Search results for: dense membrane

Authors: Wojciech Kulesza

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The north-western part of the Poland, specifically West Pomerania and Lubuskie provinces, from several years are the subject of research of the Department of Archaeology of Early Middle Ages of Institute of Archaeology of Nicolaus Copernicus University in Toruń. This area has a dense network of rivers and numerous lakes, where many of them are connected to the southern part of the Baltic Sea. During the many years of research in this area, archaeologists discovered the remains of the early Middle Ages settlement located on several islands and in most cases were encountered relics of early Middle Ages bridges linking those islands with the mainland. During the excavation, work was carried out both under water and on land for the accurate identification of islands and adjacent to them underwater areas. The result of this work is a graphic documentation, made in a three-dimensional technique, not only for the underwater trenches but also relics of bridges and objects discovered during exploration, which as the main theme will be presented in the full presentation.

Keywords: Poland, underwater archaeology, Nicolaus Copernicus University, early middle ages

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Authors: Chen Jiang, Eric Jordan, Maurice Gell, Balakrishnan Nair

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Nuclear fusion, one of the most promising options for reliably generating large amounts of carbon-free energy in the future, has seen a plethora of ground-breaking technological advances in recent years. An efficient and durable “breeding blanket”, needed to ensure a reactor’s self-sufficiency by maintaining the optimal coolant temperature as well as by minimizing radiation dosage behind the blanket, still remains a technological challenge for the various reactor designs for commercial fusion power plants. A relatively new dual-coolant lead-lithium (DCLL) breeder design has exhibited great potential for high-temperature (>700oC), high-thermal-efficiency (>40%) fusion reactor operation. However, the structural material, namely reduced activation ferritic-martensitic (RAFM) steel, is not chemically stable in contact with molten Pb-17%Li coolant. Thus, to utilize this new promising reactor design, the demand for effective corrosion-resistant coatings on RAFM steels represents a pressing need. Solution Spray Technologies LLC (SST) is developing a double-layer ceramic coating design to address the corrosion protection of RAFM steels, using a novel solution and solution/suspension plasma spray technology through a US Department of Energy-funded project. Plasma spray is a coating deposition method widely used in many energy applications. Novel derivatives of the conventional powder plasma spray process, known as the solution-precursor and solution/suspension-hybrid plasma spray process, are powerful methods to fabricate thin, dense ceramic coatings with complex compositions necessary for the corrosion protection in DCLL breeders. These processes can be used to produce ultra-fine molten splats and to allow fine adjustment of coating chemistry. Thin, dense ceramic coatings with chosen chemistry for superior chemical stability in molten Pb-Li, low activation properties, and good radiation tolerance, is ideal for corrosion-protection of RAFM steels. A key challenge is to accommodate its CTE mismatch with the RAFM substrate through the selection and incorporation of appropriate bond layers, thus allowing for enhanced coating durability and robustness. Systematic process optimization is being used to define the optimal plasma spray conditions for both the topcoat and bond-layer, and X-ray diffraction and SEM-EDS are applied to successfully validate the chemistry and phase composition of the coatings. The plasma-sprayed double-layer corrosion resistant coatings were also deposited onto simulated RAFM steel substrates, which are being tested separately under thermal cycling, high-temperature moist air oxidation as well as molten Pb-Li capsule corrosion conditions. Results from this testing on coated samples, and comparisons with bare RAFM reference samples will be presented and conclusions will be presented assessing the viability of the new ceramic coatings to be viable corrosion prevention systems for DCLL breeders in commercial nuclear fusion reactors.

Keywords: breeding blanket, corrosion protection, coating, plasma spray

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Authors: Milind D. Meshram

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Ascarids are the most frequent worm parasite of dogs and cats. There are two species that commonly infect dogs: Toxocara canis and Toxascaris leonina. Adult roundworms live in the stomach and intestines and can grow to 7 inches (18 cm) long. A female may lay 200,000 eggs in a day. The eggs are protected by a hard shell. They are extremely hardy and can live for months or years in the soil. A dog aged about 6 years, from Satara was referred to Teaching Veterinary Clinical Complex (TVCC) with a complaint of abdominal pain, anorexia, loss of condition and dull body coat with mucous pale membrane. The clinical examination revealed Anaemia, palpation of abdomen revealed enlargement of liver, slimy feel of the intestine loop, diarrhea.

Keywords: therapeutic management, Toxocara canis, induced hepatitis, dogs

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Authors: Lucas L. L. Fortes, Sandro T. M. Gonçalves

