Development of an experimental set-up for low-temperature spectroscopic studies of matrix-isolated molecules and molecular ices using synchrotron radiation

2018 ◽  
Vol 25 (5) ◽  
pp. 1425-1432
Author(s):  
Param Jeet Singh ◽  
K. Sundararajan ◽  
Aparna Shastri ◽  
Vijay Kumar ◽  
Asim Kumar Das ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Low Temperature ◽  
Low Temperatures ◽  
Spectroscopic Studies ◽  
Performance Criteria ◽  
Experimental Chamber ◽  
Closed Cycle ◽  
Design Development ◽  
Set Up ◽  
Ice Phase

An experimental set-up for studying photophysics and photochemistry of molecules in an inert gas medium (matrix-isolated) and in the ice phase at low temperatures has been developed and commissioned at the Photophysics beamline, Indus-1 synchrotron radiation source. This end-station uses an in-house-developed closed-cycle cryostat for achieving cryo-temperatures (∼10 K). Synchrotron radiation from the Photophysics beamline is used as the source of UV–VUV photons and the system is equipped with a Fourier transform infrared spectrometer for characterization of the molecular species formed at low temperature. Various individual components of the end-station like closed-cycle cryostat, experimental chamber, gas mixing and deposition systems are tested to ascertain that the desired performance criteria are satisfied. The performance of the composite system after integration with the Photophysics beamline is evaluated by recording IR and UV–VUV photoabsorption spectra of sulfur dioxide at low temperatures (10 K), both in the ice phase as well as isolated in argon matrices. Results obtained are in good agreement with earlier literature, thus validating the satisfactory performance of the system. As an off-shoot of the study, the VUV absorption spectrum of matrix-isolated SO2 in argon matrix up to 10.2 eV is reported here for the first time. This experimental end-station will provide new opportunities to study photon-induced reactions in molecules of environmental, astrochemical and industrial importance. Details of the design, development and initial experimental results obtained are presented.

scholarly journals Variations in growth and genetic properties of Zea mays L. germinants exposed to cold shock

2020 ◽  
Vol 44 (1) ◽  
Author(s):  
Beckley Ikhajiagbe ◽  
Vona D. Odenore ◽  
Josiah E. Ifie ◽  
Esther O. Umeokeke ◽  
Pieter-Jan Loveniers ◽  
...  
Keyword(s):  
Zea Mays ◽  
Low Temperature ◽  
Low Temperatures ◽  
Cold Shock ◽  
Rapd Marker ◽  
Complementary Sequence ◽  
Maize Seeds ◽  
Set Up ◽  
Genetic Responses ◽  
Plant Germination

Abstract Background Abiotic stresses like low temperatures are contributory factors to the variations observed among species during plant germination, growth, and development. The present study evaluated the morphological and genetic responses of maize (Zea mays L.) seedling to cold shock induced by a one-time exposure to low temperature. Seeds were originally exposed to distilled water at room temperature for 48 h before they were completely submerged in buckets of ice for 0.5, 1.5, 3, 6, and 12 h, respectively, and then transferred into Petri dishes. The set up was left on the laboratory bench for an additional 5 days, and plant germination parameters were measured. DNA was extracted and this was followed by RAPD—polymerase chain reaction. Results Significant growth impairment upon exposure to cold shock corresponding to the length of time of exposure was shown. The length of the prominent root significantly reduced upon exposure to a cold shock from 141.8 mm to as low as 91.4 mm in those plants exposed at 1.5 h. The length of the prominent leaf also significantly reduced from 100.6 mm in the control to between 62.6 and 85.5 mm in low-temperature-exposed plants (p < 0.05), notwithstanding the time of exposure. There were significant reductions in final germination percent in the low-temperature-exposed germinants (35.8–60.5%) when compared to the control (88.5%). The RAPD marker (OPA04) revealed variations in germinated maize seeds after treatment with different duration of low temperatures. The test plantlets treated for 0, 0.5, and 1.5 h have an unrecognizable complementary sequence to the primer OPA04, whereas the primer amplified regions of the genome of test plantlets treated for 3, 6, and 12 h. Primer OPA05 also presented diversity among maize seedlings stressed for various durations of cold shock. Conclusion The existence of genetic variations in the present study has far-reaching effects on the development of maize exposed to varying degrees of cold stress. Though restricted to germination only, they are important because the development of plants begins at the germination stage. These changes may affect the characteristics of economic importance or perhaps impact on the physiology of the maize plant eventually.

In situ Tensile Experiments at Low Temperatures on Niobium Single Crystals by H.V.E.M.

