FPGA Based Acoustic Modem for Underwater Communication

The underwater communication modem is based on ultrasound a sensor which gives efficient result underwater applications. System performs Amplitude shift Key (ASK) also known as On-Off Shift Key (OOK) at the transmitter part and this signal is demodulated at receiver point with audio amplifier and diode detector. ASK modulation is the simplest type of digital modulation technique. In this carrier signal is getting modulated with baseband signal so for positive signal it gives level ‘1’ and at negative signal it gives level 0. This design uses commercial ultrasound transducer of 200 kHz bandwidth. The underwater channel is highly variable; each point can have changes in signal, which change according to environmental factors as well as the locations of the communicating nodes. So distance vs. voltage of the received signal is measured. It is observed that voltage decreases with increasing distance

New Concepts for Next Generation of High Performance Concretes

AbstractWith the development of high-speed railway, long span bridges and high-rise buildings, new concretes need to increase strength and toughness. Adding fibers to concrete matrix has been long recognized as a way to enhance the energy absorption capacity and crack resistance of the plain concrete. In recent years, particular attention has been paid to the distribution of fibers: very small and well dispersed fibers may control the microcracks in the matrix from the very beginning of their opening and particularly high deformability of the composite may be obtained [3–5]. Carbon nanotubes (CNTs) used as reinforcing fibers has been also explored [6–8], the functional effect of their addition in a concrete equals to the one obtained with the addition of fibers. CNTs also provide a better ductility and an increase of the fracture energy. However, agglomeration and the relative high price seem to limit their application in cement based composite materials [14]. In this work, the potential beneficial effects of carbon micro/nanoparticles addition to cement pastes for improving the mechanical properties of the resulting composites has been investigated [15]. Pyrolyzed polyethylene beads (CNBs) and coconuts shells (Cocos nucifera, CCNs) were produced at Politecnico di Torino and characterized by Raman spectroscopy, thermogravimetry and scanning electron microscopy (SEM). When added to cement paste, up to 0.08 wt%, both materials were effective in increasing the cement matrix compressive strength and toughness. From SEM observations it is evident that the presence of these small particles disturb the propagation of microcracks, which has to deviate from its trajectory and has to follow the carbon nano/micro-particles contour. This mechanism increases strongly the fracture surface during the test performed by imposing the monotonic increment of crack opening. Crack and crack pinning are the mechanisms which can explain the increase of toughness in the composite samples

An expert system for optimizing computer aided design of post frame buildings

A procedure has been developed to optimize designs of metal-clad post-frame buildings using an expert system. The novel part of the study is the development of a procedure that extends the solution of an engineering problem from a conventional algorithmic Computer Aided Design (CAD) program to be used by the knowledge base of an expert system. The expert system then uses this information to optimize the design based on specified rules. The system shows a procedure for linking and sharing information between CAD and expert system programs.This is the publisher’s final pdf. The published article is copyrighted by the American Society of Agricultural Engineers and can be found at: http://elibrary.asabe.org/toc_landing.asp?conf=aeaj.Keywords: Knowledge base, Decision making, CAD, Frame analysisKeywords: Knowledge base, Decision making, CAD, Frame analysi

Electroceutical fabric lowers zeta potential and eradicates coronavirus infectivity upon contact

Coronavirus with intact infectivity attached to PPE surfaces pose significant threat to the spread of COVID-19. We tested the hypothesis that an electroceutical fabric, generating weak potential difference of 0.5 V, disrupts the infectivity of coronavirus upon contact by destabilizing the electrokinetic properties of the virion. Porcine respiratory coronavirus AR310 particles (105) were placed in direct contact with the fabric for 1 or 5 min. Following one minute of contact, zeta potential of the porcine coronavirus was significantly lowered indicating destabilization of its electrokinetic properties. Size-distribution plot showed appearance of aggregation of the virus. Testing of the cytopathic effects of the virus showed eradication of infectivity as quantitatively assessed by PI-calcein and MTT cell viability tests. This work provides the rationale to consider the studied electroceutical fabric, or other materials with comparable property, as material of choice for the development of PPE in the fight against COVID-19

