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Abstract

For underground mine workings, the shape of the computational domain may be difficult to define. Historically, the geometry models of mine drifts were not accurate representations of the object but rather a simplified approximation. To fully understand a phenomenon and save time on computations, simplification is often required. Nevertheless, in some situations, a detailed depiction of the geometry of the object may be necessary to obtain adequate simulation results. Laser Scanning enables the generation of 3D digital models with precision beyond the needs of applicable CFD models. Images composed of millions of points must be processed to obtain geometry suitable for computational mesh generation. A section of an underground mine excavation has been selected as an example of such transformation. Defining appropriate boundary conditions, especially the inlet velocity profile, is a challenging issue. Difficult environmental conditions in underground workings exclude the application of the most efficient and precise methods of velocity field measurements. Two attempts to define the inlet velocity profile have been compared. The first one used a sequence of simulations starting from a flat profile of a magnitude equal to the average velocity. The second one was based on the sixteen-point simultaneous velocity measurement, which gave consistency with measurement results within the range of applied velocity measurement method uncertainty. The article introduces a novel methodology that allows for more accurate replication of the mine excavation under study and the attainment of an appropriate inlet velocity profile, validated by a satisfactory correspondence between simulation outcomes and field measurements. The method involves analysing laser-scanned data of a mine excavation, conducting multi-point velocity measurements at specific cross-sections of the excavation that are unique to mining conditions, and utilising the k-ω SST turbulence model that has been validated for similar ventilation problems in mines.
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Authors and Affiliations

Jakub Janus
1
ORCID: ORCID
Jerzy Krawczyk
1
ORCID: ORCID

  1. Strata Mechanics Research Institutes of Polish Academy of Science, 27 Reymonta Str., 30-059 Kraków, Poland
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Abstract

It was expected that there would be a relationship between plant density and arrangement within soybean plantations and ground beetles due to changes of abiotic habitat conditions. The aim of this study was to determinate the effect of different plant arrangements of soybean plants on the abundance and species diversity of ground beetles (Coleoptera, Carabidae). The studies were conducted from 2015 to 2017 at the Experimental Research Station, Wrocław, Poland. The occurrence of beetles was examined on soybeans, growing in four different treatments: row spacing of 15 cm or 30 cm, and seeding density of 50 or 90 seeds per m2. The experiment was conducted in a split-plot design in four replicates. Ground beetles were collected with 16 pitfall traps, with one trap in the middle part of each plot. The obtained results show that the general number of ground beetles was similar between the treatments. Some minor effects were found in species number, which was higher in the lower row spacing treatment. Only less abundant species were significantly affected. The most abundant species in all years and treatments were Pseudoophonus rufipes, Harpalus affinis, Calathus fuscipes and Pterostichus melanarius. The abundance of the above-listed common ground beetle species did not differ significantly between treatments.

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Authors and Affiliations

Marcin Cierpisz
Jacek Twardowski
Iwona Gruss
Marcin Kozak
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Abstract

For a solar photovoltaic power system on a university campus, the electricity generated by the system meets the campus load, and the extra electricity is delivered to the grid. Generally, the price of the photovoltaic system is cheaper than that of the utility power system. The full use of solar electricity can reduce the electricity cost of the school. The deep belief network is used to predict solar photovoltaic generation and electricity load, and the gap is found. According to the gap, the power loads on the campus are adjusted to improve the utilization rate of solar power generation. Through the practical application of Changqing Campus of Qilu University of Technology in China, it is found that the utilization rate of solar photovoltaic power generation effectively improved from 91.24% in 2017 to 98.16% in 2019, and the annual electricity is saved by 68 610 yuan (in 2019).
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Authors and Affiliations

Guozheng Han
1
ORCID: ORCID
Shujuan Tan
1
ORCID: ORCID
Zihan Zhang
1
ORCID: ORCID

  1. School of Information and Automation Engineering, Qilu University of Technology (Shandong Academy of Sciences), No. 3501, Daxue Road, Changqing District, Jinan 250353 Shandong Province, PR China
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Abstract

Nowadays, Aluminium (Al) based hybrid surface composites are amongst the fastest developing advanced materials used for structural applications. Friction Stir Processing (FSP) has emerged as a clean and flexible solid-state surface composites fabrication technique. Intensive research in this field resulted in numerous research output; which hinders in finding relevant meta-data for further research with objectivity. In order to facilitate this research need, present article summarizes current state of the art and advances in aluminium based hybrid surface composites fabrication by FSP with in-situ and ex-situ approach. Reported literature were read and systematically categorized to show impacts of different types of reinforcements, deposition techniques, hybrid reinforcement ratio and FSP machine parameters on microstructures, mechanical and tribological characteristics of different Al alloys. Challenges and opportunities in this field have been summarized at the end, which will be beneficial to researchers working on solid state FSP technique.

