Dissipation equals production in the log layer of wall-induced turbulence

Asymptotic analysis is presented of the energy balance equations derived from statistically averagedNavier-Stokes equations pertinent to wall-induced turbulence. Attention is focused on the inertialsublayer, the region outside the viscous sublayer, and the buffer layer where the log-law for meanflow holds. Production and dissipation of turbulence are shown to be equal with a relative error of order(x2 /L), where x2 is the distance from the wall and L is the external length (pipe radius, channelhalf-height, boundary layer thickness). Diffusion of pressure and kinetic energy together are only ofrelative magnitude order (x2 /L). Pressure gradient terms are shown to redistribute longitudinalturbulence production in equal portions dissipated in the three orthogonal directions

Barriers to and facilitators for finding and keeping competitive employment:A focus group study on autistic adults with and without paid employment

PurposeThe aim of the study was to gain more insight into barriers to and facilitators for finding and keeping competitive employment for autistic adults. Research questions were: (1) What barriers and facilitators do autistic adults report in finding and keeping competitive employment?; and (2) What are differences and similarities between autistic adults with and without paid employment regarding barriers and facilitators for sustainable employment?MethodsEight focus groups were conducted (N = 64 autistic adults). Four groups included only participants without paid employment (N = 24), and four groups consisted exclusively of participants with current paid employment (including part-time, N = 40). All discussions were audiotaped and transcribed verbatim to enable inductive thematic content analysis. Data were analyzed using ATLAS.ti 9.ResultsTen themes and thirty-four subthemes were found. Many were interconnected. Themes facilitating sustainable employment included a positive workplace atmosphere, a supportive supervisor, being able to do work that aligns with interests and talents, favorable physical working conditions, coaching, higher self-insight, higher self-esteem, and proactivity. Most themes and subthemes emerged from both groups. Differences between the groups were that those with paid employment seemed to have experienced more friendly workplaces and supervisors, had received better coaching in finding and keeping employment, had higher self-insight and higher self-esteem, were more assertive and proactive.ConclusionsAs many (sub-)themes were interrelated, the results suggest that to improve work participation, particularly two key areas are promising: (1) to realize more friendly, well-being oriented and inclusive workplaces, and (2) to increase autistic adults’ self-insight into personal needs for positive wellbeing and self-knowledge regarding talents, wishes and well-being boundaries

Pauli graphs, Riemann hypothesis, Goldbach pairs

Let consider the Pauli group $\mathcal{P}_q=$ with unitary quantum generators $X$ (shift) and $Z$ (clock) acting on the vectors of the $q$-dimensional Hilbert space via $X|s> =|s+1>$ and $Z|s> =\omega^s |s>$, with $\omega=\exp(2i\pi/q)$. It has been found that the number of maximal mutually commuting sets within $\mathcal{P}_q$ is controlled by the Dedekind psi function $\psi(q)=q \prod_{p|q}(1+\frac{1}{p})$ (with $p$ a prime) \cite{Planat2011} and that there exists a specific inequality $\frac{\psi (q)}{q}>e^{\gamma}\log \log q$, involving the Euler constant $\gamma \sim 0.577$, that is only satisfied at specific low dimensions $q \in \mathcal {A}=\{2,3,4,5,6,8,10,12,18,30\}$. The set $\mathcal{A}$ is closely related to the set $\mathcal{A} \cup \{1,24\}$ of integers that are totally Goldbach, i.e. that consist of all primes $p2$) is equivalent to Riemann hypothesis. Introducing the Hardy-Littlewood function $R(q)=2 C_2 \prod_{p|n}\frac{p-1}{p-2}$ (with $C_2 \sim 0.660$ the twin prime constant), that is used for estimating the number $g(q) \sim R(q) \frac{q}{\ln^2 q}$ of Goldbach pairs, one shows that the new inequality $\frac{R(N_r)}{\log \log N_r} \gtrapprox e^{\gamma}$ is also equivalent to Riemann hypothesis. In this paper, these number theoretical properties are discusssed in the context of the qudit commutation structure.Comment: 11 page

Rheology Modifying Admixtures: The Key to Innovation in Concrete Technology – A General Overview and Implications for Africa

