1,019 research outputs found

    Visible and infrared photocurrent enhancement in a graphene-silicon Schottky photodetector through surface-states and electric field engineering

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    The design of efficient graphene-silicon (GSi) Schottky junction photodetectors requires detailed understanding of the spatial origin of the photoresponse. Scanning-photocurrent-microscopy (SPM) studies have been carried out in the visible wavelengths regions only, in which the response due to silicon is dominant. Here we present comparative SPM studies in the visible (λ\lambda = 633nm) and infrared (λ\lambda = 1550nm) wavelength regions for a number of GSi Schottky junction photodetector architectures, revealing the photoresponse mechanisms for silicon and graphene dominated responses, respectively, and demonstrating the influence of electrostatics on the device performance. Local electric field enhancement at the graphene edges leads to a more than ten-fold increased photoresponse compared to the bulk of the graphene-silicon junction. Intentional design and patterning of such graphene edges is demonstrated as an efficient strategy to increase the overall photoresponse of the devices. Complementary simulations and modeling illuminate observed effects and highlight the importance of considering graphene's shape and pattern and device geometry in the device design

    A case study of corporate social responsibility in nashik MIDC

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    771/5" paper analyses Che awareness of corporate social responsibility in Nashik MIDC. It also helps to identify the awareness and effectiveness of existing environmental protection programs like Carbon emissions and treading among these companies.The study analyses the corporate responsibility with respect to Customers, Employees, Government, Environment and Society. The study involves opinions of corporate about, problems to implement corporate social responsibility. The study also involves case lets of major corporate in India like J K Tyre's, Infosys, Siemens, Tata group, Godrej Group, Mahindra And Mahindra and many more that are already implementing such programs. The result of the study indicates that in Nashik MIDC, there are few companies that are doing programs periodically. However, there are few companies, which feel that they cannot do these activities individually but there can be collective efforts. The study concludes that in addition to government agencies some management institutes should also take initiatives collectively to motivate and run such programs with these companies. It is found that Nashik Industrial Manufacturing Association (NIMA) are taking lead and arranging social programs for society.Though big Indian companies have started practicing corporate citizenship, the degree to which it is belong done is inadequate. Growing awareness among the academic institutions towards CSR as a subject, to sensitize the future managers of this nation to the societal needs besides generating profits for their organizations with increased efficiency will need a greater deal from the managers to do the balancing act. Keywords

    Development of technology for modified starch incorporated grains and pulse blended bakery and pasta products

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    The study aimed to investigate the appropriate technology for the development of modified starch and standardize the millet-based bakery and pasta products incorporated with modified starch and measure the glycemic index of the standardized therapeutic baked and pasta products. The physical modification and chemical modification techniques were performed to optimize the technology for modified starch. Refined wheat flour was substituted with millet flour, modified starch and pulse flour at various percentages to optimize the flour blend for pasta and bakery products. The products were subjected to in vitro study to measure the glycemic index. Physical modification technique, i.e. autoclave-cooling, was found to be optimum for the development of modified starch. The optimum flour blend for pasta products was whole wheat flour(50%), millet flour (25 and 50%), cassava modified starch (15 and 25%) and green ram flour (10%) and it was found to be acceptable without affecting its sensory attributes. The optimum blend for bread was whole wheat flour (50%), kodo / barnyard millet flour (50%) with cassava modified starch (10%) and for low-fat cookies, it was millet flour (20%) and modified starch (15 %). Among the three pasta products, noodles and macaroni were found to be highly acceptable with minimum cooking loss. The in vitro study showed that the pasta products have a hypoglycemic effect suitable for lifestyle disorder patients and do not involve high production costs and earn good returns to the entrepreneurs

    Preparation and characterization of MAO-Si3N4 composite coating on AZ31B magnesium alloy

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    Micro arc oxidation process was carried out on AZ 31 B magnesium alloy using alkaline silicate based bath at a constant current density of 0.04 A/cm2. Nano size silicon nitride (Si3N4) particles were added in the bath to obtain MAO- Si3N4 composite coatings. Plain oxide coatings were also prepared for comparison. The developed coatings were characterised for their surface morphology, composition, structure, roughness, nanohardness and wear resistance properties. Field Emission Scanning Electron Microscopy (FE-SEM) analysis of the coating exhibited the irregular porous structure with cracked morphology. Energy Dispersive Analysis of X-ray (EDX) over the surface of the composite coating showed the presence of O (42.8 wt.%), Si (13.2 wt.%), F (4.8 wt.%), Al (0.63 wt.%) and N (7.8 wt.%) with balance Mg respectively. XRD pattern obtained for composite coating revealed the characteristic peaks corresponding to Mg, MgO and Mg2SiO4. Apart from these peaks the presence of a low intensity peak corresponding to Si3N4 was also observed. Composite coating exhibited about 56% increase in nanohardness value (387 HV) compared to plain oxide coating (167 HV). Dry reciprocating wear test experiment was carried out for composite, plain oxide and substrate materials against alumina ball. Wear loss obtained for the composite is 3 times less (10 µms) compared to plain oxide coating which indicated improved wear resistance of the MAO-Si3N4 composite