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In this work, it is analyzed the wideband performance with the mesh discretization impoverishment of the Conformal Finite Difference Time-Domain (C-FDTD) approaches developed by Raj Mittra, Supriyo Dey and Wenhua Yu for the Finite Difference Time-Domain (FDTD) method. These approaches are a simple and efficient way to optimize the scattering simulation of curved surfaces for Dielectric and Perfect Electric Conducting (PEC) structures in the FDTD method, since curved surfaces require dense meshes to reduce the error introduced due to the surface staircasing. Defined, on this work, as D-FDTD-Diel and D-FDTD-PEC, these approaches are well-known in the literature, but the improvement upon their application is not quantified broadly regarding wide frequency bands and poorly discretized meshes. Both approaches bring improvement of the accuracy of the simulation without requiring dense meshes, also making it possible to explore poorly discretized meshes which bring a reduction in simulation time and the computational expense while retaining a desired accuracy. However, their applications present limitations regarding the mesh impoverishment and the frequency range desired. Therefore, the goal of this work is to explore the approaches regarding both the wideband and mesh impoverishment performance to bring a wider insight over these aspects in FDTD applications. The D-FDTD-Diel approach consists in modifying the electric field update in the cells intersected by the dielectric surface, taking into account the amount of dielectric material within the mesh cells edges. By taking into account the intersections, the D-FDTD-Diel provides accuracy improvement at the cost of computational preprocessing, which is a fair trade-off, since the update modification is quite simple. Likewise, the D-FDTD-PEC approach consists in modifying the magnetic field update, taking into account the PEC curved surface intersections within the mesh cells and, considering a PEC structure in vacuum, the air portion that fills the intersected cells when updating the magnetic fields values. Also likewise to D-FDTD-Diel, the D-FDTD-PEC provides a better accuracy at the cost of computational preprocessing, although with a drawback of having to meet stability criterion requirements. The algorithms are formulated and applied to a PEC and a dielectric spherical scattering surface with meshes presenting different levels of discretization, with Polytetrafluoroethylene (PTFE) as the dielectric, being a very common material in coaxial cables and connectors for radiofrequency (RF) and wideband application. The accuracy of the algorithms is quantified, showing the approaches wideband performance drop along with the mesh impoverishment. The benefits in computational efficiency, simulation time and accuracy are also shown and discussed, according to the frequency range desired, showing that poorly discretized mesh FDTD simulations can be exploited more efficiently, retaining the desired accuracy. The results obtained provided a broader insight over the limitations in the application of the C-FDTD approaches in poorly discretized and wide frequency band simulations for Dielectric and PEC curved surfaces, which are not clearly defined or detailed in the literature and are, therefore, a novelty. These approaches are also expected to be applied in the modeling of curved RF components for wideband and high-speed communication devices in future works.

Keywords: accuracy, computational efficiency, finite difference time-domain, mesh impoverishment

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Authors: Ines Antunes, Andrea Massari, Concetta Bartucca

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Greenhouse gasses (GHG) role in the atmosphere has been well known since the 19th century; however, researchers have begun to relate them to climate changes only in the second half of the following century. From this moment, scientists started to correlate the presence of GHG such as CO₂ with the global warming phenomena. This has raised the awareness not only of those who were experts in this field but also of public opinion, which is becoming more and more sensitive to environmental pollution and sustainability issues. Nowadays the reduction of GHG emissions is one of the principal objectives of EU nations. The target is an 80% reduction of emissions in 2050 and to reach the important goal of carbon neutrality. Road sector is responsible for an important amount of those emissions (about 20%). The most part is due to traffic, but a good contribution is also given directly or indirectly from road construction and maintenance. Raw material choice and reuse of post-consumer plastic rather than a cleverer design of roads have an important contribution to reducing carbon footprint. Bituminous membranes can be successfully used as reinforcement systems in asphalt layers to improve road pavement performance against cracking. Composite materials coupling membranes with grids and/or fabrics should be able to combine improved tensile properties of the reinforcement with stress absorbing and waterproofing effects of membranes. Polyglass, with its brand dedicated to road construction and maintenance called Polystrada, has done more than this. The company's target was not only to focus sustainability on the final application but also to implement a greener mentality from the cradle to the grave. Starting from production, Polyglass has made important improvements finalized to increase efficiency and minimize waste. The installation of a trigeneration plant and the usage of selected production scraps inside the products as well as the reduction of emissions into the environment, are one of the main efforts of the company to reduce impact during final product build-up. Moreover, the benefit given by installing Polystrada products brings a significant improvement in road lifetime. This has an impact not only on the number of maintenance or renewal that needs to be done (build less) but also on traffic density due to works and road deviation in case of operations. During the end of the life of a road, Polystrada products can be 100% recycled and milled with classical systems used without changing the normal maintenance procedures. In this work, all these contributions were quantified in terms of CO₂ emission thanks to an LCA analysis. The data obtained were compared with a classical system or a standard production of a membrane. What it is possible to see is that the usage of Polyglass products for street maintenance and building gives a significant reduction of emissions in case of membrane installation under the road wearing course.

Keywords: CO₂ emission, LCA, maintenance, sustainability

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Authors: Keivan Jamshidi

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Myiasis is defined as the infestation of living tissues of vertebrates by larvae of flies. Gingival myiasis is an uncommon type of myiasis. In oral inspection of a death dog (Garmsar, Iran) for routine training postmortem investigation, gingival myiasis was found. Only one larva was removed from the lesions and sent to a parasitology laboratory for identification. For histopathological studies, affected area of the gingiva was cut and placed in 10% formalin, and then sent to pathology laboratory. On parasitological examination the causative agent of this condition was found as larva of Wohlfahrtia magnifica. Histopathological examination of the injured gingiva showed hyperplasia of squamous epithelial tissue and acanthosis in mucosal membrane, hyperemia and infiltration of mononuclear cells and eosinophils into lamina propria. The present report seems to be the first report of gingival myiasis in dog in Iran.

