Ion beam induced enhanced diffusion from gold thin films in silicon

Enhanced diffusion of gold atoms into silicon substrate has been studied in Au thin films of various thicknesses (2.0, 5.3, 10.9 and 27.5 nm) deposited on Si(111) and followed by irradiation with 1.5 MeV Au2+ at a flux of 6.3x10^12 ions cm-2 s-1 and fluence up to 1x10^15 ions cm-2. The high resolution transmission electron microscopy measurements showed the presence of gold silicide formation for the above-mentioned systems at fluence greater than equal to 1x1014 ions cm-2. The maximum depth to which the gold atoms have been diffused at a fluence of 1x10^14 ions cm-2 for the cases of 2.0, 5.3, 10.9 and 27.5 nm thick films has been found to be 60, 95, 160 and 13 nm respectively. Interestingly, at higher fluence of 1x1015 ions cm-2 in case of 27.5 nm thick film, gold atoms from the film transported to a maximum depth of 265 nm in the substrate. The substrate silicon is found to be amorphous at the above fluence values where unusually large mass transport occurred. Enhanced diffusion has been explained on the basis of ion beam induced, flux dependent amorphous nature of the substrate, and transient beam induced temperature effects. This work confirms the absence of confinement effects that arise from spatially confined structures and existence of thermal and chemical reactions during ion irradiation.Comment: 15 pages, 3 figure

Zincovit syrup ameliorates oxidative stress induced by carbon tetrachloride in rats

Background: Zincovit (ZVT) syrup is a combined formulation of vitamins, minerals and lysine. The present study was aimed to investigate the in vivo antioxidant potential of ZVT syrup in carbon tetrachloride (CCl4) intoxicated Wistar rats.Methods: A total of 36 Wistar rats were divided into six groups of six rats each. Antioxidant potential of ZVT syrup at the dose of 15 mg/kg/day, 30 mg/kg/day and 60 mg/kg/day was evaluated in CCl4 intoxicated rats. The extent of CCl4 induced oxidative stress was studied by estimating malondialdehyde (MDA), glutathione-S-transferase (GST) and catalase (CAT).Results: Oral treatment with ZVT syrup, especially at the dose of 30 mg/kg/day and 60 mg/kg/day reversed CCl4 - induced alterations in MDA (p<0.05), GST (p<0.01) and CAT (p<0.01) compared to CCl4 intoxicated control (untreated) animals.Conclusion: The present findings revealed that ZVT syrup may be useful in oxidative stress associated tissue damage as a nutritional food supplement

Cepstrum Analysis: An Advanced Technique in Vibration Analysis of Defects in Rotating Machinery

Conventional frequency analysis in machinery vibration is not adequate to find out accurately defects in gears, bearings, and blades where sidebands and harmonics are present. Also such an approach is dependent on the transmission path. On the other hand, cepstrum analysis accurately identifies harmonics and sideband families and is a better technique available for fault diagnosis in gears, bearings, and turbine blades of ships and submarines. Cepstrum represents the global power content of a whole family of harmonics and sidebands when more than one family of sidebands are presents at the same time. Also it is insensitive to the transmission path effects since source and transmission path effects are additive and can be separated in cepstrum. The concept, underlying theory and the measurement and analysis involved for using the technique are briefly outlined. Two cases were taken to demonstrate advantage of cepstrum technique over the spectrum analysis. An LP compressor was chosen to study the transmission path effects and a marine gearbox having two sets of sideband families was studied to diagnose the problematic sideband and its severity

Flux dependent 1.5 MeV self-ion beam induced sputtering from Gold nanostructured thin films

We discuss four important aspects of 1.5 MeV Au2+ ion-induced flux dependent sputtering from gold nanostrcutures (of an average size 7.6 nm and height 6.9 nm) that are deposited on silicon substrates: (a) Au sputtering yield at the ion flux of 6.3x10^12 ions cm-2 s-1 is found to be 312 atoms/ion which is about five times the sputtering yield reported earlier under identical irradiation conditions at a lower beam flux of 10^9 ions cm-2 s-1, (b) the sputtered yield increases with increasing flux at lower fluence and reduces at higher fluence (1.0x10^15 ions cm-2) for nanostructured thin films while the sputtering yield increases with increasing flux and fluence for thick films (27.5 nm Au deposited on Si) (c) Size distribution of sputtered particles has been found to vary with the incident beam flux showing a bimodal distribution at higher flux and (d) the decay exponent obtained from the size distributions of sputtered particles showed an inverse power law dependence ranging from 1.5 to 2.5 as a function of incident beam flux. The exponent values have been compared with existing theoretical models to understand the underlying mechanism. The role of wafer temperature associated with the beam flux has been invoked for a qualitative understanding of the sputtering results in both the nanostructured thin films and thick films.Comment: 25 pages, 5 figures, 1 table To be Appeared in J. Phys. D: Appl. Phy

Universal Electro-Optical Hybrid Logic Gates

An Electro-Optical Hybrid Logic Gate is defined as a circuit which accepts either electrical or optical signals and produces both electrical and optical signals. This paper explores the feasibility to develop universal hybrid NOR and NAND gates which can be used for implementing any basic gate like AND, OR, or any complex logic function. These hybrid logic gates are proposed and implemented using phototransistors and LEDs. The logic circuits are found to be working satisfactorily for the defined logic levels

