Search results

Filters

  • Journals
  • Date

Search results

Number of results: 7
items per page: 25 50 75
Sort by:

Abstract

Gala Lake National Park that has an international importance is one of the most important wetland ecosystems for Turkey. As same as many aquatic habitats, Gala Lake is under a significant anthropogenic pressure originated from agricultural activities conducted around the lake and from industrial discharges by means of Ergene River. The aim of this study was to evaluate the sediment quality of Gala Lake and Irrigation Canal by investigating some toxic element accumulations (As, B, Ni, Cr, Pb, Cd, Zn and Cu) from a statistical perspective. Pearson Correlation Index (PCI) and Factor Analysis (FA) were applied to detected data in order to determine the associated contaminants and effective factors on the system. Potential Ecological Risk Index (RI) and Biological Risk Index based sediment quality guidelines (mERM-Q) applied to detected data in order to assess the ecological and biological risks of heavy metals in the ecosystem. Also Geographic Information System (GIS) technology was used to make visual explanations by presenting distribution maps of investigated elements. According to the results of PCI, significant positive correlations were recorded among the investigated toxic elements at 0.01 significance level. According to the results of FA, two factors, which were named as “Agricultural Factor” and “Industrial Factor”, explained 86.6% of the total variance. According to the results of Potential Ecological Risk Index, cadmium was found to be the highest risk factor and according to results of Biological Risk Index, nickel and chromium were found to be the highest risk factors for Gala Lake and Irrigation Canal. As a result of the present study, it was also determined that heavy metal contents in sediments of Gala Lake National Park reached to critical levels and the system is intensively under effect of agricultural and industrial originated pollution.
Go to article

Abstract

Two violins were investigated. The only intentionally introduced difference between them was the type of varnish. One of the instruments was covered with a spirit varnish, the other was oil varnished. Experimental modal analysis was done for unvarnished/varnished violins and a questionnaire inquiry on the instrument’s sound quality was performed. The aim of both examinations was to find differences and similarities between the two instruments in the objective (modal parameters) and subjective domain (subjective evaluation of sound quality). In the modal analysis, three strongly radiating signature modes were taken into account. Varnishing did not change the sequence of mode shapes. Modal frequencies A0 and B(1+) were not changed by oil varnishing compared to the unvarnished condition. For the oil varnished instrument, the frequency of mode B(1+) was lower than that of the same mode of the spirit varnished instrument. Our two violins were not excellent instruments, but before varnishing they were practically identical. However, after varnishing it appeared that the oil-varnished violin was better than the spirit-varnished instrument. Therefore, it can be assumed with a fairly high probability that also in general, the oil-varnished violins sound somewhat better than initially identical spirit-varnished ones.
Go to article

Abstract

The multi-stimulus test with hidden reference and anchors (MUSHRA) is commonly used for subjective quality assessment of audio systems. Despite its wide acceptance in scientific and industrial sectors, the method is not free from bias. One possible source of bias in the MUSHRA method may be attributed to a graphical design of its user interface. This paper examines the hypothesis that replacement of the standard multi-slider layout with a single-slider version could reduce a stimulus spacing bias observed in the MUSHRA test. Contrary to the expectation, the aforementioned modification did not reduce the bias. This outcome formally supports the validity of using multiple sliders in the MUSHRA graphical interface.
Go to article

Abstract

The Traffic Flow Description (TFD) option of the IP protocol is an experimental option, designed by the Authors and described by the IETF’s Internet Draft. This option was intended for signalling for QoS purposes. Knowledge about forthcoming traffic (such as the amount of data that will be transferred in a given period of time) is conveyed in the fields of the option between end-systems. TFD-capable routers on a path (or a multicast tree) between the sender and receiver(s) are able to read this information, process it and use it for bandwidth allocation. If the time horizons are short enough, bandwidth allocation will be performed dynamically. In the paper a performance evaluation of an HD video transmission QoS assured with the use of the TFD option is presented. The analysis was made for a variable number of video streams and a variable number of TCP flows that compete with the videos for the bandwidth of the shared link. Results show that the dynamic bandwidth allocation using the TFD option better assures the QoS of HD video than the classic solution, based on the RSVP protocol.
Go to article

Abstract

This study presents a customized root cause analysis approach to investigate the reasons, provide improvements measures for the cost overruns, and schedule slippage in papermachine- building projects. The proposed approach is an analytical-survey approach that uses both actual technical data and experts’ opinions. Various analysis tools are embedded in the approach including: data collection and clustering, interviews with experts, 5-Whys, Pareto charts, cause and effect diagram, and critical ratio control charts. The approach was implemented on seven projects obtained from a leading international paper machine supplier. As a result, it was found that the main causes behind cost and schedule deviations are products’ related; including technical accidents in the Press section, damaged parts, design issues, optimization of the machine and missing parts. Based on the results, prevention measures were perceived.
Go to article

Abstract

Noise spectroscopy and I-V characteristic non-linearity measurement were applied as diagnostic tools in order to characterize the volume and contact quality of positive temperature coefficient (PTC) chip sensors and to predict possible contact failure. Correctly made and stable contacts are crucial for proper sensing. I-V characteristics and time dependences of resistance were measured for studied sensors and, besides the samples with stable resistance value, spike type resistance fluctuation was observed for some samples. These spikes often disappear after about 24 hours of voltage application. Linear I-V characteristics were measured for the samples with stable resistance. The resistance fluctuation of burst noise type was observed for some samples showing the I-V characteristic dependent on the electric field orientation. We have found that the thermistors with high quality contacts had a linear I-V characteristic, the noise spectral density is of 1/f type and the third harmonic index is lower than 60 dB. The samples with poor quality contacts show non-linear I-V characteristics and excess noise is given by superposition of g-r and 1/fn type noises, and the third harmonic index is higher than 60 dB.
Go to article

Abstract

Based on the publications regarding new or recent measurement systems for the tokamak plasma experiments, it can be found that the monitoring and quality validation of input signals for the computation stage is done in different, often simple, ways. In the paper is described the unique approach to implement the novel evaluation and data quality monitoring (EDQM) model for use in various measurement systems. The adaptation of the model is made for the GEM-based soft X-ray measurement system FPGA-based. The EDQM elements has been connected to the base firmware using PCI-E DMA real-time data streaming with minimal modification. As additional storage, on-board DDR3 memory has been used. Description of implemented elements is provided, along with designed data processing tools and advanced simulation environment based on Questa software.
Go to article

This page uses 'cookies'. Learn more