Keywords: Wohlfahrtia magnifica, gingiva, myiasis, dog

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Authors: Lucille Alonso, Florent Renard

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The characterizations of urban heat island (UHI) and their interactions with climate change and urban climates are the main research and public health issue, due to the increasing urbanization of the population. These solutions require a better knowledge of the UHI and micro-climate in urban areas, by combining measurements and modelling. This study is part of this topic by evaluating microclimatic conditions in dense urban areas in the Lyon Metropolitan Area (France) using a combination of data traditionally used such as topography, but also from LiDAR (Light Detection And Ranging) data, Landsat 8 satellite observation and Sentinel and ground measurements by bike. These bicycle-dependent weather data collections are used to build the database of the variable to be modelled, the air temperature, over Lyon’s hyper-center. This study aims to model the air temperature, measured during 6 mobile campaigns in Lyon in clear weather, using multiple linear regressions based on 33 explanatory variables. They are of various categories such as meteorological parameters from remote sensing, topographic variables, vegetation indices, the presence of water, humidity, bare soil, buildings, radiation, urban morphology or proximity and density to various land uses (water surfaces, vegetation, bare soil, etc.). The acquisition sources are multiple and come from the Landsat 8 and Sentinel satellites, LiDAR points, and cartographic products downloaded from an open data platform in Greater Lyon. Regarding the presence of low, medium, and high vegetation, the presence of buildings and ground, several buffers close to these factors were tested (5, 10, 20, 25, 50, 100, 200 and 500m). The buffers with the best linear correlations with air temperature for ground are 5m around the measurement points, for low and medium vegetation, and for building 50m and for high vegetation is 100m. The explanatory model of the dependent variable is obtained by multiple linear regression of the remaining explanatory variables (Pearson correlation matrix with a |r| < 0.7 and VIF with < 5) by integrating a stepwise sorting algorithm. Moreover, holdout cross-validation is performed, due to its ability to detect over-fitting of multiple regression, although multiple regression provides internal validation and randomization (80% training, 20% testing). Multiple linear regression explained, on average, 72% of the variance for the study days, with an average RMSE of only 0.20°C. The impact on the model of surface temperature in the estimation of air temperature is the most important variable. Other variables are recurrent such as distance to subway stations, distance to water areas, NDVI, digital elevation model, sky view factor, average vegetation density, or building density. Changing urban morphology influences the city's thermal patterns. The thermal atmosphere in dense urban areas can only be analysed on a microscale to be able to consider the local impact of trees, streets, and buildings. There is currently no network of fixed weather stations sufficiently deployed in central Lyon and most major urban areas. Therefore, it is necessary to use mobile measurements, followed by modelling to characterize the city's multiple thermal environments.

Keywords: air temperature, LIDAR, multiple linear regression, surface temperature, urban heat island

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Authors: Pawas Suren

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The conflict between livelihood and forest protection has been a perpetual phenomenon in India. In the era of climate change, the problem is expected to aggravate the declining trend of dense forest in the country, creating impediments in the climate change adaptation by the forest dependent communities. In order to access the complexity of the problem, Hazarinagh and Chatra districts of Jharkhand were selected as a case study. To identify norms practiced by the communities to manage community forestry, the ethnographic study was designed to understand the values, traditions, and cultures of forest dependent communities, most of whom were tribal. It was observed that internalization of efficient forest norms is reflected in the pride and honor of such behavior while violators are sanctioned through guilt and shame. The study analyzes the effect of norms being practiced in the management and ecology of community forestry as common property resource. The light of the findings led towards the gaps in the prevalent forest laws to address efficient allocation of property rights. The conclusion embarks on reconsidering accepted factors of forest degradation in India.

Keywords: climate change, common property resource, community forestry, norms

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Authors: Divya Dharshini Omprakash, Anjali Subramani

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Most of the tall structures are constructed using shear walls and tube systems in the recent decades. This makes the structure heavy and less resistant to lateral effects as the height of the structure goes up. This paper aims in the reduction of self-weight in tall structures by the use of Taper Cladding System (TCS) and also enumerates the construction techniques used in TCS. TCS has a tapering clad either fixed at the top or bottom of the structural core at the tapered end. This system eliminates the use of RC structural elements on the exterior of the structure and uses fewer columns only on the interior part to take up the gravity loads in order to reduce the self-weight of the structure. The self-weight reduction by TCS is 50% more compared to the present structural systems. The lateral loads on the hull will be taken care of by the tapered steel frame. Analysis were done to study the structural behaviour of taper cladded buildings subjected to lateral loads. TCS has a great impact in the construction of tall structures in seismic and dense urban areas. An effective construction management can be done by the use of Taper Cladding System. In this paper, sustainability, design considerations and implications of the system has also been discussed.

Keywords: Lateral Loads Resistance, reduction of self-weight, sustainable, taper clads

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Authors: B. T. Naveen Kumar, Anuj Tyagi, Niraj Kumar Singh, Visanu Boonyawiwat, A. H. Shanthanagouda, Orawan Boodde, K. M. Shankar, Prakash Patil, Shubhkaramjeet Kaur

