Probing Selective Deposition of Aluminum Using in Situ Infrared Spectroscopy

1993 ◽  
Vol 334 ◽  
Author(s):  
Wayne L. Gladfelter ◽  
Michael G. Simmonds ◽  
Larry A. Zazzera ◽  
John F. Evans
Keyword(s):  
Room Temperature ◽  
Silicon Oxide ◽  
Silica Surface ◽  
Effect Of Temperature ◽  
Weakly Bound ◽  
Weak Absorption ◽  
Dimethylethylamine Alane ◽  
The Impact ◽  
In Situ Infrared Spectroscopy

AbstractDimethylethylamine alane (DMEAA) has been used to deposit thin films of aluminum selectively on gold in the presence of silicon oxide. This paper presents studies of the effect of temperature, pressure, and substrate pattern on the selectivity. A specially designed reactor allowed us to probe the structure of the species on the silica surface using infraed spectroscopy. At room temperature two absorptions in the Al-H stretching region were assigned to two species; weakly bound molecules of the intact precursor and a strongly bound dihydride formed from the reaction of DMEAA with surface bound (and H-bonded) hydroxyls (from H2O or silanol groups). At higher temperatures the CH vibrations of the amine disappeared, and the Al-H stretch shifted to higher energy. A weak absorption at 2250 cm−1 attributable to a Si-H also appeared. The impact of these observations on the loss of selectivity is discussed.

scholarly journals Effects of Extender Type, Storage Time, and Temperature on Bull Semen Parameters

Biology ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 630
Author(s):  
Aitor Fernandez-Novo ◽  
Sergio Santos-Lopez ◽  
Clara Barrajon-Masa ◽  
Patricia Mozas ◽  
Eduardo de Mercado ◽  
...  
Keyword(s):  
Room Temperature ◽  
Semen Quality ◽  
Storage Conditions ◽  
Semen Parameters ◽  
Bull Semen ◽  
Colony Forming Units ◽  
The Impact ◽  
Diagnostic Centre ◽  
Holding Temperature

Seminal parameters can be evaluated in situ, or samples can be delivered to a diagnostic centre. How storage conditions affect ejaculates up to evaluation is unclear. We assessed, in 25 commercial bulls electroejaculated in the field, the impact of time until evaluation (0–2 h, 4–6 h, and 24 h post-ejaculation), holding temperature (5 °C vs. room temperature), and extender (AndroMed®, BIOXcell® or INRA96®) on semen quality. Acrosome integrity, sperm viability and morphology, CASA-total and progressive motility, pH, and colony-forming units were assessed. Semen quality was preserved for up to 4–6 h post-ejaculation, except for INRA96® at 5 °C. Regardless of extender or temperature, motility decreased from 4 to 6 h up to 24 h, with the best values obtained with BIOXcell® at 5 °C. pH differed from 4 to 6 h up to 24 h, acidifying when stored at room temperature. Microbiological load was stable over time with AndroMed® and BIOXcell®, and increased at room temperature with INRA96®. Our results suggest that AndroMed® and BIOXcell® can preserve semen quality for up to 6 h, either at 5 °C or room temperature, while INRA96® only at room temperature. These results help to fix adequate protocols for short-term storage and shipment of bovine semen collected under field conditions.

scholarly journals Effect of Temperature on Host Preference in Two Lineages of the Brown Dog Tick, Rhipicephalus sanguineus

2021 ◽  
Author(s):  
Laura H. Backus ◽  
Andrés M. López Pérez ◽  
Janet E. Foley
Keyword(s):  
Disease Transmission ◽  
Room Temperature ◽  
Disease Outbreaks ◽  
Rhipicephalus Sanguineus ◽  
Pathogen Transmission ◽  
Effect Of Temperature ◽  
Rickettsia Rickettsii ◽  
Hot Weather ◽  
Dog Tick ◽  
The Impact

Rhipicephalus sanguineus is a species complex of ticks that vector disease worldwide. Feeding primarily on dogs, members of the complex also feed incidentally on humans, potentially transmitting disease agents such as Rickettsia rickettsii, R. conorii, and Ehrlichia species. There are two genetic Rh. sanguineus lineages in North America, designated as the temperate and tropical lineages, which had occurred in discrete locations, although there is now range overlap in parts of California and Arizona. Rh. sanguineus in Europe are reportedly more aggressive toward humans during hot weather, increasing the risk of pathogen transmission to humans. The aim of this study was to assess the impact of hot weather on choice between humans and dog hosts among tropical and temperate lineage Rh. sanguineus individuals. Ticks in a two-choice olfactometer migrated toward a dog or human in trials at room (23.5°C) or high temperature (38°C). At 38°C, 2.5 times more tropical lineage adults chose humans compared with room temperature, whereas temperate lineage adults demonstrated a 66% reduction in preference for dogs and a slight increase in preference for humans. Fewer nymphs chose either host at 38°C than at room temperature in both lineages. These results demonstrate that risk of disease transmission to humans may be increased during periods of hot weather, where either lineage is present, and that hot weather events associated with climatic change may result in more frequent rickettsial disease outbreaks.

