Energy expenditure of cycle rickshaw pullers in different places in India

The cycle rickshaw is a popular transportation device. The aim of the study was to assess workload of cycle rickshaw pullers--physiological and subjective at four different places in India. Subjects were instructed to pull a cycle rickshaw with two passengers, for 20 min. Working and recovery heart rates were recorded. The mean values of energy expenditure of pulling a cycle rickshaw varied from 23.5 +/- 2.66 to 25.35 +/- 1.51 kJ/min. Relative cardiac strain and cardiac cost indicated that the job is 'heavy' to 'very heavy'. Subjective assessment of workload was 'heavy' to 'very heavy'. The combined workload assessed from physiological parameters and subjective assessment indicated that the job could be categorised as 'heavy' to 'very heavy' at all the places studied and needs to be reduced by redesigning the structural and functional components of the cycle rickshaw. The rickshaw pullers carry out the jobs many times per day, sometimes without proper rest pauses between trips. The outcome of the research project is beneficial for cycle rickshaw pullers, health administrators as well as manufacturers of cycle rickshaws. Primarily, the manufacturers would be able to use the data for producing a newer model of cycle rickshaw, which would require less energy to drive. The health administrators would be able to take policy decisions for administering better health care for the unorganised and underprivileged workers. The pullers could be guided into taking care of their health by improving their work practice, i.e. taking a sufficient rest pause between trips.     

Developing a modular hydrogeology ontology by extending the SWEET upper-level ontologies

Upper-level ontologies comprise general concepts and properties which need to be extended to include more diverse and specific domain vocabularies. We present the extension of NASA's Semantic Web for Earth and Environmental Terminology (SWEET) ontologies to include part of the hydrogeology domain. We describe a methodology that can be followed by other allied domain experts who intend to adopt the SWEET ontologies in their own discipline. We have maintained the modular design of the SWEET ontologies for maximum extensibility and reusability of our ontology in other fields, to ensure inter-disciplinary knowledge reuse, management, and discovery.The extension of the SWEET ontologies involved identification of the general SWEET concepts (classes) to serve as the super-class of the domain concepts. This was followed by establishing the special inter-relationships between domain concepts (e.g., equivalence for vadose zone and unsaturated zone), and identifying the dependent concepts such as physical properties and units, and their relationship to external concepts. Ontology editing tools such as SWOOP and Protégé were used to analyze and visualize the structure of the existing OWL files. Domain concepts were introduced either as standalone new classes or as subclasses of existing SWEET ontologies. This involved changing the relationships (properties) and/or adding new relationships based on domain theories. In places, in the Owl files, the entire structure of the existing concepts needed to be changed to represent the domain concept more meaningfully. Throughout this process, the orthogonal structure of SWEET ontologies was maintained and the consistency of the concepts was tested using the Racer reasoner. Individuals were added to the new concepts to test the modified ontologies. Our work shows that SWEET ontologies can successfully be extended and reused in any field without losing their modular or reference structure, or disrupting their URI links.     

Interacting sequential Monte Carlo samplers for trans-dimensional simulation

The methodology of interacting sequential Monte Carlo (SMC) samplers is introduced. SMC samplers are methods for sampling from a sequence of densities on a common measurable space using a combination of Markov chain Monte Carlo (MCMC) and sequential importance sampling/resampling (SIR) methodology. One of the main problems with SMC samplers when simulating from trans-dimensional, multimodal static targets is that transition kernels do not mix which leads to low particle diversity. In such situations poor Monte Carlo estimates may be derived. To deal with this problem an interacting SMC approach for static inference is introduced. The method proceeds by running SMC samplers in parallel on, initially, different regions of the state space and then moving the corresponding samples onto the entire state space. Once the samplers reach a common space the samplers are combined and allowed to interact. The method is intended to increase the diversity of the population of samples. It is established that interacting SMC admit a Feynman-Kac representation; this provides a framework for the convergence results that are developed. In addition, the methodology is demonstrated on a trans-dimensional inference problem in Bayesian mixture modelling and also, using adaptive methods, a mixture modelling problem in population genetics.     

Data-stream-based global event monitoring using pairwise interactions

The problem of global state observation is fundamental to distributed systems and to the analysis of data streams. Many interactions in distributed systems can be analyzed in terms of the building block formed by the pairwise interactions of intervals at two processes. Considering causality-based pairwise interactions by which two processes may interact with each other, there are 40 orthogonal interaction types. For each pair of processes (_Pi,_Pj)$(P_i,P_j)$, let interaction type _ri,j$r_{i,j}$ be of interest. This paper examines the problem: “If a global state of interest to an application is specified in terms of such pairwise interaction types, one per pair of processes, how can such a global state be detected?” A solution identifies a global state in which the interaction type specified for each process pair is satisfied. This paper formulates the specific conditions on the communication structures to determine which of the intervals being examined at any time may never satisfy the stipulated interaction type for that pair of processes, and therefore that interval(s) need no longer be considered as forming a part of any solution. Based on this theory, the paper proposes two on-line distributed algorithms to solve the problem.     

Performance investigation of a permanent magnet generator

Computer simulation using the finite-element method (FEM) is an important tool for the design of highly efficient power devices. In this work combination of FEM-software for magnetic analysis and Simulink-software for non-linear parameter identification for dynamics of a permanent magnet (PM) generator is discussed. An FE model of the generator is developed and its electromagnetic torque analysis is carried out using FEM-software. Simulink has been used for analysis of rotor moment of inertia (MI) due to variation of winding resistance and winding inductance. It is shown that system MI has a significant effect on optimal winding resistance and inductance to achieve steady state operation in shortest period of time.     

