40 research outputs found

    Direct bandgap materials based on the thin films of SexTe100 - x nanoparticles

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    In this study, we fabricated thin films of Se(x)Te(100 − x) (x = 0, 3, 6, 9, 12, and 24) nanoparticles using thermal evaporation technique. The results obtained by X-ray diffraction show that the as-synthesized nanoparticles have polycrystalline structure, but their crystallinity decreases by increasing the concentration of Se. They were found to have direct bandgap (E(g)), whose value increases by increasing the Se content. These results are completely different than those obtained in the films of Se(x)Te(100 − x) microstructure counterparts. Photoluminescence and Raman spectra for these films were also demonstrated. The remarkable results obtained in these nanoparticles specially their controlled direct bandgap might be useful for the development of optical disks and other semiconductor devices

    Classification and evaluation of digital forensic tools

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    Digital forensic tools (DFTs) are used to detect the authenticity of digital images. Different DFTs have been developed to detect the forgery like (i) forensic focused operating system, (ii) computer forensics, (iii) memory forensics, (iv) mobile device forensics, and (v) software forensics tools (SFTs). These tools are dedicated to detect the forged images depending on the type of the applications. Based on our review, we found that in literature of the DFTs less attention is given to the evaluation and analysis of the forensic tools. Among various DFTs, we choose SFTs because it is concerned with the detection of the forged digital images. Therefore,the purpose of this study is to classify the different DFTs and evaluate the software forensic tools (SFTs) based on the different features which are present in the SFTs. In our work, we evaluate the following five SFTs, i.e.,“FotoForensics”, “JPEGsnoop”, “Ghiro”, “Forensically”, and “Izitru”, based on different features so that new research directions can be identified for the development of the SFTs

    An incidentally discovered asymptomatic para-aortic paraganglioma with Peutz-Jeghers syndrome

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    Peutz-Jeghers syndrome (PJS) is an autosomal dominant inherited disorder characterized by mucocutaneous melanin pigmentation and gastrointestinal (GI) tract hamartomatous polyps and an increased risk of malignancy. In addition to polyposis, previous studies have reported increased risk of GI and extraGI malignancies in PJS patients, compared with that of the general population. The most common extraintestinal malignancies reported in previous studies are pancreatic, breast, ovarian and testicular cancers.We report the case of a 17-year-old boy who presented with generalized weakness, recurrent sharp abdominal pain and melena, had exploratory laparotomy and ileal resection for ileo-ileal intussusception. Pigmentation of the buccal mucosa was noted. An abdominal computed tomography scan (CT) revealed multiple polyps in small bowel loops. Gastroscopy revealed multiple dimunitive polyps in stomach and pedunculated polyp in duodenum. Colonoscopy revealed multiple colonic polyps. Pathological examination of the polyps confirmed hamartomas with smooth muscle arborization, compatible with Peutz-Jeghers polyps. CT scan guided left para-aortic lymph node biopsy revealed the characteristic features of extra-adrenal para-aortic paraganglioma. Although cases of various GI and extra GI malignancies in PJS patients has been reported, the present case appears to be the first in literature in which the PJS syndrome was associated with asymptomatic extraadrenal para-aortic paraganglioma. Patients with PJS should be treated by endoscopic or surgical resection and need whole-body screening

    High-energy ball milling technique for ZnO nanoparticles as antibacterial material

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    Nanoparticles of zinc oxide (ZnO) are increasingly recognized for their utility in biological applications. In this study, the high-energy ball milling (HEBM) technique was used to produce nanoparticles of ZnO from its microcrystalline powder. Four samples were ball milled for 2, 10, 20, and 50 hours, respectively. The structural and optical modifications induced in the ‘as synthesized’ nanomaterials were determined by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), and photoluminescence emission spectra (PL). SEM and TEM results show a gradual decrease in particle size from around 600 to ∌30 nm, with increased milling time. The initial microstructures had random shapes, while the final shape became quite spherical. XRD analysis showed ZnO in a hexagonal structure, broadening in the diffracted peaks and going from larger to smaller particles along with a relaxation in the lattice constant c. The value of c was found to increase from 5.204 to 5.217 Å with a decrease in particle size (600 to ∌30 nm). PL result showed a new band at around 365 nm, whose intensity is found to increase as the particles size decreases. These remarkable structural and optical modifications induced in ZnO nanoparticles might prove useful for various applications. The increase in c value is an important factor for increasing the antibacterial effects of ZnO, suggesting that the HEBM technique is quite suitable for producing these nanoparticles for this purpose

    Liver-boosting potential: chicory compound-mediated silver nanoparticles for hepatoprotection—biochemical and histopathological insights

