The Small and Silent Force Multiplier: A Swarm UAV—Electronic Attack

At the last two decades, according to UAVs concepts and technological advances, there have been lots of unimagined improvements. Nowadays there are serious works and researches about the usage of UAVs in military operations at electronic warfare (EW) missions. But most of the work on UAV platforms is based upon the advantages of a single, big, expensive, and non-expendable platform. In this study, to get rid off the disadvantages of a stand alone platform a new concept is developed consisting of multiple UAVs with smaller dimensions, at a cheaper price and a wider coverage. According to clarify the study, firstly the EW and RADAR systems and then the swarm UAV concepts are explained. In this manner the current and previous works are pointed out and then the use of the swarm UAVs for EA in military operations is stated. Objectively, the swarm UAV concept’s advantages and some outstanding challenges to the intra-theater space have been put forward regarding the information mentioned above. As a result it is considered that the swarm UAV systems will be tasked important EW missions in the future operation theatres, as soon as the technical handicaps are solved.     

Use of multisensor and multitemporal geospatial datasets to extract the foundation characteristics of a large building: a case study

Bulletin of Engineering Geology and the Environment - The assessment of the ground conditions for large buildings is important because the results are sensitive to the ground conditions, especially...     

Structural properties and kinetics of nitro-niobized steels

In the present study, structural characterization and kinetics of nitro-niobized AISI 1010, AISI D2, and AISI M2 steels by thermo-reactive deposition technique in the powder mixture consisting of ferro-niobium, ammonium chloride, and alumina at the temperatures of 1173, 1273, and 1373 K for 60–240 min were investigated. The thickness of the niobium nitride layers formed on the nitro-niobized AISI 1010, AISI D2, and AISI M2 steels are ranged from 2.80 ± 0.90 to 11.89 ± 1.10 μm, 3.16 ± 0.60 to 13.16 ± 1.51 μm, and 3.85 ± 0.91 to 16.77 ± 2.10 μm, respectively. The phases formed in the coating layer deposited on the surface of the steel substrates are NbN_0.95 and Nb₂CN. The hardness of the niobium nitride coating layers produced on AISI 1010, AISI D2, and AISI M2 steels are changing from 1151 ± 126 to 1446 ± 121 HV_0.005, 1359 ± 413 to 1594 ± 761 HV_0.005, and 1321 ± 51 to 1915 ± 134 HV_0.005, respectively. Diffusion constants of the coating layers were changing between 1.517 × 10⁻¹⁵ and 2.043 × 10⁻¹⁴ m²/s, depending on steel compositions, treatment time and temperatures, and activation energies of the AISI 1010, AISI D2, and AISI M2 steels for the process were calculated as 128.7, 123.8, and 132.5 kJ/mol, respectively. Moreover, an attempt was made to investigate the possibility of predicting the contour diagram of niobium nitride coating thickness variation, depending on process time and temperature.     

A Fully Integrated 10-Gb/s Receiver With Adaptive Optical Dispersion Equalizer in 0.13-μm CMOS

A 10 Gb/s receiver, containing an adaptive equalizer, a clock and data recovery, and a de-multiplexer, is implemented in 0.13-mum CMOS. The chip is intended for long-haul optical fiber links where chromatic and polarization mode dispersions are reach-limiting factors. The equalization is performed by a continuous time filter and a two-tap decision feedback equalizer while automatic threshold and phase adjustments are embedded in the CDR. Use of an analog equalizer with digital adaptation garners total power dissipation of 950 mW. Error-free operation over 200 km of single mode fiber is demonstrated. With 140 km of single mode fiber, optical signal to noise ratio penalty is only 2dB. Differential group delay of 100 ps can also be tolerated     

Substitution of Reduction Clearing Step by Ozone Treatment at Disperse Dyeing of Polyester

