On the influence of molecular layer and surface properties on the turn-over time of climatically relevant gases

Background. The surface properties of implants are effective factors for increasing the osseointegration and activity of osteoprogenitor cells. This study compared the stability of dental implants with sandblasted and acid-etched (SLA) and modified surfaces (SLActive) using the resonance frequency analysis (RFA). Methods. In a split-mouth design, 50 dental implants with either SLA surface properties (n=25) or modified (SLActive) surface properties (n=25) were placed in the mandibles of 12 patients with a bilateral posterior edentulous area. Implant stability was measured using RFA (Osstell) at implant placement time and every week for 1, 2, and 3 months before the conventional loading time. Results. One week following the implantation, implant stability increased from 70 to 77.67 for SLA and from 71.67 to 79 for SLActive (P<0.05). Stability improved each week except in the 4th week in SLActive surface measurements. No significant differences were observed between the groups at 2 and 3 months (P>0.05). Conclusions. For both implant surfaces, increased stability was observed over time, with no significant differences between the groups.

Download Full-text

The cycle of atmospheric nitrous oxide

Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences ◽

10.1098/rsta.1979.0009 ◽

1979 ◽

Vol 290 (1376) ◽

pp. 495-504 ◽

Cited By ~ 9

Keyword(s):

Laboratory Experiments ◽

Nitrogen Fertilizers ◽

Time Range ◽

Microbial Activities ◽

Electrical Discharges ◽

Soil Systems ◽

To Come ◽

Turn Over ◽

Over Time ◽

Horizontal And Vertical Distribution

An attempt has been made to construct an N 2 O balance of the troposphere in order to demonstrate the state of knowledge of the cycle of atmospheric N 2 O. This balance has been constructed considering the parameters relevant for atmospheric N 2 O as far as known such as the horizontal and vertical distribution in the atmosphere and in the oceans, the variation of the atmospheric mixing ratio with time, the fluxes in the air-sea and in the air-soil systems, and man-made fluxes. The total atmospheric burden of N 2 O appears to be in the range 1600-2100 Mt, the tropospheric turn-over time between 4 and 12 years. Most of the atmospheric N 2 O seems to originate from microbial activities at the Earth’s surface with the oceans apparently being the major source with about 35 % of the total source as obtained from the tropospheric N 2 O mass and turn-over time (range of uncertainty 5-100 %) followed by soil and fresh water with about 25 % of the total source (range of uncertainty 4-100 %) including the contribution of industrial nitrogen fertilizers with about 10 % of the total source (range of uncertainty 2-24 %). Direct man-made N 2 O sources seem to be relatively small with about 2 % of the total source (range of uncertainty 0.5-5 %), but may grow considerably in the future. The N 2 O production by chemical reactions in the troposphere itself (e.g. electrical discharges) is not known; a figure of between 3 and 70 % of the total source has been inferred from laboratory experiments. The sinks of atmospheric N 2 O are poorly known. The only known major N 2 O destruction appears to occur in the stratosphere. The rate of transport into the stratosphere, however, limits this sink to about 10 % of the total amount of N 2 O to be destroyed under steady state conditions (range of uncertainty 3-22 %). The major problem of the cycle of atmospheric N 2 O is the unknown main sink. Since the stratosphere does not seem to come into question, the missing sink should be found somewhere in the troposphere, pedosphere, and/or hydrosphere.

Download Full-text

Visualizing differential principal turnover

Journal of Educational Administration ◽

10.1108/jea-03-2020-0054 ◽

2020 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Bradley Davis ◽

Erin Anderson

Keyword(s):

Data Visualization ◽

Educational Administration ◽

School Principals ◽

School Level ◽

Complex Data ◽

Content Type ◽

Principal Turnover ◽

Turn Over ◽

First Time ◽

Over Time

PurposeThe authors demonstrate the usage of data visualization for conveying educational administration research, with a specific focus on differential principal turnover. They model when and how principals move, over time, between six categories of turnover.Design/methodology/approachThe authors construct several easy-to-interpret alluvial diagrams that reveal the patterns of differential turnover among 1,113 first-time Texas principals. Furthermore, the authors investigate how these patterns differ across educator characteristics (i.e. race and sex) and school contexts (i.e. school level and campus urbanicity).FindingsHalf of all first-time principals turn over within two years. Most principals who stay in leadership roles leave the district where they were first entered the principalship. Men are promoted more and women turn over less. In a connected finding, the authors conclude that elementary principals turn over less, and middle and high school principals are promoted more often. Principals of color are demoted more often than White principals. Urban school principals exit the system at a greater rate than rural principals.Originality/valueThe significance of this study lies in its direct response to two problems facing the administrator turnover knowledge base – a lack of methodological accessibility and the underutilization of data visualization. The authors’ is the first study to contain visualization of differential turnover outcomes over time. Second, the authors’ study provides a blueprint for data visualization that not only creates new knowledge but also speaks to a wider variety of education stakeholders by presenting complex data in a visual format.

