Resistance determination of joints of plastic components, made by additive technologies, to effect of negative temperatures

2021 ◽  
Vol 0 (1) ◽  
pp. 23-27
Author(s):  
I. S. Nefyolov ◽  
◽  
N. I. Baurova ◽  
Keyword(s):  
Low Temperature ◽  
Room Temperature ◽  
Negative Influence ◽  
Strength Properties ◽  
Additive Technologies ◽  
Strength Characteristics ◽  
Hot Gas ◽  
Negative Temperatures ◽  
Plastic Components

The effect of negative temperatures on strength characteristics of plastic component joints (hot gas welding, gluing, 3D-welding) made with the use of additive technologies has been examined. It has been found out that 3D-wlding allows one to produce joints with the highest strength properties. It was shown that low temperature values (–30 °С) did not have the negative influence on strength properties of ABS-plastic joints but even increased them as compared with analogues samples tested at the room temperature.

Order and disorder in acenaphthylene

1973 ◽  
Vol 334 (1596) ◽  
pp. 19-48 ◽  
Keyword(s):  
Low Temperature ◽  
Room Temperature ◽  
Temperature Structure ◽  
Intermediate Form ◽  
X Ray Diffraction ◽  
Space Group ◽  
Order And Disorder ◽  
Temperature Form ◽  
Diffraction Effects

Acenaphthylene, C 12 H 8 , occurs in space group Pbam (or Pba2) at room temperatures (23 °C) with a = 7.705 (5), b = 7.865 (5), c = 14.071 (5) Å and Z = 4, and is disordered. At about 130 K it undergoes a reversible transition to space group P2 1 nm with a = 7.588 (13), b = 7.549 (10), c = 27.822 (2) Å and Z = 8 (85 K) with an ordered structure. A general study of the system has revealed that the structure of both forms consists of layers of closely packed molecules stacked in the c direction. The room temperature structure has a two-layer repeat and the low temperature form a four-layer repeat. Observation of diffuse X-ray diffraction effects at temperatures close to the transition indicates that an intermediate form having a six-layer repeat is formed. A preliminary structure determination of the low-temperature form reveals that the four layers though having a similar packing scheme differ in the orientation of the constituent molecules relative to c . It is proposed that the almost circular shape of the molecules allows each layer to change its identity under thermal agitation by a rotation of its constituent molecules in their own planes. The transition can be explained in terms of changes of the correlations between neighbouring layers. A simple model based on short-range order parameters is described, which explains the occurrence of the six-layer intermediate and the observed sequence of diffuse diffraction phenomena. The nature of the structure of the disordered room temperature form, which is predicted by this model, is confirmed as far as possible with the data available which are limited because of the dearth of high-angle diffraction maxima.

Corrosion resistance and strength characteristics of hot gas sprayed coatings saturated with low-temperature alloys

1990 ◽  
Vol 26 (3) ◽  
pp. 351-353
Author(s):  
A. M. Sedenkov ◽  
A. V. Granovskii ◽  
V. M. Dotsenko ◽  
V. A. Gorbachev
Keyword(s):  
Corrosion Resistance ◽  
Low Temperature ◽  
Strength Characteristics ◽  
Hot Gas ◽  
Sprayed Coatings

scholarly journals TECHNOLOGICAL ADDITIVES FOR OIL AND PETROL RESISTANCE RUBBERS BASED ON BUTADIENE-NITRILE CAOUTCHOUCS

2021 ◽  
Vol 64 (6) ◽  
pp. 41-46
Author(s):  
Evgeny N. Egorov ◽  
Nikolay I. Kol'tsov ◽  
Nikolay F. Ushmarin
Keyword(s):  
Carbon Black ◽  
Room Temperature ◽  
Strength Properties ◽  
Technological Properties ◽  
Rubber Mixture ◽  
Operational Characteristics ◽  
Two Stages ◽  
Processing Aids ◽  
Hydrocarbon Media

