Impacts of increased levels of wind penetration on the Electric Power System of the Åland Islands

The application of VSC-HVDC technology throughout the world has turned out to be an efficient solution regarding a large share of wind power in different power systems. This technology enhances the overall reliability of the grid by utilization of the active and reactive power control schemes which allows to maintain frequency and voltage on busbars of the end-consumers at the required level stated by the network operator. This master’s thesis is focused on the existing and planned wind farms as well as electric power system of the Åland Islands. The goal is to analyze the wind conditions of the islands and appropriately predict a possible production of the existing and planned wind farms with a help of WAsP software program. Further, to investigate the influence of increased wind power it is necessary to develop a simulation model of the electric grid and VSC-HVDC system in PSCAD and examine grid response to different wind power production cases with respect to the grid code requirements and ensure the stability of the power system.

Controlling full penetration in MAG welding by the application of infrared thermography and neural network

In this study, an infrared thermography based sensor was studied with regard to usability and the accuracy of sensor data as a weld penetration signal in gas metal arc welding. The object of the study was to evaluate a specific sensor type which measures thermography from solidified weld surface. The purpose of the study was to provide expert data for developing a sensor system in adaptive metal active gas (MAG) welding. Welding experiments with considered process variables and recorded thermal profiles were saved to a database for further analysis. To perform the analysis within a reasonable amount of experiments, the process parameter variables were gradually altered by at least 10 %. Later, the effects of process variables on weld penetration and thermography itself were considered. SFS-EN ISO 5817 standard (2014) was applied for classifying the quality of the experiments. As a final step, a neural network was taught based on the experiments. The experiments show that the studied thermography sensor and the neural network can be used for controlling full penetration though they have minor limitations, which are presented in results and discussion. The results are consistent with previous studies and experiments found in the literature.

Calculation of the magnetic field penetration depth for high-Tc cuprate superconductors based on the Interlayer Pair Tunneling model /

In this work, the magnetic field penetration depth for high-Tc cuprate superconductors is calculated using a recent Interlayer Pair Tunneling (ILPT) model proposed by Chakravarty, Sudb0, Anderson, and Strong [1] to explain high temperature superconductivity. This model involves a "hopping" of Cooper pairs between layers of the unit cell which acts to amplify the pairing mechanism within the planes themselves. Recent work has shown that this model can account reasonably well for the isotope effect and the dependence of Tc on nonmagnetic in-plane impurities [2] , as well as the Knight shift curves [3] and the presence of a magnetic peak in the neutron scattering intensity [4]. In the latter case, Yin et al. emphasize that the pair tunneling must be the dominant pairing mechanism in the high-Tc cuprates in order to capture the features found in experiments. The goal of this work is to determine whether or not the ILPT model can account for the experimental observations of the magnetic field penetration depth in YBa2Cu307_a7. Calculations are performed in the weak and strong coupling limits, and the efi"ects of both small and large strengths of interlayer pair tunneling are investigated. Furthermore, as a follow up to the penetration depth calculations, both the neutron scattering intensity and the Knight shift are calculated within the ILPT formalism. The aim is to determine if the ILPT model can yield results consistent with experiments performed for these properties. The results for all three thermodynamic properties considered are not consistent with the notion that the interlayer pair tunneling must be the dominate pairing mechanism in these high-Tc cuprate superconductors. Instead, it is found that reasonable agreement with experiments is obtained for small strengths of pair tunneling, and that large pair tunneling yields results which do not resemble those of the experiments.

A study of the thermal decomposition of allyl t-butyl peroxide and 3-hydroperoxy-1-propene (allyl hydroperoxide) in toluene /|nby Krishnankutty Nair V. G. -- 260 St. Catharines [Ont. : s. n.],

Kinetics and product studies of the decompositions of allyl-t-butyl peroxide and 3-hydroperoxy- l-propene (allyl hydroperoxide ) in tolune were investigated. Decompositions of allyl-t-butyl peroxide in toluene at 130-1600 followed first order kinetics with an activation energy of 32.8 K.cals/mol and a log A factor of 13.65. The rates of decomposition were lowered in presence of the radical trap~methyl styrene. By the radical trap method, the induced decomposition at 1300 is shown to be 12.5%. From the yield of 4-phenyl-l,2- epoxy butane the major path of induced decomposition is shown to be via an addition mechanism. On the other hand, di-t-butYl peroxyoxalate induced decomposition of this peroxide at 600 proceeded by an abstraction mechanism. Induced decomposition of peroxides and hydroperoxides containing the allyl system is proposed to occur mainly through an addition mechanism at these higher temperatures. Allyl hydroperoxide in toluene at 165-1850 decomposes following 3/2 order kinetics with an Ea of 30.2 K.cals per mole and log A of 10.6. Enormous production of radicals through chain branching may explain these relatively low values of E and log A. The complexity of the reaction is indicated a by the formation of various products of the decomposition. A study of the radical attack of the hydro peroxide at lower temperatures is suggested as a further work to throw more light on the nature of decomposition of this hydroperoxide.

