On the robustness of separation control by streamwise vortices

The robustness of vane-type vortex generators (VGs) for separation flow control was studied in a separating turbulent boundary layer on a flat plate. VG arrays of different sizes and streamwise positions were positioned upstream of the separation bubble and their effect on the flow field was studied with the help of particle image velocimetry (PIV). The extent of the separated region was varied by changing the pressure gradient. Three different separation bubbles were produced and their extent was approximately doubled for each increase in pressure gradient. It was found that the sensitivity of the control effect to changes in the size of the separation bubble is small within the applied range of pressure gradients. Furthermore, the importance of the relative position of the VGs with respect to the separated region is small.     

Total Release of 21 Indicator Pharmaceuticals Listed by the Swedish Medical Products Agency from Wastewater Treatment Plants to Surface Water Bodies in the 1.3 Million Populated County Skåne (Scania), Sweden

In 2017, the Swedish Environmental Protection Agency published a report on advanced wastewater treatment for the removal of pharmaceutical residues and stated that advanced treatment should be implemented where it will make the largest difference from an environmental perspective. However, the report also concluded that this need cannot be specified with existing data, but consideration must be made of local conditions. Two considerations are (1) the discharged amount of pharmaceutical into receiving water bodies and (2) the turnover of water in the recipient, where the highest risks are related to recipients with a low water turnover and low dilution. The current project comprised eight different WWTPs distributed throughout the entire County Skåne (Scania) in Sweden, with a population of ca. 1,300,000 persons. In total, 21 of 22 pharmaceuticals were analyzed according to the list proposed by the Swedish Medical Products Agency 2015. The results show that large amounts of pharmaceuticals are released from the WWTPs yearly to Scanian recipients. The total discharge of pharmaceuticals from the eight treatment plants adds up to 71 kg of these 21 substances alone, mainly comprising metoprolol, which is a drug that lowers blood pressure, and the analgesic drug diclofenac. Additionally, carbamazepine, losartan, naproxen and oxazepam were present in significant concentrations. These represented three illnesses that are very common: high blood pressure, inflammation/pain and depression/anxiety. The concentrations were generally in line with previous national Swedish screenings. It was estimated that, when one million cubic meters (1,000,000 m³) of wastewater is discharged, almost 4 kg of the 21 pharmaceuticals is released. The total volume wastewater release by the >90 WWTPs in Scania was estimated to 152,887,000 m³, which corresponded to 590 kg/year. The investigated 21 drugs cover only a small part of many hundred pharmaceuticals that are in use in Sweden. Thus, most likely, one or several tons of pharmaceuticals leak out to the Scanian recipients annually. The analysis of river samples shows that the dilution of wastewater is a key parameter in reducing concentrations. However, some locations have remarkably high concentrations, which occur when the volume wastewater is large in relation to the flow in the river. These kinds of regional results are of importance when selecting where advanced treatment should be prioritized in a first instance, as requested by the Swedish EPA.     

Partial data inverse problems for Maxwell equations via Carleman estimates

In this article we consider an inverse boundary value problem for the time-harmonic Maxwell equations. We show that the electromagnetic material parameters are determined by boundary measurements where part of the boundary data is measured on a possibly very small set. This is an extension of earlier scalar results of Bukhgeim–Uhlmann and Kenig–Sjöstrand–Uhlmann to the Maxwell system. The main contribution is to show that the Carleman estimate approach to scalar partial data inverse problems introduced in those works can be carried over to the Maxwell system.     

Synthesis of some substituted benzimidazoles with potential antimicrobial activity

Summary The synthesis andin vitro antimicrobial evaluation of several benzimidazole derivatives with different heterocyclic nuclei at position-2 are described.

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Synthese einiger substituierter Benzimidazole mit potentieller antimikrobieller Aktivität

Zusammenfassung Die Synthese und antimikrobielle Prüfung einiger Benzimidazole mit verschiedenen heterozyklischen Substituenten in 2-Stellung wird beschrieben.

     

