Preparation of Graphene Oxide from Expanded Graphite at Different Microwave Heating Times

Exfoliated graphite (EG)  was prepared by mixing graphite with HNO3 and KMnO4 at weight ratio 1:2:1 using microwave heating at times 20, 60, 80 and 120 sec. Graphene  oxide (GO) was then prepared using EG as precursor by the modified Hummer’s method. Atomic force microscopy (AFM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy analyses  showed successful conversion of EG into GO. The XRD results of the GO showed that the maximum interplanar distance (d-spacing) increased from 0.344 to 0.831 nm. The AFM showed a minimum thickness of  0.519 nm for a single layer of GO prepared from EG 80 sec. The XRD examination also showed an increase in the d-spacing between the GO layers after sonication compared to before sonication

Preparation and Characterization of Porous Anodic Alumina membrane

Porous Anodic Alumina (PAA) was prepared by two-step anodization on both sides of an aluminium foil. The anodization carried out at anodizing temperature 17oC using oxalic acid as an anodizing electrolyte. The (PAA) template was characterized with optical microscope and SEM. The optical microscope image showed two (PAA) layers after the dissolution of the residual aluminium. The average pore diameter was found to be (75) nm. The average interpore distance of (PAA) prepared was found to be (99) nm. The thickness of (PAA) was found to be (59.5) μm

Predictors of poor quality of life after primary lower limb deep venous thrombosis: A perspective from a developing nation

Objective: We aimed to determine predictors of poor long term quality of life, using the VEINES Quality of Life (QOL) questionnaire, in patients with lower limb deep venous thrombosis (DVT).Material and Methods: This study included adult patients with primary lower limb DVT between January 2007 and December 2017. Post thrombotic syndrome (PTS) was assessed using the Villalta score and Quality of Life (QoL) by the VEINES quality of life questionnaire.Results: Our study included 125 patients, 57 (45.6%) of whom were males. The patient population\u27s median age was 41 years (IQR: 34-47 years). The median follow up was 450 days (IQR: 390-1020 days). PTS occurred in 49 (39.2%) patients. Independent predictors of poor quality of life post DVT were progression to PTS, complete occlusion of vein, proximal (Ileofemoral) DVT, poor control of INR, poor compliance with compression stockings, severity of PTS, ileofemoral DVT and poor control of therapeutic anticoagulation.Conclusion: Predictors who are independently associated with poor quality of life post DVT are PTS, inability to maintain therapeutic anticoagulation and ileofemoral DVT

A Sandwich Porous Alumina Nanostructures Based on Anodic Alumina

A sandwich porous anodic alumina membrane (PAA/Al/PAA) films was producedusing two-step anodization approach on both sides of (250) μm pure aluminum foilelectrode as an anode. A single sheet of stainless steel or graphite was used as acathode. Anodization on both sides of aluminum sheet was achieved. The anodizationprocesses and pore formation were studied and discussed in this work. The producedalumina membrane (5-30) μm thick was analyzed using scanning electron microscopy(SEM). The SEM image shows the PAA membranes has a well-defined nanostructure.The average pore diameter reaches (25) nm. The produced Al 2O3 membrane growingon both sides of aluminum sheet was separated into a twin nano membrane

Synthesis of Carbon Nanotubes Growth Using FeCl3 / Ethanol Catalyst by CVD Method

Carbon nanotubes (CNTs) were grown by chemical vapor deposition (CVD) method. FeCl3 was used as the precursor of iron which acts as the catalyst .Solution of FeCl3 in ethanol at concentration of (0.05 mole/litter) has been chosen. Silicon (100) substrates were spin- coated with the prepared catalyst solution (FeCl3) .Carbon nanotubes were grown on Si (100) substrate coated with catalyst in tube furnace using argon and acetylene gases at temperature of 750°C for 30 minutes. The structures of the produced material were characterized with Raman spectroscopy and FESEM. Raman spectra showed MWCNTs with the presence of radial breathing mode (RBM) at low frequency. The morphology of carbon nanotubes called noodles–like CNTs with an average diameter of 45nm was observed with FESEM micrograph

Early Clinical and Subclinical Visual Evoked Potential and Humphrey's Visual Field Defects in Cryptococcal Meningitis.