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Early mortality syndrome (EMS)/Acute Hepatopancreatic Necrosis Disease (AHPND) has emerged as a major obstacle for the shrimp farming around the world. It is caused by a strain of Vibrio parahaemolyticus. The possible preventive and control measure is, early and rapid detection of the pathogen in the broodstock, post-larvae and monitoring the shrimp during the culture period. Polymerase chain reaction (PCR) based early detection methods are good, but they are costly, time taking and requires a sophisticated laboratory. The present study was conducted to develop a simple, sensitive and rapid diagnostic farmer level kit for the reliable detection of AHPND in shrimp. A panel of monoclonal antibodies (MAbs) were raised against the recombinant Pir B protein (rPirB). First, an immunodot was developed by using MAbs G3B8 and Mab G3H2 which showed specific reactivity to purified r-PirB protein with no cross-reactivity to other shrimp bacterial pathogens (AHPND free Vibrio parahaemolyticus (Indian strains), V. anguillarum, WSSV, Aeromonas hydrophila, and Aphanomyces invadans). Immunodot developed using Mab G3B8 is more sensitive than that with the Mab G3H2. However, immunodot takes almost 2.5 hours to complete with several hands-on steps. Therefore, the flow-through assay (FTA) was developed by using a plastic cassette containing the nitrocellulose membrane with absorbing pads below. The sample was dotted in the test zone on the nitrocellulose membrane followed by continuos addition of five solutions in the order of i) blocking buffer (BSA) ii) primary antibody (MAb) iii) washing Solution iv) secondary antibody and v) chromogen substrate (TMB) clear purple dots against a white background were considered as positive reactions. The FTA developed using MAbG3B8 is more sensitive than that with MAb G3H2. In FTA the two MAbs showed specific reactivity to purified r-PirB protein and not to other shrimp bacterial pathogens. The FTA is simple to farmer/field level, sensitive and rapid requiring only 8-10 min for completion. Tests can be developed to kits, which will be ideal for use in biosecurity, for the first line of screening (at the port or pond site) and during monitoring and surveillance programmes overall for the good management practices to reduce the risk of the disease.

Keywords: acute hepatopancreatic necrosis disease, AHPND, flow-through assay, FTA, farmer level, immunodot, pond site, shrimp

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Authors: Mohamed Hashelaf, Ahmed Al-Osdody

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In this paper, we focused our efforts on one of the vaguest subjects in astrophysics that is the formation and evolution of the universe until the arrival of humans. Through an in-depth exploration of the origins of the universe, understanding what has happened since the Big Bang until now and checking the history of creation, we can answer questions about the future of life, the possibility of its existence elsewhere in the universe and to be able to understand how we came, what our role in the circle of life is and what the future of our development will be. Here is where we used systematic steps that allowed us first and foremost to identify the reason behind the big bang itself that formed a large cloud of cosmic dust. Then after a period of time from the expansion of the universe and its coolness, the initial molecules of gases from the cosmic cloud began to condense, forming a very dense field of gravity that after millions of years led to the formation of stars, galaxies, even earth and the else planets. Finally, it became clear before us that after the earth has formed, the existence of liquid water made it possible for life to form, starting from the bacteria all the way until the appearance of the humans that we know today. But it does not stop here. If we look and contemplate in ourselves as humans, we will understand that the universe is inside us and that’s what makes us exceptional. All of this means that just as life on earth was created, it could have been on other planets as well. It also means that we are the universe’s key to understand itself.

Keywords: Big Bang, cosmic dust, primary elements, universe

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Authors: Ismayanti Magfirah, Sartohadi Junun, Samodra Guruh

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Landslides are one of the most frequent and devastating natural disasters in Indonesia. Many studies have been conducted regarding this phenomenon. However, there is a lack of attention in the landslide inventory mapping. The natural condition (dense forest area) and the limited human and economic resources are some of the major problems in building landslide inventory in Indonesia. Considering the importance of landslide inventory data in susceptibility, hazard, and risk analysis, it is essential to generate landslide inventory based on available resources. In order to achieve this, the first thing we have to do is identify the landslides' location. The presence of Sentinel-1A and Sentinel-2A data gives new insights into land monitoring investigation. The free access, high spatial resolution, and short revisit time, make the data become one of the most trending open sources data used in landslide mapping. Sentinel-1A and Sentinel-2A data have been used broadly for landslide detection and landuse/landcover mapping. This study aims to generate landslide map by integrating Sentinel-1A and Sentinel-2A data use change detection method. The result will be validated by field investigation to make preliminary landslide inventory in the study area.

Keywords: change detection method, landslide inventory mapping, Sentinel-1A, Sentinel-2A

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Authors: Elif Erdem, Nalan Kaya, Gonca Ozan, Durrin Ozlem Dabak, Enver Ozan

