Characterizations of friction welding joint interface for AISI 316

Because of heat amount is different from peripheral to central of friction welding interface, which is leaded to vary the characterizations along that interface. Current study, respectively, focused on the effect of different friction pressure on micro-structural and mechanical properties of that friction welding joint interface. Presently, these friction pressures are 110, 130, 150 and 170 MPa while kept all other conditions constant. The effects of different friction pressure on welding interface characterization were investigated by EDX, SEM, tensile, compression, impact and hardness tests. The tensile tests carried out on the standardized test piece with diameter 6 mm and 8 mm, thus, compression tests were extracted from the positions of 0°, 45° 90° with test specimen of 4 mm diameter and 6.5 mm length at weld center. Whereas, the impact test pieces were picked up in two positions, the first one is symmetrical, which it obtained to the respect of the rotation axis and the interface, on the other hand, the second one is non-symmetrical with the axis of rotation and symmetrical to the interface, for making the notch head coincide with the center of the welded joint, The obtained results showed that with reducing of friction pressure will present lack of bonding increasing from peripheral toward the welding center, which will responsible on reducing of the mechanical properties such as tensile, compression and impact strength.     

The Peculiar Structure of Acetobacter pasteurianus CIP103108 LPS Core Oligosaccharide

Acetobacter pasteurianus, a member of the Alphaproteobacteria, is an acetic acid-producing bacterium present on sugar-rich substrates such as such as fruits, flowers and vegetables and traditionally used in the production of fermented food. The preferred living habitat associated with acid conditions makes the structure of the bacterial cell wall interesting to study, due to expected uncommon features. We have used a combination of chemical, analytical and NMR spectroscopy approaches to define the complete structure of the core oligosaccharide from A. pasteurianus CIP103108 LPS. Interestingly, the core oligosaccharide displays a high concentration of negatively charged groups, structural features that might contribute to reinforcing the bacterial membrane.     

Amino acid composition,foaming, emulsifying properties and surface hydrophobicity of mustard protein isolate as affected by pH and NaCl

Amino acid composition, protein hydrophobicity, foaming and emulsifying properties of mustard protein isolate at pH 3, 5, 7 and in 0.05 and 0.1 m NaCl were studied. Glutamic (19.18 ± 0.30%) and aspartic (7.49 ± 0.11%) acids were the dominants. Foaming ability was enhanced by NaCl. Time to reach 75 mL foam was 23% higher in water than in NaCl. Drained volume after 10 min was concentration dependent and was the lowest in 0.05 and 0.1 m NaCl at protein concentration of 2.5% and 5%. The emulsifying properties were pH and concentration dependent, and the best results were obtained at pH 3, corresponding to the highest positive charge density of the protein surface. The highest emulsion stability (90.22 ± 3.52%) was obtained in 0.05 m NaCl and 5% protein concentration, whereas the lowest (63.00 ± 1.06%) was in water at all protein concentrations. Protein hydrophobicity was low and depended of pH but not of NaCl.     

On the performance of heterogeneous MANETs

Recent decades have witnessed the birth of major applications of wireless communication technology, further supported by the increasing capabilities of portable devices, low cost and ubiquitous presence. Despite radio technology diversity, a great deal of existing research focuses on a single and isolated wireless technology at a time, where homogeneous elements are identified by IP addresses. This work presents a heterogeneous technology routing (HTR) Framework, targeted towards scenarios where the heterogeneity of devices and networking technologies is present. Our contribution is many fold. It consists of a framework, which encompasses a process for bootstrapping networks, a routing protocol capable of dealing with multiple network interfaces, and a tuning with multipath extensions. We evaluate the performance of the bootstrap, routing and multipath mechanisms by way of simulation and an actual testbed implementation. The multipath evaluation simulates HTR networks with WiMAX, 3GPP LTE and Wi-Fi support. Results show that our proposal can effectively improve the data delivery ratio for ad-hoc networks and that it reduces the end-to-end delay without major impact on network energy consumption. As part of HTR tuning, we investigate next the impacts of tuning the HELLO refresh interval timer on route convergence and its subsequent energy consumption reduction during this phase. We also compare our tuned HTR with the widely used optimized link state routing protocol. Results show that varying the HELLO refresh interval can improve the convergence time and reduce the energy consumption without major impact on network behavior. Our proposal also includes a new distributed address allocation algorithm, namely, the dynamic node configuration protocol (DNCP). This paper conducts a comparative analysis between the Prime, Prophet and the DNCP schemes using static and dynamic topologies in terms of network setup time, energy consumption and control message overhead. Results show that the DNCP had a lower battery power consumption and less control message overhead while it slightly suffers with regard to setup.