Download Full-text

Color changes in beef meat during pan cooking: kinetics, modeling and application to predict turn over time

European Food Research and Technology ◽

10.1007/s00217-021-03821-y ◽

2021 ◽

Author(s):

Jara Moya ◽

Silvia Lorente-Bailo ◽

Ana Ferrer-Mairal ◽

Miguel A. Martínez ◽

Begoña Calvo ◽

...

Keyword(s):

Color Space ◽

Response Surfaces ◽

Color Changes ◽

Beef Meat ◽

Color Profile ◽

Turn Over ◽

Cooked Meat ◽

Kinetics Of ◽

Evolution With Time ◽

Over Time

AbstractThe kinetics of heat-induced color changes in beef meat was determined and implemented in a numerical model for double-sided pan cooking of steak. The CIELab color space was used to obtain the lightness (coordinate $$L^*$$ L ∗ ) and the reddish tone (coordinate $$a^*$$ a ∗ ) of the cooked meat. $$L^*$$ L ∗ was the CIELab coordinate that contributed the most to the change in the absolute color. Two response surfaces were found to describe the evolution with time and temperature of both color coordinates, $$L^*$$ L ∗ and $$a^*$$ a ∗ . The model results were successfully verified with experimental data of the two coordinates along the thickness of the meat for three degrees of cooking. The Root-Mean-Squared Errors (RMSE) for coordinate $$L^*$$ L ∗ were 5.17 (very rare), 2.02 (medium rare) and 3.83 (done), and for coordinate $$a^*$$ a ∗ 1.44 (very rare), 1.26 (medium rare) and 0.89 (done). The applicability of the model for practical cooking purposes was illustrated by determining the optimum turn over time to achieve a similar color profile on both sides of the meat. The turn over time depended on the desired degrees of cooking, and were comprised between one-half and two-thirds of the final cooking time, increasing from very rare cooking degree to done cooking degree.

Download Full-text

Overview on Miss Management in Turn over Time in Orthopaedic Operative Room

Health Care Current Reviews ◽

10.4172/2375-4273.1000224 ◽

2018 ◽

Vol 06 (02) ◽

Author(s):

Zandi R ◽

Ebrahimpour A ◽

Sajadi MM ◽

Sedighi M ◽

Okhovatpour MA ◽

...

Keyword(s):

Turn Over ◽

Over Time

Download Full-text

The Descriptions and Attitudes of Riders and Arena Owners to 656 Equestrian Sport Surfaces in Sweden

Frontiers in Veterinary Science ◽

10.3389/fvets.2021.798910 ◽

2021 ◽

Vol 8 ◽

Author(s):

Agneta Egenvall ◽

Lars Roepstorff ◽

Michael Peterson ◽

Marcus Lundholm ◽

Elin Hernlund

Keyword(s):

Surface Properties ◽

Large Population ◽

Maintenance Costs ◽

Construction Companies ◽

Equestrian Sports ◽

Usage Frequency ◽

Equestrian Sport ◽

Show Jumping ◽

Over Time ◽

The Ideal

Horses in equestrian sports are commonly trained in arenas with prepared footing. Information on the number and variants of such arenas is generally unknown. This paper provides an overview of the primary construction types of riding surfaces in Sweden including details on composition, constructions principles, usage frequency, maintenance, and cost of operation as well as to investigate rider perception of the ideal arena properties using a large population of riders. Data on 656 equestrian surfaces in Sweden obtained up to 2014 are presented, of which 373 were outdoor and 283 were indoor arenas. Dressage and show-jumping were the main disciplines conducted in the arenas. Sand-mineral arenas were most common outdoors and sand-woodchips arenas most common indoors, followed by sand-fibre arenas and even fewer synthetic arenas. Comparing the three most common arena types, dragging was most often done on sand-woodchips and sand-fibre arenas. Harrowing was less often done on sand-mineral arenas compared to sand-woodchips and sand-fibre arenas. Combining dragging, harrowing, deep harrowing, and rolling, arenas with higher usage were maintained more frequently, compared to those used less frequently. It was commonly claimed that the top-layer needs renovation every other-4th year or every 5th to 10th year. Few respondents allocated more than 10,000 SEK in yearly maintenance costs, with the exception for sand-woodchips and sand-fibre arenas followed by synthetic arenas. The shortest duration perceived between required renovations was found for sand-woodchips top-layer arenas. Ideal surface properties were evaluated by 3,158 riders. Dressage and show-jumping riders differed somewhat regarding ideal spans of functional arena properties: for impact firmness, responsiveness, and grip. The current study likely included well-utilised arenas, compared to those less well-utilised. The resources necessary to keep an arena consistent over time seemed underestimated. Knowledge of maintenance and priorities for arenas are important to users and arenas managers, be they construction companies or arena managers in order to maximise the outcome of efforts for arena improvement and optimise locomotor health for horses that use them. Further, many arenas were new and research into organic arena management is important, especially if equestrians continue to build and renew arena surfaces.

