Inter- and intra-layer excitons in MoS2_2/WS2_2 and MoSe2_2/WSe2_2 heterobilayers

Accurately described excitonic properties of transition metal dichalcogenide heterobilayers (HBLs) are crucial to comprehend the optical response and the charge carrier dynamics of them. Excitons in multilayer systems posses inter or intralayer character whose spectral positions depend on their binding energy and the band alignment of the constituent single-layers. In this study, we report the electronic structure and the absorption spectra of MoS$_2$/WS$_2$ and MoSe$_2$/WSe$_2$ HBLs from first-principles calculations. We explore the spectral positions, binding energies and the origins of inter and intralayer excitons and compare our results with experimental observations. The absorption spectra of the systems are obtained by solving the Bethe-Salpeter equation on top of a G$_0$W$_0$ calculation which corrects the independent particle eigenvalues obtained from density functional theory calculations. Our calculations reveal that the lowest energy exciton in both HBLs possesses interlayer character which is decisive regarding their possible device applications. Due to the spatially separated nature of the charge carriers, the binding energy of inter-layer excitons might be expected to be considerably smaller than that of intra-layer ones. However, according to our calculations the binding energy of lowest energy interlayer excitons is only $\sim$ 20\% lower due to the weaker screening of the Coulomb interaction between layers of the HBLs. Therefore, it can be deduced that the spectral positions of the interlayer excitons with respect to intralayer ones are mostly determined by the band offset of the constituent single-layers. By comparing oscillator strengths and thermal occupation factors, we show that in luminescence at low temperature, the interlayer exciton peak becomes dominant, while in absorption it is almost invisible.Comment: 17 pages, 4 figure

Intra- and inter-examiner Reliability of Direct Facial Soft Tissue Measurements Using Digital Calipers

Background: The objective of this study is to determine if facial soft tissue measurements using digital calipers can be reliably taken by the same examiner and by a large group of examiners. Materials and Methods: Ten examiners performed a set of 18 in-clinic measurements on 10 female and 10 male dental students using a digital caliper twice over a 3-week period. The intra-class correlation coefficient and the Shrout-Fleiss method were used for the statistical analysis. Results: Anthropometric intra-examiner reliability was high for all measurements (none fell below R = 0.934). However, inter-examiner reliability exhibited a wide range of values, some reliable (nasal width at widest nostrils [R = 0.922] and subnasale to upper lip [R = 0.926]), and others unreliable [base of nose (R = 0.590), mouth height (R = 0.585), and soft tissue B point to gnathion (R = 0.623)]. Conclusions: Soft tissue measurements of clearly identifiable points measured by the same examiner produced highly consistent, accurate and reliable measurements. Soft tissue points with poor definition resulted in average-to-poor reliabilities measurements

Has Revenue Management Become Acceptable? Findings from an International Study on the Perceived Fairness of Rate Fences

Demand-based pricing is underused in many service industries, because customers are believed to perceive such pricing as unfair. Fencing can be highly effective in improving the perceived fairness of demand-based pricing. In this study, five fences were explored in a restaurant context across three countries (Singapore, Sweden, and the United States). Demand-based pricing in the form of coupons (two for the price of one), time-of-day pricing, and lunch/dinner pricing were perceived as fair. Weekday/weekend pricing was seen as neutral to slightly unfair. Table location pricing was seen as somewhat unfair with potential negative consumer reactions to this practice. Furthermore, framing demand-based pricing as discounts improved perceived fairness. The findings were largely consistent for the three countries. Specifically, framing demand-based pricing as discounts or gains showed no country-specific effect

Perceived Fairness of Revenue Management in the US Golf Industry

Experience in other industries has shown that revenue management can increase revenue without affecting customer satisfaction. Revenue management, however, is underutilized in the golf industry, as customers are believed to perceive such practices as unacceptable and unfair. This paper explores six revenue management practices that might be suitable in a golf context and examines their perceived fairness. The results show that golfers perceive arrival duration control practices in the form of reservation fees or no-show fees as fair. In addition, it was found that golfers perceive demand-based pricing in the form of coupons (two for the price of one), time-of-day and reduced tee time intervals as fair. Conversely, time-of-booking pricing was perceived as neutral to slightly unfair. Varying price levels were seen as unfair, with potential negative consumer reactions to this practice. Furthermore, the paper explores whether framing demand-based pricing as discounts rather than surcharges would make a difference. It was found that demand-based pricing presented as discounts were generally seen as fairer and therefore less likely to have a negative impact on consumer perceptions and reactions

Revenue Management in Restaurants: Unbundling Pricing for Reservations from the Core Service

A substantial minority of restaurant guests would be willing to pay separately for a restaurant reservation, while a much larger group is not supportive of this approach, according to an online survey of 297 U.S. residents. Those respondents who are most likely to accept the idea of paying for a reservation represent customers who are also relatively familiar with this practice. The survey respondents were reacting to three possible scenarios for unbundling the value of the reservation from that of the meal itself. Based in part on actual industry practice, the three scenarios are (1) a reservations company charges for a reservation but does not share the proceeds with the restaurant; (2) a reservations company charges for a reservation and shares the revenue with the restaurant; and (3) the restaurant charges a reservation fee without involving a third party. For revenue management purposes, familiarity with the unbundling practice is related to guest acceptance of that practice. Since numerous companies now sell prime restaurant reservations as a separate product, it seems likely that over time the guests’ familiarity with paying for at least some reservations will grow, along with their acceptance of the practice

