1,277 research outputs found
Surface Characterization and Machining of Blind Pockets on Ti6Al4V by Abrasive Water Jet Machining
AbstractPresent work discusses the method of machining and characterization of blind pockets on Ti-6Al-4V alloy fabricated using Abrasive water jet machining (AWJM) by varying the process parameters; pressure, stand-off distance (SOD) and abrasive size. Depth of pockets was measured by coordinate measuring machine (CMM). Deeper pocket were formed at higher pressure; craters and high waviness were observed on machined surface. Surface waviness (SW) and craters sphericity were observed at many places of machined pocket through 3-D optical profilometer with objective lens (5x) and field of view (FOV 2x) along with the SPIP software. SW was found high at corners (side wall) of the pockets. Digital microscope of 230x and a scanning electron microscope (SEM) were used to observe and analyze the micro structure of the machined pockets
Suitability of commercially available Bacillus probiotics on growth, survival and production of black tiger shrimp (Penaeus monodon Fab.)
Different forms of Bacillus probiotics was assessed in the earthen ponds on tiger shrimp (Penaeus monodon) culture. The experiment was designed with three different treatments depending on the mode of application (T1=oral probiotics; T2=spreading probiotics and T3=oral+ spreading probiotics). The shrimp was cultured for 120 days with the stocking density of 6-PL/m².Oral probiotics in the respective ponds were supplied with feeds. Whereas, spreading probiotics was applied to the pond water during pond preparation at 30, 60 and 90 days of culture period. Results of the experiment revealed that, all forms of Bacillus probiotic had effective role to keep the culture environment friendly in terms of mineralization of organic matter, nitrogen and phosphorus content in bottom sediment; holding of water transparency in a congenial state, increasing the density of planktonic biomass and boosting the THB-Vibrio ratio in water and sediment with insignificance (p>0.05) difference between different treatments. Whilst, spreading form of Bacillus pro biotic showed higher weight gain (27.58±1.18g), survival rate (70.75±8.54%) and production (1167.66±109.62 kg/ha) and expected lower FCR (1.81 ±0.06) values with significant difference (p<0.01) with others methods of application, indicated its superiority in tiger shrimp culture
Evaluation of pre-jamming indication parameter during blind backfilling technique
AbstractHydraulic blind backfilling is used to reduce subsidence problems above old underground water-logged coal mines. This paper describes experimental research on a fully transparent model of a straight underground mine gallery. An automatic data acquisition system was installed in the model to continuously record the sand and water flowrates along with the inlet pressure of the slurry near the model's inlet. Pressure signature graphs and pressure loss curves with bed advancement under different flow conditions are examined. Pressure signature analyses for various flowrates and sand slurry concentrations are conducted to evaluate a pre-jamming indication parameter, which could be used to indicate the arrival of the final stage of filling
Designing Secure and Survivable Stegosystems
Steganography, the art and science of carrying out hidden communication, is an emergingsub-discipline of information security. Unlike cryptography, steganography conceals the existenceof a secret message by embedding it in an innocuous container digital media, thereby enablingunobstrusive communication over insecure channels. Detection and extraction of steganographiccontents is another challenge for the information security professional and this activity iscommonly known as steganalysis. Recent progress in steganalysis has posed a challenge fordesign and development of stegosystems with high levels of security and survivability. In thispaper, different strategies have been presented that can be used to escape detection and foilan eavesdropper having high technical capabilities as well as adequate infrastructure. Based onthe strength and weaknesses of current steganographic schemes, ideas have been progressedto make detection and destruction of hidden information more difficult
Liquid-gas phase transition in finite nuclei
In a finite temperature Thomas-Fermi framework, we calculate density
distributions of hot nuclei enclosed in a freeze-out volume of few times the
normal nuclear volume and then construct the caloric curve, with and without
inclusion of radial collective flow. In both cases, the calculated specific
heats show a peaked structure signalling a liquid-gas phase transition.