Innovative admixture technology has significantly widened up the range of possibilities of concrete engineers. For many decades the water to cement ratio (w/c) was the major influencing factor for the performance of concrete. Due to the need to adjust a consistency, which still allowed reasonable workability, the w/c was typically significantly higher than technologically reasonable. Rheology modifying admixtures support adjusting the concrete consistency largely independent of the w/c. It was only after the invention of the first superplasticizers that modern concrete technology significantly evolved in terms of flowability, strength, and durability, and only due to the steady evolution of the technology modern innovations, such as Self-Compacting Concrete, Ultra-High-Performance Concrete, or Engineered Cementitious Composites were made possible. Today’s superplasticizers are extremely versatile and can be adjusted to individual technological specifications. However, the other side of the coin of versatility is that cementitious systems incorporating superplasticizers have become more sensitive against environmental influences, such as the environmental temperature, which may cause unwanted effects or demand for supplementary admixture use such as stabilizing admixtures. Hence, concrete mixture composition with admixtures demands for a high level of expertise and often there is lack of awareness about the mode of operation of rheology modifying admixtures among concrete technologists. The paper gives a comprehensive overview about rheology modifying admixtures such as superplasticizers or stabilizing agents, and how they can be used depending upon the application in the most favourable way. Based on experiences with the sub-Saharan African concreting boundary conditions, which exhibit many challenges in terms of environmental boundary conditions and construction site logistics, conclusions are finally drawn, how admixtures can be used in the most beneficial way to improve the concrete casting situation

PO-0674: Factors influencing patient reported cosmetic outcome: results of the Young Boost Trial

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The association between active tumor volume, total lesion glycolysis and levels of S-100B and LDH in stage IV melanoma patients

Introduction: The Standardized Uptake Value (SUV) in single lesions on F-18-FDG PET/CT scans and serum S-100B concentrations are inversely associated with disease-free survival in stage IV melanoma. The aim of this study was to assess the association between biomarkers (S-100B, LDH) and the PET-derived metrics SUVmean/max, metabolic active tumor volume (MATV), and total lesion glycolysis (TLG) in stage IV melanoma in order to understand what these biomarkers reflect and their possible utility for follow-up. Methods: In 52 stage IV patients the association between PET-derived metrics and the biomarkers S-100B and LDH was assessed and the impact on survival analyzed. Results: S-100B was elevated (>0.15 mu g/l) in 37 patients (71%), LDH in 11 (21%). There was a correlation between S-100B and LDH (R-2 = 0.19). S-100B was correlated to both MATV (R-2 = 0.375) and TLG (R-2 = 0.352), but LDH was not. Higher MATV and TLG levels were found in patients with elevated S-100B (p 250 U/l) (p <0.001). There was no association between the biomarkers and SUVmean/max. Survival analysis indicated that LDH was the only predictor of melanoma-specific survival. Conclusion: In newly diagnosed stage IV melanoma patients S-100B correlates with F-18-FDG PET/CT derived MATV and TLG in contrast to LDH, is more often elevated than LDH (71% vs. 21%) and seems to be a better predictor of disease load and disease progression. However, elevated LDH is the only predictor for survival. The biomarkers, S-100B and LDH appear to describe different aspects of the extent of metastatic disease and of tumornecrosis. (C) 2020 The Authors. Published by Elsevier Ltd

Use of population input functions for reduced scan duration whole-body Patlak F-18-FDG PET imaging

Abstract: Whole-body Patlak images can be obtained from an acquisition of first 6 min of dynamic imaging over the heart to obtain the arterial input function (IF), followed by multiple whole-body sweeps up to 60 min pi. The use of a population-averaged IF (PIF) could exclude the first dynamic scan and minimize whole-body sweeps to 30–60 min pi. Here, the effects of (incorrect) PIFs on the accuracy of the proposed Patlak method were assessed. In addition, the extent of mitigating these biases through rescaling of the PIF to image-derived IF values at 30–60 min pi was evaluated. Methods: Using a representative IF and rate constants from the literature, various tumour time-activity curves (TACs) were simulated. Variations included multiplication of the IF with a positive and negative gradual linear bias over 60 min of 5, 10, 15, 20, and 25% (generating TACs using an IF different from the PIF); use of rate constants (K 1, k 3, and both K 1 and k 2) multiplied by 2, 1.5, and 0.75; and addition of noise (μ = 0 and σ = 5, 10 and 15%). Subsequent Patlak analysis using the original IF (representing the PIF) was used to obtain the influx constant (K i) for the differently simulated TACs. Next, the PIF was scaled towards the (simulated) IF value using the 30–60-min pi time interval, simulating scaling of the PIF to image-derived values. Influence of variabilities in IF and rate constants, and rescaling the PIF on bias in K i was evaluated. Results: Percentage bias in K i observed using simulated modified IFs varied from − 16 to 16% depending on the simulated amplitude and direction of the IF modifications. Subsequent scaling of the PIF reduced these K i biases in most cases (287 out of 290) to < 5%. Conclusions: Simulations suggest that scaling of a (possibly incorrect) PIF to IF values seen in whole-body dynamic imaging from 30 to 60 min pi can provide accurate Ki estimates. Consequently, dynamic Patlak imaging protocols may be performed for 30–60 min pi making whole-body Patlak imaging clinically feasible