DEDICATED MULTIPROCESSOR SYSTEM FOR AUTOMATIC RAIL FLAW DETECTION

An automatized ultrasonic rail flaw detection system has been developed for real-time rail flaw detection and evaluation. The whole system installed on a testing vehicle, working under rough environmental conditions must determine the internal irregularities of the rail, document them on the basis of a table containing the danger information, and immediately mark the rail in order to make easy the identification of the faulty segments for maintenance staff. During the measurement, three pairs of ultrasonic transmitters and receivers, with different orientation, scan the rail providing indirect information about the vertical section. The rail flaw detection procedure itself is a twodimensional pattern recognition problem consisting of image reconstruction, spatial filtering with thresholding and classifying phases

A Malom-Tisza holtág nyári rétegződési stabilitása és oxigénviszonyai 2007-2010-ben = Characteristics of the summer thermal stratification and the oxygen profile in the Malom-Tisza oxbow (2007-2010)

A Malom-Tisza holtág nyári vízoszlop stabilitását vizsgáltuk a termikus és oxigén viszonyok tükrében (2007-2010), különös hangsúlyt fektetve az epilimnion és hipolimnion évek közötti különbségeire. Vizsgálatainkkal igazoltuk, hogy a holtág stabilan rétegződik minden évben (dimiktikus). A holtág a 4 év során minden nyáron rendkívül stabilan rétegződött (RWCSmax = 479), mely minden esetben anoxikus hipolimnionnal párosult. A nyári rétegződés kialakulásában jelentős szerepe volt a (i) fetchhossznak, (ii) tavaszi időjárási körülményeknek, melyek meghatározzák a termoklin induló mélységét és a hipolimnion hőmérsékletét, (iii) a nyári időjárási körülményeknek, melyek befolyásolják az epilimnion évszakos, és napszakos hőmérséklet viszonyait. Ezen évek közötti különbségek tükröződhetnek rétegződő állóvizeink vízminősítésekor, mivel a vízoszlop stabilitás változása nagyban meghatározza a fitoplankton fajösszetételét, és azon keresztül annak minősítését

Novel Method for the Determination of Process Safety Time

Nowadays process safety is a key issue at the design and operation of a production process. Unfortunately, at the application of process hazard analysis (PHA) techniques the time aspect of operation and the dynamical behaviour of the process are neglected. This is due to the small number of easily available tools which can be applied to perform dynamical process simulation and dynamical analysis. However, in recent times dynamical models are increasingly applied to support the solution of any tasks related to process safety. Another problem that makes it difficult to take into account time, is the lack of a standardized concept and evaluation system to integrate the obtained information into the design procedure of safety integrated system (SIS). The aim of this article is to investigate the role of time in the design of process safety elements (PSEs), and to define the connection between the process and the time by using the process safety time (PST) term, as well as to give a methodology how PST can be designed based on the process simulator and applied in the development of PSEs. The developed methodology is based on dynamical analysis of the system and the possible safety actions. Based on this methodology, an algorithm has been developed to detect unsafe situations and to determine the necessary safety actions that can be used to avoid the undesired states of operation. The algorithm has been applied in the solution of an industrial problem related to reactor runaway

Incidence of community acquired ESBL-producing bacteria among asymptomatic University students in Anambra State, Nigeria

This study was conducted to investigate the incidence of community acquired extended-spectrum β-lactamase (ESBL)-producing bacteria among asymptomatic students of Nnamdi Azikiwe University, Awka, Anambra State, South-East Nigeria. A total of 102 non-duplicate strains of Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa were isolated from fecal samples (n=273) collected from the participating students. The isolates were subjected to antimicrobial susceptibility tests to determine their antimicrobial resistance profile. Their multiple antibiotic resistance (MAR) indices were also evaluated.  Screening of the isolates for possible ESBL production was carried out by disk diffusion test using cefotaxime and ceftazidime disks. ESBL-production by the resistant strains was confirmed using the double-disk synergy test. Most of the isolates were found to be multi-drug resistant, as all K. pneumoniae and P. aeruginosa strains (100%), and 98.4% of the E. coli strains, had MAR indices ≥0.2. A total of 22 ESBL-producing bacterial species were confirmed, and the frequency of E. coli, K. pneumoniae and P. aeruginosa isolates among the ESBL-producing bacteria were n=20 (90.9%), n=2 (9.1%), and n=0 (0.0%) respectively. The total number of ESBL-producing bacterial strains isolated accounted for 8.1 % of the entire sample population. Although this prevalence rate may not indicate an alarming situation, it is important that the proliferation of ESBL-producing bacteria in the community be contained, since a high incidence of ESBL-producing organisms will create significant therapeutic problems in the near future. There is therefore need to develop strategies to reduce their spread in the community especially through monitoring, surveillance and proper detection protocol. DOI: http://dx.doi.org/10.5281/zenodo.131471