The article investigated the influence of various technological additives (zincolet BB 222, lubstab-01 and MA-L22) on the technological properties of the rubber mixture, physical, mechanical and operational characteristics of rubber based on nitrile butadiene caoutchouc BNKS-40AMN. Basic rubber mixture studied included caoutchouc, BC-FF percadox, zinc monomethacrylate, maleide F, triallyl isocyanurate, acetonanil N, MGF-9 and THM-3 oligoester acrylates, carbon black P 514 and other ingredients. The rubber mixture was prepared on laboratory rolls LB 320 160/160 in two stages. At the first stage, BNKS-40AMN caoutchouc was mixed with ingredients and processing aids. As technological additives, zincolet BB 222, lubstab-01 and MA-L22 were used. In the second mixing step, BC-FF percadox and vulcanization coagents were introduced. For the obtained variants of the rubber mixture the vulcanization characteristics were studied on an MDR 3000 Basic rheometer at a temperature of 170 °C. The rubber mixture prepared was vulcanized in a P-V-100-3RT-2-PCD type vulcanizing press at 150 °C for 40 min. Determination of elastic-strength and operational properties of rubber were carried out according to the standards existing for the rubber industry. The oil resistance of the vulcanizates was evaluated by changing their elastic strength after exposure to standard liquid SZHR-1 at a temperature of 125 °C, as well as by changing the mass of the samples after exposure to a mixture of isooctane with toluene at room temperature. It was found that the introduction of technological additives in the rubber compound improves the distribution of carbon black P 514 and powdered ingredients (zinc monomethacrylate, maleide F, triallyl isocyanurate, acetonanil H) in the caoutchouc matrix. Increased elastic strength indicators and their smallest changes after exposure to aggressive hydrocarbon media is characterized a rubber containing technological additive MA-L22. A comparison of technological, elastic-strength properties and resistance to aggressive media for rubbers containing butadiene-nitrile caoutchoucs BNKS-18AMN, BNKS-28AMN and BNKS-40AMN with optimal technological additives for them was done. It has been established that rubber containing BNKS-40AMN and technological additive MA-L22 is characterized by improved vulcanization properties, increased elastic strength indicators and their smallest changes after exposure to aggressive hydrocarbon media.

scholarly journals (E)-4-Bromo-2-[(phenylimino)methyl]phenol: a new polymorph and thermochromism

2020 ◽  
Vol 76 (11) ◽  
pp. 1001-1004
Author(s):  
Helen E. Mason ◽  
Judith A. K. Howard ◽  
Hazel A. Sparkes
Keyword(s):  
Hydrogen Bond ◽  
Low Temperature ◽  
Structure Determination ◽  
Room Temperature ◽  
Dihedral Angles ◽  
Temperature Structure ◽  
Aromatic Rings

A new polymorph of (E)-4-bromo-2-[(phenylimino)methyl]phenol, C13H10BrNO, is reported, together with a low-temperature structure determination of the previously published polymorph. Both polymorphs were found to have an intramolecular O—H...N hydrogen bond between the phenol OH group and the imine N atom, forming an S(6) ring. The crystals were observed to have different colours at room temperature, with the previously published polymorph being more orange and the new polymorph more yellow. The planarity of the molecule in the two polymorphs was found to be significantly different, with dihedral angles (Φ) between the two aromatic rings for the previously published `orange' polymorph of Φ = 1.8 (2)° at 120 K, while the new `yellow' polymorph had Φ = 45.6 (1)° at 150 K. It was also observed that both polymorphs displayed some degree of thermochromism and upon cooling the `orange' polymorph became more yellow, while the `yellow' polymorph became paler upon cooling.

Low-temperature behaviour of K2Sc[Si2O6]F: determination of the lock-in phase and its relationships with fresnoite- and melilite-type compounds

2017 ◽  
Vol 73 (5) ◽  
pp. 923-930
Author(s):  
C. Hejny ◽  
L. Bindi
Keyword(s):  
Low Temperature ◽  
Room Temperature ◽  
Temperature Structure ◽  
X Ray Diffraction ◽  
Temperature Behaviour ◽  
Modulated Structure ◽  
Incommensurate Structure ◽  
Commensurate Phase ◽  
Lock In

