Study of Impact of Dispersion of Gases From Stack on Environment Through CFD Simulation

The main objective is to analyse the dispersion of gases emitted under different conditions of mass flow rate at the exit and ambient crossflow velocity by using software ANSYS. Main focus id to find out whether designed boiler stack can disperse atmospheric pollutants away from city or surroundings where the boiler is installed. Dispersion modelling includes means of calculating ambient ground level concentrations of emitted substances, considering the information like meteor ological data, pollutants flow rates and terrain data of area. This modelling is done to assess that the Ground level concentrations (GLC) of atmospheric pollutants owing to emissions from boiler stack are less than applicable ambient air quality standard

AdSplit: Separating smartphone advertising from applications

A wide variety of smartphone applications today rely on third-party advertising services, which provide libraries that are linked into the hosting application. This situation is undesirable for both the application author and the advertiser. Advertising libraries require additional permissions, resulting in additional permission requests to users. Likewise, a malicious application could simulate the behavior of the advertising library, forging the user's interaction and effectively stealing money from the advertiser. This paper describes AdSplit, where we extended Android to allow an application and its advertising to run as separate processes, under separate user-ids, eliminating the need for applications to request permissions on behalf of their advertising libraries. We also leverage mechanisms from Quire to allow the remote server to validate the authenticity of client-side behavior. In this paper, we quantify the degree of permission bloat caused by advertising, with a study of thousands of downloaded apps. AdSplit automatically recompiles apps to extract their ad services, and we measure minimal runtime overhead. We also observe that most ad libraries just embed an HTML widget within and describe how AdSplit can be designed with this in mind to avoid any need for ads to have native code

Local Co-location Pattern Detection: A Summary of Results

Given a set of spatial objects of different features (e.g., mall, hospital) and a spatial relation (e.g., geographic proximity), the problem of local co-location pattern detection (LCPD) pairs co-location patterns and localities such that the co-location patterns tend to exist inside the paired localities. A co-location pattern is a set of spatial features, the objects of which are often related to each other. Local co-location patterns are common in many fields, such as public security, and public health. For example, assault crimes and drunk driving events co-locate near bars. The problem is computationally challenging because of the exponential number of potential co-location patterns and candidate localities. The related work applies data-unaware or clustering heuristics to partition the study area, which results in incomplete enumeration of possible localities. In this study, we formally defined the LCPD problem where the candidate locality was defined using minimum orthogonal bounding rectangles (MOBRs). Then, we proposed a Quadruplet & Grid Filter-Refine (QGFR) algorithm that leveraged an MOBR enumeration lemma, and a novel upper bound on the participation index to efficiently prune the search space. The experimental evaluation showed that the QGFR algorithm reduced the computation cost substantially. One case study using the North American Atlas-Hydrography and U.S. Major City Datasets was conducted to discover local co-location patterns which would be missed if the entire dataset was analyzed or methods proposed by the related work were applied

Plan to Fail

PresentationThe process industry has widely adopted the Functional Safety Standards IEC61508 [1] and IEC61511 [2] for achieving the Functional Safety. These standards lay the framework for achieving functional safety by considering the entire life-cycle of the safety instrumented system (SIS). Typical SIS safety life-cycle phases and functional safety assessment stages are illustrated in Figure-7 of IEC61511-1 [2]. The design and engineering of the SIS are most often focused on achieving the required risk reduction for the safety instrumented functions (SIF). However, with this single minded focus, the design and engineering of the SIS frequently progresses without a well thought out safety plan. “By failing to prepare, you are preparing to fail – Benjamin Franklin”. Taking cues from this quote, this paper, “Plan to Fail?” intends to draw attention to importance of having a well understood ‘Safety Plan’ in place. The standards provide guidance for the development of a safety plan. However it is imperative for the functional safety team to ensure that it is aligned with the particular project under consideration. This means establishing goals and concepts early in the project schedule. The plan would then be updated as more details are known and hence be more effectively deployed during each phase of the safety life-cycle

CFD analysis of heat transfer in a helical coil heat exchanger using fluent

This thesis focuses on the CFD analysis of flow of fluid through a helical coil heat exchanger. Also on the enhancement in convective heat transfer in between the fluid and the surrounding surface in these helical coils which has been a major topic of study as reported by many researchers. As helical coil have compact size and higher heat transfer coefficient they are widely used in industrial applications such as power generation, nuclear industry, process plant, refrigeration, food industry, etc. In this study, an attempt has been made to study the parallel flow and counter flow of inner hot fluid flow and outer cold fluid flow, which are separated by copper surface in a helical coil heat exchanger. The temperature contours, velocity vectors, total pressure contours, total heat dissipation rate from the wall of the tube were calculated and plotted using ANSYS 13.0. Copper was used as the base metal for the inner and outer pipe and the fluid was taken as hot water for inner flow and cold water for outer flow

