HIERARCHICAL AND MODULAR MODELING OF STRUCTURAL STEEL ERECTION PROCESS USING PETRI NETS

The construction industry is growing at a fast pace-newer project delivery methodo logies are being adopted; design of facilities is continuously improving, newer means, methods, and materials of construction are being used. All these market forces have re sulted in an increase in complexity of on-site construction processes. The construction industry needs advanced tools and techniques to plan and manage these complex con struction processes. This paper describes and utilizes a Petri Net based hierarchical and modular modeling and analysis technique for the planning of complex construction pro cesses. Petri Nets are graphical modeling tools that have been utilized in the modeling and analysis of processes in the fields of software engineering, telecommunications, manufac turing, and construction. This paper highlights advanced features of Petri Nets and their utilization in the modeling and analysis of structural steel erection processes. Through the use of hierarchy, modularity, and resource modeling Petri Nets provide clear advan tages in the modeling of complex construction processes.     

Fractions of a chloroform extract of ajenjo leaves (<i>Artemisia mendozana</i> DC. var. <i>mendozana</i>) inhibit the proliferation,viability and clonogenicity of B16-F0 melanoma cells

The ajenjo, Artemisia mendozana DC. var. mendozana (Asteraceae), grows in the Andean foothills of Mendozaand San Juan, Argentina, and is used as a medicinal plant for its antispasmodic and antifungal properties. The aim of thiswork was to obtain fractions of a chloroform extract of ajenjo leaves and to evaluate the in vitro effects on proliferation,viability and clonogenicity of B16-F0 melanoma cells. Using a silica gel chromatography column, 120 fractions werecollected and grouped according to the chromatographic profile in 9 main fractions (F1–F9). Their major compoundsidentified were: terpenes (F1), terpenes and sesquiterpene lactones (F2–F3), sesquiterpenes (F4–F6) and phenols andsesquiterpenes (F7-9). B16-F0 cells were incubated for 72 h with DMSO (vehicle) or 0.1 mg/ml F1–F9. At 72 h ofculture, F1 decreased both the growing index (GI) and cell viability. F2 and F3 both decreased GI and only F3decreased clonogenic activity. F4 and F5 both decreased GI. Only F5 decreased cell viability and F4 decreasedclonogenicity. Consequently, fractions F6–F8 did not affect any of the cell parameters assayed, while F9 decreased cellviability and inhibited clonogenicity.     

Measuring the frequency sweeping rate (dθn/dn) of a chirp signal

A circuit has been designed to estimate the rate of frequency change (dθ_n/dn) of a chirp signal. The novelty of this approach is that it presents a simple method for estimating a time varying input frequency totally derived from a first-order adaptive linear predictor technique rather than from a correlation based method. The simulation results confirm the theoretical analysis and show the potential of the new system in a noisy environment.     

INTRAPARTICLE CONVECTION,DIFFUSION AND ZERO ORDER REACTION IN POROUS CATALYSTS

An assessment is made of the influence of convective effects in the behaviour of calalyst pellets with large pores

Concentration profiles and effectiveness factors are calculated for zero order reactions in isothermal regimes using a model which involves convective transport as well as diffusion and reaction processes in the pellet

Errors made in current reactor design are discussed. A predictive method for calculating the intraparticle fluid velocity in industrial cases is reported. Finally, the analysis is applied to the design of biological reactors.     

Missing wedge computed tomography by iterative algorithm DIRECTT

A strategy to mitigate typical reconstruction artefacts in missing wedge computed tomography is presented. These artefacts appear as elongations of reconstructed details along the mean direction (i.e. the symmetry centre of the projections). Although absent in standard computed tomography applications, they are most prominent in advanced electron tomography and also in special topics of X‐ray and neutron tomography under restricted geometric boundary conditions. We investigate the performance of the DIRECTT (Direct Iterative Reconstruction of Computed Tomography Trajectories) algorithm to reduce the directional artefacts in standard procedures. In order to be sensitive to the anisotropic nature of missing wedge artefacts, we investigate isotropic substructures of metal foam as well as circular disc models. Comparison is drawn to filtered backprojection and algebraic techniques. Reference is made to reconstructions of complete data sets. For the purpose of assessing the reconstruction quality, Fourier transforms are employed to visualize the missing wedge directly. Deficient reconstructions of disc models are evaluated by a length‐weighted kernel density estimation, which yields the probabilities of boundary orientations. The DIRECTT results are assessed at different signal‐to‐noise ratios by means of local and integral evaluation parameters.     

On smoothing in linear discrete systems with time delays†

An algorithm is presented for optimal linear fixed-point and fixed-lag smoothing in non-stationary linear discrete systems with multiple time delays. Relations derived previously in the problem of filtering are used directly to obtain the fixed-point and fixed-lag smoothing filters. The smoothing error covariance matrix is obtained via a recursive matrix equation. For the particular case of systems without delay terms, the algorithm defines new smoothing procedures.     

Efficacy of oral consumption of curcumin/ for symptom improvement in inflammatory bowel disease: A systematic review of animal models and a meta-analysis of randomized clinical trials

The roots of the vegetal Curcuma due to its high content of polyphenols, has been used successfully in several clinical situations. This review assessed the effect of curcumin/Curcuma longa on symptoms and metabolic changes in inflammatory bowel disease (IBD). A systematic review of animal models and randomized clinical trials (RCTs) was conducted by searching the following electronic databases: PubMed, CENTRAL, LILACS, Science Direct, and ClinicalTrials.gov. From 997 found records, 62 were included. More than 90% of the animal studies reported an improvement in macroscopic, histologic and/or functional activity; 80% identified decreased oxidative and/or inflammatory biomarkers in animals treated with curcumin. Among the RCTs, intention-to-treat analysis showed that oral curcumin was effective in inducing clinical remission (n = 281, RR: 3.15 CI 95% [1.22–8.10] p = 0.0017; i² = 72.2%, p = 0.006) and clinical response (n = 259, RR: 1.60 CI 95% [1.09–2.35] p = 0.0017; i² = 59.7%, p = 0.042) but not endoscopic remission (n = 161, RR: 2.91 CI 95% [0.58–14.58] p = 0.195; i² = 72.7%, p = 0.026). These results confirm that oral supplementation with curcumin/Curcuma longa has beneficial actions in animal colitis and, when associated with drug therapy, is effective in the treatment of patients with IBD.