keyword(s):

Surface Morphology ◽

The Stability

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Synthesis of Cellulose Stearate Ester as Wet Strength Agent for Synthesis of Bio-polybag from Oil Palm Empty Fruit Bunch

International Journal of Engineering, Science and Information Technology ◽

10.52088/ijesty.v2i2.227 ◽

2021 ◽

Vol 2 (2) ◽

pp. 1-7

Author(s):

Eddy Kurniawan ◽

Rizka Mulyawan ◽

Angga Tri Agusna PA ◽

Wika Armadani ◽

Zainuddin Ginting

Keyword(s):

Surface Morphology ◽

Water Content ◽

Oil Palm ◽

Methyl Stearate ◽

Wet Strength ◽

Physical Strength ◽

Empty Fruit Bunches ◽

Ft Ir ◽

The Stability ◽

Wavenumber Region

Biodegradable polybags are an alternative to overcome the weakness of synthetic polybags because of their degradation properties. Oil palm empty fruit bunches contain a lot of cellulose so that they can be used as a biodegradable polybag. Wet Strength serves to increase the physical strength of bio-polybags when exposed to water (in wet conditions) so that water content stability is required. In this study, Cellulose Stearate Esters were synthesized in an effort to increase the stability of the water content in bio-polybags. Cellulose Stearate Esters are synthesized through a transesterification reaction between -Cellulose isolated from Oil Palm Empty Fruit Bunches (EFB) with methyl stearate. The synthesis of cellulose stearate esters was carried out by refluxing for 2 hours using methanol solvent with various catalysts Na2CO3 5, 10, 15, 20 mg and with volume variations of methyl stearate 5, 10, 15. And the best variation was determined based on the degree of substitution test, namely with variations Na2CO3 catalyst 20 mg and volume of methyl Stearate 15 ml, amounting to 1.95. The result of the synthesis, namely cellulose stearate, was tested for functional groups by FT-IR spectroscopy and surface morphology using SEM. The formation of cellulose stearate is supported by the FT-IR spectrum in the wavenumber region of 3468.01 cm-1 indicating an OH group, 3062.96 cm-1 indicating a CH stretching group, 1695.43 cm-1 indicating a C=O group, cm-1 indicating a CH bending group, 1095.57cm-1 indicates a COC group, 609.51cm-1 indicates a (CH2)n>4 group. The results of surface morphology analysis using SEM showed that the surface of cellulose stearate looked homogeneous, more regular and had denser cavities than -Cellulose

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Методы атомно-силовой микроскопии для исследования суперпротонных кристаллов

Журнал технической физики ◽

10.21883/jtf.2020.11.49972.116-20 ◽

2020 ◽

Vol 90 (11) ◽

pp. 1843

Author(s):

Р.В. Гайнутдинов ◽

А.Л. Толстихина ◽

Е.В. Селезнева ◽

И.П. Макарова

Keyword(s):

Atomic Force Microscopy ◽

Surface Morphology ◽

Ammonium Sulfate ◽

Paraelectric Phase ◽

Piezoelectric Response ◽

Force Microscopy ◽

Atomic Force ◽

Microscopy Data ◽

The Stability ◽

First Time

Complex studies of new superprotonic crystals - acidic salts of potassium – ammonium sulfate (K1-x(NH4)x)3H(SO4)2, x ≥ 0.57 were carried out. Data on surface morphology, domain structure and conductivity of samples were obtained using atomic force microscopy. For the first time, the stability and degradation of the surface of superprotonic crystals were studied at the nanoscale. Based on piezoelectric response microscopy data, it was found that when the temperature decreased from 296 to 282 K, the (K0.43(NH4)0.57)3H(SO4)2 crystal transits from the paraelectric phase to the ferroelectric one.