H2 adsorption and H/D exchange on Au/TS-1 and Au/S-1 catalysts

We report a combined quantum-mechanics/molecular-mechanics (QM/MM) analysis of H₂ dissociation and hydrogen–deuterium (H/D) exchange on four potential active sites inside the TS-1 pores: (1) Au₃/T6–Ti-non-defect, (2) Au₃/T6–Si-non-defect, (3) Au₃/T6–Ti-defect, and (4) Au₃/T6–Si-defect. We provide full kinetic and thermodynamic data calculated at standard conditions (298.15 K, 1 atm) for Eley–Rideal mechanisms on these sites. The H/D exchange on Au₃/TS-1 occurs in two steps: (1) first H₂ dissociation on Au₃/TS-1 to form H–Au₃–H species and (2) D₂ (or second H₂) attack on these H–Au₃–H species to form HD. The energetics of the first H₂ dissociation step is site-sensitive (with respect to Au sites), while that of the D₂ (or second H₂) addition step is not site-sensitive. We found that two different mechanisms for the second step are both kinetically and thermodynamically favorable. The most favorable mechanism (ΔE _act ~ 28 kcal/mol) involves an attack of D₂ on both the H atoms in the H–Au₃–H intermediate, and two HD molecules are formed simultaneously. The first H₂ dissociation step is almost thermoneutral and the D₂ (or second H₂) addition step is somewhat exothermic. A comparison of the pure QM and QM/MM calculations on Au₃/TS-1 suggests that the formation of the H–Au₃–H species inside the TS-1 pores becomes thermodynamically more favorable due to the long-range interactions. The activation energies for the first H₂ dissociation step (19–24 kcal/mol) are lower than those for the D₂ (or second H₂) addition step (28–31 kcal/mol). Therefore, the increase in the HD formation rate with temperature is likely to be stronger than the increase in the H–Au₃–H formation rate. On the basis of the calculated activation energies and the reaction thermochemistry, we predict a viable Eley–Rideal H/D exchange pathway that may operate at or above 573 K. We also found potential H/D exchange channels on bare TS-1 (without Au₃) where gas-phase D₂ (or second H₂) attacks the Ti–OH or Si–OH groups (of defect sites) and exchanges one of the D atoms to form HD and Ti–OD or Si–OD groups.     

Orientation in polypropylene sheets produced by die-drawing and rolling

Two orienting techniques for stiffening semicrystalline polymers, rolling and die-drawing, are compared with respect to the anisotropy they produce in isotactic polypropylene (PP). Billets of PP were either drawn at 145°C through a tapered slotted die in the Leeds large-scale die-drawing machine to reduction ratios R of 2.2, 5.1 and 7.6, or rolled between rolls of 65 mm diameter at 120°C to R = 2 to 5. Drawing increased the crystallinity, as estimated from differential scanning calorimetry, density and wide-angle X-ray diffraction (WAXD); it thus disrupts the original PP structure, developing an oriented crystalline structure. WAXD pole figures showed that both die-drawing and rolling oriented the molecular chain axis nearly parallel to the machine direction and the b axis perpendicular to the drawing plane. This approximate uniaxial symmetry was confirmed by ultrasonic measurements of the stiffness matrix. In tensile and falling-dart impact tests, samples failed by delaminating in the drawing plane. Although stresses are applied to the material in quite different ways in die-drawing and in rolling, the geometry of deformation in both is similar, close to plane strain.     

Tl(III) initiated polymerization of methyl methacrylate in micellar phase

The polymerization kinetics of methyl methacrylate (MMA) was studied, using Tl(III)‐cyclohexanone (CH) redox system as initiator, in the presence of emulsifier [i.e., sodium dodecyl sulfate (SDS), cetyltrimethylammonium bromide (CTAB), and thallium triacetate (TX‐100)] over a temperature range of 25–45°C. The effect of various concentrations of MMA, Tl(III), cyclohexanone, H⁺, and varying ionic strengths on the rate of polymerization, rate of Tl(III) consumption (?R_Tl), and the percentage of monomer conversion were examined in the presence of 0.015M SDS. The kinetic results of polymerization in the absence and presence of 0.015M SDS were compared in terms of overall activation energy (E_a) for the process. The viscosity‐average molecular weight (M_V) of the polymers, obtained in the presence of varying concentrations of anionic surfactant (SDS), was also determined. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2480–2485, 2004     

Photocatalytic Decomposition of Formic Acid Under Visible Light Irradiation Over V-ion-implanted TiO2 Thin Film Photocatalysts Prepared on Quartz Substrate by Ionized Cluster Beam (ICB) Deposition Method

Unique visible-light-responsive TiO₂ photocatalysts (λ>450 nm) were successfully developed by implantation of V ions into the TiO₂ thin films prepared on a quartz substrate by an ionized cluster beam (ICB) deposition method. After V ions implantation into TiO₂ thin film, the photocatalytic activity of the thin films for the decomposition of formic acid into CO₂ and H₂O was found to proceed efficiently under visible light irradiation longer than 450 nm. The TiO₂ thin film photocatalysts were characterized by XRD, UV-vis, XPS, FE-SEM and AFM.     

Graphite–epoxy graded material by centrifugation

A graded distribution of graphite particles in epoxy resin matrix was obtained using a centrifugation technique. By varying the centrifugation time the graded profile could be effectively controlled. Scanning electron microscopy and optical microscopy revealed the graded dispersion of graphite particles in the epoxy matrix, which is sensitive to centrifugation time. Electrical or wear properties can accurately estimate the property profile of graded material. The abrasive wear test also provided a quick estimation of the extent of gradient formed in the sample. The increased centrifugation time increased the compaction of graphite particles in the graphite‐rich phase of graded material that could be correlated with the increased capacitance of the sample. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 550–556, 2005