Download Full-text

Thomas Twyne's Appropriation of Thomas Phaer's Æneidos: ‘Worke unperfyt’ Perfected?

Translation and Literature ◽

10.3366/tal.2018.0352 ◽

2018 ◽

Vol 27 (3) ◽

pp. 287-305

Author(s):

Susanna Braund

Keyword(s):

English Translation ◽

Limited Evidence ◽

Turn Over ◽

Similar Kind ◽

Over Time

Abstract: This paper attempts to reconstruct from the limited evidence available the rationale and development of Thomas Twyne's completion (1573–84) of Thomas Phaer's unfinished English translation of the Aeneid (1555–60). In Phaer's hands, it is suggested, ‘continuation’ and ‘completion’ gradually turn over time into ‘competition’, ‘absorption’, and even ‘appropriation’. A key element in this process is Phaer's decision to add to the twelve books of Virgil's epic his translation of Maffeo Vegio's Latin Supplementum (1428): Twyne brings a similar kind of closure to Phaer's project to that involved in Vegio's Aeneid Book 13.

Download Full-text

Assembly and turnover of detyrosinated tubulin in vivo.

The Journal of Cell Biology ◽

10.1083/jcb.105.1.265 ◽

1987 ◽

Vol 105 (1) ◽

pp. 265-276 ◽

Cited By ~ 65

Author(s):

D R Webster ◽

G G Gundersen ◽

J C Bulinski ◽

G G Borisy

Keyword(s):

Dynamic Instability ◽

Human Fibroblasts ◽

Chinese Hamster ◽

Living Cells ◽

Complete Loss ◽

Almost All ◽

Turn Over ◽

Fixed Times ◽

Over Time

Detyrosinated (Glu) tubulin was prepared from porcine brain and microinjected into human fibroblasts and Chinese hamster ovary (CHO) cells. Glu tubulin assembled onto the ends of preexisting microtubules and directly from the centrosome within minutes of its microinjection. Incorporation into the cytoskeleton continued until almost all of the microtubules were copolymers of Glu and tyrosinated (Tyr) tubulin. However, further incubation resulted in the progressive and ultimately complete loss of Glu-staining microtubules. Glu tubulin injected into nocodazole-treated cells was converted to Tyr tubulin by a putative tubulin/tyrosine ligase activity. The observed decrease in staining with the Glu antibody over time was used to analyze microtubule turnover in microinjected cells. The mode of Glu disappearance was analyzed quantitatively by tabulating the number of Glu-Tyr copolymers and Tyr-only microtubules at fixed times after injection. The proportion of Glu-Tyr copolymers decreased progressively over time and no segmentally labeled microtubules were observed, indicating that microtubules turn over rapidly and individually. Our results are consistent with a closely regulated tyrosination-detyrosination cycle in living cells and suggest that microtubule turnover is mediated by dynamic instability.

Download Full-text

The interaction between swirling and recirculating velocity components in unsteady, inviscid flow

Journal of Fluid Mechanics ◽

10.1017/s0022112089003022 ◽

1989 ◽

Vol 209 ◽

pp. 35-55 ◽

Cited By ~ 14

Author(s):

P. A. Davidson

Keyword(s):

Nonlinear Oscillations ◽

Inviscid Flow ◽

Initial Time ◽

Stagnation Points ◽

Recirculating Flow ◽

Vortex Lines ◽

Reversal Time ◽

History Of ◽

Turn Over ◽

Over Time

In this paper we consider the transient evolution of a swirling, recirculating flow in a truncated cylinder. In particular, we consider an initial time period during which the evolution of the flow is controlled by inertia. Such flows exhibit a mutual interaction between the swirl and the poloidal recirculation, whereby any axial gradient in swirl alters the recirculation, which, in turn, redistributes the swirl. This interaction may be visualized as a flexing of the poloidal vortex lines, the best known example of which is the inertial wave. Physical arguments and numerical experiments suggest that, typically, a strong, oscillatory recirculation will develop. We examine the exchange of energy between the swirl and recirculation, and show that the direction of transfer depends on the relative signs of ψ and ηuθ/ηz. In addition, there is a limit to the amount of energy that may be exchanged, since conservation of angular momentum imposes a lower bound on the kinetic energy of the swirl. The characteristic reversal time for the recirculation is estimated by considering the history of fluid particles on the endwalls. Its magnitude depends on the relative strengths of the swirl and recirculation. When the recirculation is large, the reversal time exceeds the turn-over time for a poloidal eddy and, consequently, the vortex lines accumulate at the stagnation points on the endwalls. This leads to accelerated local diffusion on the axis. An elementary one-parameter model is proposed for these nonlinear oscillations. In the limit of very weak recirculation, this model is consistent with the exact solution for inertial waves, while for strong recirculation, it confirms that the reversal time is greater than the turn-over time, and that the vortex lines accumulate on the axis.

Download Full-text