Biologically active phenolic acids produced by Aspergillus sp., an endophyte of Moringa oleifera

This study investigates the secondary metabolites of an endophytic Aspergillus sp. isolated from leaves of M. oleifera growing in Anambra State, South-Eastern Nigeria. Antimicrobial and antioxidant screening of the fungal extract and isolated compounds, as well as cytotoxicity assay of the extract against cisplatin-sensitive A2780 (sens) and cisplatin-resistant A2780 (cisR) ovarian cancer cell lines were carried out using standard methods. Chemical investigations of the fungal extract involving a combination of different chromato-graphic methods and spectroscopic techniques were carried out to isolate and characterize the constituents of the extract. At a concentration range of 1-4 mg/ml, the crude extract of Aspergillus sp. showed mild antimicrobial activity against Bacillus subtilis, Klebsiella pneumoniae, and Candida albicans. The fungal extract showed good antioxidant activity at 500 µg/ml, with an inhibition of 72.1%. Also, at 100 µg/ml, the extract showed excellent cytotoxic activity against A2780 (sens) and A2780 (cisR), with growth inhibitions of 105.1% and 105.5% respectively. Two known pharmacologically active phenolic compounds (p-hydroxyphenyl acetic acid and ferulic acid) were isolated from the fermentation extract of the endophytic fungus. At 250 µg/ml, ferulic acid exhibited an excellent antioxidant activity with an inhibition of 90.4%, while an inhibition of 35.4% was recorded for p-hydroxyphenyl acetic acid. Ferulic acid also showed a mild antifungal activity at 500 µg/ml against A. niger with an IZD of 2 mm. p-Hydroxyphenyl acetic acid showed no antimicrobial activity. These results further confirm the potentials of endophytic fungi associated with Nigerian plants as source of bioactive compounds with pharmaceutical or industrial applications. DOI: http://dx.doi.org/10.5281/zenodo.140498

Influence of Blanching on the Drying Characteristics of Convective Hot Air Dried Aerial Yam

A research on the drying characteristics of aerial yam using convectional hot air was done. The raw unblanched and blanched samples were dried using convectional hot air. Fan speed, temperature and slice thickness were varied to determine the change in moisture content. The Fourier transform infrared (FTIR) and scanning electron microscopy (SEM) were done to determine the functional groups and surface morphology respectively for each sample. FTIR results revealed the presence of some important functional groups such as esters, ethers and nitro-compounds, and shows that drying at this temperatures (40-70oC) does not alter the nutrient components of this variety of yam. The SEM results showed that important cells were not destroyed at the drying temperature. Batch studies on the drying process also showed that increase in temperature and air speed increased the drying process, but decreases with increase in slice thickness. Effect of drying rate on the sample showed that drying rate increase with increase in temperature and air speed but decrease with increase in slice thickness. After 90 minutes of drying, the drying rate of the 2 mm slice thickness was 0.353 g/g.min for drying of aerial yam while for 4 mm and 6 mm slice thickness, the drying rate were 0.261 and 0.169 g/g.min respectively, for effect of drying rate on sample thickness. It showed also that blanched aerial yam sampleshad a higher drying rate than the unblanched aerial yam sample at the same conditions. Therefore, the economic advantages of this yam species can be optimized by blanching

Lake stratification in the Carpathian basin and its interesting biological consequences

Stratification of small temperate lakes of the Carpathian basin was studied. Values of Schmidt stability and Lake Number indicated stable summer stratification. Depending on their depth and wind shelter, the lakes could be characterized by various stratification patterns. A near-linear stratification was observed in the Malom Tisza oxbow where in summer during midday the whole water column belonged to the metalimnion. Mixing of the upper water layer was generated by nocturnal cooling. Stable stratification had pronounced consequences for the vertical distribution of chemical variables and phytoplankton. Concentration of sestonic chlorophyll showed bimodal distribution produced by algae in the upper and purple bacteria in the deeper layers. These results revealed that processes and phenomena associated with deep stratified lakes can be observed in shallow basins

Quaternion-Octonion Unitary Symmetries and Analogous Casimir Operators

An attempt has been made to investigate the global SU(2) and SU(3) unitary flavor symmetries systematically in terms of quaternion and octonion respectively. It is shown that these symmetries are suitably handled with quaternions and octonions in order to obtain their generators, commutation rules and symmetry properties. Accordingly, Casimir operators for SU(2)and SU(3) flavor symmetries are also constructed for the proper testing of these symmetries in terms of quaternions and octonions