     

Approaches to resource reservation for migrating real-time sessions in future mobile wireless networks

This paper presents two novel frameworks for session admission control and resource reservation in the context of next generation mobile and cellular networks. We also devised a special scheme that avoids per-user reservation signaling overhead in order to meet scalability requirements needed for next generation multi-access networks. The first proposal, Distributed Call Admission Control with Aggregate Resource Reservation (VR), uses mobility prediction based on mobile positioning system location information and takes into account the expected bandwidth to be used by calls handing off to and from neighboring cells within a configurable estimation time window. In conjunction, a novel concept called virtual reservation has been devised to prevent per-user reservation. Our second proposal, Local Call Admission Control and Time Series-based Resource Reservation, takes into account the expected bandwidth to be used by calls handed off from neighboring cells based only on local information stored into the current cell a user is seeking admission to. To this end, we suggest the use of two time series-based models for predicting handoff load: the Trigg and Leach (TL), which is an adaptive exponential smoothing technique, and Autoregressive Integrated Moving Average (ARIMA) that uses the Box and Jenkins methodology. It is worth to emphasize that the use of bandwidth prediction based on ARIMA technique still exist for wireless networks. The novelty of our approach is to build an adaptive framework based on ARIMA technique that takes into account the measured handoff dropping probability in order to tuning the prediction time window size so increasing the prediction accuracy. The proposed schemes are compared through simulations with the fixed guard channel (GC) and other optimized dynamic reservation-based proposals present in the literature. The results show that our schemes outperform many others and that the simpler local proposal based on TL can grant nearly similar levels of handoff dropping probability as compared to those from more the complex distributed approach.     

LEIS for the prediction of turbulent multifluid flows applied to thermal-hydraulics applications

The paper centres on the use of the so-defined LEIS approach (Large-Eddy & Interface Simulation) for turbulent multifluid flows present in thermal-hydraulics applications. Interfacial flows involving deformable, sheared fronts separating immiscible fluids are shown to be within reach of this new approach, featuring direct resolution of turbulence and sheared interface deformations within the interface tracking (ITM) framework, such as level sets and VOF. In this technique supergrid turbulence and interfacial scales are directly solved whereas the sub-grid (SGS) parts are modelled, at least the turbulence part of it. First results are shown (feasibility), and difficulties and open issues are discussed. The connection between these two particular scales will also be discussed, and potential modelling routes evoked, including combining two-fluid and ITM, local grid refinement, or combing particle tracking and ITM for sub-grid inclusions smaller than the grid size.     

Natural Ligands of Porcine Olfactory Binding Proteins

Knowledge of endogenous ligands of olfactory binding proteins is a prerequisite for studying their role in odor and pheromone transduction. Here, we report the extraction, derivatization, and characterization by gas chromatography-mass spectrometry of the natural ligands of pig, Sus scrofa (L.), Von Ebner’s Gland protein (VEG) and odorant binding protein (OBP). We identified two isoforms (VEG1 and VEG2), which differed only by the linkage of an O-N-acetylglucosamine (O-GlcNac) group on VEG1. The natural ligands of VEG1 were characterized as two isomers of testosterone, whereas ligands of VEG2 and OBP were fatty acids or their derivatives. Our findings suggest that the binding specificity of VEG1 for steroids is governed by the presence of an O-GlcNac moiety on the protein. This specificity was confirmed by the binding of radiolabeled testosterone only by VEG1 in an in-gel binding assay. This is the first evidence for a post-translational modification in the process of odorant discrimination by olfactory binding proteins.     

On eliminating packet droppers in MANET: A modular solution

In this paper we deal with misbehaving nodes in mobile ad hoc networks (MANETs) that drop packets supposed to be relayed, whose purpose may be either saving their resources or launching a DoS attack. We propose a new solution to monitor, detect, and safely isolate such misbehaving nodes, structured around five modules: (i) The monitor, responsible for controlling the forwarding of packets, (ii) the detector, which is in charge of detecting the misbehaving of monitored nodes, (iii) the isolator, basically responsible for isolating misbehaving nodes detected by the detector, (iv) the investigator, which investigates accusations before testifying when the node has not enough experience with the accused, and (v) finally the witness module that responds to witness requests of the isolator. These modules are based on new approaches, aiming at improving the efficiency in detecting and isolating misbehaving nodes with a minimum overhead. We describe these modules in details, and their interactions as well. We also mathematically analyze our solution and assess its performance by simulation, and compare it with the watchdog, which is a monitoring technique employed by almost all the current solutions.     

Combined microwave and enzymatic treatments for ��-lactoglobulin and bovine whey proteins and their effect on the IgE immunoreactivity

Effect of combined microwave (MW) and enzymatic hydrolysis on the human immunoglobulin E (IgE)-binding properties of ??-lactoglobulin (??-lg) and other whey proteins (WP) was investigated. Separated ??-lg and full whey protein isolate (WPI) were hydrolyzed with trypsin, chymotrypsin, mixture of trypsin/chymotrypsin, and pepsin at three microwave power levels: 50?W during 1 and 5?min, 100 and 200?W during 1 and 3?min. The immunoreactivity of the obtained hydrolysates resulting from combined microwave protease treatment was assessed using sera of young patients allergic to bovine whey proteins. The application of microwave treatment at 200?W enhances the hydrolysis of ??-lg by pepsin in 3?min and decreases significantly its immunoreactivity. The extensive hydrolysis of the microwave-treated ??-lg and WPI with trypsin, chymotrypsin, and the mixture of trypsin with chymotrypsin did not have an impact on the IgE binding of the products obtained in all the studied conditions.