The effectiveness of ozone treatment for the afterclearing of disperse dyed poly (ethylene terephthalate) (PET) fibers has been examined. Two types of disperse dyed PET samples were selected among commercial mass production range of Akbaslar textile mill. The reduction clearing procedure applied during mass production was taken as the reference reduction clearing treatment; these reference samples were taken after dyeing and reduction clearing processes at the mill. Samples of disperse dyed PET were also taken before reduction clearing in order apply ozone treatment in the laboratory as the tested afterclearing method. Color and wash-fastness properties of the reduction cleared and ozone treated fabric samples were compared and reported. Results indicated acceptable color and wash-fastness results comparable to those of reduction cleared samples for ozone treated samples. The success of ozone treatment for the black dyed PET sample at 7.0% depth of shade was especially outstanding. Ozone treatment was applied in cold water without addition of any chemicals for very short treatment times when compared to conventional reduction clearing. Ozone treatment created substantial energy and chemical savings as well as lower environmental impact.     

An investigation on TCP large initial window

Transport layer implicates a position where satellite networks form one integrated component of hybrid Internet architecture in today's advance technology. However, the Internet has emerged with an important new class of applications that exhibits significant variations of transmission rate over time. Variable‐rate traffic poses a new challenge for transmission control protocol that provides congestion control, especially for applications that need to share the limited capacity of a bottleneck over a long delay Internet path (e.g. paths that include satellite links). Variable‐rate traffic can be produced by persistent transmission control protocol connections and can be impacted by the initial window at the start or during the restart of a session. Current transport research issues are identified related to larger initial window to highlight the expected performance benefits and derive the implications on the design of geostationary satellite Internet systems as the network evolves toward a next‐generation Internet. Copyright © 2013 John Wiley & Sons, Ltd.     

Epoxy composites based on inexpensive char filler obtained from plastic waste and natural resources

In this study, plastic [polyethylene terephthalate (PET)] waste was recycled as raw material for the preparation of diglycidyl ether of bisphenol A‐type epoxy composite materials. The other inexpensive fillers used to prepare the composites were wood shavings char and pine cone char (PCC), obtained from natural resources. The thermogravimetric analysis showed that plastic waste char (PWC) and PCC can significantly improve the thermal stability of neat epoxy resin at temperatures above 300°C. The best thermal and electrical conductivity results were obtained with PWC. The residual weight of the composite with 30 wt% PWC was 69%. Surface hardness, Young's modulus, and tensile strength of the composites were higher than those with a pure epoxy polymer matrix. The composite morphology was characterized by X‐ray diffraction and scanning electron microscopy. POLYM. COMPOS., 2013. © 2013 Society of Plastics Engineers     

Improving the flame retardancy and mechanical properties of epoxy composites using flame retardants with red mud waste

In this study, a novel flame retardant ammonium tetrafluoroborate (ATFB) was successfully synthesized using boric acid (H₃BO₃) and ammonium hydrogen difluoride (NH₄HF₂) as the reactants. In addition to ATFB, aluminum hydroxide (Al(OH)₃) was used as a flame retardant and red mud (RM) waste was used as a filler to prepare epoxy composite materials with enhanced flammability properties. The appropriate ratio of RM:ATFB:Al(OH)₃ both in terms of combustion and mechanical properties was found to be 15:10:5 wt%. The tensile strength of the composite in this ratio was obtained as 112 MPa, while the neat ER was 46 MPa. The burnout of the composite with the appropriate RM:ATFB:Al(OH)₃ ratio decreased in the first 10 seconds, and extinguished in 32 seconds. Moreover, the burned area of this composite was the smallest among all the others. The experimental and estimated LOI values for this composite was found as 26 and 29, respectively.     

Probable water crisis in Thrace and Istanbul in the near future and a sustainable strategy to overcome it

Abstract

The Thrace Region of Turkey, a passageway from Asia to Europe, which includes the most populated city of Istanbul, is threatened by a water crisis in the very near future. The population of Istanbul alone is forecast to reach 30 millions by the year 2025, requiring 3 billion m³ of water, nearly equal to the total fresh water resources of the region, 3.4 billion m³. In this study, we consider not only the proportion of the available water resources to be allocated for each competing sector, civil, agriculture and industry, but also attempt to outline integrated water management strategies for each sector. The potential of small earth reservoirs, more than 1,500 in number, is emphasised as a way to develop fresh water resources. Water saving policies in the cities and ethics for water use are also briefly discussed.