scholarly journals VIII. The crystalline structure of metals. (second paper.)

1901 ◽  
Vol 195 (262-273) ◽  
pp. 279-301 ◽  
Keyword(s):  
Crystalline Structure ◽  
Critical Points ◽  
Annealing Process ◽  
Short Exposure ◽  
Iron And Steel ◽  
Prolonged Annealing ◽  
Suitable Temperature ◽  
Before And After ◽  
Rate Of Cooling ◽  
Crystalline Pattern

The investigations described in the present paper deal principally with the phenomena of annealing. They form a continuation of the research described in the Bakerian Lecture for 1899 (‘Phil. Trans.,’A, vol. 193, 1900, pp. 353-377). In iron, steel, and brass these phenomena have been studied with the aid of the microscope by various workers, among whom Arnold, Charpy, Stead, and Roberts-Austen should be particularly mentioned. As a result of their labours it is well known that annealing is accompanied by a re-arrangement of the crystalline grains of the metal. Thus, when a piece of iron is strained in tension its crystalline grains become elongated in the direction of tension ; but when the specimen has been subsequently annealed by being heated to a bright red, all signs of such elongation disappear from the crystalline pattern revealed by the microscope. In fact it is not generally possible to find any definite connection between the crystalline pattern seen in the same specimen before and after annealing. In general, the pattern seen after annealing resembles that found in a similar specimen before it has been strained, but the scale and character of the pattern produced depend very much on the details of the annealing process, particularly upon the temperature applied, the time of its application, and the rate of cooling. Arnold and Stead have shown that prolonged annealing tends to produce large crystals in iron and steel. But even short exposure to a suitable temperature is well known to produce complete re­crystallisation, and it has been suggested that these changes occur at critical points corresponding to the “arrest-points” in the cooling of the metal. These arrest-points indicate evolutions of heat, and it is natural to suppose that they are evi­dences of re-arrangement of the structure of the metal.

scholarly journals How Dead Wood in the Forest Decreases Relaxation? The Effects of Viewing of Dead Wood in the Forest Environment on Psychological Responses of Young Adults

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 871
Author(s):  
Emilia Janeczko ◽  
Ernest Bielinis ◽  
Ulfah Tiarasari ◽  
Małgorzata Woźnicka ◽  
Wojciech Kędziora ◽  
...  
Keyword(s):  
Young Adults ◽  
Dead Wood ◽  
Short Exposure ◽  
Managed Forests ◽  
Environment Impact ◽  
Forest Environment ◽  
Dead Trees ◽  
Before And After ◽  
Positive Feelings ◽  
The Impact

The intensity of the neutral environment impact on humans may be determined by specific features of space, including dead wood occurrence. Dead wood is claimed to be disliked by the public because it reduces the scenic beauty and recreational values of the forest. The attractiveness of a forest with dead wood may be determined by its variants. Much is known about the preference for landscape with dead wood, but there is little information available about how such a landscape affects a person’s mental relaxation, improves mood, increases positive feelings, levels of vitality, etc. Hence, the aim of our research was to investigate the psycho-logical relaxing effects of short 15-min exposures to natural and managed forests with dead wood. In the study, three areas within the Białowieża Primeval Forest were used to measure the impact of different types of forest with dead wood (A: forest reserve with dead wood subject to natural decomposition processes; B: managed forest with visible cut wood and stumps; C: man-aged forest with dead trees from bark beetle outbreak standing) on human psychological relaxation in a randomized experiment. The participants of the experiment were forty-one young adults aged 19–20. Each respondent experienced each type of forest at intervals visiting it. Four psychological questionnaires were used in the project (Profile of Mood States (POMS), Positive and Negative Affect Schedule (PANAS), Subjective Vitality Scale (SVS), and Restorative Outcome Scale (ROS)) before and after the short exposure to the forest were evaluated. The results show that a forest landscape with dead wood affects the human psyche, and the relaxing properties of such a landscape are better in a protected forest with natural, slow processes of tree dieback than those obtained in managed forests

Structural, Textural and Thermal Characterization of Nano-Mg/Al Hydrotalcite before and after Cr (VI) Removal

2013 ◽  
Vol 755 ◽  
pp. 53-60
Author(s):  
Esthela Ramos Ramírez ◽  
Norma Leticia Gutiérrez Ortega ◽  
Cesar Augusto Contreras Soto ◽  
Gustavo Rangel Porras
Keyword(s):  
Crystalline Structure ◽  
Sol Gel ◽  
Textural Properties ◽  
Kinetic Studies ◽  
Thermal Characterization ◽  
Gel Method ◽  
Sol Gel Method ◽  
Before And After ◽  
Short Time

