26,199 research outputs found

    Emission Characteristics of the Projectile Fragments at Relativistic Energy

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    A projectile (84^Kr_36) having kinetic energy around 1 A GeV was used to expose NIKFI BR-2 emulsion target. A total of 700 inelastic events are used in the present studies on projectile fragments. The emission angle of the projectile fragments are strongly affected by charge of the other projectile fragments emitted at same time with different emission angle is observed. The angular distribution studies show symmetrical nature for lighter charge projectile fragments. The symmetrical nature decreased with the charge of projectile fragments. At ~4o of emission angle for double charge projectile fragments, the momentum transfer during interaction is similar for various target species of emulsion were observed. We also observed a small but significant amplitude peaks on both side of the big peak for almost all light charge projectile fragments having different delta angle values. It reflects that there are few percent of projectile fragments that are coming from the decay of heavy projectile fragments or any other process.Comment: 32 pages, 17 Figure

    Synoptic climatology of the daily 700 - mb summer monsoon flow pattern over India

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    The daily (mean of 0000 and 1200 GMT) 700 mb contour patterns over India are classified in five broad types for each summer monsoon month by using a chart-to-chart correlation method. Certain characteristics of these patterns, such as mutual transitions, persistence, preferred periods of occurrence and interrelationships are studied. Statistical probabilities of two threshold 24 h rainfall amounts (2.5 and 10 mm) being equated or exceeded for each type are computed for 107 stations, more or less uniformly distributed over India. This knowledge of the spatial distribution of precipitation probabilities associated with various circulation types can be used in forecasting probabilities of precipitation over the country if the circulation patterns can he forecast by numerical methods. These probabilities are then compared to the climatological and conditional probabilities of obtaining threshold rainfall amounts on different days of the subsequent 5-day period—given that the threshold rainfall occurred on the current day. The results, if averaged for all types and months, show that persistence is superior to the synoptic climatology developed in this study for forecasting precipitation probability for the next day over an regions and for forecasting precipitation probability up to 2–4 days—depending on region and threshold rainfall criteria. Synoptic climatology is superior to persistence as an aid for forecasting precipitation probability after 4 days over all the regions. Some shortcomings of the present study and future plans are described briefly

    Investigating IoT Middleware Platforms for Smart Application Development

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    With the growing number of Internet of Things (IoT) devices, the data generated through these devices is also increasing. By 2030, it is been predicted that the number of IoT devices will exceed the number of human beings on earth. This gives rise to the requirement of middleware platform that can manage IoT devices, intelligently store and process gigantic data generated for building smart applications such as Smart Cities, Smart Healthcare, Smart Industry, and others. At present, market is overwhelming with the number of IoT middleware platforms with specific features. This raises one of the most serious and least discussed challenge for application developer to choose suitable platform for their application development. Across the literature, very little attempt is done in classifying or comparing IoT middleware platforms for the applications. This paper categorizes IoT platforms into four categories namely-publicly traded, open source, developer friendly and end-to-end connectivity. Some of the popular middleware platforms in each category are investigated based on general IoT architecture. Comparison of IoT middleware platforms in each category, based on basic, sensing, communication and application development features is presented. This study can be useful for IoT application developers to select the most appropriate platform according to their application requirement

    CAN HEDGING AFFECT FIRM VALUE? AN OIL, GAS AND MINING PERSPECTIVE

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    Our paper investigates the impact of financial hedging on the firm value of a sample of mining, oil and gas companies that are publicly listed on the Toronto Stock Exchange. Employing a Tobin’s Q model for the sample of companies, the study finds that hedging does not significantly affect a firm’s valuation while other financial factors impact it in a statistically and economically significant manner. The results add further evidence to the current research literature that has reported contradictory empirical findings from prior research. Our observations are consistent with the school of thought that the firm valuation effect associated with hedging is insignificant. In these resource sectors, commodity price exposure is transparent and easy to hedge by investors, so there is no reason to expect that oil, gas and mining companies hedging their production price risk(s) should have higher firm values. &nbsp