Fundamental and Applied Nematology 21 2 147 155

Cellulose acetate electrophoresis was used to determine the degree to which isozyme banding patterns differed among 4 strains of steinernematid nematodes that had been recycled or stored at 5, 10, 15, 20 and 25 degrees C: Steinernema feltiae Umea strain, S. carpocapsae A11 strain, S. riobravis [S. riobravae] TX strain and S. feltiae NF strain. In all 4 strains, isozyme banding patterns of malate dehydrogenase (MDH), mannose-6-phosphate isomerase (MPI) and phosphoglucomutase (PGM) were affected by recycling or storage temperatures. The NF and Umea strains of S. feltiae synthesized additional isozymes of MPI and MDH or PGM at cold temperatures, while S. carpocapsae A11 strain synthesized 3 isozymes of MDH at warm temperatures and an additional isozyme of PGM at cold temperatures. The implications of these findings are discussed in relation to temperature adaptation mechanisms involving synthesis of isozymes and the use of isozyme determinations in steinernematid taxonomy.

Journal of Nematology 26 1 40 45

The relative concentrations of catecholamine in the nervous system of Romanomermis culicivorax were measured under different experimental conditions by a glyoxylic acid-induced fluorescence procedure. A greater concentration of catecholamine was recorded in the nervous system of adult males and females than in postparasitic juveniles. A higher concentration of catecholamine occurred in adults maintained in physical contact with the opposite sex than in those maintained in isolation. Adult males maintained with females in the same aqueous medium but physically separated by a barrier displayed a greater concentration of catecholamine in their nervous systems than did males maintained in isolation, but the catecholamine fluorescence intensity of such males was less than in males allowed physical contact with females. In adult males, the fluorescence intensity of catecholamine declined progressively during and after copulation. In adult females, the intensity of catecholamine remained constant before, during and after copulation. Catecholamine(s) may play a role in regulating copulatory behaviour, egg production, or oviposition.

Journal of Nematology 26 2 235 237

Distribution of caudal papillae in adult Romanomermis culicivorax was determined by scanning electron microscopy. Ninety-eight caudal papillae, each containing one pore, were present in males but absent in females. Papillae were arranged in 3 longitudinal rows, one ventral and 2 ventrolateral; the middle ventral row bifurcated anterior to the spicule. The appearance of the papillae was different anterior and posterior to the spicule. The role of the caudal papillae in mediating copulatory behaviour was discussed.

Heat Transfer Enhancement Through Swirl Flow Devices

This survey suggests a broad review of the various heat transfer enhancement techniques caused due to swirl flowhas various applications in the area related toengineering field such as chemical and mechanical mixing and separation devices, turbo machinery, chemical reactors, combustion chambers. To enhance the heat andmass transfer, there is a need of the better utilization of swirl flow. The swirl flow canbe generated by various techniques either by active or passive.Passive techniques, where inserts are used in the flow passage to increase the heat transfer rate, are advantageous compared with active techniques, because the insert manufacturing process is simple and these techniques can be easily employed in an existing heat exchanger. Twisted-tape is one of the most important members of enhancement techniques, which employed extensively in heat exchangers. Twisted tapes are the metallic strips twisted with some suitable techniques with desired shape and dimension, inserted in the flow. This paper demonstrates the various studies heat transfer through swirl flow devices

Optimization of Laser Process Parameters Using Machine Learning Algorithms and Performance Comparison

Laser powder bed fusion (L-PBF) can be used to produce near net-shaped functional metal components. Despite offering high flexibility in producing components with intricate geometries, L-PBF has many constraints in terms of controllability and repeatability because of large number of processing parameters. There is a need for a robust computational model which can predict the properties of L-PBF parts using a wide range of processing parameters. In this work, several Machine learning-based algorithms like Random Forest, k Nearest Neighbors, XGBOOST, Support Vector Machine (SVM), and Deep Neural Networks are used to model the property- processing parameters relation for SS 316L samples prepared by LPBF. Laser power, scan speed, hatch spacing, scan strategy, volumetric energy density, and density are used as the input to these models. The developed model is then used to predict and analyze the surface roughness of as- fabricated SS 316L specimens. The prediction and experimental results are compared for the above-mentioned models to evaluate the capabilities and accuracy of each model.Mechanical Engineerin