Assessment of the performance of different compost models to manage urban household organic solid wastes

The environmental, cultural, socio-economic and political conditions of each community greatly affect the municipality’s effort and decision-making in managing household wastes. Composting at home can be used as a sound method of SWM, can manage the waste at source itself thereby can increase their recycling. And vermicomposting is a viable and completely feasible option at household level, provided it is acceptable to family members to handle the worms and to remove worm-casts subsequently. In this regard, the present paper gives a methodological framework for assessing the management of urban household organic wastes using different compost models to influence the actual efficiency and effectiveness of a municipality’s collection and management services. The current study also deals with the challenges of solid waste management with a focus on the segregation of compostable wastes from the non-compostable ones and their composting, recycling or disposal. The non-compostable wastes can be left for recycling and re-use by the concerned authorities. The composting behavior and the efficiency of different compost models have been dealt with, and it is concluded that vermicomposting model is the best option. Urban residents can be educated to vermicompost not only their entire kitchen wastes but also garden wastes to reduce the burden on the municipal councils.     

Vectorial scale-based fuzzy-connected image segmentation

This paper presents an extension of previously published theory and algorithms for fuzzy-connected image segmentation. In this approach, a strength of connectedness is assigned to every pair of image elements. This is done by finding the strongest among all possible connecting paths between the two elements in each pair. The strength assigned to a particular path is defined as the weakest affinity between successive pairs of elements along the path. Affinity specifies the degree to which elements hang together locally in the image. A scale is determined at every element in the image that indicates the size of the largest homogeneous hyperball region centered at the element. In determining affinity between any two elements, all elements within their scale regions are considered. This method has been effectively utilized in several medical applications. In this paper, we generalize this method from scalar images to vectorial images. In a vectorial image, scale is defined as the radius of the largest hyperball contained in the same homogeneous region under a predefined condition of homogeneity of the image vector field. Two different components of affinity, namely homogeneity-based affinity and object-feature-based affinity, are devised in a fully vectorial manner. The original relative fuzzy connectedness algorithm is utilized to delineate a specified object via a competing strategy among multiple objects. We have presented several studies to evaluate the performance of this method based on simulated MR images, 20 clinical MR images, and 250 mathematical phantom images. These studies indicate that the fully vectorial fuzzy connectedness formulation has generally overall better accuracy than the method using some intermediate ad hoc steps to fit the vectorial image to a scalar fuzzy connectedness formulation, and precision and efficiency are similar for these two methods.     

A call admission and control scheme for quality‐of‐service (QoS) provisioning in next generation wireless networks

We propose a framework for quality‐of‐service (QoS) provisioning for multimedia services in next generation wireless access networks. This framework aims at providing a differentiated treatment to multimedia traffic flows at the link layer, which can be broadly classified as real‐time (or delay‐sensitive) and non‐real‐time (or delay‐tolerant). Various novel schemes are proposed to support the differential treatment and guarantee QoS. These schemes include bandwidth compaction, channel reservation and degradation, with the help of which a call admission and control algorithm is developed. The performance of the proposed framework is captured through analytical modeling and simulation experiments. Analytically, the average carried traffic and the worst case buffer requirements for real‐time and non‐real‐time calls are estimated. Simulation results show up to 21% improvement in the admission probability of real‐time calls and up to 17% improvement in the admission probability of non‐real‐time calls, when various call control techniques like bandwidth compaction are employed. Using our channel reservation technique, we observe a 12% improvement in the call admission probability compared to another scheme proposed in the literature. This revised version was published online in August 2006 with corrections to the Cover Date.     

Industry case studies in the use of immersive virtual assembly

In this paper, we report on two engineering case studies that have been conducted as part of a Virtual Assembly Technology Consortium. The objectives of the case studies were to determine if immersive virtual assembly capabilities allow industry assembly situations to be modelled and studied realistically, and to demonstrate the downstream value of the virtual assembly capabilities in areas such as ergonomics, assembly installation, process planning, installation, and serviceability. What is of special significance is that instead of modelling simplified problems or perceived representative situations, the case studies were constructed from actual assembly floor projects and situations encountered at industry member sites and with considerable participation from industry engineers and manufacturing shop floor personnel. Based on the success of the case studies, the consortium members inferred that virtual assembly methods are poised to move out of the realm of special projects and test scenarios to deployment in the actual design and manufacturing cycle. However, in order to be truly accepted in industry, there are still issues to be addressed in terms of ease of use, portability of the applications, and preparation of the models for the evaluations. Thus, the case studies added a new dimension to the exploration and understanding of how this new technology could be of practical value in industry.     