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This study was carried out to determine the histological and biochemical changes in the lungs of the rat pups exposed to tobacco smoke during pregnancy period and to investigate the protective effects of alpha lipoic acid, which is administered during pregnancy, on these changes. In our study, 24 six-week old Spraque-Dawley female rats weighing 160 ± 10 g were used (n:7). Rats were randomly divided into four equal groups: group I (control), group II (tobacco smoke), group III (tobacco smoke + alpha lipoic acid) and group IV (alpha lipoic acid). Rats in the group II, group III were exposed to tobacco smoke twice a day for one hour starting from eight weeks before mating and during pregnancy. In addition to tobacco smoke, 20 mg/kg of alpha lipoic acid was administered via oral gavage to the rats in the group III. Only alpha lipoic acid was administered to the rats in the group IV. Once after the delivery, all administrations were stopped. On the 7 and 21th days, the seven pups of all groups were decapitated. A portion of the lung was taken and stained with HE, PAS and Masson. In addition to immunohistochemical staining of surfactant protein A, vascular endothelial growth factor, caspase-3, TUNEL method was also used to determine apoptosis. Biochemical analyzes were performed with some part of the lung tissue specimens. In the histological evaluations performed under light microscopy, inflammatory cell increase, hemorrhagic areas, edema, interalveolar septal thickening, alveolar numbers decrease, degeneration of some bronchi and bronchial epithelium, epithelial cells that were fallen into the lumen and hyaline membrane formation were observed in tobacco smoke group. These findings were ameliorated in tobacco smoke + ALA group. Hyaline membrane formation was not detected in this group. The TUNEL positive cell numbers a significant increase was detected in the tobacco smoke group, whereas a significant decrease was detected in the tobacco smoke + ALA group. In terms of the immunoreactivity of both SP-A and VEGF, a significant decrease was observed in the tobacco smoke group, and a significant increase was observed in the tobacco smoke + ALA group. Regarding the immunoreactivity of caspase-3, there was a significant increase in the group of tobacco smoke and a significant decrease in the group of tobacco smoke + ALA. The malondialdehyde levels were determined to be significantly increased in the tobacco smoke group, and a significant decreased in the tobacco smoke + ALA. Glutathione and superoxide dismutase enzyme activities showed a significant decrease in the group of tobacco smoke and a significant increase in the tobacco smoke + ALA group. In conclusion, we suggest that the exposure to tobacco smoke during pregnancy leads to morphological, histopathological and functional changes on lung development by causing oxidative damage in lung tissues of neonatal rats and the maternal use of alpha lipoic acid can provide a protective effect on the neonatal lung development against this oxidative stress originating from tobacco smoke.

Keywords: alpha lipoic acid, lung, neonate, tobacco smoke, pregnancy

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Authors: Debajyoti Mukherjee, Arathy B. S., Arpita Sahu, Saranga P. Pogula

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A Functional Model to mimic the functional correctness of a Neural Network Compute Accelerator IP is very crucial for design validation. Neural network workloads are based on a Brain Floating Point (BF-16) data type. The major challenge we were facing was the incompatibility of gcc compilers to BF-16 datatype, which we addressed with a native BF-16 generator integrated to our functional model. Moreover, working with big GEMM (General Matrix Multiplication) or SpMM (Sparse Matrix Multiplication) Work Loads (Dense or Sparse) and debugging the failures related to data integrity is highly painstaking. In this paper, we are addressing the quality challenge of such a complex Neural Network Accelerator design by proposing a Functional Model-based scoreboard or Software model using SystemC. The proposed Functional Model executes the assembly code based on the ISA of the processor IP, decodes all instructions, and executes as expected to be done by the DUT. The said model would give a lot of visibility and debug capability in the DUT bringing up micro-steps of execution.

Keywords: ISA (instruction set architecture), NN (neural network), TLM (transaction-level modeling), GEMM (general matrix multiplication)

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Authors: G. Bharath, K. S. Reddy, Vivek Tandon, M. Amaranatha Reddy

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This paper presents the details of a study conducted to evaluate the interaction between recycled binder and fresh binder in Recycled Asphalt Pavement (RAP) mixes. When RAP is mixed with virgin aggregates in the presence of fresh binder there will be partial blending in a hot mix asphalt mixture. A recent approach used by some researchers for studying the degree of blending of RAP binder with virgin binder has been adopted in this study. Dense Bituminous Macadam mix of Ministry of Road Transport of India with a nominal maximum aggregate size of 19 mm was studied. Two proportions of RAP-20% and 35% and two types of virgin binders – viscosity grade VG10 and VG30 were considered. Design binder contents were determined for all the four types of mixes (two RAP contents and two virgin binders) as per Marshall mix design procedure. The degree of blending of RAP and virgin binders was evaluated in terms of the complex modulus of the binder. Laboratory test results showed that with an increase in RAP content, the degree of blending decreases. Better blending was observed for softer grade binder (VG10).

Keywords: blending, complex modulus, recycled asphalt pavement, virgin binder

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Authors: Mohanad Alhabo, Naveed Nawaz, Mahmoud Al-Faris

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The dense deployment of small cells is a promising solution to enhance the coverage and capacity of the heterogeneous networks (HetNets). However, the unplanned deployment could bring new challenges to the network ranging from interference, unnecessary handovers and handover failures. This will cause a degradation in the quality of service (QoS) delivered to the end user. In this paper, we propose an integrated Grey Rational Analysis Standard Deviation based handover method (GRA-SD) for HetNet. The proposed method integrates the Standard Deviation (SD) technique to acquire the weight of the handover metrics and the GRA method to select the best handover base station. The performance of the GRA-SD method is evaluated and compared with the traditional Multiple Attribute Decision Making (MADM) methods including Simple Additive Weighting (SAW) and VIKOR methods. Results reveal that the proposed method has outperformed the other methods in terms of minimizing the number of frequent unnecessary handovers and handover failures, in addition to improving the energy efficiency.

Keywords: energy efficiency, handover, HetNets, MADM, small cells

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Authors: Andrew Randles, Ilker Ocak, Cheam Daw Don, Navab Singh, Alex Gu

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Nine Degrees of Freedom (9 DOF) systems are already in development in many areas. In this paper, an integrated pressure sensor is proposed that will make use of an already existing monolithic 9 DOF inertial MEMS platform. Capacitive pressure sensors can suffer from limited sensitivity for a given size of membrane. This novel pressure sensor design increases the sensitivity by over 5 times compared to a traditional array of square diaphragms while still fitting within a 2 mm x 2 mm chip and maintaining a fixed static capacitance. The improved design uses one large diaphragm supported by pillars with fixed electrodes placed above the areas of maximum deflection. The design optimization increases the sensitivity from 0.22 fF/kPa to 1.16 fF/kPa. Temperature sensitivity was also examined through simulation.