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Evaluation of Biocompatibility and Release Profile of Ginger Extract Loaded Hyaluronic Acid Nanocapsules for Medical Applications

Journal of Shahid Sadoughi University of Medical Sciences ◽

10.18502/ssu.v27i10.2403 ◽

2020 ◽

Author(s):

Marjan Ashegh Moalla ◽

Mahboobeh Mahmoodi ◽

Masoumeh Tabatabaee

Keyword(s):

Hyaluronic Acid ◽

Surface Morphology ◽

Control Sample ◽

Particle Diameter ◽

Spherical Particles ◽

Medical Applications ◽

Average Particle ◽

In Vitro Test ◽

Ginger Extract ◽

The Stability

Introduction: Ginger is a plant that is used as a drug for pain relieving and anti-inflammatory in traditional medicine, but conventional prescribing of it faces serious challenges. One way to overcome these problems is the loading of ginger extract in polymer carriers. The aim of this study was characterization and evaluation of the loading and releasing of ginger extract from hyaluronic acid nanocapsules for medical applications. Methods: In this applied study, ginger extract as a pain-relieving drug was loaded in hyaluronic acid nanocapsules. The hyaluronic acid nanocapsules containing ginger extract were fabricated by emulsion method. The surface morphology, particle size and zeta potential, surface roughness and functional groups on the sample surface were evaluated by field emission electron microscopy (FESEM), dynamic light scattering (DLS), atomic force microscopy (AFM) and fourier transform infrared spectroscopy (FTIR), respectively. The stability and ginger release from nanocapsules were also determined via DLS and HPLC, respectively. The toxicity and fibroblast cells viability of ginger extract encapsulated in hyaluronic acid were evaluated by MTT assay. Data were analyzed by SPSS 16 Software. The t-Student test was performed for statistical comparison of data and statistically significant was P < 0.05. Results: The ginger entrapment efficiency (EE %) in nanocapsules was 74%. The average particle diameter and charge surface of the samples were calculated 413 nm and -10 mV, respectively. The negative charge of samples showed the stability of samples without agglomeration. Therefore, the surface morphology of the samples was observed as relatively spherical particles. In vitro test showed 95% fibroblast cell growth and proliferation on nanocapsules compared to the control sample (P < 0.05). Conclusion: The hyaluronic acid nanocapsules have a great potential for delivery of ginger extract in the area of pain and inflammation.

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Bioinspired Hydrogel Coating Based on Methacryloyl Gelatin Bioactivates Polypropylene Meshes for Abdominal Wall Repair

Polymers ◽

10.3390/polym12081677 ◽

2020 ◽

Vol 12 (8) ◽

pp. 1677

Author(s):

Andrada Serafim ◽

Sergiu Cecoltan ◽

Elena Olăreț ◽

Diana-Maria Dragusin ◽

Eugeniu Vasile ◽

...

Keyword(s):

Surface Morphology ◽

Cellular Response ◽

Platelet Rich Plasma ◽

Advanced Characterization ◽

Micro Ct ◽

Micro Computed Tomography ◽

High Concentration ◽

Pre Treatment ◽

The Stability ◽

Hydrogel Coating

Considering the potential of hydrogels to mimic the cellular microenvironment, methacryloyl gelatin (GelMA) and methacryloyl mucin (MuMA) were selected and compared as bioinspired coatings for commercially available polypropylene (PP) meshes for ventral hernia repair. Thin, elastic hydrated hydrogel layers were obtained through network-forming photo-polymerization, after immobilization of derivatives on the surface of the PP fibers. Fourier transform infrared spectroscopy (FTIR) proved the successful coating while the surface morphology and homogeneity were investigated by scanning electron microscopy (SEM) and micro-computed tomography (micro-CT). The stability of the hydrogel layers was evaluated through biodynamic tests performed on the coated meshes for seven days, followed by inspection of surface morphology through SEM and micro-CT. Taking into account that platelet-rich plasma (PRP) may improve healing due to its high concentration of growth factors, this extract was used as pre-treatment for the hydrogel coating to additionally stimulate cell interactions. The performed advanced characterization proved that GelMA and MuMA coatings can modulate fibroblasts response on PP meshes, either as such or supplemented with PRP extract as a blood-derived bioactivator. GelMA supported the best cellular response. These findings may extend the applicative potential of functionalized gelatin opening a new path on the research and engineering of a new generation of bioactive meshes.

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