Without flow, the caloric curve indicates a continuous phase transition whereas
with inclusion of flow, the transition is very sharp. In the latter case, the
nucleus undergoes a shape change to a bubble from a diffuse sphere at the
transition temperature.Comment: Proc. of 6th Int. Conf. on N-N Collisions (Gatlinburg); Nuclear
Physics A (in press
Ytterbium doped nano-crystalline optical fiber for reduced photodarkening
We report suppression of photodarkening in Yb-doped nano-crystalline fibers in silica host. The photodarkening induced loss reduced by 20 times compared to Yb-doped aluminosilicate fibers. The laser efficiency of the nano-crystalline fiber was 79%
Rough Set-hypergraph-based Feature Selection Approach for Intrusion Detection Systems
Immense growth in network-based services had resulted in the upsurge of internet users, security threats and cyber-attacks. Intrusion detection systems (IDSs) have become an essential component of any network architecture, in order to secure an IT infrastructure from the malicious activities of the intruders. An efficient IDS should be able to detect, identify and track the malicious attempts made by the intruders. With many IDSs available in the literature, the most common challenge due to voluminous network traffic patterns is the curse of dimensionality. This scenario emphasizes the importance of feature selection algorithm, which can identify the relevant features and ignore the rest without any information loss. In this paper, a novel rough set κ-Helly property technique (RSKHT) feature selection algorithm had been proposed to identify the key features for network IDSs. Experiments carried using benchmark KDD cup 1999 dataset were found to be promising, when compared with the existing feature selection algorithms with respect to reduct size, classifier’s performance and time complexity. RSKHT was found to be computationally attractive and flexible for massive datasets
Private information, institutional distance, and the failure of cross-border acquisitions: Evidence from the banking sector in Central and Eastern Europe
In this paper, we develop an information theory-based framework about cross-border acquisitions in the financial intermediation industry. We argue that even though “soft” information embedded in customer relationships of local banks can, in principle, help multinational banks (MNBs) overcome informational disadvantage in host countries, the cost of verification of this private information may, paradoxically, make local banks with significant customer relationships unattractive for cross-border acquisition. Further, we propose that the relationship between the amount of customer information embedded in an incumbent bank and the likelihood of its acquisition by a MNB is modified by the institutional distance between the home and host countries of the MNB. Specifically, the strength of the negative relationship increases with institutional distance between home and host countries because it increases the verification cost of private information with institutional distance. Our hypotheses find support in the context of Central and Eastern Europe
Multi-wavelength fiber laser with erbium doped zirconia fiber and semiconductor optical amplifier
Multi-wavelength hybrid fiber lasers are demonstrated in both ring and linear cavities using a fabricated Erbium-doped Zirconia fiber (EDZF) and semiconductor optical amplifier (SOA) as gain media. In both configurations, the a fiber loop mirror, which is constructed using a 3 m long polarization maintaining fiber (PMF) and a polarization insensitive 3dB coupler is used as a comb filter for the fiber laser. In the ring cavity, 10 simultaneous lines with peak power above -26 dBm is obtained at 1550 nm region. This is an improvement compared to the linear cavity configuration which has only 5 simultaneous lines observed from wavelength 1556.1 nm to 1563.0 nm with the peak power above -40 dBm. Both hybrid lasers has a constant line spacing of 1.7 nm, which is suitable for wavelength division multiplexing and sensing applications and shows a stable operation at room temperature
An Outbreak of Cholera Associated with an Unprotected Well in Parbatia, Orissa, Eastern India
In November 2003, an outbreak (41 cases; attack rate–4.3%; no deaths) of severe diarrhoea was reported from a village in Orissa, eastern India. Thirteen of these cases were hospitalized. A matched case-control study was conducted to identify the possible exposure variables. Since all wells were heavily chlorinated immediately after the outbreak, water samples were not tested. The cases were managed symptomatically. Descriptive epidemiology suggested clustering of cases around one public well. Vibrio cholerae El Tor O1, serotype Ogawa was isolated from four of six rectal swabs. The water from the public well was associated with the outbreak (matched odds ratio: 12; 95% confidence interval 1.2–44.1). On the basis of these conclusions, access to the well was barred immediately, and it was protected. This investigation highlighted the broader use of field epidemiology methods to implement public-health actions guided by epidemiologic data to control a cholera epidemic
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