Interaction of the ionic liquid [BMP][TFSA] with rutile TiO2(110) and coadsorbed lithium

Aiming at a fundamental understanding of the processes at the electrode|ionic liquid interface in Li ion batteries, we investigated the interaction of the ionic liquid n-butyl-n-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide [BMP][TFSA] and of Li with a reduced rutile TiO2(110) (1 × 1) surface as well as the interaction between [BMP][TFSA] and Li on the TiO2(110) surface under ultrahigh vacuum (UHV) conditions by X-ray photoelectron spectroscopy and scanning tunnelling microscopy. Between 80 K and 340 K [BMP][TFSA] adsorbs molecularly on the surface and at higher temperatures decomposition is observed, resulting in products such as Sad, Fad and TiNx. The decomposition pattern is compared to proposals based on theory. Small amounts of Li intercalate even at 80 K into TiO2(110), forming Li+ and Ti3+ species. The stoichiometry in the near surface region corresponds to Li7Ti5O12. For higher coverages in the range of several monolayers part of the Li remains on the surface, forming a Li2O cover layer. At 300 K, Ti3+ species become sufficiently mobile to diffuse into the bulk. Li post-deposition on a [BMP][TFSA] covered TiO2(110) surface at 80 K results in two competing reactions, Li intercalation and reaction with the IL, resulting in the decomposition of the IL. Upon warming up, the Ti3+ formed at low T is consumed by reaction with the IL adlayer and intermediate decomposition products. Post-deposition of [BMP][TFSA] (300 K) on a surface pre-covered with a Li2O/Li7Ti5O12 layer results in the partial reaction of [BMP][TFSA] with the Li+ and Ti3+ species, which gets completed at higher temperatures

A Tailored Systems Engineering Framework for Science and Technology Projects

As government and industry becomes subject to a wider range of technology initiatives, science and technology (S&T) research project leadership recognizes the need to incorporate more systems engineering (SE) rigor into their projects. The objective of this research is to develop a tailorable systems engineering framework for S&T project planning, execution, assessment and transition. The key deliverable is an Excel-based tool instantiating the SE framework for a wide range of S&T projects in technology development organizations. It includes a report with tailored methods based on programmatic discriminants. To develop this framework, a comprehensive understanding of SE principles is applied to several case studies across government and supporting industry-sponsored S&T activities. This research followed a six-step approach: (1) Literature Review; (2) Formulate Taxonomy; (3) Prepare Data Gathering Approach; (4) Review Case Studies; (5) Develop Tailorable SE Framework for Technology Development and Transition; and (6) Validate Framework.The framework allows S&T project leaders and engineers to customize a recommended set of SE processes, methods and tools for their specific project type, size, maturity, budget, and integration level. Recommendations for SE methods are made at a summary level, with additional details available for desired activities. References to established SE documentation is also included for further investigation of appropriate SE techniques

Interaction of ionic liquids with noble metal surfaces: Structure formation and stability of [OMIM][TFSA] and [EMIM][TFSA] on Au(111) and Ag(111)

Principles of structure formation and adsorbate–adsorbate interactions in ionic liquid adlayers on metal surfaces were investigated in a comparative STM study on Ag(111) and Au(111) surfaces.</p

A Combined XPS and Computational Study of the Chemical Reduction of BMP‐TFSI by Lithium

Employing density functional theory (DFT) calculations and X-ray photoelectron spectroscopy (XPS), we identify products of the reaction of the ionic liquid N,N-butylmethylpyrrolidinum bis(trifluoromethylsulfonyl)imide (BMP-TFSI) with lithium in order to model the initial chemical processes contributing to the formation of the solid electrolyte interphase in batteries. Besides lithium oxide, sulfide, carbide and fluoride, we find lithium cyanide or cyanamide as possible, thermodynamically stable product in the Li-poor regime, whilst Li$_{3}$N is the stable product in the Li-rich regime. The thermodynamically controlled reaction products as well as larger fragments of TFSI persisting due to kinetic barriers could be identified by a comparison of experimentally and computationally determined core level binding energies

Reconstruction and subsurface lattice distortions in the (2 × 1)O-Ni(110) structure: A LEED analysis

LEED analysis of the reconstructed (2 × 1)O-Ni(110) system clearly favors the “missing row” structure over the “saw-tooth” and “buckled row” models. By using a novel computational procedure 8 structural parameters could be refined simultaneously, leading to excellent R-factors (RZJ = 0.09, RP = 0.18). The adsorbed O atoms are located 0.2 Å above the long bridge sites in [001] direction, presumably with a slight displacement ( 0.1 Å) in [1 0] direction to an asymmetric adsorption site. The nearest-neighbor Ni---O bond lengths (1.77 Å) are rather short. The separation between the topmost two Ni layers is expanded to 1.30 Å (bulk value 1.25 Å), while that between the second and third layer is slightly contracted to 1.23 Å. The third layer is, in addition, slightly buckled (±0.05 Å). The results are discussed on the basis of our present general knowledge about the structure of adsorbate covered metallic surfaces

Trends of complications and innovative techniques' utilization for colectomies in the United States.