The kinetics and mechanism of the thermal decomposition of sec-Butyl peroxide in liquid phase /|nby Sandor Szilagyi. -- 260 St. Catharines, Ont. : [s. n.],

Re~tes artd pJ~oducts of tllerma]. d,ecom.position of sec-butyl peroxide at 110 - 150°C i.n four solvents h,ave been determined. The d,ecompos i tion vJas sb.o\'\Tn to be tlnlmolecl.llar wi tho energies of activation in toluene, benzene, and cyclohexane of 36 .7-+ 1.0, 33.2 +- 1..0, 33.t~) +.. 1.0 I'(:cal/mol respectively. The activation energy of thermal decomposition for the d,et.1terated peroxide was found to be 37.2 4:- 1.0 KC8:1/1TIol in toluene. A.bo1J.t 70 - 80/~ ol~ tJJ.e' pl~od.1..1CtS could, be explained by kn01rJ11 reactions of free allcoxy raclicals J and very littJ...e, i.f allY, disPl"Opox~tiol'lation of tll10 sec-butoxy radica.ls in t116 solvent cage could be detected. The oth,er 20 - 30% of the peroxide yielded H2 and metb.:'ll etb..yl 1{etol1e. Tl1.e yield. o:f H2 "'lIas unafJ:'ected by the nature or the viscosity of the solvent, but H2 was not formed when s-t1U202 lrJaS phctolyzed. in tolttene at 35°C nor 'tl!Jrl.en the peroxide 1;'JaS tl1.ermally o..ecoJnposed. in the gas p11ase. ~pC-Dideutero-~-butYlperoxide was prepared and decomposed in toluene at 110 - 150°C. The yield of D2 was about ·•e1ne same 248 the yield. of I{2 from s-Bu202, bU.t th.e rate of decomposition (at 135°C) 1iJas only 1/1.55 as fast. Ivlecl1.anisms fOl') J:1ydrogen produ.ction are discussed, but none satisfactorily explains all the evidence.

The kinetics and solvent effects on the thermal decomposition of isopropyl peroxide and 1, 2-dioxane

Rates of H2 formation have been determined for the thermal decomposition of isopropyl peroxide at l30o-l50oC in toluene and methanol and at l400C in isopropyl alcohol and water. Product studies have been carried out at l400C in these solvents. The decomposition of isopropyl peroxide was shown to be unimolecular with energies of activation in toluene, and methanol of 39.1, 23.08 Kcal/mole respectively. It has been shown that the rates of H2 formation in decomposition of isopropyl peroxide are solvent dependent and that the ~ vs "'2';' values (parameters for solvent polarity) givesastraight line. Mechanisms for hydrogen production are discussed which satisfactorily explain the stabilization of the six-centered transition state by the solvent. One possibility is that of conformation stabilization by solvent and the other, a transition state with sufficient ionic character to be stabilized by a polar solvent. Rates of thermal decomposition of 1,2-dioxane in tert-butylbenzene at l40o-l70oC have been determined. The activation energy was found to be 33.4 Kcal/mole. This lower activation energy, compared to that for the decomposition of isopropyl peroxide in toluene (39.1 Kcal/mole) has been explained in terms of ring strain. Decomposition of 1,2 dioxane in MeOH does not follow a first order reaction. Several mechanisms have been suggested for the products observed for decomposition of 1;2-dioxane in toluene and methanol.

Hydrogen peroxide enhances the expression and function of Giα proteins in aortic vascular smooth muscle cells from Sprague-Dawley rats : role of growth factor receptors transactivation

