Gas metal arc welding of modified X2CrNi12 ferritic stainless steel

X2CrNi12 ferritic stainless steel is a low cost stainless steel grade exhibiting good corrosion and abrasion resistance. Typical applications for this steel are bus frames and chassis, railway wagons for coal and iron ore, mining and mineral processing, sugar and chemical process equipment, furnace parts etc. The modern production routes now allow fabricating this grade with low carbon content (< 0.015 %) and low impurity levels improving the weldability substantially. Regarding to these conditions, this modified stainless steel grade becomes more attractive. In this paper, microstructural and toughness properties and mechanical properties of gas metal arc welded 6 mm thick modified X2CrNi12 stainless steel with two different heat inputs are presented. Promising results have been obtained. Interesting correlation has been found between microstructure (e.g. grain size) and impact toughness

Successful Indian model in producing modern computers

Interview of Denis Nicole by Taban Panahi

Novel wireless modulation technique based on noise

In this paper, a new RF modulation technique is presented. Instead of using sinusoidal carriers as information bearer, pure noise is applied. This allows very simple radio architectures to be used. Spread-spectrum based technology is applied to modulate the noise bearer. Since the transmission bandwidth of the noise bearer can be made very wide, up to ultra-wideband regions, extremely large processing gains can be obtained. This will provide robustness in interference-prone environments. To avoid the local regeneration of the noise reference at the receiver, the Transmit-Reference (TR) concept is applied. In this concept, both the reference noise signal and the modulated noise signal are transmitted, together forming\ud the bearer. The reference and modulated signals are separated by applying a time offset. By applying different delay times for different channels (users) a new multiple access scheme results based on delay: Delay Division Multiple Access (DDMA). A theoretical analysis is given for the link performance of a single-user and a multi-user system. A testbed has been built to demonstrate the concept. The demonstrator operates in a 50 MHz bandwidth centered at 2.4 GHz. Processing gains ranging from 10¿30 dB have been tested. The testbed confirms the basic behavior as predicted by the theory

Synthesis, molecular modelling and CYP24A1 inhibitory activity of novel of (E)-N-(2-(1H-imidazol-1-yl)-2-(phenylethyl)-3/4-styrylbenzamides

CYP24A1 (25-hydroxyvitamin D-24-hydroxylase) is a useful enzyme target for a range of medical conditions including cancer, cardiovascular and autoimmune disease, which show elevated CYP24A1 levels and corresponding reduction of calcitriol (the biologically active form of vitamin D). A series of (E)-N-(2-(1H-imidazol-1-yl)-2-(phenylethyl)-3/4-styrylbenzamides have been synthesised using an efficient synthetic route and shown to be potent inhibitors of CYP24A1 (IC50 0.11–0.35 μM) compared with the standard ketoconazole. Molecular modelling using our CYP24A1 homology model showed the inhibitors to fill the hydrophobic binding site, forming key transition metal interaction between the imidazole nitrogen and the haem Fe3+ and multiple interactions with the active site amino acid residues

Adiabatic Formation of Rydberg Crystals with Chirped Laser Pulses

Ultracold atomic gases have been used extensively in recent years to realize textbook examples of condensed matter phenomena. Recently, phase transitions to ordered structures have been predicted for gases of highly excited, 'frozen' Rydberg atoms. Such Rydberg crystals are a model for dilute metallic solids with tunable lattice parameters, and provide access to a wide variety of fundamental phenomena. We investigate theoretically how such structures can be created in four distinct cold atomic systems, by using tailored laser-excitation in the presence of strong Rydberg-Rydberg interactions. We study in detail the experimental requirements and limitations for these systems, and characterize the basic properties of small crystalline Rydberg structures in one, two and three dimensions.Comment: 23 pages, 10 figures, MPIPKS-ITAMP Tandem Workshop, Cold Rydberg Gases and Ultracold Plasmas (CRYP10), Sept. 6-17, 201

Breast cancer management and outcome according to surgeon's affiliation: a population-based comparison adjusted for patient's selection bias

