Low Temperature Pre-Epi Treatment: Critical Parameters to Control Interface Contamination

2009 ◽  
Vol 145-146 ◽  
pp. 177-180 ◽  
Author(s):  
Roger Loo ◽  
Andriy Hikavyy ◽  
Frederik E. Leys ◽  
Masayuki Wada ◽  
Kenichi Sano ◽  
...  
Keyword(s):  
Low Temperature ◽  
Sige Layer ◽  
Ex Situ ◽  
Critical Parameters ◽  
Process Equipment ◽  
Successful Implementation ◽  
Lifetime Measurements ◽  
Deposition Processes ◽  
Cleaning Methods ◽  
The Impact

Several device concepts have been further evaluated after the successful implementation of epitaxial Si, SiGe and/or Si:C layers. Most of the next device generations will put limitations on the thermal budget of the deposition processes without making concessions on the epitaxial layer quality. In this work we address the impact of ex-situ wet chemical cleans and in-situ pre-epi bake steps, which are required to obtain oxide free Si surfaces for epitaxial growth. The combination of defect measurements, Secondary Ion Mass Spectroscopy, photoluminescence, lifetime measurements, and electrical diode characterization gives a very complete overview of the performance of low-temperature pre-epi cleaning methods. Contamination at the epi/substrate interface cannot be avoided if the pre-epi bake temperature is too low. This interface contamination is traceable by the photoluminescence and lifetime measurements. It may affect device characteristics by enhanced leakage currents and eventually by yield issues due to SiGe layer relaxation or other defect generation. A comparison of state of the art 200 mm and 300 mm process equipment indicates that for the same thermal budgets the lowest contamination levels are obtained for the 300 mm equipments.

Electrical Evaluation of the Epi/Substrate Interface Quality after Different In-Situ and Ex-Situ Low-Temperature Pre-Epi Cleaning Methods

1998 ◽  
Vol 65-66 ◽  
pp. 237-240 ◽  
Author(s):  
Matty Caymax ◽  
S. Decoutere ◽  
Erika Röhr ◽  
W. Vandervorst ◽  
Marc M. Heyns ◽  
...  
Keyword(s):  
Low Temperature ◽  
Ex Situ ◽  
Interface Quality ◽  
Substrate Interface ◽  
Cleaning Methods

Seeking the Good Fitting Procedure of PALS Polymer Spectra

2008 ◽  
Vol 607 ◽  
pp. 64-66
Author(s):  
Nicolas Laforest ◽  
Jérémie De Baerdemaeker ◽  
Corine Bas ◽  
Charles Dauwe
Keyword(s):  
Experimental Data ◽  
Low Temperature ◽  
Positron Annihilation ◽  
Physical Meaning ◽  
Lifetime Measurements ◽  
Positron Annihilation Lifetime ◽  
Fitting Procedure ◽  
Fitting Procedures ◽  
Blob Model

Positron annihilation lifetime measurements on polymethylmethacrylate (PMMA) at low temperature were performed. Different discrete fitting procedures have been used to analyze the experimental data. It shows that the extracted parameters depend strongly on the fitting procedure. The physical meaning of the results is discussed. The blob model seems to give the best annihilation parameters.

scholarly journals The Impact of Ex Situ Heart Perfusion in Pediatric Transplantation: An Analysis of the UNOS Registry

2021 ◽  
Vol 40 (4) ◽  
pp. S39
Author(s):  
J. Conway ◽  
Y. Hong ◽  
T. Pidborochynski ◽  
M. Khan ◽  
D.H. Freed
Keyword(s):  
Ex Situ ◽  
Pediatric Transplantation ◽  
Heart Perfusion ◽  
The Impact

scholarly journals Minimization of the Line Resistance Impact on Memdiode-Based Simulations of Multilayer Perceptron Arrays Applied to Pattern Recognition

2021 ◽  
Vol 11 (1) ◽  
pp. 9
Author(s):  
Fernando Leonel Aguirre ◽  
Nicolás M. Gomez ◽  
Sebastián Matías Pazos ◽  
Félix Palumbo ◽  
Jordi Suñé ◽  
...  
Keyword(s):  
Pattern Recognition ◽  
Ex Situ ◽  
Multilayer Perceptrons ◽  
Spice Simulation ◽  
Large Dataset ◽  
High Line ◽  
Calibration Algorithm ◽  
The Impact ◽  
Line Resistance

In this paper, we extend the application of the Quasi-Static Memdiode model to the realistic SPICE simulation of memristor-based single (SLPs) and multilayer perceptrons (MLPs) intended for large dataset pattern recognition. By considering ex-situ training and the classification of the hand-written characters of the MNIST database, we evaluate the degradation of the inference accuracy due to the interconnection resistances for MLPs involving up to three hidden neural layers. Two approaches to reduce the impact of the line resistance are considered and implemented in our simulations, they are the inclusion of an iterative calibration algorithm and the partitioning of the synaptic layers into smaller blocks. The obtained results indicate that MLPs are more sensitive to the line resistance effect than SLPs and that partitioning is the most effective way to minimize the impact of high line resistance values.

