Modal analysis of prestressed draft pad of freight wagons using finite element method

The present work intends to investigate dynamic behaviour of draft gear using finite element method. The longitudinal force that the draft gear absorbs usually leads to the failure of its components, especially, the load bearing draft pads. Dynamic behaviour of an individual draft pad and a draft gear is determined and characterized with exciting frequencies and corresponding mode shapes. The effect of compressive prestress load on the dynamic behaviour of an individual draft pad is also determined as the draft pads in assembled state are under constant axial compressive force in the draft gear. The vibration characteristics of individual draft pad are compared with draft pads that are part of draft gear. The modal analysis gives us a basis for subjecting a draft pad to higher frequency loading for determining its fatigue behaviour.

     

Pedestrian Detection and Tracking Using Deformable Part Models and Kalman Filtering

Abstract： Pedestrian detection techniques are important and challenging especially for complex real world scenes. They can be used for ensuring pedestrian safety, ADASs （advance driver assistance systems） and safety surveillance systems. In this paper, we propose a novel approach for multi-person tracking-by-detection using deformable part models in Kalman filtering framework. The Kalman filter is used to keep track of each person and a unique label is assigned to each tracked individual. Based on this approach, people can enter and leave the scene randomly. We test and demonstrate our results on Caltech Pedestrian benchmark, which is two orders of magnitude larger than any other existing datasets and consists of pedestrians varying widely in appearance, pose and scale. Complex situations such as people occluded by each other are handled gracefully and individual persons can be tracked correctly after a group of people split. Experiments confirm the real-time performance and robustness of our system, working in complex scenes. Our tracking model gives a tracking accuracy of 72.8% and a tracking precision of 82.3%. We can further reduce false positives by 2.8%, using Kalman filtering.     

Inhibitory effect of parthenium (Parthenium hysterophorus L.) residue on growth of water hyacinth (Eichhornia crassipes Mart Solms.) II. Relative effect of flower,leaf, stem,and root residue

The relative effect of residue of leaf, flower, stem, and root of parthenium (Parthenium hysterophorus L.) on growth of water hyacinth was studied. The inhibitory activity of the residue as shown by its effect on biomass and healthy leaf number (HLN) of treated plants was in the order: leaf and flower >stem >root. Total phenolic acids in the medium after 72 hr of suspending the plant part residue were maximum in flower followed by leaf, root, and stem, successively. The dry leaf powder (DLP) and dry flower powder (DFP) at and above 0.50% (w/v) and dry stem powder (DSP) at 1.00% (w/v) killed water hyacinth in about one month. Dry root powder (DRP) at the highest dose (1.25% w/v) reduced the growth of the treated plants drastically, but the plants recovered after about one month. The DSP at 0.50% (w/v) and DRP at 0.25–0.75% (w/v) supported growth of treated plants, probably due to lower levels of inhibitors, allowing utilization of constituents of the residue as nutrients. Using wheat seedlings as a reference material, it was observed that in aquaculture at different levels of parthenium plant parts residue, water hyacinth plants were much more sensitive to inhibitory activity. Thus, water hyacinth is suggested as a material for bioassay of inhibitory activity of the parthenium plant residue.     

SLDG: a metamodel for Simulink/Stateflow models and its applications

Simulink and Stateflow (SL/SF) models are being widely used to design and develop embedded systems. Often the SL/SF models of embedded controllers turn out to be large and consist of many subsystems and hierarchies. When such a system is maintained, it becomes difficult to manually analyse the model to identify the impacted elements due to the existence of several explicit and implicit dependencies among the model elements. To automate the analysis of an SL/SF model, we propose a metamodel to capture various types of dependencies existing across the basic blocks. We have named this metamodel Simulink dependency graph (SLDG). We investigate the use of SLDG in change impact visualization and regression test selection. We have developed a prototype tool by implementing our approach for the aforementioned applications.     

Natural rubber (Hevea Brasiliensis)-based quasi-solid electrolyte as a potential candidate for arresting recombination and improving performance in aqueous dye-sensitized solar cells

Journal of Materials Science: Materials in Electronics - We successfully fabricated dye sensitized solar cells (DSSCs) employing a quasi-solid state electrolyte based on pristine insulator natural...     

Double-positive thymocytes resistant to antigen-MHC-induced negative selection lack active caspase

The aim of the current study was to elucidate the synergism of dietary calcium restriction and exhaustive exercise in the antioxidant enzyme system of rat soleus muscle, and to investigate the involvement of neutrophils in exercise-induced muscle damage. Forty-eight male Wistar rats were assigned to the following groups: control (C) or calcium-restricted [1 month (1 M) or 3 months (3 M)]. Each group was subdivided into acutely exercised or non-exercised groups. Soleus muscle from each rat was analysed to determine the levels of antioxidant enzymes [Mn-superoxide dismutase (SOD), Cu, Zn-SOD, glutathione peroxidase (GPX), and catalase (CAT)]. Dietary calcium restriction resulted in calcium deficiency and upregulated the antioxidant enzymes examined except GPX. Conversely, exhaustive exercise significantly decreased GPX and CAT, but not SODs activities in the calcium-restricted (1 M and/or 3 M) rats. Contents of immunoreactive Mn-SOD and Cu,Zn-SOD were only increased in the 3 M rats. During calcium restriction, the mRNA expression of both forms of SOD showed initial upregulation, followed by downregulation. Exhaustive exercise significantly increased the mRNA expressions only in the 3 M rats. Moreover, exhaustive exercise markedly increased myeloperoxidase activity in soleus muscles from the 1 M and 3 M rats compared with the C rats, and significantly enhanced the ability of neutrophils to generate superoxide in the 3 M rats. The results demonstrate that dietary calcium restriction upregulates certain antioxidant enzyme activities in rat soleus muscle, indicating an enhanced resistance to potential increases in intracellular reactive oxygen species. The results also suggest that exhaustive exercise may cause oxidative damage in soleus muscle of calcium-deficient rats through the activation of neutrophils.