Interannual variability of chlorophyll-a concentration along the southwest coast of India

The interannual variability of chlorophyll concentration along the southwest coast of India is studied using remote-sensing data from SeaWiFS. The data are analysed in conjunction with satellite-measured sea surface winds. The satellite-measured chlorophyll data for a period of 10 years from 1998 to 2007 were made use of for indexing the maximum offshore extent of chlorophyll along the coast for each month. From the empirical orthogonal functional analysis of chlorophyll data, it is observed that the dominant mode is annual. Interestingly, intraseasonal variability and the influence of climatic events like El Niño are observed in the secondary principle component of the time series. The variability of chlorophyll coincided well with variability of Ekman transport all along the coast with higher chlorophyll (>1 mg m^?3) when the Ekman transport is greater than 1000 kg/m/s. During the years 2005–2007, reduction in the meridional (along shore) component of wind resulted in reduction of Ekman transport, the phenomenon which leads to a decrease in chlorophyll. This is due to the reduction in the amount of nutrients that entrained to surface layers during upwelling of the southwest monsoon. The chlorophyll-a is minimum when Ekman transport is less than 0.5 kg/m/s on the normalized scale. For higher values of chlorophyll, the Ekman transport is higher, indicating the contribution of wind in enhancing the already upwelled chlorophyll production. The smaller value of R ² infers that there exist other forces as well involved in augmenting the surface chlorophyll. The enhanced knowledge on the offshore extent and the intraseasonal and interannual variability of chlorophyll can provide valuable inputs on fisheries and primary productivity for this region.     

Deposition of ZnO Films by Combustion Flame Pyrolysis of Solution Precursors

The structural features, including preferred orientation and surface morphology of zinc oxide (ZnO) films deposited by combustion flame pyrolysis were investigated as a function of process parameters, which include precursor solution concentration, substrate–nozzle (S–N) distance, gas flow rate, and duration of deposition. In this technique, the precursor droplets react within the flame and form a coating on an amorphous silica substrate held in or near the flame. Depending on the process parameters, the state of decomposition at which the precursor arrives on the substrate varies substantially and this in turn dictates the orientation and microstructure of the films.     

Real-time gaseous, PM and ultrafine particle emissions from a modern marine engine operating on biodiesel

Emissions from harbor-craft significantly affect air quality in populated regions near ports and inland waterways. This research measured regulated and unregulated emissions from an in-use EPA Tier 2 marine propulsion engine on a ferry operating in a bay following standard methods. A special effort was made to monitor continuously both the total Particulate Mass (PM) mass emissions and the real-time Particle Size Distribution (PSD). The engine was operated following the loads in ISO 8178-4 E3 cycle for comparison with the certification standards and across biodiesel blends. Real-time measurements were also made during a typical cruise in the bay. Results showed the in-use nitrogen oxide (NOx) and PM(2.5) emission factors were within the not to exceed standard for Tier 2 marine engines. Comparing across fuels we observed the following: a) no statistically significant change in NO(x) emissions with biodiesel blends (B20, B50); b) ～ 16% and ～ 25% reduction of PM(2.5) mass emissions with B20 and B50 respectively; c) a larger organic carbon (OC) to elemental carbon (EC) ratio and organic mass (OM) to OC ratio with B50 compared to B20 and B0; d) a significant number of ultrafine nuclei and a smaller mass mean diameter with increasing blend-levels of biodiesel. The real-time monitoring of gaseous and particulate emissions during a typical cruise in the San Francisco Bay (in-use cycle) revealed important effects of ocean/bay currents on emissions: NO(x) and CO(2) increased 3-fold; PM(2.5) mass increased 6-fold; and ultrafine particles disappeared due to the effect of bay currents. This finding has implications on the use of certification values instead of actual in-use emission values when developing inventories. Emission factors for some volatile organic compounds (VOCs), carbonyls, and poly aromatic hydrocarbons (PAHs) are reported as supplemental data.     

Heat conduction mechanisms in hot pressed ZrB2 and ZrB2–SiC composites

Thermal diffusivity and conductivity of hot pressed ZrB₂ with different amounts of B₄C (0–5 wt%) and ZrB₂–SiC composites (10–30 vol% SiC) were investigated experimentally over a wide range of temperature (25–1500 °C). Both thermal diffusivity and thermal conductivity were found to decrease with increase in temperature for all the hot pressed ZrB₂ and ZrB₂–SiC composites. At around 200 °C, thermal conductivity of ZrB₂–SiC composites was found to be composition independent. Thermal conductivity of ZrB₂–SiC composites was also correlated with theoretical predictions of the Maxwell–Eucken relation. The dominated mechanisms of heat transport for all hot pressed ZrB₂ and ZrB₂–SiC composites at room temperature were confirmed by Wiedemann–Franz analysis by using measured electrical conductivity of these materials at room temperature. It was found that electronic thermal conductivity dominated for all monolithic ZrB₂ whereas the phonon contribution to thermal conductivity increased with SiC contents for ZrB₂–SiC composites.     

A novel catalyst for the Knoevenagel condensation of aldehydes with malononitrile and ethyl cyanoacetate under solvent free conditions

A novel, efficient and eco-friendly MgO/ZrO₂ catalyst is put forward for the Knoevenagel condensation. The as synthesized catalyst MgO/ZrO₂ was characterized by elemental analysis, XRD, FTIR, particle size, SEM–EDXS, average pore diameter, BET surface area analysis, and thermal gravimetric analysis. The Knoevenagel condensation of several aldehydes with ethyl cyanoacetate and malononitrile was carried out at 60 °C on MgO/ZrO₂ catalyst in the absence of solvent.