scholarly journals Effects of equal channel angular pressing and heat treatments on the microstructures and mechanical properties of selective laser melted and cast AlSi10Mg alloys

2021 ◽  
Vol 21 (3) ◽  
Author(s):  
Przemysław Snopiński ◽  
Mariusz Król ◽  
Marek Pagáč ◽  
Jana Petrů ◽  
Jiří Hajnyš ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Equal Channel Angular Pressing ◽  
Heat Treatments ◽  
Electron Backscattered Diffraction ◽  
Angular Pressing ◽  
Low Temperature Annealing ◽  
Transmission Electron ◽  
Before And After ◽  
The Impact

AbstractThis study investigated the impact of the equal channel angular pressing (ECAP) combined with heat treatments on the microstructure and mechanical properties of AlSi10Mg alloys fabricated via selective laser melting (SLM) and gravity casting. Special attention was directed towards determining the effect of post-fabrication heat treatments on the microstructural evolution of AlSi10Mg alloy fabricated using two different routes. Three initial alloy conditions were considered prior to ECAP deformation: (1) as-cast in solution treated (T4) condition, (2) SLM in T4 condition, (3) SLM subjected to low-temperature annealing. Light microscopy, transmission electron microscopy, X-ray diffraction line broadening analysis, and electron backscattered diffraction analysis were used to characterize the microstructures before and after ECAP. The results indicated that SLM followed by low-temperature annealing led to superior mechanical properties, relative to the two other conditions. Microscopic analyses revealed that the partial-cellular structure contributed to strong work hardening. This behavior enhanced the material’s strength because of the enhanced accumulation of geometrically necessary dislocations during ECAP deformation.

scholarly journals Start-up Strategies for Anaerobic Ammonia Oxidation (Anammox) in In-Situ Nitrogen Removal from Polluted Groundwater in Rare Earth Mining Areas

2021 ◽  
Vol 13 (8) ◽  
pp. 4591
Author(s):  
Shuanglei Huang ◽  
Daishe Wu
Keyword(s):  
Rare Earth ◽  
Low Temperature ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Ex Situ ◽  
High Concentration ◽  
Low Concentration ◽  
Start Up ◽  
Anammox Activity

The tremendous input of ammonium and rare earth element (REE) ions released by the enormous consumption of (NH4)2SO4 in in situ leaching for ion-adsorption RE mining caused serious ground and surface water contamination. Anaerobic ammonium oxidation (anammox) was a sustainable in situ technology that can reduce this nitrogen pollution. In this research, in situ, semi in situ, and ex situ method of inoculation that included low-concentration (0.02 mg·L−1) and high-concentration (0.10 mg·L−1) lanthanum (La)(III) were adopted to explore effective start-up strategies for starting up anammox reactors seeded with activated sludge and anammox sludge. The reactors were refrigerated for 30 days at 4 °C to investigate the effects of La(III) during a period of low-temperature. The results showed that the in situ and semi in situ enrichment strategies with the addition of La(III) at a low-concentration La(III) addition (0.02 mg·L−1) reduced the length of time required to reactivate the sludge until it reached a state of stable anammox activity and high nitrogen removal efficiency by 60–71 days. The addition of La(III) promoted the formation of sludge floc with a compact structure that enabled it to resist the adverse effects of low temperature and so to maintain a high abundance of AnAOB and microbacterial community diversity of sludge during refrigeration period. The addition of La(III) at a high concentration caused the cellular percentage of AnAOB to decrease from 54.60 ± 6.19% to 17.35 ± 6.69% during the enrichment and reduced nitrogen removal efficiency to an unrecoverable level to post-refrigeration.

scholarly journals Implementation of a Female External Urinary Catheter Reduces Indwelling Urinary Catheter Use and Catheter-Associated Urinary Tract Infections

2020 ◽  
Vol 41 (S1) ◽  
pp. s482-s483
Author(s):  
Paul Gentile ◽  
Jesse Jacob ◽  
Shanza Ashraf
Keyword(s):  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Urinary Catheter ◽  
Improve Patient Safety ◽  
Academic Medical Center ◽  
Secondary Outcome ◽  
Successful Implementation ◽  
Urinary Catheters ◽  
Tract Infections ◽  
The Impact

