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1.
Materials (Basel) ; 13(23)2020 Nov 27.
Article in English | MEDLINE | ID: mdl-33261206

ABSTRACT

In this work, African maize cobs (AMC) were used as a rich biomass precursor to synthesize carbon material through a chemical activation process for application in electrochemical energy storage devices. The carbonization and activation were carried out with concentrated Sulphuric acid at three different temperatures of 600, 700 and 800 °C, respectively. The activated carbon exhibited excellent microporous and mesoporous structure with a specific surface area that ranges between 30 and 254 m2·g-1 as measured by BET analysis. The morphology and structure of the produced materials are analyzed through Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Boehm titration, X-ray Photoelectron Spectroscopy (XPS) and Raman Spectroscopy. X-ray photoelectron spectroscopy indicates that a considerable amount of oxygen is present in the materials. The functional groups in the activated carbon enhanced the electrochemical performance and improved the material's double-layer capacitance. The carbonized composite activated at 700 °C exhibited excellent capacitance of 456 F g-1 at a specific current of 0.25 A g-1 in 6 M KOH electrolyte and showed excellent stability after 10,000 cycles. Besides being a low cost, the produced materials offer good stability and electrochemical properties, making them suitable for supercapacitor applications.

2.
Br J Neurosurg ; 34(2): 219-223, 2020 Apr.
Article in English | MEDLINE | ID: mdl-29363350

ABSTRACT

Elevation of a depressed skull fracture (DSF) overlying a venous sinus is generally avoided due to risk of sinus injury. Rarely, the sinus may be compressed by the fractured segment, causing intracranial hypertension (IH) or encephalopathy and can only be diagnosed with cerebral angiography or MR imaging techniques. The posterior third of the superior sagittal sinus (SSS) was found involved in all the reported cases. There is no consensus on its management, but most patients did not have any sinus thrombosis and improved after elevation of the compressing DSF alone. There are isolated reports of improvement with serial lumbar punctures or ventriculoperitoneal shunt.We report for the first time, a single session lumboperitoneal shunt and DSF elevation for a patient with thrombosis of the posterior part of SSS due to an overlying DSF, causing florid papilledema and impending blindness. Elevation of the DSF alone would not have achieved patency of the thrombosed sinus immediately to save his vision. Hence a lumboperitoneal shunt was done for immediate relief of IH. This CSF diversion alone was insufficient to achieve patency of the thrombosed sinus in the presence of significant external compression by the DSF; even if anticoagulants were used. Hence we elevated the DSF after craniotomy using a technical modification; by making a wide gutter circumferentially around the DSF with a high speed drill, to avoid sinus injury; prior to its elevation. The patient's vision improved in 48 hours and anticoagulants were used till 2 months when sinuses were found normal on MRI. Serial CT &MR images showing progression to thrombosis and recovery after decompression are presented. Both CSF diversion and DSF elevation are necessary when vision is threatened by IH due to sinus thrombosis with an overlying DSF.


Subject(s)
Sinus Thrombosis, Intracranial , Skull Fracture, Depressed , Decompression , Humans , Intracranial Hypertension , Sinus Thrombosis, Intracranial/etiology , Skull Fracture, Depressed/complications , Superior Sagittal Sinus
3.
J Assoc Physicians India ; 64(3): 80-81, 2016 03.
Article in English | MEDLINE | ID: mdl-27731565

ABSTRACT

Pseudocyst is a common complication of Acute and chronic pancreatitis. However, its extension into the mediastinum is a rare entity. We present a case of 52 years male with acute on chronic pancreatitis (alcohol related) who presented with dysphagia and dyspnoea and was found to have a pancreatic pseudocyst extending upto the neck. Ultrasound fails to pick up mediastinal pseudocysts and requires additional imaging modalities - CT and MRI. Management of Mediastinal pseudocyst depends upon underlying etiology, ductal anatomy, size of the pseudocyst, and availability of expertise. Small pseudocysts in asymptomatic patients may resolve spontaneously, but requires prolonged conservative therapy with somatostatin or its analogue and Total Parenteral Nutrition. Ruptured pseudocyst in a symptomatic unstable patient requires surgical resection. Endoscopic ultrasound guided drainage (transmural or transpapillary) and Main Pancreatic Duct stenting are safe and effective treatment modality.


Subject(s)
Mediastinal Cyst/diagnostic imaging , Mediastinal Cyst/surgery , Pancreatic Pseudocyst/diagnostic imaging , Pancreatic Pseudocyst/surgery , Pancreatitis/complications , Deglutition Disorders/etiology , Dyspnea/etiology , Endoscopy , Humans , Magnetic Resonance Imaging , Male , Mediastinal Cyst/complications , Pancreatic Pseudocyst/complications , Tomography, X-Ray Computed
6.
J Nanosci Nanotechnol ; 15(1): 742-6, 2015 Jan.
Article in English | MEDLINE | ID: mdl-26328436

ABSTRACT

Carbon nanofibers (CNF) have been synthesized under partial combustion conditions in a flame reactor using different mixtures of hydrocarbon gases in the presence and absence of precursors. The hydrogen (H2) adsorption studies have been carried out using a high pressure Sievert's apparatus maintained at a constant temperature (24 degrees C). The flame synthesized CNFs showed high degree of H2 adsorption capacities at 100 atm pressure. The highest H2 capacities recorded have been 4.1 wt% [for CNF produced by liquefied petroleum gas (LPG)-Air (E-17)], 3.7 wt% [for nano carbons produced by Methane-Acetylene-Air (EMAC-4)] and 5.04 wt% for [Lithium intercalated sample (Li-EMAC-4)] respectively.

7.
Ann Card Anaesth ; 18(3): 421-4, 2015.
Article in English | MEDLINE | ID: mdl-26139754

ABSTRACT

Cystic echinococcosis (hydatid disease) arising from infestation with a larval or adult form of the Echinococcus granulosus tapeworm is endemic in certain states of India, but affecting interventricular septum (IVS) solitarily is a scarce phenomenon. We present a rare case of transesophageal echocardiography guided management of IVS hydatid cyst even during cardiopulmonary bypass, which presented with a rather unusual complaint of repeated syncope.


Subject(s)
Cardiopulmonary Bypass , Echinococcosis/diagnostic imaging , Echocardiography, Transesophageal , Ultrasonography, Interventional , Ventricular Septum/diagnostic imaging , Ventricular Septum/parasitology , Echinococcosis/complications , Echinococcosis/therapy , Female , Humans , India , Middle Aged , Syncope/complications , Ventricular Septum/surgery
9.
Mater Sci Eng C Mater Biol Appl ; 33(2): 758-62, 2013 Mar 01.
Article in English | MEDLINE | ID: mdl-25427484

ABSTRACT

Densely agglomerated, high specific surface area carbon nano onions with diameter of 30-40 nm have been synthesized. Liquefied petroleum gas and air mixtures produced carbon nano onions in diffusion flames without catalyst. The optimized oxidant to fuel ratio which produces carbon nano onions has been found to be 0.1 slpm/slpm. The experiment yielded 70% pure carbon nano onions with a rate of 5 g/h. X-ray diffraction, high-resolution electron microscopy and Raman spectrum reveal the densely packed sp(2) hybridized carbon with (002) semi-crystalline hexagonal graphite reflection. The carbon nano onions are thermally stable up to 600 °C.


Subject(s)
Carbon/chemistry , Nanostructures/chemistry , Petroleum/analysis , Diffusion , Microscopy, Electron, Transmission , Oxidation-Reduction , Particle Size , Spectrum Analysis, Raman , Temperature , X-Ray Diffraction
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