Keywords: capacitive pressure sensor, 9 DOF, 10 DOF, sensor, capacitive, inertial measurement unit, IMU, inertial navigation system, INS

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Authors: Cuong D. Dao, Rob J.I. Basten, Andreas Hartmann

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This paper studies the optimal maintenance planning of preventive maintenance and renewal activities for components in a single railway track when the available time for maintenance is limited. The rail-track system consists of several types of components, such as rail, ballast, and switches with different preventive maintenance and renewal intervals. To perform maintenance or renewal on the track, a train free period for maintenance, called a possession, is required. Since a major possession directly affects the regular train schedule, maintenance and renewal activities are clustered as much as possible. In a highly dense and utilized railway network, the possession time on the track is critical since the demand for train operations is very high and a long possession has a severe impact on the regular train schedule. We present an optimization model and investigate the maintenance schedules with and without the possession capacity constraint. In addition, we also integrate the social-economic cost related to the effects of the maintenance time to the variable possession cost into the optimization model. A numerical example is provided to illustrate the model.

Keywords: rail-track components, maintenance, optimal clustering, possession capacity

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Authors: Kate Smith, Shuming Liu, Yi Liu, Dragan Savic, Gustaf Olsson, Tian Chang, Xue Wu

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In a water supply system, a great deal of care goes into sourcing, treating and delivering water to consumers, but less thought is given to the energy consumed during these processes. This study uses 2011 data to quantify energy use for urban water supply in China and investigates population density as a possible influencing factor. The objective is to provide information that can be used to develop energy-conscious water infrastructure policy, calculate the energy co-benefits of water conservation and compare energy use between China and other countries. The average electrical energy intensity and per capita electrical energy consumption for urban water supply in China in 2011 were 0.29 kWh/m3 and 33.2 kWh/cap•yr, respectively. Comparison between provinces revealed a direct correlation between energy intensity of urban water supply and population served per unit length of pipe. This could imply energy intensity is lower when more densely populated areas are supplied by relatively dense networks of pipes. This study also found that whereas the percentage of energy used for urban water supply tends to increase with the percentage of population served this increase is slower where water supply is more energy efficient and where a larger percentage of population is already supplied.

Keywords: china, electrical energy use, water-energy nexus, water supply

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Authors: Bintao Wu, Xiangfang Xu, Yugang Miao，Duanfeng Han

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Joining of 1 mm thick aluminum 6061 to titanium TC4 was conducted using Bypass-current MIG welding-brazed, and stable welding process and good bead appearance were obtained. The Joint profile and microstructure of Ti/Al joints were observed by optical microscopy and SEM and then the structure of the interfacial reaction layers were analyzed in details. It was found that the intermetallic compound layer at the interfacial top is in the form of columnar crystal, which is in short and dense state. A mount of AlTi were observed at the interfacial layer near the Ti base metal while intermetallic compound like Al3Ti、TiSi3 were formed near the Al base metal, and the Al11Ti5 transition phase was found in the center of the interface layer due to the uneven distribution inside the weld pool during the welding process. Tensile test results show that the average tensile strength of joints is up to 182.6 MPa, which reaches about 97.6% of aluminum base metal. Fracture is prone to occur in the base metal with a certain amount of necking.

Keywords: bypass-current MIG welding-brazed, Al alloy, Ti alloy, joint characteristics, mechanical properties

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Authors: H. Özkan Gülsoy, Antonyraj Arockiasamy

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The application of powder injection molding technology for the fabrication of metallic and non-metallic components is of growing interest as the process considerably saves time and cost. Utilizing this fabrication method, full dense components are being prepared in various sizes. In this work, our effort is focused to study the densification behavior of the parts made using different size 316L stainless steel powders. The metal powders were admixed with an adequate amount of polymeric compounds and molded as standard tensile bars. Solvent and thermal debinding was carried out followed by sintering in ultra pure hydrogen atmosphere based on the differential scanning calorimetry (DSC) cycle. Mechanical property evaluation and microstructural characterization of the sintered specimens was performed using universal Instron tensile testing machine, Vicker’s microhardness tester, optical (OM) and scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction were used. The results are compared and analyzed to predict the strength and weakness of the test conditions.

Keywords: powder injection molding, sintering, particle size, stainless steels

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Authors: S. Boudali, A. M. Soliman, B. Abdulsalam, K. Ayed, D. E. Kerdal, S. Poncet

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This study investigates the potential of using crushed concrete as aggregates to produce green and sustainable concrete. Crushed concrete was sieved to powder fine recycled aggregate (PFRA) less than 80 µm and coarse recycled aggregates (CRA). Physical, mechanical, and microstructural properties for PFRA and CRA were evaluated. The effect of the additional rates of PFRA and CRA on strength development of recycled aggregate concrete (RAC) was investigated. Additionally, the characteristics of interfacial transition zone (ITZ) between cement paste and recycled aggregate were also examined. Results show that concrete mixtures made with 100% of CRA and 40% PFRA exhibited similar performance to that of the control mixture prepared with 100% natural aggregate (NA) and 40% natural pozzolan (NP). Moreover, concrete mixture incorporating recycled aggregate exhibited a slightly higher later compressive strength than that of the concrete with NA. This was confirmed by the very dense microstructure for concrete mixture incorporating recycled concrete aggregates compared to that of conventional concrete mixture.