Despite an increasing trend towards utilization of minimally invasive approaches (MIS), results regarding their safety profile are contradictory. All patients who underwent elective colectomy for any underlying disease with an identifiable operative approach available from the targeted colectomy files of the ACS-NSQIP PUFs 2013 to 2018 were included. The trend of utilization and complication rates of the different operative approaches (open, laparoscopic, robotic) were assessed during the inclusion period. Furthermore, overall, surgical, and medical complications were compared between the three approaches. The study cohort included 78,987 patients. Of them, 12,335 (15.6%) patients underwent open, 57,874 (73.3%) laparoscopic, and 8,778 (11.1%) robotic surgery. There was an increasing trend towards the utilization of robotic surgery (2.5% increase per year) at the expense of the other approaches. With the increasing trend toward the utilization of the robotic approach, a decreasing trend in overall and surgical complications and length of stay was observed. After adjusting for the baseline confounders, robotic surgery was associated with shorter length of stay, lower rate of overall (OR 0.397; p &lt; 0.05 compared to open and OR: 0.763; p &lt; 0.05 compared to laparoscopy) and surgical complications (OR: 0.464; p &lt; 0.05 compared to open and OR: 0.734; p &lt; 0.05 compared to laparoscopy). This study revealed an increasing trend toward the utilization of MIS for elective colectomy in the US. Robotic surgery was associated with a decreasing trend in overall and surgical morbidity and length of stay

Oral Antibiotics Bowel Preparation Without Mechanical Preparation For Minimally Invasive Colorectal Surgeries: Current Practice And Future Prospects.

The efficacy of preoperative oral antibiotics alone compared to mechanical bowel preparation and oral antibiotics in minimally invasive surgery is still a matter of ongoing debate. This study aimed to assess the trend of surgical site infection rates in parallel to the utilization of bowel preparation modality over time for minimally invasive surgery colorectal surgeries in the United States. Retrospective analysis. The American College of Surgeons National Surgical Quality Improvement Program database. Adult patients who underwent elective colorectal surgery and reported bowel preparation modality. The trends and compare surgical site infection rates for mutually exclusive groups according to the underlying disease (colorectal cancer, inflammatory bowel disease, and diverticular disease) who underwent bowel preparation using oral antibiotics or combined mechanical bowel preparation and oral antibiotics. Patients who had rectal surgery were analyzed separately. A total of 30,939 patients were included. Of them, 12,417 (40%) had rectal resections. Over the seven-year study period, mechanical bowel preparation and oral antibiotics utilization has increased from 29.3% in 2012 to 64.0% in 2018; p&lt;0.0001 at the expense of no preparation and mechanical bowel preparation alone. Similarly, oral antibiotics utilization has increased from 2.3% in 2012 to 5.5% in 2018; p&lt;0.0001. For colon cancer patients, patients who had oral antibiotics alone had higher superficial surgical site infection rates compared to patients who had combined mechanical bowel preparation and oral antibiotics (1.9% vs. 1.1%; p=0.043). Superficial, deep and organ space surgical site infection rates were similar for all other comparative colon surgery groups (cancer, inflammatory bowel disease, and diverticular disease). Patients with rectal cancer who had oral antibiotics had higher rates of deep surgical site infection (0.9% vs. 0.1%; p=0.004). However, superficial, deep and organ space surgical site infection rates were similar for all other comparative rectal surgery groups. Retrospective nature of the analysis. This study revealed widespread adoption of mechanical bowel preparation and oral antibiotics mechanical bowel preparation and oral antibiotics and increased adoption of oral antibiotics over the study period. Surgical site infection rates appear to be similar from a clinical relevance standpoint among most comparative groups, questioning systematic preoperative addition of mechanical bowel preparation to oral antibiotics alone in all patients for minimally invasive colorectal surgery. See Video Abstract at http://links.lww.com/DCR/B828

Association between sagittal alignment and loads at the adjacent segment in the fused spine: a combined clinical and musculoskeletal modeling study of 205 patients with adult spinal deformity

Fusion surgery; Sagittal alignment; Spine surgeryCirugía de fusión; Alineación sagital; Cirugía de columnaCirurgia de fusió; Alineació sagital; Cirurgia de columnaPurpose Sagittal malalignment is a risk factor for mechanical complications after surgery for adult spinal deformity (ASD). Spinal loads, modulated by sagittal alignment, may explain this relationship. The aims of this study were to investigate the relationships between: (1) postoperative changes in loads at the proximal segment and realignment, and (2) absolute postoperative loads and postoperative alignment measures. Methods A previously validated musculoskeletal model of the whole spine was applied to study a clinical sample of 205 patients with ASD. Based on clinical and radiographic data, pre-and postoperative patient-specific alignments were simulated to predict loads at the proximal segment adjacent to the spinal fusion. Results Weak-to-moderate associations were found between pre-to-postop changes in lumbar lordosis, LL (r =  − 0.23, r =  − 0.43; p < 0.001), global tilt, GT (r = 0.26, r = 0.38; p < 0.001) and the Global Alignment and Proportion score, GAP (r = 0.26, r = 0.37; p < 0.001), and changes in compressive and shear forces at the proximal segment. GAP score parameters, thoracic kyphosis measurements and the slope of upper instrumented vertebra were associated with changes in shear. In patients with T10-pelvis fusion, moderate-to-strong associations were found between postoperative sagittal alignment measures and compressive and shear loads, with GT showing the strongest correlations (r = 0.75, r = 0.73, p < 0.001). Conclusions Spinal loads were estimated for patient-specific full spinal alignment profiles in a large cohort of patients with ASD pre-and postoperatively. Loads on the proximal segments were greater in association with sagittal malalignment and malorientation of proximal vertebra. Future work should explore whether they provide a causative mechanism explaining the associated risk of proximal junction complications.Study funding was provided by Maxi Foundation. Open access funding was provided by Swiss Federal Institute of Technology Zurich