K2Sc[Si2O6]F exhibits, at room temperature, a (3 + 2)-dimensional incommensurately modulated structure [a= 8.9878 (1),c= 8.2694 (2) Å,V= 668.01 (2) Å3; superspace groupP42/mnm(α,α,0)000s(−α,α,0)0000] with modulation wavevectorsq1= 0.2982 (4)(a* +b*) andq2= 0.2982 (4)(−a* +b*). Its low-temperature behaviour has been studied by single-crystal X-ray diffraction. Down to 45 K, the irrational component α of the modulation wavevectors is quite constant varying from 0.2982 (4) (RT), through 0.2955 (8) (120 K), 0.297 (1) (90 K), 0.298 (1) (75 K), to 0.299 (1) (45 K). At 25 K it approaches the commensurate value of one-third [i.e.0.332 (3)]: thus indicating that the incommensurate–commensurate phase transition takes place between 45 K and 25 K. The commensurate lock-in phase of K2Sc[Si2O6]F has been solved and refined with a 3 × 3 × 1 supercell compared with the tetragonal incommensurately modulated structure stable at room temperature. This corresponds to a 3 × 1 × 3 supercell in the pseudo-orthorhombic monoclinic setting of the low-temperature structure, space groupP2/m, with lattice parametersa= 26.786 (3),b= 8.245 (2)c= 26.824 (3) Å, β = 90.00 (1)°. The structure is a mixed tetrahedral–octahedral framework composed of chains of [ScO4F2] octahedra that are interconnected by [Si4O12] rings with K atoms in fourfold to ninefold coordination. Distorted [ScO4F2] octahedra are connected to distorted Si tetrahedra to form octagonal arrangements closely resembling those observed in the incommensurate structure of fresnoite- and melilite-type compounds.

A Simple Cryostat

1961 ◽  
Vol 14 (4) ◽  
pp. 527
Author(s):  
AS Buchanan ◽  
F Creutzberg
Keyword(s):  
Low Temperature ◽  
Room Temperature ◽  
Temperature Range

A simple all-glass cryostat, based on the LeRoy low-temperature fractionating column, is described. It can be used for the separation, purification, and the determination of vapour pressures of volatile and gaseous compounds in the temperature range -196 �C to room temperature. The vapour pressures of boron trimethyl have been remeasured and the reliability of Stock's data is confirmed.

A Study of the Structure and Properties of Austenitic Metastable Steels under Strain

2018 ◽  
Vol 284 ◽  
pp. 207-211
Author(s):  
N. Ozerets ◽  
Valentina A. Sharapova ◽  
A. Levina ◽  
T. Mal'tseva ◽  
M. Pavlov
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Negative Temperature ◽  
Strength Properties ◽  
Austenitic Steels ◽  
Structure And Properties ◽  
Corrosion Resistant ◽  
Equal Degree ◽  
Negative Temperatures ◽  
Strain Induced Martensite

The structure and mechanical properties of the corrosion-resistant metastable austenitic steels 03Kh14N11К5М2YuТ and 03Kh14N11КМ2YuТ have been investigated. The steels have been deformed by tagging them at room and negative temperatures. It has been established that the amount of martensite and the strength properties are higher at a negative temperature than at room temperature with an equal degree of strain. The investigated austenitic steels are strain-metastable. The higher the strain degree and the lower the deformation temperature, the greater the amount of strain-induced martensite and, correspondingly, the higher the strength properties. Martensite is not observed upon cooling to the temperature of liquid nitrogen.

Low-Temperature Fish Storage Facility with Precise Temperature Control

1969 ◽  
Vol 26 (1) ◽  
pp. 154-161
Author(s):  
K. R. Scott
Keyword(s):  
Steady State ◽  
Low Temperature ◽  
Temperature Control ◽  
Room Temperature ◽  
Storage Facility ◽  
Hot Gas ◽  
Long Term Storage ◽  
Straight Line ◽  
Term Storage

A coldroom complex recently installed at the Fisheries Research Board of Canada, Freshwater Institute laboratory at Winnipeg features several design aspects that are considered novel. These include foamed-in-place urethane insulation, two alternating R-502 refrigeration systems incorporating automatic safety switch-over and adjustable defrost, "straight-line" pneumatic temperature control, hot gas bypass control, and a master panel. The facility combines a cold laboratory at +2 C, a long-term storage room at −37 C, a small anteroom at −26 C, and a room containing eight 10.0-ft3 precise temperature cabinets at −40 C. Room temperature variation is ±0.25 degrees C during steady state conditions. Temperature rise during daily defrosting is less than 2 degrees C for a duration of 1 hr.

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