Studies on buried layer resistors

Multilayer thick-film technology is one of the important technologies adopted in the miniaturization of electronic systems. Generally, only interconnections are made in the intermediate layers. The possibility of fabricating resistors along with interconnections in the buried layers/intermediate layers using conventional thick-film materials has been examined in this study. The fabrication has been carried out by processing layer after layer. It has been found that the buried layer resistors exhibited a sheet resistivity lower than those fabricated as open resistors. This change in sheet resistivity has been attributed to multiple firings that the resistors undergo during the fabrication. This reduction in sheet resistivity has been found to be due to segregation of active materials. A model has been proposed to explain this change in sheet resistivity through segregation of the active material. The work reported in the paper clearly indicates that buried resistors with consistent values (+/-10%) can be fabricated using conventional materials. However, the design of the resistors has to be carried out using modified sheet resistivities. The model that is proposed also indicates how one can make a paste that is likely to exhibit the same sheet resistivity for buried resistors and open resistors. (C) 2002 Kluwer Academic Publishers

The selection of rain gauges and rainfall parameters in estimating intensity-duration thresholds for landslide occurrence: Case study from Wayanad (India)

© 2020 by the authors. Recurring landslides in theWestern Ghats have become an important concern for authorities, considering the recent disasters that occurred during the 2018 and 2019 monsoons. Wayanad is one of the highly affected districts in Kerala State (India), where landslides have become a threat to lives and properties. Rainfall is the major factor which triggers landslides in this region, and hence, an early warning system could be developed based on empirical rainfall thresholds considering the relationship between rainfall events and their potential to initiate landslides. As an initial step in achieving this goal, a detailed study was conducted to develop a regional scale rainfall threshold for the area using intensity and duration conditions, using the landslides that occurred during the years from 2010 to 2018. Detailed analyses were conducted in order to select the most effective method for choosing a reference rain gauge and rainfall event associated with the occurrence of landslides. The study ponders the effect of the selection of rainfall parameters for this data-sparse region by considering four different approaches. First, a regional scale threshold was defined using the nearest rain gauge. The second approach was achieved by selecting the most extreme rainfall event recorded in the area, irrespective of the location of landslide and rain gauge. Third, the classical definition of intensity was modified from average intensity to peak daily intensity measured by the nearest rain gauge. In the last approach, four different local scale thresholds were defined, exploring the possibility of developing a threshold for a uniform meteo-hydro-geological condition instead of merging the data and developing a regional scale threshold. All developed thresholds were then validated and empirically compared to find the best suited approach for the study area. From the analysis, it was observed that the approach selecting the rain gauge based on the most extreme rainfall parameters performed better than the other approaches. The results are useful in understanding the sensitivity of Intensity-Duration threshold models to some boundary conditions such as rain gauge selection, the intensity definition and the strategy of subdividing the area into independent alert zones. The results were discussed with perspective on a future application in a regional scale Landslide Early Warning System (LEWS) and on further improvements needed for this objective

Automated Agricultural System for Multipurpose Activities of Farmers

Agriculture plays vital role in the development of country. In India about 70% of population depends upon farming and one third of the nation’s capital comes from farming. Issues concerning agriculture have been always hindering the development of the country. The only solution to this problem is smart agriculture by modernizing the current traditional methods of agriculture. Agricultural tasks automation is significant in recent days to reduce the labor work and increase the yield of crop, efficiency and profit. The project aims on the design, development & the fabrication of the agricultural system which can plough the land, sow the seeds, water spray, pesticides spray, monitor the crops and soil, cut the cultivated crops, separate the grains from the crops, cut the grass. It also aims on upgrading of existing marketing methods. The whole agricultural system works with battery and controlled through Bluetooth technology. Various operations are performed in the agriculture field like seeding, weeding, waste plant cutting, plowing etc. Very basic operation is seeding, plowing & crop cutting. But the present method of seeding, plowing & crop cutting are problematic. The equipments used for seed sowing are very difficult and inconvenient to handle. The machine can be advanced for sowing seeds in farm with particular distance between seed is adjusted. In this project system direction is provided by using Software programming. The current warehouse management system fails to preserve the quality of the stored products overtime, monitor the temperature, humidity, theft and fire attacks in the warehouse. The project also includes smart warehouse management system which includes temperature and moisture maintenance, theft and fire detection in the warehouse and delivers the real time notifications through GSM without human intervention

Efficacy of zincoderm G cream against wound infection by Pseudomonas aeruginosa in Sprague-Dawley rats

Background: Zincoderm G cream is a fixed dose combination of clobetasol, gentamicin and zinc. Studies have been carried out for efficacy of each component such as clobetasol and gentamicin in bacterial infections, but as fixed dose combination including zinc has not been reported yet. Hence, a study was planned to assess the efficacy of Zincoderm G cream in experimental wound infection by Pseudomonas aerugionosa.Methods: In the experiment a total of 18 Sprague-Dawley rats (male, pathogen free, 6-8 weeks old) were used. The rats were divided into three groups of six rats each. 25-30 mg of test drugs (Zincoderm G cream with or without zinc) was applied on Pseudomonas aeruginosa infected burn wound affected area of back of rats for 2 weeks. Bacterial infection was assessed by quantification of bacteria.Results: There was 80% mortality observed in P. aeruginosa infected toxic control (cream base) group. Whereas, only 40% mortality was seen in both Zincoderm G cream with/without zinc groups, which were inoculated with P. aeruginosa. Bacterial concentration (Number of colony forming unit/ml wound fluid) was significantly decreased (p<0.001) in P. aeruginosa infected rats treated with Zincoderm G cream with zinc when compared with P. aeruginosa infected control (untreated) rats.Conclusions: We found that Zincoderm G cream with zinc exhibited distinct killing profiles against P. aeruginosa