Subelliptic operators on Lie groups: Variable coefficients

Let G be a Lie group with Lie algebra g and a _i,...,a _d and algebraic basic of g. Futher, if A _i=dL(a_i) are the corresponding generators of left translations by G on one of the usual function spaces over G, let% MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqefm0B1jxALjhiov2D% aebbfv3ySLgzGueE0jxyaibaiGc9yrFr0xXdbba91rFfpec8Eeeu0x% Xdbba9frFj0-OqFfea0dXdd9vqaq-JfrVkFHe9pgea0dXdar-Jb9hs% 0dXdbPYxe9vr0-vr0-vqpWqaaeaabiGaciaacaqabeaadaqaaqGaaO% qaamXvP5wqonvsaeHbfv3ySLgzaGqbciab-Heaijaab2dadaaeqbqa% aiaadogadaWgaaWcbaqedmvETj2BSbacgmGae4xSdegabeaakiaadg% eadaahaaWcbeqaaiab+f7aHbaaaeaacqGFXoqycaGG6aGaaiiFaiab% +f7aHjaacYhatuuDJXwAK1uy0HMmaeXbfv3ySLgzG0uy0HgiuD3BaG% Wbbiab9rMiekaaikdaaeqaniabggHiLdaaaa!5EC1!\[H{\rm{ = }}\sum\limits_{\alpha :|\alpha | \le 2} {c_\alpha A^\alpha } \] be a second-order differential operator with real bounded coefficients c . The operator is defined to be subelliptic if% MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqefm0B1jxALjhiov2D% aebbfv3ySLgzGueE0jxyaibaiGc9yrFr0xXdbba91rFfpec8Eeeu0x% Xdbba9frFj0-OqFfea0dXdd9vqaq-JfrVkFHe9pgea0dXdar-Jb9hs% 0dXdbPYxe9vr0-vr0-vqpWqaaeaabiGaciaacaqabeaadaqaaqGaaO% qaaiGacMgacaGGUbGaaiOzamXvP5wqonvsaeHbfv3ySLgzaGqbaKaz% aasacqWF7bWEcqWFTaqlkmaaqafabaGaam4yamaaBaaaleaarmWu51% MyVXgaiyWacqGFXoqyaeqaaaqaaiab+f7aHjaacQdacaGG8bGae4xS% deMaaiiFaiabg2da9iaaikdaaeqaniabggHiLdGccqWFOaakiuGacq% qFNbWzcqWFPaqkcqaH+oaEdaahaaWcbeqaamaaBaaameaacqGFXoqy% aeqaaaaakiaacUdacqqFNbWzcqGHiiIZcqqFhbWrcqqFSaalcqqFGa% aicqaH+oaEcqGHiiIZrqqtubsr4rNCHbachaGaeWxhHe6aaWbaaSqa% beaacqqFKbazcqqFNaWjcqaFaC-jaaGccaGGSaGaaiiFaiabe67a4j% aacYhacqGH9aqpjqgaGeGae8xFa0NccqGH+aGpcaaIWaGaaiOlaaaa% !7884!\[\inf \{ - \sum\limits_{\alpha :|\alpha | = 2} {c_\alpha } (g)\xi ^{_\alpha } ;g \in G, \xi \in ^{d'} ,|\xi | = \} > 0.\]We prove that if the principal coefficients {c ; ||=2} of the subelliptic operator are once left differentiable in the directions a ₁,...,a _d with bounded derivatives, then the operator has a family of semigroup generator extensions on the L _p-spaces with respect to left Haar measure dg, or right Haar measure d, and the corresponding semigroups S are given by a positive integral kernel,% MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqefm0B1jxALjhiov2D% aebbfv3ySLgzGueE0jxyaibaiGc9yrFr0xXdbba91rFfpec8Eeeu0x% Xdbba9frFj0-OqFfea0dXdd9vqaq-JfrVkFHe9pgea0dXdar-Jb9hs% 0dXdbPYxe9vr0-vr0-vqpWqaaeaabiGaciaacaqabeaadaqaaqGaaO% qaamXvP5wqonvsaeHbfv3ySLgzaGqbaiab-HcaOGqbciab+nfatnaa% BaaaleaacaWG0baabeaaruqqYLwySbacgiGccaqFgpGae8xkaKIae8% hkaGIae43zaCMae8xkaKIae8xpa0Zaa8qeaeaacaqGKbaaleaacqGF% hbWraeqaniabgUIiYdGcceWGObGbaKaacaWGlbWaaSbaaSqaaiaads% haaeqaaOGae8hkaGIae43zaCMae43oaSJae4hAaGMae8xkaKIaa0NX% diab-HcaOiab+HgaOjab-LcaPiab-5caUaaa!5DFA!\[(S_t \phi )(g) = \int_G {\rm{d}} \hat hK_t (g;h)\phi (h).\]The semigroups are holomorphic and the kernel satisfies Gaussian upper bounds. If in addition the coefficients with ||=2 are three times differentiable and those with ||=1 are once differentiable, then the kernel also satisfies Gaussian lower bounds.Some original features of this article are the use of the following: a priori inequalities on L in Section 3, fractional operator expansions for resolvent estimates in Section 4, a parametrix method based on reduction to constant coefficient operators on the Lie group rather than the usual Euclidean space in Section 5, approximation theory of semigroups in Section 11 and time dependent perturbation theory to treat the lower order terms of H in Sections 11 and 12.     

Determination of nitrate in pickling baths with a nitrate-selective electrode and a standard addition procedure

A reverse addition method for the determination of nitrate in pickling baths is described. Calibration solutions of nitric acid were added to the standard solution so that the slope and intercept of the electrode response function could be determined. The standard deviation of the method was better than 1 %. Nitrate in pickling baths containing hydrofluoric and nitric acids was measured and compared to measured hydrogen ion concentrations as a function of running time for the bath. The effects of iron(III) and hydrofluoric acid on the results were studied.     

Singlet Excited States and the Light-Harvesting Function of Carotenoids in Bacterial Photosynthesis

Abstract— The recent results of stationary-state and time-resolved absorption, fluorescence and Raman spectroscopies of some typical carotenoids are summarized. Theoretical analyses of carotenoid singlet states and of carotenoid-to-bacteriochlorophyll singlet-energy transfer are also included. On the bases of the energies, the lifetimes and other properties of singlet excited states of the carotenoids in solution and bound to the light-harvesting complexes, the energetics and the dynamics of the light-harvesting function in purple photosynthetic bacteria are discussed with emphasis on the 2A_g and B_u⁺ states.