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Authors and Affiliations

Namdev A. Patil
Srinivasa Rao Pedapati
Othman Bin Mamat
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Abstract

The studies on lexical availability deal with the available lexicon, the set of words that speakers have in the mental lexicon and which use is determined by the specific topic of the communication. This article presents the preliminary results of an exploratory research on the lexical availability in the Polish language of a sample of 147 students from 6 secondary schools in 6 Polish cities. Following a sociolinguistic methodology, the analysis considers the incidence of variables such as ‘sex’, ‘sociocultural level’ and ‘educational level’.
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Authors and Affiliations

Antonio María López González
1
ORCID: ORCID

  1. Uniwersytet Łódzki
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Abstract

The article presents the results of research on the development of a method for improving the positioning accuracy of an UAV equipped with a single-frequency GPS receiver for determining the linear elements of exterior orientation in aerial photogrammetry. Thus, the paper presents a computational strategy for improving UAV position determination using the SPP code method and the products of the IGS service. The developed algorithmswere tested in two independent research experiments performed with theUAVplatform on which an AsteRx-m2 UAS single-frequency receiver was installed. As a result of the experiments, it was shown that the use of IGS products in the SPP code method made it possible to improve the accuracy of the linear elements to the level of about ±2.088 m for X coordinate, ±1.547 m for Y coordinate, ±3.712 m for Z coordinate. The paper also shows the trend of changes in the obtained accuracy in determining linear elements of exterior orientation in the form of a linear regression function. Finally, the paper also applies the SBAS corrections model for the improvement of UAV position calculation and determination of linear elements of exterior orientation. In this case, the improvement in the accuracy of determining the linear elements of exterior orientation is about ±1.843 m for X coordinate, ±1.658 m for Y coordinate, ±7.930 m for Z coordinate. As the obtained test results show, the use of IGS products and SBAS corrections in the SPP code method makes it possible to improve the determination ofUAVpositions for the use in aerial photogrammetry. Keywords: UAV, GNSS measurements, linear elements of exterior orientation, accuracy.
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Authors and Affiliations

Kamil Krasuski
1
Damian Wierzbicki
2
Marta Lalak
1
Adam Ciecko
3

  1. Polish Air Force University, Institute of Navigation, Dywizjonu 303/35 Street, 08-521 Deblin, Poland
  2. Military University of Technology, Faculty of Civil Engineering and Geodesy, Department of Imagery Intelligence,gen. S. Kaliskiego 2 Street, 00-908 Warsaw, Poland
  3. University of Warmia and Mazury, Faculty of Geoengineering, M. Oczapowskiego 2 Street, 10-724 Olsztyn, Poland
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Abstract

This paper focuses on automatic locking of tracking filters used in optical frequency transfer systems. General concept of such a system is briefly described and the problems with its automatic startup, originating in the use of the analog phase locked loop to filter weak, received signal, are discussed. A supervisory circuitry and algorithm to solve these problems is proposed. The frequency of the signal to be filtered is measured indirectly and the output frequency of the tracking filter is monitored. In the case of lack of synchronism (i:e: after the startup) a significant difference of these frequencies is measured and the supervisory algorithm forces the filter to tune into the right frequency and then allows it to synchronize. A system with the proposed solution was implemented and tested experimentally on a fiber optic link with high attenuation and multiple optical connectors. Transient signals during locking were recorded to investigate the system’s behavior in real environment. The system was evaluated in the link causing synchronization losses every 17 min on average. During measurements over 3 days, the whole system was synchronized for over 99.98% of time despite these difficult conditions.