Background: Using alternatives to indwelling urinary catheters plays a vital role in reducing catheter-associated urinary tract infections (CAUTIs). We assessed the impact of introducing female external catheters on urinary catheter utilization and CAUTIs. Methods: In a 500-bed academic medical center, female external catheters were implemented on October 1, 2017, with use encouraged for eligible females with urinary incontinence but not meeting other standard indications for urinary catheters. Nurses were educated and trained on female external catheter application and maintenance, and infection prevention staff performed surveillance case reviews with nursing and medical staff. We determined the number of catheter days for both devices based on nursing documentation of device insertion or application, maintenance, and removal. We used the CAUTI and DUR (device utilization ratio) definitions from the CDC NHSN. Our primary outcomes were changes in DUR for both devices 21 months before and 24 months after the intervention in both intensive care units (ICUs) and non-ICU wards. We used a generalized least-squares model to account for temporal autocorrelation and compare the trends before and after the intervention. Our secondary outcome was a reduction in CAUTIs, comparing females to males. Results: In total, there were 346,213 patient days in 35 months. The mean rate of patient days per month increased from 7,436.4 to 7,601.9 after the implementation of female external catheters, with higher catheter days for both urinary catheters (18,040 vs 19,625) and female external catheters (22 vs 12,675). After the intervention, the DUR for female external catheters increased (0 vs 0.07; P < .001) and for urinary catheters the DUR decreased (0.12 vs 0.10; P < .001) (Fig. 1). A reduction in urinary catheter DUR was observed in ICUs (0.29 vs 0.27; P < .001) but not wards (0.08 vs 0.08; P = NS) (Fig. 2). Of the 39 CAUTIs, there was no significant overall change in the rate per 1,000 catheter days (1.22 vs 0.87; P = .27). In females (n = 20 CAUTI), there was a 61% reduction in the CAUTI rate per 1,000 catheter days (0.78 vs 0.31; P = .02), but no significant change in the rate in males (0.44 vs 0.56; P = .64). The CAUTI rate per 1,000 catheter days among females decreased in the ICUs (1.14 vs 0.31; P = .04) but not in wards (0.6 vs 0.33; P = .96). Conclusions: In a setting with a baseline low UC DUR, successful implementation of female external catheters further modestly reduced UC DUR and was associated with a 61% decrease in CAUTI among females in the ICU but not in wards. Further interventions to better identify appropriate patients for female external catheters may improve patient safety and prevent patient harm.Funding: NoneDisclosures: None

scholarly journals Structural Changes in French VF Treatment Wetland Porous Media during the Rest Period: An Ex Situ Study Using X-ray Tomography

Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 389
Author(s):  
German Dario Martinez-Carvajal ◽  
Laurent Oxarango ◽  
Jérôme Adrien ◽  
Pascal Molle ◽  
Nicolas Forquet
Keyword(s):  
Porous Media ◽  
Structural Changes ◽  
Rest Period ◽  
Treatment Wetlands ◽  
Ex Situ ◽  
Initial Value ◽  
Treatment Wetland ◽  
X Ray ◽  
The Impact ◽  
Deposit Layer

Clogging constitutes a major operational issue for treatment wetlands. The rest period is a key feature of French Vertical Flow (VF) treatment wetlands and serves to mitigate clogging. An ex-situ drying experiment was performed to mimic the rest period and record structural changes in the porous media using X-ray Computed Tomography (CT). Samples containing the deposit and gravel layers of a first stage French VF treatment wetland were extracted and left to dry in a control environment. Based on CT scans, three phases were identified (voids, biosolids, and gravels). The impact of the rest period was assessed by means of different pore-scale variables. Ultimately, the volume of biosolids had reduced to 58% of its initial value, the deposit layer thickness dropped to 68% of its initial value, and the void/biosolid specific surface area ratio increased from a minimum value of 1.1 to a maximum of 4.2. Cracks greater than 3 mm developed at the uppermost part of the deposit layer, while, in the gravel layer, the rise in void volume corresponds to pores smaller than 2 mm in diameter. Lastly, the air-filled microporosity is estimated to have increased by 0.11 v/v.

scholarly journals Viability Assessment in Liver Transplantation—What Is the Impact of Dynamic Organ Preservation?

Biomedicines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 161
Author(s):  
Rebecca Panconesi ◽  
Mauricio Flores Carvalho ◽  
Matteo Mueller ◽  
David Meierhofer ◽  
Philipp Dutkowski ◽  
...  
Keyword(s):  
Liver Function ◽  
Organ Preservation ◽  
Ex Situ ◽  
Current Status ◽  
Intensive Care Treatment ◽  
Viability Assessment ◽  
Great Opportunity ◽  
Continuous Increase ◽  
Diagnostic Time ◽  
The Impact

Based on the continuous increase of donor risk, with a majority of organs classified as marginal, quality assessment and prediction of liver function is of utmost importance. This is also caused by the notoriously lack of effective replacement of a failing liver by a device or intensive care treatment. While various parameters of liver function and injury are well-known from clinical practice, the majority of specific tests require prolonged diagnostic time and are more difficult to assess ex situ. In addition, viability assessment of procured organs needs time, because the development of the full picture of cellular injury and the initiation of repair processes depends on metabolic active tissue and reoxygenation with full blood over several hours or days. Measuring injury during cold storage preservation is therefore unlikely to predict the viability after transplantation. In contrast, dynamic organ preservation strategies offer a great opportunity to assess organs before implantation through analysis of recirculating perfusates, bile and perfused liver tissue. Accordingly, several parameters targeting hepatocyte or cholangiocyte function or metabolism have been recently suggested as potential viability tests before organ transplantation. We summarize here a current status of respective machine perfusion tests, and report their clinical relevance.

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