High-frequency Oscillations in Small Magnetic Elements Observed with Sunrise/SuFI

We characterize waves in small magnetic elements and investigate their propagation in the lower solar atmosphere from observations at high spatial and temporal resolution. We use the wavelet transform to analyze oscillations of both horizontal displacement and intensity in magnetic bright points found in the 300 nm and the Ca II H 396.8 nm passbands of the filter imager on board the Sunrise balloon-borne solar observatory. Phase differences between the oscillations at the two atmospheric layers corresponding to the two passbands reveal upward propagating waves at high frequencies (up to 30 mHz). Weak signatures of standing as well as downward propagating waves are also obtained. Both compressible and incompressible (kink) waves are found in the small-scale magnetic features. The two types of waves have different, though overlapping, period distributions. Two independent estimates give a height difference of approximately 450+-100 km between the two atmospheric layers sampled by the employed spectral bands. This value, together with the determined short travel times of the transverse and longitudinal waves provide us with phase speeds of 29+-2 km/s and 31+-2 km/s, respectively. We speculate that these phase speeds may not reflect the true propagation speeds of the waves. Thus, effects such as the refraction of fast longitudinal waves may contribute to an overestimate of the phase speed.Comment: 14 pages, 7 figure

Design of a high voltage input – output ratio dc-dc converter dedicated to small power fuel cell systems

International audienceConsuming chemical energy, fuel cells produce simultaneously heat, water and useful electrical power [J.M. Andújar, F. Segura, Renew. Sust. Energy Rev. , 2309 (2009)], [J. Larminie, A. Dicks, , 2nd edn. (John Wiley & Sons, 2003)]. As a matter of fact, the voltage generated by a fuel cell strongly depends on both the load power demand and the operating conditions. Besides, as a result of many design aspects, fuel cells are low voltage and high current electric generators. On the contrary, electric loads are commonly designed for small voltage swing and a high V/I ratio in order to minimize Joule losses. Therefore, electric loads supplied by fuel cells are typically fed by means of an intermediate power voltage regulator. The specifications of such a power converter are to be able to step up the input voltage with a high ratio (a ratio of 10 is a classic situation) and also to work with an excellent efficiency (in order to minimize its size, its weight and its losses) [A. Shahin, B. Huang, J.P. Martin, S. Pierfederici, B. Davat, Energy Conv. Manag. , 56 (2010)]. This paper deals with the design of this essential ancillary device. It intends to bring out the best structure for fulfilling this function. Several dc-dc converters with large voltage step-up ratios are introduced. A topology based on a coupled inductor or tapped inductor is closely studied. A detailed modelling is performed with the purpose of providing designing rules. This model is validated with both simulation and implementation. The experimental prototype is based on the following specifications: the fuel cell output voltage ranges from a 50 V open-voltage to a 25 V rated voltage while the load requires a constant 250 V voltage. The studied coupled inductor converter is compared with a classic boost converter commonly used in this voltage elevating application. Even though the voltage regulator faces severe FC specifications, the measured efficiency reaches 96% at the rated power whereas conventional boost efficiency barely achieves 91.5% in the same operating conditions

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Abstract Objectives: To evaluate the performance of the Anoxomat, in comparison with the conventional anaerobic GasPak jar system, for the isolation of obligate anaerobes. Method: Anoxomat, model WS800, and anaerobic GasPak jar system (Oxoid) were evaluated. Anoxomat system utilized a gas mixture of 80% N 2 , 10% CO 2 and 10% H 2 , while the GasPak used a gas mixture of 90% H 2 and 10% CO 2 . An anaerobic indicator within the jars monitored anaerobiosis. A total of 227 obligate anaerobic bacteria comprising 116 stock strains, 5 ATCC reference strains and 106 fresh strains, representing different genera, were investigated for growth on anaerobic agar plates and scored for density, colony sizes, susceptibility zones of antibiotic inhibition and the speed of anaerobiosis (reducing the indicator). Results: The results demonstrate that the growth of anaerobic bacteria is faster inside the Anoxomat jar than in the anaerobic GasPak jar system. Of the 227 strains tested, the colonies of 152 (67%) were larger (by size range of 0.2-2.4 mm) in the Anoxomat at 48 h than in the GasPak jar compared with only 21% (range 0.1-0.3 mm) that were larger in the GasPak than in the Anoxomat. The remaining 12% were equal in their sizes. There was no measurable difference in the colony sizes of the reference strains. The Porphyromonas asaccharolytica strains failed to grow within the GasPak system but grew inside the Anoxomat. With the Anoxomat, anaerobiosis was achieved about 35 min faster than in the GasPak system. The density of growth recorded for 177 (78%) strains was heavier in the Anoxomat than in the GasPak jar. The zones of inhibition of the antibiotics tested were not different in the two systems. Conclusion: The Anoxomat system provided superior growth, in terms of density and colony size, and achieved anaerobiosis more rapidly. Evidently, the Anoxomat method is more reliable and appears to support the growth of strict anaerobes better

Pulpal blood flow changes and pain scores related to using superelastic 0.018-inch nickel titanium as the first orthodontic alignment archwire: A prospective clinical trial

