scholarly journals Performance and Sensitivity Properties of Solid Heterogeneous Rocket Propellant Based on a Binary System of Oxidizers (PSAN and AP)

Processes ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 2201
Author(s):  
Katarzyna Gańczyk-Specjalska ◽  
Paulina Paziewska ◽  
Rafał Bogusz ◽  
Rafał Lewczuk ◽  
Katarzyna Cieślak ◽  
...  
Keyword(s):  
Phase Transition ◽  
Ammonium Nitrate ◽  
Environmental Performance ◽  
Room Temperature ◽  
Environmental Issues ◽  
Thermomechanical Properties ◽  
Mechanical Stimuli ◽  
Operational Parameters ◽  
Potassium Salts ◽  
Rocket Propellants

Solid heterogeneous rocket propellants (SHRP) containing ammonium perchlorate (AP) emit a lot of hydrogen chloride (HCl) during combustion, which poses various environmental issues and makes the detection of the rockets easier. Part of the AP can be replaced by ammonium nitrate (V) (AN), which does not lead to the production of HCl. AN is a commonly used environmentally friendly oxidizer, but it is not usually applied in SHRP due to its disadvantages. One of these disadvantages is a phase transition near room temperature, which causes the density change of AN. Three types of phase stabilized ammonium nitrate (V) (PSAN) with inorganic potassium salts were obtained in order to shift this transition into higher temperatures (above the temperature range of the storage and the usage of SHRP). The SHRP with the PSAN were obtained, and the measurements of the heat of combustion, density, hardness, the sensitivity to mechanical stimuli and the thermomechanical properties were performed. The obtained propellants were characterized by similar operational parameters or were slightly lower than those without the PSAN. This means that AP can be partially replaced without significantly compromising the handling, safety or functionality of the propellants, while increasing the environmental performance of the solution.

Electron Microscope study of commensurate-incommensurate phase transition in BaZnGeO4

1990 ◽  
Vol 48 (4) ◽  
pp. 172-173
Author(s):  
Naoki Yamamoto ◽  
Makoto Kikuchi ◽  
Tooru Atake ◽  
Akihiro Hamano ◽  
Yasutoshi Saito
Keyword(s):  
Phase Transition ◽  
Electron Microscope Study ◽  
Room Temperature ◽  
Hexagonal Lattice ◽  
Ferroelectric Materials ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Periodic Arrays ◽  
Modulation Wave Vector

BaZnGeO4 undergoes many phase transitions from I to V phase. The highest temperature phase I has a BaAl2O4 type structure with a hexagonal lattice. Recent X-ray diffraction study showed that the incommensurate (IC) lattice modulation appears along the c axis in the III and IV phases with a period of about 4c, and a commensurate (C) phase with a modulated period of 4c exists between the III and IV phases in the narrow temperature region (—58°C to —47°C on cooling), called the III' phase. The modulations in the IC phases are considered displacive type, but the detailed structures have not been studied. It is also not clear whether the modulation changes into periodic arrays of discommensurations (DC’s) near the III-III' and IV-V phase transition temperature as found in the ferroelectric materials such as Rb2ZnCl4.At room temperature (III phase) satellite reflections were seen around the fundamental reflections in a diffraction pattern (Fig.1) and they aligned along a certain direction deviated from the c* direction, which indicates that the modulation wave vector q tilts from the c* axis. The tilt angle is about 2 degree at room temperature and depends on temperature.