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Authors and Affiliations

Przemysław Włodarczyk
Przemysław Krehlik
Łukasz Śliwczyński
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Abstract

Applications of cold atmospheric plasma/nitric oxide (CAP/NO) gas have recently garnered popularity when treating impaired wound healing in patients with diabetes. In this study, we aimed to investigate the effects of NO gas application for 60 and 120 s on wound healing in diabetic rats. A dorsal excision 3 cm in diameter was performed in 15 diabetic rats; these rats were categorized into the following 3 groups: DC (untreated diabetic control); DNO/60 (exposure to 200 ppm NO gas for 60 s/day); and DNO/120 (exposure to 200 ppm NO gas for 120 s/day). Wound contraction on days 0, 3, 7, 11, and 14 and wound contraction rate between days 0 and 14 were evaluated. On day 14, tissue samples were collected for histopathologic assessment of inflammation, epithelial regeneration, angiogenesis congestion, and collagen fiber organization. Normality of distribution was assessed using the Shapiro-Wilk test, and intergroup comparisons were performed using the Mann-Whitney U test (NPar Test) and the Kruskal-Wallis test (non-parametric ANOVA). Wound contraction during treatment days 7-14 was significantly greater in the NO-treatment groups than in the DC group (p<0.05). The NO60 s and NO120 s groups showed a significantly higher wound contraction rate than the DC group (p=0.033, p=0.049, respectively). Significant differences were noted between the control and NO groups in terms of inflammation (p<0.05) and between the control group and DNO/60 and DNO/120 groups in terms of collagen organization (p<0.05, p<0.01, respectively). Evaluation of epithelialization revealed significant intergroup differences between the control and NO treatment groups (p<0.01). In this study, the application of NO once a day for 60 seconds and 120 seconds in diabetic wounds contributed equally to wound healing.
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Bibliography

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  2. Anuk T, Öztürk S, Özaydın İ, Kahramanca Ş, Yayla S, Aksoy, Demirkan I (2016) Comparison of Three Fixation Methods for the prevention of wound contractions in diabetic and non-diabetic mice with full-thickness skin excision. Kafkas Univ Vet Fak Derg 22: 647-651.
  3. Bae SH, Bae YC, Nam SB, Choi SJ (2012) A skin fixation method for decreasing the influence of wound contraction on wound healing in a rat model. Arch Plast Surg 39: 457-462.
  4. Bryan NS (2015) Nitric oxide enhancement strategies. Future Sci OA 1: FSO48.
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  7. Förstermann U, Sessa WC (2012) Nitric oxide synthases: Regulation and function. Eur Heart J 33: 829-837
  8. Fridman G, Friedman G, Gutsol A, Shekhter AB, Vasilets VN, Fridman A (2008) Applied Plasma Medicine. Plasma Process Polym 5: 503-533.
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  10. Ghaffari A, Miller CC, McMullin B, Ghahary A (2006) Potential application of gaseous nitric oxide as a topical antimicrobial agent. Nitric Ox-ide 14: 21-29.
  11. Ghaffari A, Neil DH, Ardakani A, Road J, Ghahary A, Miller CC (2005) A direct nitric oxide gas delivery system for bacterial and mammalian cell cultures. Nitric Oxide 12: 129-140.
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Authors and Affiliations

G. Tatlıcıoğlu
1
A. Çürükoğlu
1
G. Akan
2
G. Yeşilovalı
1
G. Öğütçü
3
R. Aktaş
1
A. Kükner
3
M. Temizel
4
Z.K. Sarıtaş
5
F.E. Özgencil
1

  1. Surgery Department, Near East University, Faculty of Veterinary Medicine, Yakın Doğu St, VIC: 99138 Nicosia / TRNC Mersin 10 – Turkey
  2. DESAM Institute, Near East University, Yakın Doğu St, VIC: 99138 Nicosia / TRNC Mersin 10 – Turkey
  3. Histology Department, Near East University, Faculty of Medicine, Yakın Doğu St, VIC: 99138 Nicosia / TRNC Mersin 10 – Turkey
  4. Experimental Animal Research Center, Near East University Faculty of Veterinary Medicine, Yakın Doğu St, VIC: 99138 Nicosia / TRNC Mersin 10- Turkey
  5. Surgery Department, Afyon Kocatepe University, Faculty of Veterinary Medicine, ANS Campus, Erenler, Afyonkarahisar/Turkey
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Abstract

The concept of a hybrid scheme with connection of SIDH and ECDH is nowadays very popular. In hardware implementations it is convenient to use a classical key exchange algorithm, which is based on the same finite field as SIDH. Most frequently used hybrid scheme is SIDH-ECDH. On the other hand, using the same field as in SIDH, one can construct schemes over Fpn, like Diffie-Hellman or XTR scheme, whose security is based on the discrete logarithm problem. In this paper, idea of such schemes will be presented. The security of schemes, which are based on the discrete logarithm problem over fields Fp; Fp2 ; Fp4 ; Fp6 and Fp8 , for primes p used in SIDH, will be analyzed. At the end, the propositions of practical applications of these schemes will be presented.