Keywords: compressive strength, recycled concrete aggregates, microstructure, interfacial transition zone, powder fine recycled aggregate

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Authors: Ghada Al-Kafaji, Mohamed Sabry

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Mitochondria are the site of cellular respiration and produce energy in the form of adenosine triphosphate (ATP) via oxidative phosphorylation. They are the major source of intracellular reactive oxygen species (ROS) and are also direct target to ROS attack. Oxidative stress and ROS-mediated disruptions of mitochondrial function are major components involved in the pathogenicity of diabetic complications. In this work, the changes in mitochondrial DNA (mtDNA) copy number, biogenesis, gene expression of mtDNA-encoded subunits of electron transport chain (ETC) complexes, and mitochondrial function in response to hyperglycemia-induced ROS and the effect of direct inhibition of ROS on mitochondria were investigated in an in vitro model of diabetic nephropathy using human renal mesangial cells. The cells were exposed to normoglycemic and hyperglycemic conditions in the presence and absence of Mn(III)tetrakis(4-benzoic acid) porphyrin chloride (MnTBAP) or catalase for 1, 4 and 7 days. ROS production was assessed by the confocal microscope and flow cytometry. mtDNA copy number and PGC-1a, NRF-1, and TFAM, as well as ND2, CYTB, COI, and ATPase 6 transcripts, were all analyzed by real-time PCR. PGC-1a, NRF-1, and TFAM, as well as ND2, CYTB, COI, and ATPase 6 proteins, were analyzed by Western blotting. Mitochondrial function was determined by assessing mitochondrial membrane potential and adenosine triphosphate (ATP) levels. Hyperglycemia-induced a significant increase in the production of mitochondrial superoxide and hydrogen peroxide at day 1 (P < 0.05), and this increase remained significantly elevated at days 4 and 7 (P < 0.05). The copy number of mtDNA and expression of PGC-1a, NRF-1, and TFAM as well as ND2, CYTB, CO1 and ATPase 6 increased after one day of hyperglycemia (P < 0.05), with a significant reduction in all those parameters at 4 and 7 days (P < 0.05). The mitochondrial membrane potential decreased progressively at 1 to 7 days of hyperglycemia with the parallel progressive reduction in ATP levels over time (P < 0.05). MnTBAP and catalase treatment of cells cultured under hyperglycemic conditions attenuated ROS production reversed renal mitochondrial oxidative stress and improved mtDNA, mitochondrial biogenesis, and function. These results show that hyperglycemia-induced ROS caused an early increase in mtDNA copy number, mitochondrial biogenesis and mtDNA-encoded gene expression of the ETC subunits in human mesangial cells as a compensatory response to the decline in mitochondrial function, which precede the mtDNA defect and mitochondrial dysfunction with a progressive oxidative response. Protection from ROS-mediated damage to renal mitochondria induced by hyperglycemia may be a novel therapeutic approach for the prevention/treatment of DN.

Keywords: diabetic nephropathy, hyperglycemia, reactive oxygen species, oxidative stress, mtDNA, mitochondrial dysfunction, manganese superoxide dismutase, catalase

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Authors: Barun Chakrabarti, Dan Nir, Vladimir Yufit, P. V. Aravind, Nigel Brandon

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Fuel cell grade gas-diffusion layer carbon paper (CP) electrodes are subjected to electrophoresis in N,N’-dimethylformamide (DMF) consisting of reduced graphene oxide (rGO). The rGO modified electrodes are compared with CP in a single asymmetric all-vanadium redox battery system (employing a double serpentine flow channel for each half-cell). Peak power densities improved by 4% when the rGO deposits were facing the ion-exchange membrane (cell performance was poorer when the rGO was facing the flow field). Cycling of the cells showed least degradation of the CP electrodes that were coated with rGO in comparison to pristine samples.

Keywords: all-vanadium redox flow batteries, carbon paper electrodes, electrophoretic deposition, reduced graphene oxide

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Authors: Rachid El Aidani, Phuong Nguyen-Tri, Toan Vu-Khanh

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This study intends to show the influence of the hydrolytic degradation on the properties of the e-PTFE/NOMEX® membranes used in fire-protective clothing. The modification of water vapour permeability, morphology and chemical structure was examined by MOCON Permatran, electron microscopy scanning (SEM), and ATR-FTIR, respectively. A decrease in permeability to water vapour of the aged samples was observed following closure of transpiration pores. Analysis of fiber morphology indicates the appearance of defects at the fibers surface with the presence of micro cavities as well as the of fibrils. ATR-FTIR analysis reveals the presence of a new absorption band attributed to carboxylic acid terminal groups generated during the amide bond hydrolysis.