1975 ◽  
Vol 33 ◽  
pp. 58-59
Author(s):  
F. H. Louchet ◽  
L. P. Kubin
Keyword(s):  
Electron Microscope ◽  
Transition Temperature ◽  
Low Temperature ◽  
Slip System ◽  
Low Temperatures ◽  
Tensile Axis ◽  
Image Intensifier ◽  
Screw Dislocations ◽  
Source Operation

Experiments have been carried out on the 3 MeV electron microscope in Toulouse. The low temperature straining holder has been previously described Images given by an image intensifier are recorded on magnetic tape.The microtensile niobium samples are cut in a plane with the two operative slip directions [111] and lying in the foil plane. The tensile axis is near [011].Our results concern:- The transition temperature of niobium near 220 K: at this temperature and below an increasing difference appears between the mobilities of the screw and edge portions of dislocations loops. Source operation and interactions between screw dislocations of different slip system have been recorded.

INVAR M93

Alloy Digest ◽  
2008 ◽  
Vol 57 (1) ◽  
Keyword(s):  
Fracture Toughness ◽  
Low Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Low Temperatures ◽  
Bend Strength ◽  
Temperature Performance ◽  
Ni Content ◽  
Precision Alloys ◽  
Ni Alloy

Abstract Invar is an Fe-Ni alloy with 36% Ni content that exhibits the lowest expansion of known metals from very low temperatures up to approximately 230 deg C (445 deg F). Invar M93 is a cryogenic Invar with improved weldability. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear and bend strength as well as fracture toughness and fatigue. It also includes information on low temperature performance as well as forming and joining. Filing Code: FE-143. Producer or source: Metalimphy Precision Alloys.

scholarly journals Design framework for a seamless smart glove using a digital knitting system

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Yewon Song ◽  
Seulah Lee ◽  
Yuna Choi ◽  
Sora Han ◽  
Hyuna Won ◽  
...  
Keyword(s):  
Systematic Approach ◽  
Performance Criteria ◽  
Wearable Electronics ◽  
Design Development ◽  
Performance Requirements ◽  
Development Framework ◽  
Promising Strategy ◽  
Cad Cam ◽  
Wearable Electronic ◽  
Electronic Textile

AbstractThe wearable electronics integrated with textile-based devices is a promising strategy to meet the requirements of human comfort as well as electrical performances. This research presents a design and development framework for a seamless glove sensor system using digital knitting fabrication. Based on the performance requirements of glove sensors for controlling a prosthetic hand, desirable design components include electrical conductivity, comfort, formfit, electrical sensitivity, and customizable design. These attributes are determined and achieved by applying appropriate materials and fabrication technologies. In this study, a digital knitting CAD/CAM system is utilized to meet the desired performance criteria, and two prototypes of the seamless glove sensor systems are successfully developed for the detection of both human and robotic finger motions. This digital knitting system will provide considerable potential for customized design development as well as a sustainable production process. This structured, systematic approach could be adapted in the future development of wearable electronic textile systems.

Low-temperature luminescence of CdI2 under synchrotron radiation

2020 ◽  
Vol 46 (12) ◽  
pp. 1213-1216
Author(s):  
I. Karbovnyk ◽  
V. Pankratov ◽  
S. Velgosh ◽  
I. Bolesta ◽  
R. Lys ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Low Temperature

FEC-LiTFSI-Pyr1ATFSI Ionic Liquid Electrolyte to Improve Low Temperature Performance of Lithium-Ion Batteries

2014 ◽  
Vol 986-987 ◽  
pp. 80-83
Author(s):  
Xiao Xue Zhang ◽  
Zhen Feng Wang ◽  
Cui Hua Li ◽  
Jian Hong Liu ◽  
Qian Ling Zhang
Keyword(s):  
Low Temperature ◽  
Lithium Ion Batteries ◽  
Low Temperatures ◽  
Freezing Point ◽  
Lithium Ion ◽  
Liquid Electrolyte ◽  
Capacity Retention ◽  
Composite Electrolyte ◽  
Ionic Liquid Electrolyte ◽  
Fluoroethylene Carbonate

N-methyl-N-allylpyrrolidinium bis (trifluoromethanesulfonyl) imide (PYR1ATFSI) with substantial supercooling behavior is synthesized to develop low temperature electrolyte for lithium-ion batteries. Additive fluoroethylene carbonate (FEC) in LiTFSI/PYR1ATFSI/EC/PC/EMC is found that it can reduce the freezing point. LiFePO4/Li coin cells with the FEC-PYR1ATFSI electrolyte exhibit good capacity retention, reversible cycling behavior at low temperatures. The good performance can be attributed to the decrease in the freezing point and the polarization of the composite electrolyte.

