8,811 research outputs found

    Seismic vulnerability assessment and evaluation of high rise buildings in Islamabad

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    Primarily the aim of this research is to carry out seismic evaluation study of buildings structures in Islamabad in order to propose basic guidelines and suggestions for Pakistan Code. Knowing the important nature of the subject, the earthquake based organizations are serious to compile a document for seismic threatened countries and areas. It is aimed that the document will work as a guideline source for the seismic evaluation, calculation and assessment of strength, behavior and expected performance and also the safety of already existing buildings. This study is based on review of already available documents on seismic vulnerability and evaluation of present buildings at different sites is carried out in order to know the key components of this very procedure so that it can be used in Pakistan and also in other developing countries as well. This would not only be robust, safe and reliable, but also can be convenient to use within the domain of available resources. ASCE 31-03 guidelines among the available documents are considered to be a suitable and the most reliable for to be in Pakistan

    Observational Constraints on Phantom Crossing DGP Gravity

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    We study the observational constraints on the Phantom Crossing DGP model. We demonstrate that the crossing of the phantom divide does not occur within the framework of the original Dvali-Gabadadze-Porrati (DGP) model or the DGP model developed by Dvali and Turner. By extending their model in the framework of an extra dimension scenario, we study a model that realizes crossing of the phantom divide. We investigate the cosmological constraints obtained from the recent observational data of Type Ia Supernovae, Cosmic Microwave Background anisotropies, and Baryon Acoustic Oscillations. The best fit values of the parameters with 1σ\sigma (68%) errors for the Phantom Crossing DGP model are Ωm,0=0.270.02+0.02\Omega_{m,0}=0.27^{+0.02}_{-0.02}, β=0.540.30+0.24\beta=0.54^{+0.24}_{-0.30}. We find that the Phantom Crossing DGP model is more compatible with the observations than the original DGP model or the DGP model developed by Dvali and Turner. Our model can realize late-time acceleration of the universe, similar to that of Λ\LambdaCDM model, without dark energy due to the effect of DGP gravity. In our model, crossing of the phantom divide occurs at a redshift of z0.2z \sim 0.2.Comment: 17 pages, 9 figures, 1 table, Accepted for publication in International Journal of Modern Physics

    Experimental and numerical evaluation of cured in place pipe lining system for high temperature applications in sewer pipes

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    Some of the older cities across North America and Europe had been using steam driven HVAC systems since beginning of the last century. Consolidated Edison (Con Ed.) of New York operates the New York City steam system, the largest commercial district heating system in the world, with more than 100 miles of transmission and distribution pipes serving Manhattan Island. Other steam district systems exist in San Francisco, Harrisburg, Minneapolis, Pittsburgh, San Diego, and Detroit, some dating back to 1903. In those cities the sewer pipes are used as venues for discharging the waste steam condensate from the HVAC system. The city of New York is considering the rehabilitation of the Time Square, including the near-by sewer pipes which pass beneath the subway station and/or along the concrete wall. Rehabilitation of these sewer pipes requires trenchless technique, installation of CIPP liners. Therefore, in the event of a malfunction of the aging steam system and failed steam trap, the sewer pipes lined with CIPP liners might be subjected to direct steam injection and the temperature may soar as high as 212°F. The presence of steam and the associated elevated temperature inside the lined pipe could result in an environment, incompatible with standard CIPP lining products. The main objective achieved within the first phase of the research was to experimentally determine the thermal effects on the aging of resin used in CIPP liner. Therefore, the resins expected to perform well under prolonged exposure to elevated temperature (up to 212°F) were identified first. Total 1890 specimens (ASTM D638 and ASTM D790) were prepared using epoxy, vinyl ester and polyester resin which were subjected to cyclic thermal loading (maximum 540 cycles intermittently changing between 90°F and 212°F). Next the specimens were tested to obtain the modulus of elasticity value and stress-strain curve; thus to indentify the best resin to serve at elevated cyclic temperature. Raman spectroscopy, a technique used for studying the chemical composition and chemical bonds of materials, was also used to provide more fundamental understanding of the degradation of the resin materials at the molecular level. It was found that vinyl ester and epoxy resin performs better at elevated temperature application than polyester resin, although polyester resin is used in more than 90 percent of the CIPP projects as it is economical. Another objective completed at the second phase was to evaluate the stresses generated due to the thermal strain on the full scale specimens. At this phase CIPP liners were impregnated using the best two resin types performed at elevated cyclic temperature in the phase one and full scale specimens were prepared by lining steel host pipe. The full scale specimens were kept inside custom built oven and cyclic thermal load was applied. Stresses generated on the specimen due to thermal loading were observed by analyzing strain gage data. It was found that stresses developed in the liners impregnated with vinyl ester resin were significantly lower in comparison to the liners impregnated with the epoxy resin. In the third phase, numerical simulation of the effect of high temperature on a CIPP liner was performed and parametric study was carried out to compare and validate the results obtained in the second phase

