Inducing nano-confined crystallization in PLLA and PET by elastic melt stretching

Soft Matter ◽  
2021 ◽  
Vol 17 (6) ◽  
pp. 1457-1462
Author(s):  
Masoud Razavi ◽  
Wenwen Zhang ◽  
Hossein Ali Khonakdar ◽  
Andreas Janke ◽  
Liangbin Li ◽  
...  

Cold crystallization of pre-melt stretched PLLA and PET permits growth of nano-confined crystals with entanglement mesh size in undisrupted chain networking.  Such PLLA and PET are ductile, transparent, rigid at the water-boiling temperature.

Author(s):  
Jovan Vukovié

Conventional electron microscope TEM -100 (Made by “ELECTRON”, Sumy, USSR; Fig. 1) was presented at the XI Int. Congress on Electron Microscopy (Kyoto) by I.S. Lyalko et al. (1,2). The purpose of the microscope constructors were to design a small-sized general conventional TEM for various application fields. The microscope have mini lenses, which winding is placed in closed casing and soaked in working liquid (low boiling temperature) but upper part of the casing being water cooled.In this communication we gave our first experience and impression as a customer, beginning from the montage, the instruction and the testing of the microscope to our application in the field of biological specimens. Just after montage of the microscope on the second floor, the test of the point resolution power was performed by Ir specimen. It was achieved 0.5 nm (Fig. 2 and 3) on the roll film (ORWO 22 DIN) with 300 OOOx magnification and anticontamination device. The ultimate vacuum (about 10exp-6 mm Hg, ion discharge pump) also achieved using large trap cooled by liquid nitrogen.


2013 ◽  
Vol 5 (1) ◽  
Author(s):  
Lumban Nauli Lumban Toruan ◽  
Dedi Soedharma ◽  
Kresna Tri Dewi

Composition and distribution of foraminifers are affected by human activities and have close association with coral reef ecosystem. The aims of this research were to investigate the benthic foraminifers’ composition and distribution in sediment of coral reef ecosystem. Eleven stations of Karang Bongkok, Pramuka, and Onrust Island were observed in this study. The sediments were taken from surface substrate up to 2 cm under the substrate. Samples were washed on sieve with mesh size 0,063 mm, and then dried in oven with 50°C of temperature  for two hours. After separating from the sediment, the foraminifers were laid on foraminiferal slide and indentified using binocular microscope. The highest composition of symbiont-bearing foraminiferal assemblages which associated with reef ecosystem was in East Pramuka (78.17%) and the lowest was in South Onrust (21,83%). The opportunistic type had the highest composition in South Onrust (38.67%) and the lowest was in South Karang Bongkok. In west Pramuka had the highest composition of heterotrophic type (57.17%) and the lowest was in North Onrust (11.33%). Onrust Island was dominated by opportunistic type, indicating high nutrient. The highest amount of foraminifers’ taxa was found in Karang Bongkok with good coral reef coverage, while the lowest in Onrust facing with Jakarta Bay. Keywords: composition, distribution, benthic foraminifers, coral reef.


Alloy Digest ◽  
1995 ◽  
Vol 44 (8) ◽  

Abstract Wallex Nos. 55 and 505 are similar composite hardfacing powders with different mesh size for different application methods. The minimum hardness is RC 58. This datasheet provides information on composition, physical properties, and hardness. It also includes information on corrosion resistance as well as powder metal forms. Filing Code: CO-98. Producer or source: Wall Colmonoy Corporation.


2016 ◽  
pp. 514-516
Author(s):  
Martin Bruhns

The massecuite circulates in a loop within the evaporating crystallizing vessel. The massecuite flows upwards through the heating tubes. In the room above the calandria the massecuite flow changes its direction to radial inwards and then to vertical downwards. An impeller in the central tube forces the circulation. Below the calandria the main direction of flow is radially outwards until threads of the massecuite stream enter the heating tubes in upwards direction. Within the tubes heat is transferred to the massecuite. At low temperature differences between heating steam and massecuite and higher levels of the massecuite in the crystallizer vapor bubbles are not found in the tubes. Vapor bubbles can be formed at a massecuite level in the crystallizer where the temperature of the massecuite is higher than the local boiling temperature of water, which depends on the local pressure (including the static pressure of the massecuite at this point) and the boiling point elevation of the mother liquor. The surface tension of the liquid is a resistance against the bubble formation, which has to be overcome by the local superheating i.e. the part of the enthalpy of the massecuite exceeding the local boiling temperature. The formation and the flow of the bubbles change the density of the massecuite/bubbles mixture and has an influence on the massecuite flow. The formation of a vapour bubble is connected with a local drop of the massecuite temperature which changes the local supersaturation. Today the heat transfer into the magma is quite well known but the process of bubble formation is quite unknown. Some basic considerations about the formation of bubbles and its influence on local supersaturation based on calculation of heat and mass balances and models of bubble formation are be given and discussed. Experiments for basic investigations are proposed.


2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110090
Author(s):  
Peiyu He ◽  
Qinrong Qian ◽  
Yun Wang ◽  
Hong Liu ◽  
Erkuo Guo ◽  
...  

Slewing bearings are widely used in industry to provide rotary support and carry heavy load. The load-carrying capacity is one of the most important features of a slewing bearing, and needs to be calculated cautiously. This paper investigates the effect of mesh size on the finite element (FE) analysis of the carrying capacity of slewing bearings. A local finite element contact model of the slewing bearing is firstly established, and verified using Hertz contact theory. The optimal mesh size of finite element model under specified loads is determined by analyzing the maximum contact stress and the contact area. The overall FE model of the slewing bearing is established and strain tests were performed to verify the FE results. The effect of mesh size on the carrying capacity of the slewing bearing is investigated by analyzing the maximum contact load, deformation, and load distribution. This study of finite element mesh size verification provides an important guidance for the accuracy and efficiency of carrying capacity of slewing bearings.


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