    Phantom Friedmann Cosmologies and Higher-Order Characteristics of Expansion

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    We discuss a more general class of phantom (p<−ϱp < -\varrho) cosmologies with various forms of both phantom (w−1w -1) matter. We show that many types of evolution which include both Big-Bang and Big-Rip singularities are admitted and give explicit examples. Among some interesting models, there exist non-singular oscillating (or "bounce") cosmologies, which appear due to a competition between positive and negative pressure of variety of matter content. From the point of view of the current observations the most interesting cosmologies are the ones which start with a Big-Bang and terminate at a Big-Rip. A related consequence of having a possibility of two types of singularities is that there exists an unstable static universe approached by the two asymptotic models - one of them reaches Big-Bang, and another reaches Big-Rip. We also give explicit relations between density parameters Ω\Omega and the dynamical characteristics for these generalized phantom models, including higher-order observational characteristics such as jerk and "kerk". Finally, we discuss the observational quantities such as luminosity distance, angular diameter, and source counts, both in series expansion and explicitly, for phantom models. Our series expansion formulas for the luminosity distance and the apparent magnitude go as far as to the fourth-order in redshift zz term, which includes explicitly not only the jerk, but also the "kerk" (or "snap") which may serve as an indicator of the curvature of the universe.Comment: REVTEX 4, 23 pages, references updated, to appear in Annals of Physics (N.Y.

    Game On? Smoking Cessation Through the Gamification of mHealth: A Longitudinal Qualitative Study

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    BACKGROUND: Finding ways to increase and sustain engagement with mHealth interventions has become a challenge during application development. While gamification shows promise and has proven effective in many fields, critical questions remain concerning how to use gamification to modify health behavior. OBJECTIVE: The objective of this study is to investigate how the gamification of mHealth interventions leads to a change in health behavior, specifically with respect to smoking cessation. METHODS: We conducted a qualitative longitudinal study using a sample of 16 smokers divided into 2 cohorts (one used a gamified intervention and the other used a nongamified intervention). Each participant underwent 4 semistructured interviews over a period of 5 weeks. Semistructured interviews were also conducted with 4 experts in gamification, mHealth, and smoking cessation. Interviews were transcribed verbatim and thematic analysis undertaken. RESULTS: Results indicated perceived behavioral control and intrinsic motivation acted as positive drivers to game engagement and consequently positive health behavior. Importantly, external social influences exerted a negative effect. We identified 3 critical factors, whose presence was necessary for game engagement: purpose (explicit purpose known by the user), user alignment (congruency of game and user objectives), and functional utility (a well-designed game). We summarize these findings in a framework to guide the future development of gamified mHealth interventions. CONCLUSIONS: Gamification holds the potential for a low-cost, highly effective mHealth solution that may replace or supplement the behavioral support component found in current smoking cessation programs. The framework reported here has been built on evidence specific to smoking cessation, however it can be adapted to health interventions in other disease categories. Future research is required to evaluate the generalizability and effectiveness of the framework, directly against current behavioral support therapy interventions in smoking cessation and beyond

    Bed and suspended sediment-associated rare earth element concentrations and fluxes in a polluted Brazilian river system

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    Rare earth elements (REEs) have been recently recognized as emergent pollutants in rivers. However, data regarding REE fluxes in association with either bed or suspended are scarce. To address this knowledge gap, we determined the concentrations and fluxes of La, Ce, Pr, Nd, Sm, Eu, Gd, Yb, Lu, Dy, Er, Ho, Tb, and Tm in bed and suspended sediment samples of a representative polluted Brazilian River. Sediment-associated data on REEs were placed in the context of corresponding background concentrations in soils under natural conditions along the Ipojuca watershed. Light rare earth elements (LREEs) comprised more than 94% of the total REEs associated with bed and suspended sediments. Suspended sediments accounted for more than 95% of the total REE flux. The Ce and Nd fluxes of about 7 t year−1 underscore the importance of including REEs in future estimations of global suspended sediment-associated element fluxes. In contrast, bedload often transported less than 0.0007 t year−1 of each REE. The main sources of pollution in the Ipojuca River are anthropogenic, likely due to domestic effluent and waste water from industrial and agricultural operations—major causes of sediment-associated Gd transport in polluted streams
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