    On entropy, specific heat, susceptibility and Rushbrooke inequality in percolation

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    We investigate percolation, a probabilistic model for continuous phase transition (CPT), on square and weighted planar stochastic lattices. In its thermal counterpart, entropy is minimally low where order parameter (OP) is maximally high and vice versa. Besides, specific heat, OP and susceptibility exhibit power-law when approaching the critical point and the corresponding critical exponents α,β,γ\alpha, \beta, \gamma respectably obey the Rushbrooke inequality (RI) α+2β+γ2\alpha+2\beta+\gamma\geq 2. Their analogues in percolation, however, remain elusive. We define entropy, specific heat and redefine susceptibility for percolation and show that they behave exactly in the same way as their thermal counterpart. We also show that RI holds for both the lattices albeit they belong to different universality classes.Comment: 5 pages, 3 captioned figures, to appear as a Rapid Communication in Physical Review E, 201

    Transient engine model for calibration using two-stage regression approach

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    Engine mapping is the process of empirically modelling engine behaviour as a function of adjustable engine parameters, predicting the output of the engine. The aim is to calibrate the electronic engine controller to meet decreasing emission requirements and increasing fuel economy demands. Modern engines have an increasing number of control parameters that are having a dramatic impact on time and e ort required to obtain optimal engine calibrations. These are further complicated due to transient engine operating mode. A new model-based transient calibration method has been built on the application of hierarchical statistical modelling methods, and analysis of repeated experiments for the application of engine mapping. The methodology is based on two-stage regression approach, which organise the engine data for the mapping process in sweeps. The introduction of time-dependent covariates in the hierarchy of the modelling led to the development of a new approach for the problem of transient engine calibration. This new approach for transient engine modelling is analysed using a small designed data set for a throttle body inferred air ow phenomenon. The data collection for the model was performed on a transient engine test bed as a part of this work, with sophisticated software and hardware installed on it. Models and their associated experimental design protocols have been identi ed that permits the models capable of accurately predicting the desired response features over the whole region of operability. Further, during the course of the work, the utility of multi-layer perceptron (MLP) neural network based model for the multi-covariate case has been demonstrated. The MLP neural network performs slightly better than the radial basis function (RBF) model. The basis of this comparison is made on assessing relevant model selection criteria, as well as internal and external validation ts. Finally, the general ability of the model was demonstrated through the implementation of this methodology for use in the calibration process, for populating the electronic engine control module lookup tables

    Implementasi Perda Nomor 1 Tahun 2012 Tentang Kawasan tanpa Rokok di Kota Bukittinggi ( Studi pada Angkutan Umum )

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    Alam Syahuri, Nim: 1201135119. Implementation Regulation No. 1 Year 2012 on Smoking Area In Bukittinggi. (Study on Public Transportation). Guided by Zulkarnaini,S.Sos,.M.SINo Smoking Area establishment on Public Transportation was an act as protection for the people to the risk of healt problems for effect smoking act absorbed that purposely or involuntary. No smoking area has to be implemented at health facility, school, playground, worship pleace, office, and other public places. In fact,the offenders of on smoking area was not yet gave strict punishment, bad suggestion and lead to offender. This could be seen on many chauffeur and passenger to smoking area on public transportation.The porpose of this research was to analize implementation Non Smoking Area in Bukittinggi city and to know the influenced factor.This research using Van Meter Van Horn theory.The result of this research shows that implementation non smoking area in bukittiggi city (Study on Public Transportation) not totality implemented yet eventhough it already has clear standars, goals, and objectives. Human resource the monitoring of non smoking area team is clear. Coordination and communication between government agency running well and the execution of task fit in with the regulation. Factors that become an obstade in the implementation is less by action smoking area supervisory team and civil service police uni