Cryptococcal induced visual loss is a devastating complication in survivors of cryptococcal meningitis (CM). Early detection is paramount in prevention and treatment. Subclinical optic nerve dysfunction in CM has not hitherto been investigated by electrophysiological means. We undertook a prospective study on 90 HIV sero-positive patients with culture confirmed CM. Seventy-four patients underwent visual evoked potential (VEP) testing and 47 patients underwent Humphrey's visual field (HVF) testing. Decreased best corrected visual acuity (BCVA) was detected in 46.5% of patients. VEP was abnormal in 51/74 (68.9%) right eyes and 50/74 (67.6%) left eyes. VEP P100 latency was the main abnormality with mean latency values of 118.9 (±16.5) ms and 119.8 (±15.7) ms for the right and left eyes respectively, mildly prolonged when compared to our laboratory references of 104 (±10) ms (p<0.001). Subclinical VEP abnormality was detected in 56.5% of normal eyes and constituted mostly latency abnormality. VEP amplitude was also significantly reduced in this cohort but minimally so in the visually unimpaired. HVF was abnormal in 36/47 (76.6%) right eyes and 32/45 (71.1%) left eyes. The predominant field defect was peripheral constriction with an enlarged blind spot suggesting the greater impact by raised intracranial pressure over that of optic neuritis. Whether this was due to papilloedema or a compartment syndrome is open to further investigation. Subclinical HVF abnormalities were minimal and therefore a poor screening test for early optic nerve dysfunction. However, early optic nerve dysfunction can be detected by testing of VEP P100 latency, which may precede the onset of visual loss in CM

Perceptions on the accessibility of Islamic banking in the UK—Challenges, opportunities and divergence in opinion

This study examines the views of UK-based Muslims, Islamic Scholars and Islamic banking employees on the current state of the latter industry, both in practical terms and as regards engagement with the nation’s large, but often marginalised Islamic community. The British Government has recently championed the Islamic banking sector and committed to supporting it as a means of addressing financial services needs and consolidating London’s position as the global centre for Islamic investment. The analysis adds to the substantive literature in two principal ways: (i) by contextualising the evidence via the notions of empowerment, engagement and social justice that underpin both the state’s attempts to foster growth and the central tenets of Islam; and (ii) by placing comparison of the opinions of key groups at the heart of the investigation. The findings reveal that while progress has been made, UK-based Muslims see several substantive impediments to access, including the complex terminology of Islamic banking products, the lack of internet banking facilities and branch networks as well as a generalised lack of interest in marketing on the part of the institutions. Whilst some coincidence of perception is evident, the views of bankers are shown to be out of line with those of the other parties in a number of key areas. For example, bankers appear to see less potential in the role of the internet as a medium for spreading awareness than do either potential customers or religious scholars. The paper therefore concludes with a call for multi-party Ijtihad and Qiyas (deductive analogy) that will encourage industrial outreach and, in so doing, support long-term growth

Political connections and corporate financial decision making

This paper investigates whether and how political connections influence managerial financial decisions. Our study reveals that those firms that have a politician on its board of directors are highly leveraged, use more long-term debt, hold large excess cash and are associated with low quality financial reporting compared to their non-connected counterparts. These effects escalate with the strength of the connected politician and whether he or his party is in power. The winning party effect is observed to be stronger than victory by the politician himself. Overall, our paper provides strong evidence that political connection is a two-edged sword. It is indeed a valuable resource for connected firms, but it comes at a cost of higher agency problems

Comparative genomics of two jute species and insight into fibre biogenesis

Jute (Corchorus sp.) is one of the most important sources of natural fibre, covering ∼80% of global bast fibre production1. Only Corchorus olitorius and Corchorus capsularis are commercially cultivated, though there are more than 100 Corchorus species2 in the Malvaceae family. Here we describe high-quality draft genomes of these two species and their comparisons at the functional genomics level to support tailor-designed breeding. The assemblies cover 91.6% and 82.2% of the estimated genome sizes for C. olitorius and C. capsularis, respectively. In total, 37,031 C. olitorius and 30,096 C. capsularis genes are identified, and most of the genes are validated by cDNA and RNA-seq data. Analyses of clustered gene families and gene collinearity show that jute underwent shared whole-genome duplication ∼18.66 million years (Myr) ago prior to speciation. RNA expression analysis from isolated fibre cells reveals the key regulatory and structural genes involved in fibre formation. This work expands our understanding of the molecular basis of fibre formation laying the foundation for the genetic improvement of jute. Bast (phloem) fibres are obtained from the stem of the plants such as jute, flax, hemp, ramie and kenaf. The annual global production of jute generates a farm value of ∼US$2.3 billion1. The cultivated species of jute, C. olitorius and C. capsularis, are morphologically and physiologically distinct (Supplementary Fig. 1), and a combination of useful traits from these species into a single genotype is highly desirable3. However, interspecific hybridization is limited because of their cross-incompatibility4,5. To facilitate comparative functional genomics and to understand the molecular basis of bast fibre biogenesis, genomes of two popular jute cultivars C. olitorius var. O-4 and C. capsularis var. CVL-1 are sequenced and analysed