Performance Evaluation of CANCAR Algorithm in Realistic Wireless Mesh Networks

Wireless Personal Communications - A new technique for designing compact, notched filter is presented in this paper. The proposed approach is based on the design and optimization of micro strip...     

Application of in-situ electrical resistance measurements to the study of phase transformations in ferrous alloys

Phase transformations have been studied in a variety of different steels with the use of “in situ” electrical resistance measurements. The results were evaluated by metallography of the initial and final microstructures and with consideration of data from the published literature. On this basis a good correlation has been established and it was shown that this method is suitable for such investigations. It even presents certain advantages, thus providing a more complete understanding of the physical metallurgy of steels. We out-lined the field in which the measurement of electrical resistance is particularly suitable and an example of processes that are difficult to monitor using other commonly used methods.     

Photodegradation of methyl orange under visible light by micro-nano hierarchical Cu2O structure fabricated by hybrid laser processing and chemical dealloying

Micro-nano hierarchical structure on the substrate was fabricated by a hybrid approach including laser deposition, laser ablation and chemical dealloying. The structure consists of micro bumps with a width of 50 μm and a height of 100 μm, and nanoporous structures with a size of 70-150 nm on the micro bumps. XRD and XPS results confirm that these hierarchical structures were made of Cu(2)O. For use in comparison, three additional structures with feature size in milliscale, microscale, and nanoscale were also prepared respectively by the proposed methods. Under visible light, the micro-nano structure exhibited the best performance of photodegradation. It is the result of the large specific surface and the catalytic reaction driven by the cuprous oxides.     

Use of the kriging method in determining the properties of gases in large channels

Properties of fluids can vary significantly over a cross-section of a channel. The variations can be graphically presented by means of profiles which are typically based on a limited number of measured points. The article presents suitability of the kriging interpolation method for data analysis at measuring properties of fluids in large channels in various thermal and process plants. Using a practical example rather than complex statistical analyses the advantages of the kriging over other interpolation methods are presented. Several examples also give some guidelines on choosing number and distribution of measuring points to ensure accurate profiles.     

Elasto-Plastic Springback of Beams Subjected to Repeated Bending/Unbending Histories

This contribution investigated repeated elastoplastic pure plane bending/unbending process of beams made of material with an elastic-linear hardening rheological model. The attention is focused on beams with cross sections which have at least one axis of symmetry and are initially straight or have constant radius of curvature. Elastoplastic deflection states of beams after repeated bending/unbending process are determined using the large displacement theory. Experiments were conducted to verify the theory for beams made of aluminium alloy AA 5050-H38 with rectangular cross sections. It is shown that maximal relative difference between experimental and theoretical results in the case of a largely curved beams after repeated bending/unbending process is 1.27%.     

Life expectancy prediction and application properties of novel polyurethane based thickness sensitive and thickness insensitive spectrally selective paint coatings for solar absorbers

A novel Thickness Sensitive Spectrally Selective (TSSS PU B: a_s=0.90, e_T=0.20) paint coating on aluminium substrate was prepared from commercially available polyurethane binder (Binder B) (HELIOS TBLUS, SI) and black pigment (spinel (Mn–Fe)), in combination with trisilanol polyhedral oligomeric silsesquioxane (POSS), which served as pigment dispersant. Polyurethane resin binder B was selected because of its higher thermal stability (determined from thermogravimetric measurements (TG)) than polyurethane resin binder A, which has previously been used for making Thickness Insensitive Spectrally Selective (TISS PU A) coatings (a_s=0.90, e_T=0.38) deposited on copper absorbers (Kuni?, 2009 [36]).Thermal degradation of the TSSS PU B and TISS PU A coatings, both deposited on aluminium substrates, was studied by following, as close as possible, the methodology worked out within TASK 10 of the IEA's Solar and Heating Programme. Thermal load tests were performed in the temperature range from 170 to 200 °C at various time intervals (1, 6, 10, 15, 21 days). Degradation of the coatings was assessed using a variety of degradation indicators: changes of solar absorptance and thermal emittance determined from the hemispherical IR and VIS/NIR spectra, intensity changes of selected vibrational modes attributed to the polymeric backbone and ester and urethane linkages and combined with peel-off tests used as adhesion and cohesion indicators. The results revealed that degradation of the polyurethane resin binder was attributable to the breaking of the urethane linkages, also shown from the AFM and XPS spectra measurements. For the TISS PU A coating, the life expectancy was estimated to be 22.77 years (activation energy (E_a)=163.2 kJ/mol, T_eff=113.4 °C) while for the TSSS PU B coatings, it was at least 25.96 years (activation energy (E_a)=96 kJ/mol, T_eff=102 °C).     