    Response of combined abiotic stresses on maize (Zea mays L.) inbred lines and interaction among various stresses

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    In tropics, maize is largely grown as rain fed crop in marginal areas often faces drought and waterlogging simultaneouslyin same season that critically affects plant growth and development. The aim of the research was to studythe response of combined abiotic stresses and the interaction among various stresses on maize inbred plants. Inthe present study, eighty maize (Zea mays L.) inbred lines were screened, for multiple abiotic stresses at the vegetativestage. All the traits, observed were severely affected, in drought x low-N stress compare to waterloggingx low-N stress. However in both the stress combinations (drought x low-N and waterlogging x low-N) chlorophyllcontent decreases significantly, low-N stress has synergistic effect on the maize plants. Hence the overall effectof stress combination was negative causing enhanced damage to plants. Whereas, interaction of drought x waterloggingstress showed the antagonized each other response that primarily enhanced growth parameters (leafarea, plant height and stem diameter) and it has improved the tolerant mechanism of maize plants. Therefore weconcluded, the response of maize various plants exposed to combinations of stresses is depend on interactionof stresses

    MEDIA OPTIMIZATION FOR BIOPROTEINS PRODUCTION FROM CHEAPER CARBON SOURCE

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    There are high demands for animal and human food supply especially protein, which is an important dietary component. Agricultural wastes, cheap carbon sources- which are rich and have high energy, can be used for producing the value added bioprotein. A lab scale study was carried out to optimize the media composition for bioprotein production from a cheaper carbon source - wheat flour using potential strain, which was selected earlier by screening different microorganisms. The performance of the selected strain was enhanced by media optimization with varied substrate concentration, nitrogen sources and nutrient supplementation according to the central composite design from STATISTICA software. Statistical optimization was carried out to evaluate the polynomial regression model through effect of linear, quadratic and interaction of the factors. The maximum biomass produced was 21.89 g/L with optimum fermentation conditions of wheat flour (4 g/L), nitrogen concentration (0.5 g/L), nutrient concentration (0.1 g/L), and four days of fermentation

    Suitability of using palm oil mill effluent as a medium for lipase production

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    Lipases are enzymes that can be secreted by several microorganisms using agro-industrial residues as potential substrates. This work screened ten microorganisms for their potential to produce lipase in palm oil mill effluent (POME)-based medium. Among the 10 organisms, the most promising strain was Candida cylindracea (ATCC 14830) which showed appreciable activity both on agar plates and liquid cultures. Medium supplementation by NH4Cl and olive oil led to an enzyme activity of 2.07 U/ml. However, supplementation with organic nitrogen sources resulted in better enzyme activity. Addition of malt extract, peptone and olive oil into the medium greatly influenced the lipase production. Among the oils that were tested, olive oil was found to be the best for the expression of extracellular lipase at 0.5% (v/v) with an activity of 4.02 U/ml in an optimized POME supplemented medium.Key words: Lipase, agro-industrial residue, palm oil mill effluent, Candida cylindrace

    Accelerating Universe as Window for Extra Dimensions

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    Homogeneous cosmological solutions are obtained in five dimensional space time assuming equations of state p=kρ p = k\rho and p5=γρ p_{5}= \gamma\rho where p is the isotropic 3 - pressure and p5p_{5}, that for the fifth dimension. Using different values for the constants k and γ\gamma many known solutions are rediscovered. Further the current acceleration of the universe has led us to investigate higher dimensional gravity theory, which is able to explain acceleration from a theoretical view point without the need of introducing dark energy by hand. We argue that the terms containing higher dimensional metric coefficients produce an extra negative pressure that apparently drives an acceleration of the 3D space, tempting us to suggest that the accelerating universe seems to act as a window to the existence of extra spatial dimensions. Interestingly the 5D matter field remains regular while the \emph{effective} negative pressure is responsible for the inflation. Relaxing the assumptions of two equations of state we also present a class of solutions which provide early deceleration followed by a late acceleration in a unified manner. Interesting to point out that in this case our cosmology apparently mimics the well known quintessence scenario fuelled by a generalised Chaplygin-type of fluid where a smooth transition from a dust dominated model to a de Sitter like one takes place.Comment: 20 pages,3 figure
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