Keywords: hydrolytic ageing, moisture membrane, water vapor permeability, morphology

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Authors: Nikita Sankhe

Abstract:

A Frenum is a band or fold of mucous membrane, which is usually with enclosed muscle fibers, that attaches the lip and cheek to the alveolar mucosa or the gingiva and the underlying periosteum. It curbs or limits the movements of an organ. A frenum becomes a problem if its attachment is too close to the marginal or papillary gingiva, namely localized gingival recession and a midline diastema or it may pull the gingival margin away from the tooth allowing plaque accumulation and inhibit toothbrushing. Frenectomy is the complete removal of the frenum including its attachment to the underlying bone. Miller suggested a technique where by a closure was done across the midline by laterally positioned gingiva. Healing by primary intention resulted in aesthetically acceptable attached gingiva across the midline. This paper aims at showing how a lateral pedicle graft technique combined with frenectomy proves to be more advantageous than any other technique.

Keywords: frenum , frenectomy , lateral pedicle graft , classical frenectomy

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Authors: Bilge Yaman Islak, Erhan Ayas

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The densification behavior of TiB₂ – Ti₃SiC₂ composites is investigated for temperatures in the range of 1200°C to 1400°C, for the pressure of 40 and 50MPa, and for holding time between 15-30 min by spark plasma sintering (SPS) technique. Ti, Si, TiC and 5 wt.% TiB₂ were used to synthesize TiB₂ – Ti₃SiC₂ composites and the effect of different sintering parameters on the densification and phase evolution of these composites were investigated. The bulk densities were determined by using the Archimedes method. The polished and fractured surfaces of the samples were examined using a scanning electron microscope equipped with an energy dispersive spectroscopy (EDS). The phase analyses were accomplished by using the X-Ray diffractometer. Sintering temperature and holding time are found to play a dominant role in the phase development of composites. TiₓCᵧ and TiSi₂ secondary phases were found in 5 wt.%TiB₂ – Ti₃SiC₂ composites densified at 1200°C and 1400°C under the pressure of 40 MPa, due to decomposition of Ti₃SiC₂. The results indicated that 5 wt.%TiB₂ – Ti₃SiC₂ composites were densified into the dense parts with a relative density of 98.77% by sintering at 1300 °C, for 15 min, under a pressure of 50 MPa via SPS without the formation of any other ancillary phase. This work was funded and supported by Scientific Research Projects Commission of Eskisehir Osmangazi University with the Project Number 201915C103 (2019-2517).

Keywords: densification, phase evolution, sintering, TiB₂ – Ti₃SiC₂ composites

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Authors: Konstantinos G. Dassios, Guillaume Bonnefont, Gilbert Fantozzi, Theodore E. Matikas, Costas Galiotis

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We report herein the development and preliminary mechanical characterization of fully-dense multi-wall carbon nanotube (MWCNT)-reinforced ceramics and glasses based on a completely new methodology termed High Shear Compaction (HSC). The tubes are introduced and bound to the matrix grains by aid of polymeric binders to form flexible green bodies which are sintered and densified by spark plasma sintering to unprecedentedly high densities of 100% of the pure-matrix value. The strategy was validated across a PyrexTM glass / MWCNT composite while no identifiable factors limit application to other types of matrices. Non-destructive evaluation, based on ultrasonics, of the dynamic mechanical properties of the materials including elastic, shear and bulk modulus as well as Poisson’s ratio showed optimum property improvement at 0.5 %wt tube loading while evidence of nanoscale-specific energy dissipative characteristics acting complementary to nanotube bridging and pull-out indicate a high potential in a wide range of reinforcing and multifunctional applications.

Keywords: ceramic matrix composites, carbon nanotubes, toughening, ultrasonics

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Authors: Ting-YuLiu, Yi-Feng Lin

Abstract:

Porous Prussian Blue (PB) nanoparticles were successfully incorporated into chitosan (CS) membranes to form PB/CS mixed-matrix membranes (MMMs) and the as-prepared PB/CS MMMs were used to dehydration of ethanol at 25 oC in the pervaporation process. The effect of PB loading in CS matrix on pervaporation performance was investigated. The FESEM, EDS, FTIR and XRD measurements were also used for the characterization of the PB/CS MMMs. The PB/CS membranes with 30 wt% PB loading show the best performance with the permeate flux of 614 g/m2h and the separation factor of 1472. The pervaporation using the PB/CS membranes exhibits outstanding performance as compared with the previously reported CS based membranes and MMMs. The present work demonstrates good pervaporation performance of the PB/CS MMMs for the separation of 90wt% ethanol aqueous solution, moreover, it has an opportunity for dehydration of bioethanol in this system of pervaporation.

Keywords: pervaporation, chitosan, Prussian blue, mixed-matrix membrane

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Authors: Abdulmajeed Dabwan, Saqib Anwar, Ali Al-Samhan

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Electron Beam Melting (EBM) is a metal powder bed-based Additive Manufacturing (AM) technology, which uses computer-controlled electron beams to create fully dense three-dimensional near-net-shaped parts from metal powder. It gives the ability to produce any complex parts directly from a computer-aided design (CAD) model without tools and dies, and with a variety of materials. However, the quality of the surface finish in EBM process has limitations to meeting the performance requirements of additively manufactured components. The aim of this study is to investigate the cutting forces induced during milling Ti6Al4V produced by EBM as well as the surface quality of the milled surfaces. The effects of cutting speed and radial depth of cut on the cutting forces, surface roughness, and surface morphology were investigated. The results indicated that the cutting speed was found to be proportional to the resultant cutting force at any cutting conditions while the surface roughness improved significantly with the increase in cutting speed and radial depth of cut.

Keywords: electron beam melting, additive manufacturing, Ti6Al4V, surface morphology

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