Designing Dental Student Portfolios to Assess Performance

The purpose of this poster is to share a project developed by Marquette University’s liaisons to the American Dental Education Association’s Commission on Change and Innovation in Dental Education with others interested in learning about the use of portfolios to assess the quality of student performance in dental school. Sample components from the pilot portfolios will be integrated into the poster to provide participants with a view from portfolio design to completion. Portfolios are becoming a more common method of assessing the quality of student performance in health professions education. Portfolios can assist in documenting evidence of specific competencies at the student level and also serve as a longitudinal measure of a student’s development

Customer Satisfaction with Seating Policies in Casual-Dining Restaurants

Restaurant guests prefer the control that making reservations gives them, according to a survey conducted at Cornell University. The survey tested three strategies for managing demand in casual restaurants, namely, accepting reservations, permitting guests to call ahead for a place on a waitlist with an approximate seating time, and seating guests from a first-come, first-served waitlist. Respondents particularly favored reservations for business dinners, and well over half of the respondents would not consider a restaurant for a business meal if they could not make a reservation. Call-ahead seating was a poor substitute for reservations, in the respondents\u27 estimation, but was still seen as better than first-come, first-served seating, with an estimated wait time. The survey found that guests thought reservations gave them better control over their schedule and that reservations demonstrated that the restaurant cared about its customers. Since reservations come with their own special operational problems, managers of casual restaurants might consider using call-ahead seating if reservations do not work for the restaurant. Those that continue with seating from a first-come, first-served waitlist should consider ways to empower guests, for example, by giving accurate wait times or issuing pagers

How Long Should Dinner Take? Measuring Expected Meal Duration for Restaurant Revenue Management

Restaurants have two strategic levers for revenue management: duration control and demand-based pricing. Reducing dining times, especially during peak periods, can add considerable revenue for the restaurant. Managing meal duration, however, can be far more complex than manipulating the price. This paper examines dinner duration expectations for a casual restaurant using an adaptation of a price sensitivity measurement tool, naming it \u27Time Sensitivity Measurement\u27 or TSM. TSM is then used to derive the expected dining time, the optimal and indifference duration points. The results show that there is a relatively wide spread of acceptable dining duration times. Furthermore, the optimal and indifference points were significantly shorter than the mean expected dining time, suggesting that many restaurants may be able to shorten dining duration significantly (some 20 per cent in this present study) without compromising customer satisfaction. Furthermore, the paper explores whether demographic variables have an impact on time preferences and finds only nationality effects to be significant. Specifically, North Americans and Asians have similar duration expectations, while Europeans preferred a significantly longer dining time

Quantification of the Individual Characteristics of the Human Dentition

The considerations for admissibility suggested by the Daubert trilogy challenge forensic experts to provide scientific support for opinion testimony. The defense bar has questioned the reliability of bitemark analysis. Under an award from the U. S. Department of Justice, via the Midwest Forensic Resource Center, a two-year feasibility study was undertaken to quantify six dental characteristics. Using two computer programs, the exemplars of 419 volunteers were digitally scanned, characteristics were measured, and frequency was calculated. The study demonstrates that there were outliers or rare dental characteristics in measurements. An analysis of the intra-observer and inter-observer consistency demonstrated a high degree of agreement. Expansion of the sample size through collaboration with other academic researchers will be necessary to be able to quantify the occurrence of these characteristics in the general population. The automated software application, Tom\u27s Toolbox, developed specifically for this research project, could also provide a template for precisely quantifying other pattern evidence

A retrospective analysis of controlled active motion (CAM) versus modified Kleinert/Duran (modKD) rehabilitation protocol in flexor tendon repair (zones I and II) in a single center.

INTRODUCTION The aim of this study was to analyze primary flexor tendon repair results in zones I and II, comparing the rupture rate and clinical outcomes of the controlled active motion (CAM) protocol with the modified Kleinert/Duran (mKD) protocol. MATERIALS AND METHODS Patients who underwent surgery with traumatic flexor tendon lacerations in zones I and II were divided in three groups according to the type of rehabilitation protocol and period of management: group 1 included patients who underwent CAM rehabilitation protocol with six-strand Lim and Tsai suture after May 2014. Group 2 and 3 included patients treated by six-strand Lim Tsai suture followed by a modified Kleinert/Duran (modK/D) protocol with additional place and hold exercises between 2003 and 2005 (group 2) and between 2011 and 2013 (group 3). RESULTS Rupture rate was 4.7% at 12 weeks in group 1 (3/63 flexor tendon repairs) compared to 2% (1/51 flexor tendon repairs) in group 2 and 8% in group 3 (7/86 flexor tendon repairs). The grip strength at 12 weeks was significantly better in group 2 compared to the group 1 (35 kg/25 kg, p = 0.006). The TAM in group 1 [113° (30-175°)] was significantly worse (p < 0.001) than the TAM in group 2 [141° (90-195°)] but with similar extension deficits in both groups. The assessment of range of motion by the original Strickland classification system resulted in 20% excellent and 15% good outcomes in the CAM group 1 compared with 42% and 36% in the modK/D group 2. Subanalysis demonstrated improvement of good/excellent results according to Strickland from 45% at 3 months to 63.6% after 6-month follow-up in the CAM group. CONCLUSION The gut feeling that lead to change in our rehabilitation protocol could be explained by the heterogenous bias. A precise outcome analysis of group 1 could underline that in patients with complex hand trauma, nerve reconstruction, oedema or early extension deficit, an even more intensive and individual rehabilitation has to be performed to achieve better TAM at 6 or 12 weeks. Our study explicitly demonstrated a significant better outcome in the modK/D group compared to CAM group. This monocenter study is limited by its retrospective nature and the low number of patients