Survival of mouse blastocysts after low-temperature preservation under high pressure

2004 ◽  
Vol 52 (4) ◽  
pp. 479-487 ◽  
Author(s):  
Cs. Pribenszky ◽  
M. Molnár ◽  
S. Cseh ◽  
L. Solti
Keyword(s):  
Phase Transition ◽  
Hydrostatic Pressure ◽  
Low Temperature ◽  
High Hydrostatic Pressure ◽  
Room Temperature ◽  
Freezing Point ◽  
Significant Loss ◽  
Embryo Cryopreservation ◽  
Subzero Temperatures ◽  
Survival Capacity

Cryoinjuries are almost inevitable during the freezing of embryos. The present study examines the possibility of using high hydrostatic pressure to reduce substantially the freezing point of the embryo-holding solution, in order to preserve embryos at subzero temperatures, thus avoiding all the disadvantages of freezing. The pressure of 210 MPa lowers the phase transition temperature of water to -21°C. According to the results of this study, embryos can survive in high hydrostatic pressure environment at room temperature; the time embryos spend under pressure without significant loss in their survival could be lengthened by gradual decompression. Pressurisation at 0°C significantly reduced the survival capacity of the embryos; gradual decompression had no beneficial effect on survival at that stage. Based on the findings, the use of the phenomena is not applicable in this form, since pressure and low temperature together proved to be lethal to the embryos in these experiments. The application of hydrostatic pressure in embryo cryopreservation requires more detailed research, although the experience gained in this study can be applied usefully in different circumstances.

scholarly journals ECO-DESIGN ACTIONS TO IMPROVE LIFE CYCLE ENVIRONMENTAL PERFORMANCE OF FACE MASKS IN THE PANDEMIC ERA

2021 ◽  
Vol 1 ◽  
pp. 1333-1342
Author(s):  
Núria Boix Rodríguez ◽  
Marco Marconi ◽  
Claudio Favi ◽  
Giovanni Formentini
Keyword(s):  
Life Cycle ◽  
Environmental Performance ◽  
Climate Changes ◽  
Environmental Problem ◽  
Negative Impact ◽  
Environmental Issues ◽  
Design Guidelines ◽  
Protective Equipment ◽  
Single Use ◽  
Near Future

AbstractFace masks are currently considered essential devices that people must wear today and in the near future, until the COVID-19 pandemic will be completely defeated through specific medicines and vaccines. Such devices are generally made of thermoplastic polymers, as polypropylene and polyethylene and are single use products. Even if in this period the sanitary emergency must have the maximum priority, the world society should not completely forget the environmental problem that are causing more and more obvious climate changes with correlated damages to ecosystems and human health. Despite the well-known correlation among anti-COVID protective equipment (or more generally medical devices) and environmental issues, the Life Cycle Assessment (LCA) and eco-design-based studies in this field is very scarce. The present study aims to derive the most important environmental criticalities of such products, by using LCA and product circularity indicators of five different common masks. The final aim is to provide eco-design guidelines, useful to design new face masks by preventing negative impact on the environment.

Room-temperature NaI/H2O compression icing: solute–solute interactions

2017 ◽  
Vol 19 (39) ◽  
pp. 26645-26650 ◽  
Author(s):  
Qingxin Zeng ◽  
Chuang Yao ◽  
Kai Wang ◽  
Chang Q. Sun ◽  
Bo Zou
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Bond Energy ◽  
Room Temperature ◽  
Solute Concentration ◽  
Solute Interaction ◽  
Solute Interactions

H–O bond energy governs the PCx for Na/H2O liquid–VI–VII phase transition. Solute concentration affects the path of phase transitions differently with the solute type. Solute–solute interaction lessens the PC2 sensitivity to compression. The PC1 goes along the liquid–VI boundary till the triple phase joint.