Nous avons récemment démontré que les espèces réactives oxygénées induisent une augmentation de l’expression des protéines Giα dans les cellules du muscle lisse vasculaire (CMLV) provenant d’aortes de rats spontanément hypertendus (SHR, de l’anglais spontaneously hypertensive rats). La présente étude a pour but d’étudier les effets du peroxyde d’hydrogène (H2O2), un oxydant qui induit le stress oxydatif, sur l’expression de Giα et sur l’activité de l’adénylate cyclase, et d’explorer les voies de signalisation sous-jacentes responsables de cette réponse. Nos résultats montrent que H2O2 induit une augmentation de l’expression des protéines Giα-2 et Giα-3 de manière dose- et temps-dépendante avec une augmentation maximale de 40-50% à 100 µM après 1 heure, sans affecter l’expression de Gsα. L’expression des protéines Giα a été maintenue au niveau normal en presence de AG 1478, AG1295, PD98059 et la wortmannine, des inhibiteurs d’EGF-R (de l’anglais epidermal growth factor receptor), PDGFR-β (de l’anglais platelet-derived growth factor receptor β), de la voie de signalisation ras-ERK1/2 (de l’anglais extracellular regulated kinase1/2), et de la voie de la PI3Kinase-AKT (de l’anglais phosphatidyl inositol-3 kinase), respectivement. En outre, le traitement des CMLV avec H2O2 a induit une augmentation du degré de phosphorylation d’EGF-R, PDGF-R, ERK1/2 et AKT; et cette expression a été maintenue au niveau témoin par leurs inhibiteurs respectifs. Les inhibiteurs d’EGF-R et PDGF-R ont aussi induit une diminution du degré de phosphorylation de ERK1/2, et AKT/PKB. En outre, la transfection des cellules avec le siRNA (de l’anglais, small interfering ribonucleic acid) de EGF-R et PDGFR-β a atténué la surexpression des protéines Giα-2 et Giα-3 induite par le traitement au H2O2. La surexpression des protéines Giα induite par H2O2 a été corrélée avec une augmentation de la fonction de la protéine Giα. L’inhibition de l’activité de l’adénylate cyclase par de faibles concentrations de GTPγS après stimulation par la forskoline a augmenté de 20% dans les cellules traitées au H2O2. En outre, le traitement des CMLV au H2O2 a aussi accru l’inhibition de l’activité de l’adénylate cyclase par les hormones inhibitrices telles que l’angiotensine II, oxotrémorine et C-ANP4-23. D’autre part, la stimulation de l’adénylate cyclase induite par GTPγS, glucagon, isoprotérénol, forskoline, et le fluorure de sodium (NaF) a été atténuée de façon significative dans les cellules traitées au H2O2. Ces résultats suggèrent que H2O2 induit la surexpression des protéines Giα-2 and Giα-3 via la transactivation des récepteurs des facteurs de croissance EGF-R, PDGFR-β et l’activation des voies de signalisation ras-ERK1/2 et PI3K-AKT Mot-cles: Protéines Giα, peroxyde d’hydrogène, stress oxydant, récepteurs des facteurs de croissance, MAP kinases, adénylate cyclase, hypertension

Ruthenium complexes of Schiff base ligands as efficient catalysts for catechol–hydrogen peroxide reaction

Zeolite Y-encapsulated ruthenium(III) complexes of Schiff bases derived from 3-hydroxyquinoxaline-2-carboxaldehyde and 1,2- phenylenediamine, 2-aminophenol, or 2-aminobenzimidazole (RuYqpd, RuYqap and RuYqab, respectively) and the Schiff bases derived from salicylaldehyde and 1,2-phenylenediamine, 2-aminophenol, or 2-aminobenzimidazole (RuYsalpd, RuYsalap and RuYsalab, respectively) have been prepared and characterized. These complexes, except RuYqpd, catalyze catechol oxidation by H2O2 selectively to 1,2,4-trihydroxybenzene. RuYqpd is inactive. A comparative study of the initial rates and percentage conversion of the reaction was done in all cases. Turn over frequency of the catalysts was also calculated. The catalytic activity of the complexes is in the order RuYqap > RuYqab for quinoxaline-based complexes and RuYsalap > RuYsalpd > RuYsalab for salicylidene-based complexes. The reaction is believed to proceed through the formation of a Ru(V) species.

Wet peroxide oxidation of phenol over mixed pillared montmorillonites

Wet peroxide oxidation (WPO) of phenol is an effective means for the production of diphenols, which are of great industrial importance. An added advantage of this method is the removal of phenol from wastewater effluents. Hydroxylation of phenol occurs efficiently over mixed iron aluminium pillared montmorillonites. An initial induction period is noticed in all cases. A thorough study on the reaction variables suggests free radical mechanism for the reaction.