In this work there was studied the structural, textural and effect that has treat thermal on the removal of Cr (VI) of nanoMg/Al hydrotalcite (NHT) synthesized by the sol-gel method with a ratio of Mg/Al=3. These present the characterization of the nanoMg/Al hydrotalcite before and after Cr (VI) removal, as well as the kinetic studies and of balance. In agreement with the results, when the NHT are thermal treated to 350 °C the hydrotalcite crystalline structure remains but the textural properties are improved and structural. The NHT synthesized by the sol-gel method present a good capacity of removal with values of 91 mg of Cr (VI) removed / g of NHT. The above mentioned capacity of removal gets improved after thermal treating the material, reaching values of removal of 124 mg of Cr (VI) removed / g of NHT. The NHT with the Cr (VI) absorbed show decrease of the crystalline structure, as well as a saturation of the pores that annuls the porosity due to the fact that the Cr (VI) lodges both at the pores and at the intersheets. The time that him takes the HLM to remove the Cr (VI) of the watery solution is alone of 2 minutes, with which it is possible to conclude that the NHT have an excellent aptitude to remove Cr (VI) of watery solutions in an interval of very short time.

Simulated annealing process in general state space

1991 ◽  
Vol 23 (04) ◽  
pp. 866-893 ◽  
Author(s):  
Heikki Haario ◽  
Eero Saksman
Keyword(s):  
Stochastic Process ◽  
Simulated Annealing ◽  
State Space ◽  
Annealing Process ◽  
General State ◽  
Arbitrary State ◽  
Strong And Weak Convergence ◽  
General State Space ◽  
Rate Of Cooling ◽  
Space Conditions

The stochastic process corresponding to the simulated annealing optimization algorithm is generalized to the case of an arbitrary state space. Conditions for the strong and weak convergence of the process are established. In addition the relation between the size of the generating distributions and the possible rate of cooling is studied.

Crystalline Structure and the Role of Low-Temperature-Deposited AlN and GaN on Sapphire Revealed by X-Ray CTR Scattering and X-Ray Reflectivity Measurements

2003 ◽  
Vol 10 (02n03) ◽  
pp. 537-541 ◽  
Author(s):  
Y. Takeda ◽  
M. Tabuchi ◽  
H. Amano ◽  
I. Akasaki
Keyword(s):  
Low Temperature ◽  
Crystalline Structure ◽  
Thin Layers ◽  
X Ray ◽  
Atomic Force ◽  
Crystal Truncation Rod ◽  
Before And After ◽  
Afm Observation

Crystalline and morphological quality of low-temperature (LT)-deposited and annealed AlN and GaN thin layers were investigated by X-ray crystal truncation rod (CTR) scattering and X-ray reflectivity measurements and atomic force microscope (AFM) observation. It was revealed that the LT-AlN layer was more uniform in terms of the crystalline structure and the layer thickness than the LT-GaN layer, before and after annealing. It suggests that LT-AlN is more suitable as a buffer layer between sapphire substrate and GaN.

Efficient Thin Polymer Solar Cells with Post-Annealing

2007 ◽  
Vol 1031 ◽  
Author(s):  
Shun-Wei Liu ◽  
Chih-Chien Lee ◽  
Ping-Tsung Huang ◽  
Chin-Ti Chen ◽  
Juen-Kai Wang
Keyword(s):  
Solar Cells ◽  
Polymer Solar Cells ◽  
Annealing Treatment ◽  
Open Circuit ◽  
Annealing Process ◽  
Solar Cell Performance ◽  
Post Annealing ◽  
Thin Polymer ◽  
Before And After ◽  
Process Annealing

AbstractThe authors report the study of the dependence of the device performance of polymer solar cells based on single 50-nm heterojunction poly(3-hexylthiophene)/[6,6]-phenyl-C61-butyric acid methylester (P3HT/PCBM) layer on annealing process. Annealing before and after cathode deposition were performed for comparison. In the case of post-annealing at 150¢XC for 60 min., the device attains a conversion efficiency of 4.9%, a fill factor of 53 %, and an open-circuit voltage of 0.67 V. These values are comparable with the highest values reported previously. The annealing process is expected to modify the network morphology of the P3HT/PCBM layer. This study demonstrates that it is possible to attain good solar cell performance with the combination of single thin active layer and post-annealing treatment. This may open up an opportunity to fabricate tandem polymer solar cells.

scholarly journals The structure of polychloroprene

1942 ◽  
Vol 180 (980) ◽  
pp. 100-107 ◽  
Keyword(s):  
Physical Properties ◽  
Crystalline Structure ◽  
Light Treatment ◽  
Unit Cell ◽  
Cross Linking ◽  
Chain Molecules ◽  
X Ray ◽  
Before And After ◽  
Ray Methods ◽  
Long Chain

Specimens of polychloroprene before and after light treatment have been examined by X -ray methods. There is no change in the crystalline structure, although there are differences in the physical properties ascribed to cross-linking of the long-chain molecules. The unit cell is possibly ortho­rhombic: a = 8·90 A , b = 4·70 A, c = 12·21 A, and contains four chloroprene (C 4 H 5 Cl) units.