Room temperature multiferroic properties and polymorphic phase transition-induced noticeable magnetodielectric anomalies in Fe/Co co-doped (K0.52Na0.48)NbO3 ceramics

2020 ◽  
Vol 836 ◽  
pp. 155519
Author(s):  
Min Zhou ◽  
Xiaomei Lu ◽  
Lin Liu ◽  
Junjun Wang ◽  
Dingze Lu ◽  
...  
Keyword(s):  
Phase Transition ◽  
Room Temperature ◽  
Polymorphic Phase Transition ◽  
Multiferroic Properties ◽  
Co Doped

Thermally Driven Amorphous‐Crystalline Phase Transition of Carbonized Polymer Dots for Multicolor Room‐Temperature Phosphorescence

2021 ◽  
pp. 2100421
Author(s):  
Zifei Wang ◽  
Jian Shen ◽  
Bin Xu ◽  
Qinglin Jiang ◽  
Shouli Ming ◽  
...  
Keyword(s):  
Phase Transition ◽  
Crystalline Phase ◽  
Room Temperature ◽  
Room Temperature Phosphorescence ◽  
Polymer Dots ◽  
Thermally Driven ◽  
Crystalline Phase Transition

NQR and Crystal Structure of 4,5-Dichloroimidazole, C3H2N2Cl2

1992 ◽  
Vol 47 (1-2) ◽  
pp. 177-181 ◽  
Author(s):  
Shi-Qi Dou ◽  
Alarich Weiss
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Temperature Dependence ◽  
Room Temperature ◽  
Unit Cell ◽  
Space Group ◽  
Temperature Range ◽  
Temperature Coefficients ◽  
Group D

AbstractThe two line 35Cl NQR spectrum of 4,5-dichloroimidazole was measured in the temperature range 77≦ T/K ≦ 389. The temperature dependence of the NQR frequencies conforms with the Bayer model and no phase transition is indicated in the curves v ( 35Cl)= f(T). Also the temperature coefficients of the 35Cl NQR frequencies are "normal". At 77 K the 35Cl NQR frequencies are 37.409 MHz and 36.172 MHz and at 389 K 35.758 MHz and 34.565 MHz. The compound crystallizes at room temperature with the tetragonal space group D44-P41212, Z = 8 molecules per unit cell; at 295 K : a = 684.2(5) pm, c = 2414.0(20) pm. The relations between the crystal structure and the NQR spectrum are discussed.

scholarly journals Urban debates for climate change after the Kyoto Protocol

Urban Studies ◽  
2017 ◽  
Vol 55 (1) ◽  
pp. 3-18 ◽  
Author(s):  
Yong Tu
Keyword(s):  
Urban Studies ◽  
Environmental Performance ◽  
Research Agenda ◽  
Climate Changes ◽  
Environmental Issues ◽  
Living Will ◽  
Sustainable Urban Development ◽  
Low Carbon ◽  
Holistic Understanding ◽  
Adaptation Processes

From the catalogue of environment-related publications in Urban Studies, this paper identifies and reviews 12 thought-provoking articles that have addressed the issue of climate changes and cities from complementary perspectives. It argues that to advance a holistic understanding of urban environmental issues it is necessary to embrace a broad multi-disciplinary approach, particularly as moving towards low carbon urban living will require integrated social, political and technical adaptation processes. Ultimately, the paper advances a forward-looking research agenda that extends beyond consideration of how to improve urban environmental performance to include evaluation of how urban consumers, firms and local government endeavour to achieve sustainable urban development.

Low light quantum phase transition in 1T-TaS2 at room temperature

2021 ◽  
Author(s):  
Weijian Li ◽  
Gururaj V. Naik
Keyword(s):  
Phase Transition ◽  
Quantum Phase Transition ◽  
Room Temperature ◽  
Quantum Phase ◽  
Light Quantum ◽  
Low Light

Electric-Field-Induced Room-Temperature Antiferroelectric–Ferroelectric Phase Transition in van der Waals Layered GeSe

ACS Nano ◽  
2022 ◽  
Author(s):  
Zhao Guan ◽  
Yifeng Zhao ◽  
Xiaoting Wang ◽  
Ni Zhong ◽  
Xing Deng ◽  
...  
Keyword(s):  
Phase Transition ◽  
Electric Field ◽  
Ferroelectric Phase Transition ◽  
Room Temperature ◽  
Ferroelectric Phase ◽  
Van Der Waals
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