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    Background: Liver disease is a serious health concern in today’s world, posing a challenge to both healthcare providers and pharmaceutical companies. Most synthetic drugs and chemicals cause liver damage accounting for approximately 10% of acute hepatitis and 50% of acute liver failure.Purpose: The present study aimed to evaluate the hepato-protective activity of an extract of chicory formulation assisted by silver nanoparticles against carbon tetra chloride (CCl4)-induced hepatic damage in rat’s liver.Methods: Rats of the Wistar strain (Rattus norvegicus) were used to test the in vivo hepato-protective efficacy at various doses. Rats were randomly divided into nine groups, each containing six rats. The groups were as follows: first group (control), second group (CCl4), third group, silymarin (20 mg/kg of body weight), fourth group (CCl4+chicory) (1.75 mg/kg of b. wt), fifth group (CCl4 + chicory at the dose of 2.35 mg/kg), sixth group (CCl4 + chicory of 3.25 mg/kg), seventh group (CCl4 +AgNPs 1.75 mg/kg of b. wt.), eighth group (CCl4 + AgNPs 2.35 mg/kg of body weight), and ninth group (CCl4 + AgNPs 3.25 mg/kg of b. wt.). Blood samples were taken 24 h after the last administration (i.e., 30th day). The blood samples were analyzed for different serum enzymes such as ALP (alkaline phosphatase), ALT (alanine transaminase), bilirubin (Blr), triglyceride, and cholesterol. Histology liver sections were performed.Results: Treatment with AgNPs and chicory extract showed significant hepato-protective activity in a dose-dependent manner. In three doses, the chicory extract at a rate of 3.25 mg/kg of body weight significantly reduced elevated levels of biochemical markers in comparison to CCl4-intoxicated rats. Histology of the liver sections from CCl4-treated rats revealed inflammation of hepatocytes, necrosis, cytoplasmic degeneration, vacuolization, and a deformed central vein. The chicory formulation extract exhibited a remarkable recovery percentage in the liver architecture that was higher than the drug (i.e., silymarin). While treatment with AgNPs also repaired the degenerative changes and restored the normal form of the liver, chicory formulation extract possessed more hepato-protective potential as compared to AgNPs by regulating biochemical and histo-pathological parameters.Conclusion: This study can be used as confirmation of the hepato-protective potential of chicory compounds for possible use in the development programs of drugs to treat liver diseases

    Effect of Composition on Electrical and Optical Properties of Thin Films of Amorphous GaxSe100−x Nanorods

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    We report the electrical and optical studies of thin films of a-GaxSe100−x nanorods (x = 3, 6, 9 and 12). Thin films of a-GaxSe100−x nanorods have been synthesized thermal evaporation technique. DC electrical conductivity of deposited thin films of a-GaxSe100−x nanorods is measured as a function of temperature range from 298 to 383 K. An exponential increase in the dc conductivity is observed with the increase in temperature, suggesting thereby a semiconducting behavior. The estimated value of activation energy decreases on incorporation of dopant (Ga) content in the Se system. The calculated value of pre-exponential factor (σ0) is of the order of 101 Ω−1 cm−1, which suggests that the conduction takes place in the band tails of localized states. It is suggested that the conduction is due to thermally assisted tunneling of the carriers in the localized states near the band edges. On the basis of the optical absorption measurements, an indirect optical band gap is observed in this system, and the value of optical band gap decreases on increasing Ga concentration

    Advances in nanomaterials

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    This book provides a review of the latest research findings and key applications in the field of nanomaterials. The book contains twelve chapters on different aspects of nanomaterials. It begins with key fundamental concepts to aid readers new to the discipline of nanomaterials, and then moves to the different types of nanomaterials studied. The book includes chapters based on the applications of nanomaterials for nano-biotechnology and solar energy. Overall, the book comprises chapters on a variety of topics on nanomaterials from expert authors across the globe. This book will appeal to researchers and professional alike, and may also be used as a reference for courses in nanomaterials

    Carbon nanotube and its possible applications

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    529-551Carbon nanotubes are the closed tabular structures consisting of nested cylindrical graphitic layers capped by fullerene-like ends with a hollow internal cavity, which were first discovered by Iijima in 1991. It consists of either one cylindrical graphene sheet, i.e., single-wall nanotube (SWNT)) or of several nested cylinders with an interlayer spacing of 0.34-0.36 nm, i.e., multiwall nanotube (MWNT)). The lengths of SWNTs and MWNTs are usually well over 1 m and diameters range from ~1 nm (for SWNTs) to ~50 nm (for MWNTs). SWNTs are usually closed at both ends by fullerene-like half spheres that contain both pentagons and hexagons. Carbon nanotubes show exceptional electronic and mechanical properties. They are flexible but very hard to stretch and have extremely low turn-on fields and high current densities ranking them among the best electron field emitters for future field emission displays. This article presents an overview of current state of research on carbon nanotubes. In this review, we have focused on different synthesis routes for carbon nanotubes growth, used during last 12 years and possible future applications of carbon nanotubes especially in fuel cell and field emission displays. We have also discussed various parametric studies reported by several groups and extracted from their observations the common factors, which seem to be important towards a controlled production of carbon nanotubes. The limitations of these approaches, compatibility between an up-scaled production, the quality of the grown nanotube materials as well as the question of an economic production, have also been addressed
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