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Authors and Affiliations

Michał Wroński
Elżbieta Burek
Łukasz Dzierzkowski
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Abstract

The one-part geopolymer binder was synthesis from the mixing of aluminosilicate material with solid alkali activators. The properties of one-part geopolymers vary according to the type and amount of solid alkali activators used. This paper presents the effect of various sodium metasilicate-to-sodium aluminate (NaAlO2/Na2SiO3) ratios on fly ash-based one-part geopolymer. The NaAlO2/Na2SiO3 ratios were set at 1.0 to 3.0. Setting time of fresh one-part geopolymer was examined through Vicat needle apparatus. Mechanical and microstructural properties of developed specimens were analysed after 28 days of curing in ambient condition. The study concluded that an increase in NaAlO2 content delayed the setting time of one-part geopolymer paste. The highest compressive strength was achieved at the NaAlO2/Na2SiO3 ratio of 2.5, which was 33.65 MPa. The microstructural analysis revealed a homogeneous structure at the optimum ratio. While the sodium aluminium silicate hydrate (N-A-S-H) and anorthite phases were detected from the XRD analysis.
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Authors and Affiliations

Ooi Wan-En
1 2
Yun-Ming Liew
1 2
ORCID: ORCID
Heah Cheng Yong
2 3
ORCID: ORCID
Ho Li-Ngee
2 4
Mohd Mustafa Al Bakri Abdullah
1 2
ORCID: ORCID
Ong Shee-Ween
1 2
Andrei Victor Sandu
5
ORCID: ORCID

  1. Universiti Malaysia Perlis (UNIMAP), Center of Excellence Geopolymer and Green Technology (CEGEOGTECH), Kangar, 01000 Perlis, Malaysia
  2. Universiti Malaysia Perlis (UNIMAP), Faculty of Chemical Engineering Technology, Kangar, 01000 Perlis, Malaysia
  3. Universiti Malaysia Perlis (UNIMAP), Faculty of Mechanical Engineering Technology, Kangar, 01000 Perlis, Malaysia
  4. Universiti Malaysia Perlis (UNIMAP), Centre of Excellence Frontier Materials Research, FRONTMATEKANGAR, 01000 Perlis, Malaysia
  5. Gheorghe Asachi Technical University of Iasi, Faculty of Materials Science and Engineering, 700050, Iasi, Romania
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Abstract

The fracture and fragmentation of concrete under static and dynamic loads are studied. The uniaxial compressive strength test is employed to study the concrete behavior under static loads while the split Hopkinson pressure bar is used to study the dynamic behavior of the concrete under static loads. The theories for acquiring the stress, strain and strain rate of the concrete in the dynamic test by Hopkinson pressure bar has been introduced. The fracture patterns of the concrete in the uniaxial compressive test have been obtained and the static concrete compressive strengths have been calculated. The fracture patterns of the concrete in the uniaxial compressive test have been obtained and the static concrete compressive strengths have been calculated. The fracture and fragmentation of the specimen under dynamic loads have been acquired and the stress-strain curves of concrete under various impact loads are obtained. The stress-strain curve indicates a typical brittle material failure process which includes existing micro-fracture closure stage, linear-elastic stage, nonlinear-elastic stage, and post-failure stages. The influence of the loading rate for the compressive strength of the concrete has compared. Compared with the concrete under static loads, the dynamic loads can produce more fractures and fragments. The concrete strength is influenced by the strain rate and the strength increases almost linearly with the increase of the strain rate.

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Authors and Affiliations

Huaming An
ORCID: ORCID
Lei Liu
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Abstract

Tunnel construction survey must be necessary to be very quick so that the results can be known as soon as possible. This aim can be achieved through the intelligent positioning method of tunnel excavation face. In this study, the plane parameters of the tunnel cross-section were transformed into the coordinates of the points on the cross-section to realize the automatic transformation of graphic data. According to the theoretical calculation of the lofting point accuracy, the appropriate measurement control network level and measurement accuracy and the appropriate measurement instruments were selected. The fast and intelligent positioning and setting out of tunnel excavation face was realized base on the technology of data communication between computer and measuring instruments. The intelligent positioning method of tunnel excavation face could greatly reduce the time of measurement and positioning, speed up the project progress, reduce the project risk, shorten the construction period and reduce the project cost.
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Bibliography