Simulation of an Adsorption Column for The Removal of Ethyl Acetate From Air

Adsorption of a toxic VOC, ethyl acetate is studied. The adsorbent used for this study is granular activated carbon. The adsorption isotherms are obtained at four distinct temperatures of 30, 35, 45, and 55o C. The physical properties of the adsorbent is provided by E-merck India. The Langmuir parameters and other data required in the simulations for this study are taken from Manjare & Ghoshal [2] [13]. The results are in agreement with that provided in Manjare & Ghoshal. The equation of state chosen for the modelling is Peng-Robinson equation of state and the momentum balance equation used is Ergun equation, best suited for both laminar and turbulent flow. The assumptions made while developing the mathematical model of the adsorption process include adiabatic and isothermal processes. The driving force is assumed to be linear. Results show that the isotherm best checks with the Langmuir isotherm model. The saturation capacity of the activated carbon varies from 0.73 to 0.487 kg/kg. The molecular diffusivity of the components is of the order of 10-6 m2/

Separating Smartphone advertising from applications

A wide variety of smartphone applications today rely on third-party advertising services, which provide libraries that are linked into the hosting application. This situation is undesirable for both the application author and the advertiser. Advertising libraries require additional permissions, resulting in additional permission requests to users. Likewise, a malicious application could simulate the behavior of the advertising library, forging the user's interaction and effectively stealing money from the advertiser. This thesis describes AdSplit, where we extended Android to allow an application and its advertising to run as separate processes, under separate user-ids, eliminating the need for applications to request permissions on behalf of their advertising libraries. We also leverage mechanisms from QUIRE to allow the remote server to validate the authenticity of client-side behavior. In this thesis, we quantify the degree of permission bloat caused by advertising, with a study of thousands of downloaded apps. AdSplit automatically recompiles apps to extract their ad services, and we measure minimal runtime overhead. We also observe that most ad libraries just embed an HTML widget within and describe how AdSplit can be designed with this in mind to avoid any need for ads to have native code

Quire: Lightweight Provenance for Smart Phone Operating Systems

Smartphone apps often run with full privileges to access the network and sensitive local resources, making it difficult for remote systems to have any trust in the provenance of network connections they receive. Even within the phone, different apps with different privileges can communicate with one another, allowing one app to trick another into improperly exercising its privileges (a Confused Deputy attack). In Quire, we engineered two new security mechanisms into Android to address these issues. First, we track the call chain of IPCs, allowing an app the choice of operating with the diminished privileges of its callers or to act explicitly on its own behalf. Second, a lightweight signature scheme allows any app to create a signed statement that can be verified anywhere inside the phone. Both of these mechanisms are reflected in network RPCs, allowing remote systems visibility into the state of the phone when an RPC is made. We demonstrate the usefulness of Quire with two example applications. We built an advertising service, running distinctly from the app which wants to display ads, which can validate clicks passed to it from its host. We also built a payment service, allowing an app to issue a request which the payment service validates with the user. An app cannot not forge a payment request by directly connecting to the remote server, nor can the local payment service tamper with the request

Capacity Constrained Routing Algorithms for Evacuation Route Planning

Efficient tools are needed to identify routes and schedules to evacuate affected populations to safety in face of natural disasters or terrorist attacks. Challenges arise due to violation of key assumptions (e.g. stationary ranking of alternative routes, Wardrop equilibrium) behind popular shortest path algorithms (e.g. Dijktra\u27s, A*) and microscopic traffic simulators (e.g. DYNASMART). Time-expanded graphs (TEG) based mathematical programming paradigm does not scale up to large urban scenarios due to excessive duplication of transportation network across time-points. We present a new approach, namely Capacity Constrained Route Planner (CCRP), advancing ideas such as Time-Aggregated Graph (TAG) and an ATST function to provide earliest-Arrival-Time given any Start-Time. Laboratory experiments and field use in Twincities for DHS scenarios (e.g. Nuclear power plant, terrorism) show that CCRP is much faster than the state of the art. A key Transportation Science insight suggests that walking the first mile, when appropriate, may speed-up evacuation by a factor of 2 to 3 for many scenarios. Geographic Information Science (e.g. Time Geography) contributions include a novel representation (e.g. TAG) for spatio-temporal networks. Computer Science contributions include graph theory limitations (e.g. non-stationary ranking of routes, non-FIFO behavior) and scalable algorithms for traditional routing problems in time-varying networks, as well as new problems such as identifying the best start-time (for a given arrival-time deadline) to minimize travel-time