Background: Optimal orthodontic force results in maximum rate of tooth movement without tissue damage. Even though starting orthodontic treatment with a thicker archwire may shorten treatment duration, the evidence on the effect of using 0.018-inch NiTi as the first alignment archwire on pulpal blood flow (PBF) status is still scarce. Objectives: to record PBF changes and pain scores associated with using 0.018-inch NiTi as the first alignment archwire during fixed orthodontic treatment. Methodology: Patients were selected from subjects attending postgraduate orthodontic teaching clinics at Jordan University of Science and Technology. In total, forty healthy patients who exhibited mild lower arch crowding were included. A split-mouth trial design was used. Each patient received two archwire sizes at one time joined in the midline by crimpable hook and applied in the lower arch. Patients were assigned into one of two groups based on archwire sizes used. Group 1: 0.014-inch and 0.018-inch NiTi (Six males, 14 females aged 19.4±1.33 years) and Group 2: 0.016-inch and 0.018-inch NiTi (Seven males, 13 females aged 19.6±1.45 years). The archwire size group was randomly allocated with a 1:1 allocation ratio. A Laser Doppler Flowmeter was used to measure PBF at different time intervals (T0-T5). Pain scores were recorded using a visual analogue scale (VAS). A repeated measures ANOVA and a post-hoc Bonferroni comparison tests were conducted to examine differences at the different time points before and during orthodontic alignment. Results: For all studied archwire sizes, PBF decreased 20 minutes after their placement. Most PBF changes occurred within 24hours and continued to decrease until 72 hours after archwire placement where the maximum reduction was reached. Eventually, normal values were reverted within 1 month. PBF changes were similar between all alignment – groups. Conclusions: Initial orthodontic alignment with 0.018-inch NiTi does not cause irreversible changes to pulpal vasculature or produces higher pain scores.The study was supported by the deanship of research at Jordan University of Science and Technology, research grant number (39/2018)

Interdisciplinary evidence-based recommendations for the follow-up of testicular cancer patients: a joint effort

Detailed recommendations for the treatment of testicular cancer exist and due to the stringent application of the standard therapies, most patients can nowadays be cured. Moreover in the treatment of early stage disease, active surveillance is now a cornerstone of treatment. Hence there is a clear need for recommendations regarding the long term follow-up of these young patients. These have to be safe, feasible and the intensity of procedures have to reflect the known risk of recurrence. Different proposals have been published but they differ widely especially in terms of frequency and modality of imaging. In the last few years, new evidence has become available regarding the relapse pattern of different disease stages of testicular cancer, the use of imaging in follow-up and the risks of excessive radiation due to imaging, in particular with CT scans. In this article, an interdisciplinary, multinational working group has reviewed the evidence and based on this has formulated practical recommendations for the follow-up of patients with testicular cancer

On the undulatory behaviour of metallic glass foils: a novel spring-type behaviour

The undulatory behaviour is a unique type of mechanical response that was recently observed for metallic glass foils in geometric confinement. It is manifested when normal load is applied on the top of an arc-shaped thin foil of metallic glass; the foil then deforms elastically and its shape changes by progressively increasing the number of formed sinusoidal arcs. This behaviour results from a combination of successive elastic bending and buckling events and can be utilized for developing novel types of non-linear springs. In this work, the undulatory behaviour of a Ni-Fe-Si-B-Mo metallic glass foil has been systematically studied and compared with that of the previously reported Fe-Cr-Si-B foil. The results indicate that the alloy composition and the foil thickness can significantly affect the load required for the formation of the harmonic undulations. The initial geometry of the formed sinusoidal arc including its amplitude and boundary length, can also be used to tune the load and displacement response of the foils. Upon unloading, the foil returns to its initial shape, as long as the loading remains in the elastic deformation range of the metallic glass. The findings suggest that the undulatory behaviour of thin metallic glass foils can be potentially exploited for a wide range of engineering applications including micro-springs, sensors, actuators, and shock absorbers.DMG Mor

Impact of feldspar and liquid Bio-fertilizer on fruit quantity and quality of olive trees Picual cv.

The present investigation was carried out in two consecutive seasons (2022 and 2023) on eight-year-old olive trees “Picual” cv., planted at 4×6m apart around (420 trees / Fed). Trees irrigated with drip irrigation system, at a private orchard. The experiment included 3 rates of Feldspar as source of naturel potassium at 2, 4, and 6 kg/ tree and potassium dissolving bacteria as liquid Bio-fertilizers supplemented (25 ml) at two or three times to investigate the yield and fruit quality of Picual olive trees. Data indicated that the yield of Picual olive trees fertilized with feldspar and liquid Bio-fertilizer increase to 70% over control. Picual olive trees treated with (4 kg Feldspar + 25 ml liquid Bio-fertilizer at three doses) achieved the highest increase in the yield for the both seasons and also gave the highest fruit weight, volume and fruit flesh/stone ratio of olive trees Picual cv. Concerning leaf nitrogen percentage (N%) The highest percentage of N% for the both years was recorded by treatment (6 kg Feldspar + 25 ml liquid Bio-fertilizer at three doses). With respect to leaf phosphor and potassium percentage, it could be seen that most treatments gave more or less results similar to the control

Impact of Natural stimulates and Antioxidant compounds on fruit quality and quantity of pomegranate trees cv. H116

This experiment was carried out during two seasons (2022 and 2023) to examine the effect of spraying pomegranate trees cv. H116 with extract algae at (2cm/l), salicylic acid at (0.5 g/l) and ascorbic acid at (0.5 g/l) either alone or in combination together on productivity, fruit properties and leaf mineral content. All treatments were applied as a foliar three times: at full blooming, after fruit sit and after 30 days from fruit set. The results showed that all treatments caused a significant increase in the yield and the leaf mineral content of trees compared to the control. Treated pomegranate trees with 0.5 g/l ascorbic acid + 0.5 g/l salicylic acid was the best treatment for enhancing the yield (kg), fruit weight (g) and fruit peel (%). Foliar l application on pomegranate trees with (2 cm/l algae extract + 0.5 g/l ascorbic acid + 0.5 g/l salicylic acid) was the best treatment in this study to improve the fruit juice content and its quality and obtain maximum leaf content of nitrogen, phosphorus and potassium