Distributed REM-Assisted Radio Resource Management in LTE-A Networks

The successful actions of public-safety personnel during disaster recovery depend heavily on rapidly deployable and reliable mission-critical communication networks. As part of the Aerial Base Stations with Opportunistic Links for Unexpected Temporary Events project we focused on designing, prototyping and demonstrating a high-capacity, IP, mobile-data network with a low latency and large coverage, suitable for many forms of multi-media delivery, including public-safety and temporary-event use cases. In this paper we focus on a rapidly deployable wireless network based on the LTE-A-enabled, low-altitude Platforms and portable land mobile units to support disaster-relief activities. In order to minimize the inter- and intra-network interference during the radio networks operating phase, we have proposed and evaluated a novel, central-based, dynamic radio resource management algorithm for downlink communications that applies radio-interference maps from the radio environment map and traffic demands at a particular eNB. Using this we are able to efficiently allocate radio resources based on quality-of-service demands. The radio environmental maps are used to calculate the radio coverage and signal strength. In addition, we present the developed framework, which can be applied as a tool for the design, modelling, simulation and evaluation of an LTE-A network for emergency use cases and for estimating the system capacity in a dynamic (roll-in, roll-out phase) network deployment. The proposed algorithm is evaluated with the simulation model using possible real use cases (i.e., forest fire, and earthquake in an urban area) in real remote and urban regions of Slovenia.     

Achieving profitably,operationally, and environmentally compromise flow‐sheet designs by a single‐criterion optimization

Compromise designs that can be achieved to a certain extent in process flow‐sheet optimization not only by multicriteria but also by single‐criterion optimization are described. A well‐balanced compromise between the profitability, operational, and environmental efficiencies can be achieved using a suitable economic criterion. From the financial point of view, the net present value (NPV) is the correct criterion for selection from among mutually exclusive solutions and, hence, for evaluating different designs in process optimization. Other criteria are also often used in engineering practice. It is shown that optimal designs obtained using different economic objectives vary not only in their investment and other financial indicators, but also in operational efficiencies and environmental indicators. Operationally more efficient and environmentally less harmful solutions can be obtained at lower profitability, by increasing the invested funds. The net present value generates the best compromise between these objectives, as illustrated by three flow‐sheet synthesis problems. © 2011 American Institute of Chemical Engineers AIChE J, 2012     

Levels of Circulating PD-L1 Are Decreased in Patients with Resectable Cholangiocarcinoma

Tumor resection represents the only curative treatment option for patients with biliary tract cancers (BTCs), including intrahepatic cholangiocarcinoma (CCA), perihilar and extrahepatic CCA and gallbladder cancer. However, many patients develop early tumor recurrence and are unlikely to benefit from surgery. Therefore, markers to identify ideal surgical candidates are urgently needed. Circulating programmed cell death 1 ligand 1 (PD-L1) has recently been associated with different malignancies, including pancreatic cancer which closely resembles BTC in terms of patients’ prognosis and tumor biology. Here, we aim at evaluating a potential role of circulating PD-L1 as a novel biomarker for resectable BTC. Methods: Serum levels of PD-L1 were analyzed by ELISA in 73 BTC patients and 42 healthy controls. Results: Circulating levels of preoperative PD-L1 were significantly lower in patients with BTC compared to controls. Patients with low PD-L1 levels displayed a strong trend towards an impaired prognosis, and circulating PD-L1 was negatively correlated with experimental markers of promalignant tumor characteristics such as CCL1, CCL21, CCL25 and CCL26. For 37 out of 73 patients, postoperative PD-L1 levels were available. Interestingly, after tumor resection, circulating PD-L1 raised to almost normal levels. Notably, patients with further decreasing PD-L1 concentrations after surgery showed a trend towards an impaired postoperative outcome. Conclusion: Circulating PD-L1 levels were decreased in patients with resectable BTC. Lack of normalization of PD-L1 levels after surgery might identify patients at high risk for tumor recurrence or adverse outcome.