Comparison of the effects of in vitro and in situ storage on the viability of mouse ovarian tissue collected after death

2001 ◽  
Vol 13 (6) ◽  
pp. 389 ◽  
Author(s):  
M. Snow ◽  
M. Cleary ◽  
S-L. Cox ◽  
J. Shaw ◽  
M. Paris ◽  
...  
Keyword(s):  
Room Temperature ◽  
Storage Temperature ◽  
Ovarian Tissue ◽  
The Body ◽  
Tissue Storage ◽  
Duration Of Storage ◽  
The Impact ◽  
Phosphate Buffered Saline

Ovarian tissues, collected or salvaged from endangered species at the time of gonadectomy or following their death, are being transported to genebanks for storage with the assumption that they will (subsequently) yield sufficient numbers of germ cells to help preserve the species. The present study aimed to quantify the impact of delays in collecting and/or processing ovarian tissue on the number of follicles in this tissue that remained normal after grafting. The study compared the viability of ovarian tissue stored in vitro (in phosphate-buffered saline) versus in situ (in the body) either on ice or at room temperature for 0 (non-stored fresh grafts), 3, 6, 12, 24 or 48 h. The conditions of storage had significant effects on the total number of morphologically normal follicles, with significantly more follicles in grafts developing from in vitro-stored tissue than in situ-stored tissue. Storage temperature and duration of storage, but not the storage temperature alone, influenced follicle survival. Tissue that was grafted immediately after collection (0 h) was best, but normal follicles were recovered in grafts stored in vitro (on ice or at room temperature) or in situ (on ice only) for up to 48 h before grafting. The rate of follicle loss over time was very rapid, with approximately 50% fewer follicles in grafts derived from tissue stored for only 3 h compared with non-stored fresh grafts (0 h). The results show that viable ovarian tissue can be salvaged from animals up to 48 h after death; however, in order to best protect the follicle population, the ovaries should be removed from the animal’s body as soon as possible.

Fatigue of in situ Reinforced Ti–8.5Al–1B–1Si

1997 ◽  
Vol 12 (4) ◽  
pp. 1102-1111 ◽  
Author(s):  
S. Rangarajan ◽  
P. B. Aswath ◽  
W. O. Soboyejo
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Low Cycle Fatigue ◽  
Effect Of Temperature ◽  
Crack Growth Rates ◽  
Better Than

The effect of temperature on the fatigue and fracture properties of an in situ reinforced super α alloy Ti–8.5Al–1B–1Si (wt. %) was investigated. At room temperature the as-extruded composite has a strength of 631 MPa with limited ductility. On increasing the temperature to 700 °C only a marginal drop in strength to 610 Mpa was observed along with a significant improvement in ductility to 5.9%. Low-cycle fatigue results indicate a marginal decrease in fatigue life as temperature is increased from room temperature to 700 °C. Fatigue crack growth studies in the as-extruded microstructure indicate a strong influence of R-ratio on both the threshold for fatigue crack growth and crack growth rates in the Paris regimes. At elevated temperatures, the resistance to fatigue crack growth increases with temperature below approximately 500 °C. At 600 °C, however, there is an increase in the near threshold crack growth rate due to embrittlement effects. At higher δK values , the resistance to fatigue crack growth at elevated temperatures is always better than that at room temperature. This improvement is attributed to the increase in the inherent resistance

Otoconia perfect/imperfect crystals

1994 ◽  
Vol 52 ◽  
pp. 42-43
Author(s):  
César D. Fermin ◽  
Dale Martin
Keyword(s):  
Image Processing ◽  
Room Temperature ◽  
Phosphotungstic Acid ◽  
Gallus Domesticus ◽  
Crystal Matrix ◽  
Organic Templates ◽  
Image Processing Algorithms ◽  
Processing Algorithms ◽  
Diffraction Patterns

Otoconia of higher vertebrates are interesting biological crystals that display the diffraction patterns of perfect crystals (e.g., calcite for birds and mammal) when intact, but fail to produce a regular crystallographic pattern when fixed. Image processing of the fixed crystal matrix, which resembles the organic templates of teeth and bone, failed to clarify a paradox of biomineralization described by Mann. Recently, we suggested that inner ear otoconia crystals contain growth plates that run in different directions, and that the arrangement of the plates may contribute to the turning angles seen at the hexagonal faces of the crystals.Using image processing algorithms described earlier, and Fourier Transform function (2FFT) of BioScan Optimas®, we evaluated the patterns in the packing of the otoconia fibrils of newly hatched chicks (Gallus domesticus) inner ears. Animals were fixed in situ by perfusion of 1% phosphotungstic acid (PTA) at room temperature through the left ventricle, after intraperitoneal Nembutal (35mg/Kg) deep anesthesia. Negatives were made with a Hitachi H-7100 TEM at 50K-400K magnifications. The negatives were then placed on a light box, where images were filtered and transferred to a 35 mm camera as described.