Anthracene fluorescence at low temperatures. I. Purified single crystals

1972 ◽  
Vol 25 (7) ◽  
pp. 1411 ◽  
Author(s):  
LE Lyons ◽  
LJ Warren
Keyword(s):  
Low Temperature ◽  
Single Crystals ◽  
Fluorescence Spectrum ◽  
Low Temperatures ◽  
Free Exciton ◽  
Deformation Bands ◽  
Exciton Emission ◽  
Polarized Emission ◽  
Impurity Bands ◽  
Phonon Structure

The low-temperature fluorescence spectrum of purified vapour-grown anthracene single crystals is presented and the free-exciton emission distinguished from a number of defect or impurity bands present even in the purest crystals. In assigning the observed bands the symmetry of the active vibrations and the origin of background fluorescence and deformation bands are discussed. The phonon structure in the region of the fluorescence origin was found to be almost completely b-polarized. Emission of electronic origin (25103 cm-1) was too weak to be observed. Polarization ratios of the principal vibronio bands at 5.6 K are given.

Desiccation and low temperature attenuate the effect of UVC254 nm in the photobiont of the astrobiologically relevant lichens Circinaria gyrosa and Buellia frigida

2014 ◽  
Vol 14 (3) ◽  
pp. 479-488 ◽  
Author(s):  
T. Backhaus ◽  
R. de la Torre ◽  
K. Lyhme ◽  
J.-P. de Vera ◽  
J. Meeßen
Keyword(s):  
Low Temperature ◽  
Low Temperatures ◽  
Photosynthetic Activity ◽  
Real Space ◽  
Fast Recovery ◽  
Protective Mechanisms ◽  
Subzero Temperatures ◽  
High Viability ◽  
Buellia Frigida ◽  
Insight Into

AbstractSeveral investigations on lichen photobionts (PBs) after exposure to simulated or real-space parameters consistently reported high viability and recovery of photosynthetic activity. These studies focused on PBs within lichen thalli, mostly exposed in a metabolically inactive state. In contrast, a recent study exposed isolated and metabolically active PBs to the non-terrestrial stressor UVC254 nm and found strong impairment of photosynthetic activity and photo-protective mechanisms (Meeßen et al. in 2014b). Under space and Mars conditions, UVC is accompanied by other stressors as extreme desiccation and low temperatures. The present study exposed the PBs of Buellia frigida and Circinaria gyrosa, to UVC in combination with desiccation and subzero temperatures to gain better insight into the combined stressors' effect and the PBs' inherent potential of resistance. These effects were examined by chlorophyll a fluorescence which is a good indicator of photosynthetic activity (Lüttge & Büdel in 2010) and widely used to test the viability of PBs after (simulated) space exposure. The present results reveal fast recovery of photosynthetic activity after desiccation and subzero temperatures. Moreover, they demonstrate that desiccation and cold confer an additional protective effect on the investigated PBs and attenuate the PBs' reaction to another stressor – even if it is a non-terrestrial one such as UVC. Besides other protective mechanisms (anhydrobiosis, morphological–anatomical traits and secondary lichen compounds), these findings may help to explain the high resistance of lichens observed in astrobiological studies.

LOW-TEMPERATURE NORMAL-STATE HALL EFFECT IN HIGH-TcBi2Sr2-xLaxCuO6+δ REVEALED BY 60 T MAGNETIC FIELDS

2002 ◽  
Vol 16 (20n22) ◽  
pp. 3171-3174
Author(s):  
F. F. BALAKIREV ◽  
J. B. BETTS ◽  
G. S. BOEBINGER ◽  
S. ONO ◽  
Y. ANDO ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Low Temperature ◽  
Carrier Concentration ◽  
Hall Coefficient ◽  
Normal State ◽  
Ground State ◽  
Low Temperatures ◽  
Optimal Doping ◽  
Underdoped Sample ◽  
Additional Support

We report low-temperature Hall coefficient in the normal state of the high-Tc superconductor Bi 2 Sr 2-x La x CuO 6+δ. The Hall coefficient was measured down to 0.5 K by suppressing superconductivity with a 60 T pulsed magnetic field. The carrier concentration was varied from overdoped to underdoped regimes by partially substituting Sr with La in a set of five samples. The observed saturation of the Hall coefficient at low temperatures suggests the ability to extract the carrier concentration of each sample. The most underdoped sample exhibits a diverging Hall coefficient at low temperatures, consistent with a depletion of carriers in the insulating ground state. The Hall number exhibits a sharp peak providing additional support for the existence of a phase boundary at the optimal doping.

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