Reactions of Hafnium Tetrachloride with Benzoyl Hydrazones

Hafnium tetrachloride reacts with monofunctional bidentate (BHyH) and bifunctional tridentate (BHy\u27H2) benzoyl hydrazones (derived from the condensation of benzoyl hydrazine with different aldehydes/ketones) in refluxing dichloromethane to form products of the type, HfC13(BHy), HfC12(BHy)2 and HfCb(BHy\u27). These reaction products have been characterized on the basis of elemental analysis, electrical conductance measurements and spectral (infrared and electronic) data

Reactions of Hafnium Tetrachloride with Benzoyl Hydrazones

Hafnium tetrachloride reacts with monofunctional bidentate (BHyH) and bifunctional tridentate (BHy\u27H2) benzoyl hydrazones (derived from the condensation of benzoyl hydrazine with different aldehydes/ketones) in refluxing dichloromethane to form products of the type, HfC13(BHy), HfC12(BHy)2 and HfCb(BHy\u27). These reaction products have been characterized on the basis of elemental analysis, electrical conductance measurements and spectral (infrared and electronic) data

Mechanoluminescnce and photoluminescence in gamma irradiated NaCl:Eu

Rare earth (RE) ions posses unique optical behavior when doped into phosphors. Eu2+ activated phosphors find use in many applications. Eu2+ emission arises from the lowest band of 4f6 5d configuration to 8S7/2  state of 4f7. NaCl having different concentrations of Eu were prepared by melt technique. The crystals of small sizes were cleaved from the grown crystal block and crushed to obtain powder or microcrystalline form of NaCl. Annealed samples were exposed to gamma rays at dose level 0.930kGy. Mechanoluminescnce (ML) was excited impulsively by dropping a load of mass 0.4 kg with the impact velocity of   0.6 ms-1 on to it. An intense ML peak was observed in its ML glow curve. ML intensity increases with increasing concentration of dopant. ML emission spectrum shows a single peak at 482 nm. Photoluminescence (PL) of the sample has also been recorded and a single peak at 427 nm was observed. Shift in ML and PL emission spectrum was observed

Optical properties of calcium aluminate phosphors

Thermoluminescence properties of CaAl2O4 was studied. It was found that firstly the TL intensity increases with increase in UV irradiation time and it attains a maximum value for 20 minute irradiation time. TL intensity decreases with further increase in irradiation time

Sol gel synthesis and photoluminescence study of Eu3+ doped SnO2

Tin oxide(IV) nanophosphor doped with europium had been prepared by sol-gel technique using SnCl4 as precurser. XRD, IR, SEMand TEM analyses were used for characterization of SnO2:Eu3+. The XRD analysis shows that well crystallized tetragonal rutile SnO2:Eu3+ can be obtained by this method and the crystal size was about 15-20nm as an average for the sample calcined at 400ºC for 2h. The evolution of the most important functional groups during the steps involved in this synthesis route is explained in view of the results obtained with FTIR and XRD.  A spherical like morphology of the prepared  SnO2 nanoparticles was observed in the SEM and TEM studies. The SnO2 nanoparticles show stable photoluminescence emission intensity at 612 nm (5D0/7F2) of the Eu3+ ions activated SnO2 nanocrystals  This paper discuss the mechanistic approach of origin of luminescence in SnO2

Complications of Percutaneous Nephrolithotomy and their Management

Introduction: Increasing global prevalence of nephrolithiasis has resulted in the development of new minimally invasive techniques and has also led to the resurgence of established methods such as percutaneous nephrolithotomy (PCNL). This procedure is now recommended as the first option for the treatment of single large or multiple renal stones and those in the inferior calyx. This study was done to assess the complications of PCNL and their management, in our centre. Methods: Medical records of 144 patients who underwent PCNL at Lumbini Medical College Teaching Hospital, during the last one year were reviewed. The demographic data, size, tract number and location of the calculi, and intraoperative and postoperative complications were evaluated. The various parameters of the calculi were evaluated. Descriptive analysis with frequencies was done. Results: Complications occurred in 13 (9.02%) patients. Post operative bleeding occurred in seven (4.8%) patients, out of which one patient developed pseudoaneurysms and the other developed arteriovenous fistula. One patient developed hypovolemic shock immediately after surgery. Frequent blockage of urine, excessive drainage of urine from the drain site, hemothorax and colonic perforation was seen in one  patient each. One patient had mortality due to post operative bleeding. Complications increased with the number and size of stones and number and site of the tracts. Conclusion: Percutaneous nephrolithotomy has low complication rate in experienced hands and complications depend upon stone size, history of open stone surgery, tract number, and tract location

Practical use of dabigatran etexilate for stroke prevention in atrial fibrillation.

Atrial fibrillation (AF) is associated with an increased risk of thromboembolism, and is the most prevalent factor for cardioembolic stroke. Vitamin K antagonists (VKAs) have been the standard of care for stroke prevention in patients with AF since the early 1990s. They are very effective for the prevention of cardioembolic stroke, but are limited by factors such as drug-drug interactions, food interactions, slow onset and offset of action, haemorrhage and need for routine anticoagulation monitoring to maintain a therapeutic international normalised ratio (INR). Multiple new oral anticoagulants have been developed as potential replacements for VKAs for stroke prevention in AF. Most are small synthetic molecules that target thrombin (e.g. dabigatran etexilate) or factor Xa (e.g. rivaroxaban, apixaban, edoxaban, betrixaban, YM150). These drugs have predictable pharmacokinetics that allow fixed dosing without routine laboratory monitoring. Dabigatran etexilate, the first of these new oral anticoagulants to be approved by the United States Food and Drug Administration and the European Medicines Agency for stroke prevention in patients with non-valvular AF, represents an effective and safe alternative to VKAs. Under the auspices of the Regional Anticoagulation Working Group, a multidisciplinary group of experts in thrombosis and haemostasis from Central and Eastern Europe, an expert panel with expertise in AF convened to discuss practical, clinically important issues related to the long-term use of dabigatran for stroke prevention in non-valvular AF. The practical information reviewed in this article will help clinicians make appropriate use of this new therapeutic option in daily clinical practice

Planck Scale Boundary Conditions and the Higgs Mass

If the LHC does only find a Higgs boson in the low mass region and no other new physics, then one should reconsider scenarios where the Standard Model with three right-handed neutrinos is valid up to Planck scale. We assume in this spirit that the Standard Model couplings are remnants of quantum gravity which implies certain generic boundary conditions for the Higgs quartic coupling at Planck scale. This leads to Higgs mass predictions at the electroweak scale via renormalization group equations. We find that several physically well motivated conditions yield a range of Higgs masses from 127-142 GeV. We also argue that a random quartic Higgs coupling at the Planck scale favors M_H > 150 GeV, which is clearly excluded. We discuss also the prospects for differentiating different boundary conditions imposed for \lambda(M_{pl}) at the LHC. A striking example is M_H = 127\pm 5 GeV corresponding to \lambda(M_{pl})=0, which would imply that the quartic Higgs coupling at the electroweak scale is entirely radiatively generated.Comment: 12 pages, 5 figures; references added and other minor improvements, matches version published in JHE