In Situ Localization of PPAR Gamma and Uncoupling Protein in Mouse Embryo Sections Using Digoxigenin-Labeled Riboprobes

1996 ◽  
Vol 54 ◽  
pp. 32-33
Author(s):  
C. Jennermann ◽  
S. A. Kliewer ◽  
D. C. Morris
Keyword(s):  
Alkaline Phosphatase ◽  
Room Temperature ◽  
Uncoupling Protein ◽  
Ppar Gamma ◽  
Nuclear Hormone Receptor ◽  
Full Length ◽  
Northern Analysis ◽  
Peroxisome Proliferator

Peroxisome proliferator-activated receptor gamma (PPARg) is a member of the nuclear hormone receptor superfamily and has been shown in vitro to regulate genes involved in lipid metabolism and adipocyte differentiation. By Northern analysis, we and other researchers have shown that expression of this receptor predominates in adipose tissue in adult mice, and appears first in whole-embryo mRNA at 13.5 days postconception. In situ hybridization was used to find out in which developing tissues PPARg is specifically expressed.Digoxigenin-labeled riboprobes were generated using the Genius™ 4 RNA Labeling Kit from Boehringer Mannheim. Full length PPAR gamma, obtained by PCR from mouse liver cDNA, was inserted into pBluescript SK and used as template for the transcription reaction. Probes of average size 200 base pairs were made by partial alkaline hydrolysis of the full length transcripts. The in situ hybridization assays were performed as described previously with some modifications. Frozen sections (10 μm thick) of day 18 mouse embryos were cut, fixed with 4% paraformaldehyde and acetylated with 0.25% acetic anhydride in 1.0M triethanolamine buffer. The sections were incubated for 2 hours at room temperature in pre-hybridization buffer, and were then hybridized with a probe concentration of 200μg per ml at 70° C, overnight in a humidified chamber. Following stringent washes in SSC buffers, the immunological detection steps were performed at room temperature. The alkaline phosphatase labeled, anti-digoxigenin antibody and detection buffers were purchased from Boehringer Mannheim. The sections were treated with a blocking buffer for one hour and incubated with antibody solution at a 1:5000 dilution for 2 hours, both at room temperature. Colored precipitate was formed by exposure to the alkaline phosphatase substrate nitrobluetetrazoliumchloride/ bromo-chloroindlylphosphate.

Effect of Temperature on ADP-Induced Platelet Aggregation

1973 ◽  
Vol 29 (01) ◽  
pp. 183-189
Author(s):  
C. A Praga ◽  
E. M Pogliani
Keyword(s):  
Platelet Aggregation ◽  
Incubation Period ◽  
Room Temperature ◽  
Important Variable ◽  
Practical Significance ◽  
Effect Of Temperature ◽  
Induce Platelet Aggregation ◽  
Cuvette Holder ◽  
Exact Temperature

SummaryTemperature represents a very important variable in ADP-induced platelet aggregation.When low doses of ADP ( < 1 (μM) are used to induce platelet aggregation, the length of the incubation period of PRP in the cuvette holder of the aggregometer, thermostatted at 37° C, is very critical. Samples of the same PRP previously kept at room temperature, were incubated for increasing periods of time in the cuvette of the aggregometer before adding ADP, and a significant decrease of aggregation, proportional to the length of incubation, was observed. Stirring of the PRP during the incubation period made these changes more evident.To measure the exact temperature of the PRP during incubation in the aggre- gometer, a thermocouple device was used. While the temperature of the cuvette holder was stable at 37° C, the PRP temperature itself increased exponentially, taking about ten minutes from the beginning of the incubation to reach the value of 37° C. The above results have a practical significance in the reproducibility of the platelet aggregation test in vitro and acquire particular value when the effect of inhibitors of ADP induced platelet aggregation is studied.Experiments carried out with three anti-aggregating agents (acetyl salicyclic acid, dipyridamole and metergoline) have shown that the incubation conditions which influence both the effect of the drugs on platelets and the ADP breakdown in plasma must be strictly controlled.

Single Crystal Growth of High-Pressure Phases of Ice and Salt Hydrate Far Below the Original Melting Point by Mixing Alcohol: Crystal Structure Determination of Magnesium Chloride Heptahydrate

2020 ◽  
Author(s):  
Keishiro Yamashita ◽  
Kazuki Komatsu ◽  
Hiroyuki Kagi
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Crystal Growth ◽  
Single Crystal ◽  
Room Temperature ◽  
Growth Technique ◽  
Salt Hydrate ◽  
X Ray

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.

In situ Quantification of the Impact of Episodic Enhanced Turbulent Events in Large Phytoplankton

2011 ◽  
Author(s):  
Percy L. Donaghay ◽  
Jan Rines ◽  
James Sullivan
Keyword(s):  
The Impact
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