Basis set superposition error-counterpoise corrected potential energy surfaces : application to hydrogen peroxide ... X (X=F-, Cl-, Br-, Li+, Na+) complexes

Møller-Plesset (MP2) and Becke-3-Lee-Yang-Parr (B3LYP) calculations have been used to compare the geometrical parameters, hydrogen-bonding properties, vibrational frequencies and relative energies for several X- and X+ hydrogen peroxide complexes. The geometries and interaction energies were corrected for the basis set superposition error (BSSE) in all the complexes (1-5), using the full counterpoise method, yielding small BSSE values for the 6-311 + G(3df,2p) basis set used. The interaction energies calculated ranged from medium to strong hydrogen-bonding systems (1-3) and strong electrostatic interactions (4 and 5). The molecular interactions have been characterized using the atoms in molecules theory (AIM), and by the analysis of the vibrational frequencies. The minima on the BSSE-counterpoise corrected potential-energy surface (PES) have been determined as described by S. Simón, M. Duran, and J. J. Dannenberg, and the results were compared with the uncorrected PES

¿Qué entienden los jóvenes universitarios por monogamia y sexo sin penetración, como estrategias preventivas de la transmisión sexual del virus del SIDA? = What university students understand by monogamy and sex without penetration as preventive strategies of sexual transmission of AIDS virus?

Monogamy and sex without penetration are behaviors recommended by the WHO to avoid AIDS virus sexual transmission. Seven hundred and fifty university students from 18 to 25 years (67.7% women) were surveyed and they were asked to give a maximum of three free definitions of the words monogamy and sex without penetration to prevent AIDS virus sexual transmission. Their participation was voluntary and anonymous. Although the majority of the answers was correct, there was a considerable percentage of wrong answers, either for monogamy (3.7% masturbation; 2.1% to have many partners; 0.9% homosexual relations), or for sex without penetration (20.5% oral sex; 1.1% anal coitus; 0.8% coitus without orgasm; 0.4% coitus interruptus). Some definitions or examples differ by gender. The amount of wrongs or incomplete answers put researchers on the alert about insufficient preventive knowledge in a population with a high educational level

Laser granulometry of Holocene estuarine silts: effects of hydrogen peroxide treatment

The Holocene estuarine silts of the Severn Estuary Levels (southwest Britain) are representative of their kind in northwest Europe. They contain two broad types of plant material: particles codeposited with mineral grains from the estuarine water body, and extraneous debris (stems of indigenous prior plants; post depositional root matter) which is difficult to remove completely by physical means. Treatment with hydrogen peroxide before laser granulometry removes all plant material regardless of kind, drastically reduces values for the mean grain size and median size relative to untreated samples, but has little effect on the mode, except for a restricted group of bimodal-platykurtic, medium-coarse silts. It is concluded that, in the case of sediments of the general kind examined, no advantages acrue from the treatment of samples with hydrogen peroxide prior to analysis. Although a discrete rather than continuous variable, values of the mode obtained from untreated sediments are suggested to be acceptable for most purposes where a measure of central tendency is required.

Orde Wingate, 'Guerrilla' Warfare and Long-Range Penetration, 1940-44

Major General Orde Wingate was a highly controversial figure in his time and remains so among historians. However, his eccentric and colourful personality has drawn attention away from the nature of his military ideas, the most important of which was his concept of long-range penetration, which originated from his observations of his operations in Italian-occupied Ethiopia in 1941, and evolved into the model he put into practice in the Chindit operations in Burma in 1943-44. A review of Wingate's own official writings on this subject reveals that long-range penetration combined local guerrilla irregulars, purpose-trained regular troops and airpower into large-scale offensive operations deep in the enemy rear, with the intention of disrupting his planning process and creating situations regular forces could exploit. This evolved organically from Major General Colin Gubbins' doctrine for guerrilla resistance in enemy occupied areas, and bears some resemblance to the operational model applied by US and Allied forces, post September 2001.

Topical delivery of a naproxen-dithranol co-drug: in vitro skin penetration, permeation, and staining

Purpose This work probed the topical delivery and skin-staining properties of a novel co-drug, naproxyl-dithranol (Nap-DTH), which comprises anti-inflammatory (naproxen) and anti-proliferative (dithranol) moieties. Method Freshly excised, full-thickness porcine ear skin was dosed with saturated solutions of the compounds. After 24 h, the skin was recovered and used to prepare comparative depth profiles by the tape-stripping technique and to examine the extent of skin staining. Results Depth profiles showed that Nap-DTH led to a 5-fold increase in drug retention in the skin compared to dithranol. The application of Nap-DTH also demonstrated improved stability, resulting in lower levels of dithranol degradation products in the skin. Furthermore, significantly less naproxen from hydrolysed Nap-DTH permeated into the receptor phase compared to naproxen when applied alone (0.08 ± 0.03 nmol cm-² and 180 ± 60 nmol cm-², respectively). Moreover, the reduced staining of the skin was very apparent for Nap-DTH compared to dithranol. Conclusions Topical delivery of Nap-DTH not only improves the delivery of naproxen and dithranol, but also reduces unwanted effects of the parent moieties, in particular the skin staining, which is a major issue concerning the use of dithranol.