    Muon-induced neutrons do not explain the DAMA data

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    We present an accurate model of the muon-induced background in the DAMA/LIBRA experiment. Our work challenges proposed mechanisms which seek to explain the observed DAMA signal modulation with muon-induced backgrounds. Muon generation and transport are performed using the MUSIC/MUSUN code, and subsequent interactions in the vicinity of the DAMA detector cavern are simulated with Geant4. We estimate the total muon-induced neutron flux in the detector cavern to be Φnν=1.0×109\Phi_n^\nu = 1.0\times10^{-9} cm2^{-2} s1^{-1}. We predict 3.49×1053.49\times10^{-5} counts/day/kg/keV, which accounts for less than 0.3%0.3\% of the DAMA signal modulation amplitude.Comment: 6 pages, 4 figures, accepted for publication in PR

    Detection of algorithmically generated malicious domain names using masked N-grams

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    Malware detection is a challenge that has increased in complexity in the last few years. A widely adopted strategy is to detect malware by means of analyzing network traffic, capturing the communications with their command and control (C&C) servers. However, some malware families have shifted to a stealthier communication strategy, since anti-malware companies maintain blacklists of known malicious locations. Instead of using static IP addresses or domain names, they algorithmically generate domain names that may host their C&C servers. Hence, blacklist approaches become ineffective since the number of domain names to block is large and varies from time to time. In this paper, we introduce a machine learning approach using Random Forest that relies on purely lexical features of the domain names to detect algorithmically generated domains. In particular, we propose using masked N-grams, together with other statistics obtained from the domain name. Furthermore, we provide a dataset built for experimentation that contains regular and algorithmically generated domain names, coming from different malware families. We also classify these families according to their type of domain generation algorithm. Our findings show that masked N-grams provide detection accuracy that is comparable to that of other existing techniques, but with much better performance

    A study of Metabolic Syndrome in Psoriatic Patients

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    Psoriasis is a chronic immune mediated inflammatory disorder of the skin and joints. Recent studies have shown increased prevalence of traditional cardiovascular risk factors such as diabetes mellitus, hypertension and metabolic syndrome. Thyroid gland hormones cause an increase of epidermal growth factor level which has an important role in keratinocyte proliferation, which may be involved in psoriasis disease. AIMS & OBJECTIVES: To study the relationship between psoriasis and metabolic syndrome and to correlate the same with thyroid profile. MATERIALS AND METHODS: This study was conducted in Chennai Medical College Hospital and Research Centre, Irungalur, Trichy. Hundred psoriatic patients in the age group of 20-80 years in, and 30 controls were selected for this study. Fasting blood glucose by GLUCOSE OXIDASE AND PEROXIDASE method, serum lipid profile by enzymatic method and serum thyroid profile by ENZYME LINKED IMMUNOSORBANT ASSAY method. RESULTS: Our study shows that prevalence of metabolic syndrome in cases of psoriasis to be out of 37%, compared to controls among patients with other dermatological conditions to be 3.3%, (p <0.001) and shows the FT3 (pg/ml) in cases Mean to be 2.117 and in Controls Mean was 2.037, Mean difference (0.0803), p value (0.53) .Shows the mean of FT4 (pg/ml) in cases Mean (1.284), Controls Mean (1.303),and the Mean difference was (-0.0193), p value (0.809) likewise TSH (mIU/ml) in cases Mean to be (3.580), in Controls Mean (2.277), and the Mean difference was (1.303), p value (0.001). CONCLUSION: Patients of psoriasis have higher prevalence of metabolic syndrome and subclinical hypothyroidism than general population. Therefore identification of metabolic syndrome and thyroid profile testing can be done routinely for better management of psoriasis

    An invitro antimicrobial activity and Bioactivities of Protein Isolated from Marine Sponge – Callyspongia sp.

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    The marine sponge Callyspongia sp, collected from Mandapam coast, Tamilnadu, was studied for antibacterial and antifungal activity of proteins. Sponge species were identified based on spicules morphology. Chloroform and aqueous extracts of Callyspongia sp yielded a total amount of 4.8g and 5.98g from 500g of sponge respectively. Crude protein obtained from marine sponge aqueous extract was 2.1 mg/ml and that of chloroform extract was 0.9 mg/ml. The antimicrobial activity of chloroform extract and aqueous extract showed clear inhibition zone against Pseudomonas sp. Vibrio cholerae, Aspergillus niger and Candida albicans. Both the extracts exhibited hemolytic activity which was estimated as 10.1ht/ml for chloroform extract and 8.6ht/ml for aqueous extract. The partial purification of protein was carried out using DEAE cellulose. On SDS-PAGE the crude protein yielded three well defined bands at 109.9, 28.2, 12.4 KDa respectively by both the extracts
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