scholarly journals Pulsed Laser Annealing Effect on Optical and Structural Properties of ZnS/ZnSe Heterostructures

2019 ◽  
Vol 6 (1) ◽  
pp. 23-29
Author(s):  
Haidar Howari
Keyword(s):  
Thin Films ◽  
Absorption Coefficient ◽  
Laser Annealing ◽  
Pulsed Laser ◽  
Annealing Process ◽  
Reflection Spectra ◽  
Pulsed Laser Annealing ◽  
Before And After ◽  
Transmission And Reflection Spectra ◽  
Transmission And Reflection

Studies of pulsed laser annealing (PLA) on semiconductor thin films were performed to examine changes of the optical and structural parameters due to the laser heat. Thin films of ZnS/ZnSe were deposited on quartz substrates at a pressure of 8.2*10-6 mbar using PVD technique. These thin films were annealed at different laser powers using CO2 pulsed laser. Transmission and reflection spectra were recorded before and after the annealing process. A decrease in the transmission and reflection spectra after annealing is observed. The absorption coefficient, refractive index, damping coefficient and dielectric constant were calculated before and after the annealing process. Changes in the optical parameters are found after the annealing process. The energy band gaps of ZnS and ZnSe have been determined. Upon annealing, an increase in the absorption coefficient is observed which is due to an improvement in the granular nanostructure of the ZnS/ZnSe thin films. XRD patterns of the prepared samples were obtained before and after the annealing procedure and revealed an enhancement in the crystallite structure upon annealing.

High Temperature Annealing SP-AlN Ameliorates the Crystal Quality ofAl0.5Ga0.5N Regrowth

2020 ◽  
Vol 1014 ◽  
pp. 14-21
Author(s):  
Wen Kai Yue ◽  
Zhi Min Li ◽  
Xiao Wei Zhou ◽  
Jin Xing Wu ◽  
Pei Xian Li
Keyword(s):  
Raman Spectroscopy ◽  
High Temperature ◽  
Annealing Process ◽  
High Temperature Annealing ◽  
High Quality ◽  
Rocking Curve ◽  
Stress Mode ◽  
Aln Film ◽  
Before And After ◽  
Screw Dislocation Density

In this study, the effect of a high-temperature annealing process on AlN is investigated. The high-temperature annealing process reduces the screw dislocation density of the AlN film to 2.1x107 cm-2. The AlN surface is highly flat. Through HRXRD and Raman spectroscopy, the stress mode changes in the sputtered AlN film before and after high-temperature annealing were studied in depth. Based on the HTA-AlN template, a high-quality, high-Al composition AlGaN epitaxial wafer, with a (0002) plane rocking curve FWHM of 246 arcsec , was prepared at 1080°C The growth mode of AlGaN grown directly on the AlN template at low temperature is summarized.

scholarly journals Concentration of Lead, Cadmium, and Iron in Sediment Dust and Total Suspended Particles Before and After Initialisation of Integral Production in Iron and Steel Work Plant Zenica

2012 ◽  
Vol 63 (2) ◽  
pp. 181-188 ◽  
Author(s):  
Halim Prcanović ◽  
Mirnes Duraković ◽  
Sanela Beganović
Keyword(s):  
Suspended Particles ◽  
Average Concentration ◽  
Limit Values ◽  
Iron And Steel ◽  
Steel Work ◽  
Lead And Cadmium ◽  
Total Suspended Particles ◽  
Before And After ◽  
The Impact ◽  
Steel Works

Concentration of Lead, Cadmium, and Iron in Sediment Dust and Total Suspended Particles Before and After Initialisation of Integral Production in Iron and Steel Work Plant ZenicaPoor air quality is a common fact for all areas with base industry. The city of Zenica was once the metallurgical centre of Ex-Yugoslavia and is therefore highly polluted at present. Air pollution peaked in 1987 when average concentration of pollutants was extremely high (daily average concentration of SO2 was 1800 μg m-3). With the beginning of the war in 1992, integral production in the steel work plant was shut down, to be re-launched in 2008. Limit values for iron do not exist, but iron has been monitored in Zenica for the past 28 years because of the presence of steel works. Concentrations of cadmium and lead have also been measured because they are very much present in polluted areas with steel works. The concentration of mentioned elements in air deposit and total suspended particles before and after integral production in the steel work plant was re-launched is the subject of this paper. Total suspended particles were measured in two locations using German standard VDI 2463 Blatt 4. Sediment dust was measured in nine locations using Bergerhoff method. The concentration of iron, lead, and cadmium was performed in the chemical laboratory of the Metallurgical Institute "Kemal Kapetanović" Zenica using standard methods. Higher concentrations of these parameters during the period of integral production clearly point to the impact of steel works on Zenica valley.

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