Background Studies have reported that breast cancer (BC) units could increase the quality of care but none has evaluated the efficacy of alternative options such as private BC networks, which is our study objective. Patients and methods We included all 1404 BC patients operated in the public unit or the private network and recorded at the Geneva Cancer Registry between 2000 and 2005. We compared quality indicators of care between the public BC unit and the private BC network by logistic regression and evaluated the effect of surgeon's affiliation on BC-specific mortality by the Cox model adjusting for the propensity score. Results Both the groups had high care quality scores. For invasive cancer, histological assessment before surgery and axillary lymph node dissection when indicated were less frequent in the public sector (adjusted odds ratio (OR): 0.4, 95% confidence interval (CI) 0.3-0.7, and OR: 0.4, 95% CI 0.2-0.8, respectively), while radiation therapy after breast-conserving surgery was more frequent (OR: 2.5, 95% CI 1.4-4.8). Surgeon affiliation had no substantial effect on BC-specific mortality (adjusted hazard ratio (HR): 0.8, 95% CI 0.5-1.4). Conclusions This study suggests that private BC networks could be an alternative to public BC units with both structures presenting high quality indicators of BC care and similar BC-specific mortalit

The circumstellar disk, envelope, and bi-polar outflow of the Massive Young Stellar Object W33A

The Young Stellar Object (YSO) W33A is one of the best known examples of a massive star still in the process of forming. Here we present Gemini North ALTAIR/NIFS laser-guide star adaptive-optics assisted K-band integral-field spectroscopy of W33A and its inner reflection nebula. In our data we make the first detections of a rotationally-flattened outer envelope and fast bi-polar jet of a massive YSO at near-infrared wavelengths. The predominant spectral features observed are Br-gamma, H_2, and a combination of emission and absorption from CO gas. We perform a 3-D spectro-astrometric analysis of the line emission, the first study of its kind. We find that the object's Br-gamma emission reveals evidence for a fast bi-polar jet on sub-milliarcsecond scales, which is aligned with the larger-scale outflow. The hybrid CO features can be explained as a combination of hot CO emission arising in a disk close to the central star, while cold CO absorption originates in the cooler outer envelope. Kinematic analysis of these features reveals that both structures are rotating, and consistent with being aligned perpendicularly to both the ionised jet and the large-scale outflow. Assuming Keplerian rotation, we find that the circumstellar disk orbits a central mass of >10Msun, while the outer envelope encloses a mass of ~15Msun. Our results suggest a scenario of a central star accreting material from a circumstellar disk at the centre of a cool extended rotating torus, while driving a fast bi-polar wind. These results therefore provide strong supporting evidence for the hypothesis that the formation mechanism for high-mass stars is qualitatively similar to that of low-mass stars.Comment: 13 pages, 18 figs. Accepted for publication in MNRA

Effect of Calcium on the Alleviation of Boron Toxicity and Localization of Boron and Calcium in Cell Wall of Wheat

A greenhouse experiment involving four levels of B (0, 5, 10 and 20 mg B kg-1 as boric acid, H3BO3), and three levels of Ca (0, 100 and200 mg Ca kg-1 calcium chloride, CaCl2) were conducted on wheat plants (Triticum aestivum L. 'Gerek-79'). Boron toxicity symptomsstrongly occurred at 10 and 20 mg B kg-1 levels with and without applied Ca. Without applied calcium, boron toxicity symptoms werealso weakly expressed at 5 mg B kg-1 level. Growing wheat plants with application of high levels of Ca partially alleviated the toxicitysymptoms. Shoot and root dry weight of plant was strongly depressed and decreased by applied boron; however, Ca applications reducedthe inhibitory effect of B on the plant growth. Shoot and root boron concentrations and boron uptake were increased with increasingB application, but decreased with Ca applications. Controversially, applied calcium increased calcium concentrations and uptake anddecreased boron concentrations and uptake. Most of total boron and calcium were localized in the cell wall of plant. While applied boron increased the concentration of B on the cell wall, it decreased the concentration of Ca on the cell wall. In addition, applied calciumincreased the cell wall calcium concentration, whereas decreased the cell wall boron concentration. It was determined that boron toxicitycould be alleviated by addition of calcium in plant growing media