[1] K. Rabensteiner, “Automated surveying speeds construction”, Tunnels & Tunnelling, 1996, vol. 28, no. 1, pp. 40–41.
[2] H.E. Bin, “Application of CASIO Measurement Program Assisted by Total Station in Survey of Tunnel Cross-Section”, Tunnel Construction, 2009, vol. 29, no. 1, pp. 120–122.
[3] Z. Lei, “Application of Total Station ’s Surrounding Measurement Function in Highway Survey and Design”, Peak Data Science, 2017, vol. 6, no. 4, pp. 105–107.
[4] L.F. Geng, “Analysis of mechanical properties of full section excavation of single arch four-lane highway tunnel”, Shanxi Architecture, 2009, vol. 2.
[5] Y.H. Deng, “Determination of full section excavation boundary of transition curve tunnel”, Mine Surveying, 2004, vol. 2004, no. 2, pp. 34–36.
[6] W.W. Yan, “Application of CASIO Series Programming Calculator in the Measurement of Tunnel Sections”, Shanxi ence and Technology, 2011, vol. 26, no. 4, pp. 123–124.
[7] W.B. Luo, “The realization of real-time communication between mobile intelligent equipment and total station under net environment”, Surveying and mapping equipment, 2007, vol. 9, no. 4, pp. 42–43.
[8] C.X. Niu, “Construction Survey of Tanba No. 4 Spiral Tunnel on Xiaohe-Ankang Highway”, Tunnel Construction, 2014, vol. 34, no. 2, pp. 163–166, DOI: 10.3973/j.issn.1672-741X.2014.02.013.
[9] L.H. Luo, S.L. Wei, “Application of Surveying Robot in Pipe Jacking Crossing Subway Tunnel Project”, Jiangsu Construction, 2018, vol. 2018, no. 6, pp. 65–66.
[10] W. He, C. Song, B. Du, “Chinese Longest Sea-crossing Metro Tunnel: Wuyuan Bay Station-Liuwudian Station Section of Xiamen Metro Line 3”, Tunnel Construction, 2018, vol. 38, no. 3, pp. 501–505.
[11] Y.X. Hu, Y. Yue, H.D. Zhang, et al., “Application of Gyroscope in Directional Measurement of Long Distance Cross Sea Metro Tunnel”, Urban Geotechnical Investigation & Surveying, 2019, vol. 2019, no. 6, pp. 172–175.
[12] Y. Zhou, S. Wang, M. Xi, et al., “Railway Tunnel Clearance Inspection Method Based on 3D Point Cloud from Mobile Laser Scanning”, Sensors, 2017, vol. 17, no. 9, DOI: 10.3390/s17092055.
[13] W.Wei, “3D Laser scanning technique is applied to the measurement of tunnel section deformation”, Beijing Surveying and Mapping, 2020, vol. 34, no. 4, pp. 561–565.
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Authors and Affiliations

Jiesheng Zhang
1
ORCID: ORCID
Yongzheng Qi
2
ORCID: ORCID

  1. The First Engineering Co., LTD. of CTCE Group, No. 434 Fuyang North Road, Hefei 230041, China
  2. Jiangsu University of Science and Technology, School of Civil Engineering and Architecture, No. 2 Mengxi Road, Zhenjiang 212003, China
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Abstract

Pinnipeds were monitored in Admiralty Bay between 1988 and 1992. No particular trends during this period were found, but seasonal changes in each are distinct. It is suggested that the phenology of pinnipeds and that of penguins ensures low competition for food between these groups.

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Authors and Affiliations

Stanisław Rakusa-Suszczewski
Kazimierz Sierakowski
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Abstract

This study attempted to examine the impacts of academic locus of control and metacognitive awareness on the academic adjustment of the student participants. The convenient sampling was applied to select the sample of 368 participants comprising 246 internals with age ranging from 17 to 28 years (M = 20.52, SD = 2.10) and 122 externals with age spanning from 17 to 28 years (M = 20.57, SD = 2.08). The findings indicated that there were significant differences in the various dimensions of metacognition, academic lifestyle and academic achievement of the internals and externals except for academic motivation and overall academic adjustment. There were significant gender differences in declarative knowledge, procedural knowledge, conditional knowledge, planning, information management, monitoring, evaluation and overall metacognitive awareness. Likewise, the internals and externals differed significantly in their mean scores of declarative knowledge, procedural knowledge, conditional knowledge, planning, information management, monitoring, debugging, evaluation and overall metacognitive awareness, academic lifestyle and academic achievement. The significant positive correlations existed between the scores of metacognitive awareness and academic adjustment. It was evident that the internal academic locus of control and metacognitive awareness were significant predictors of academic adjustment of the students. The findings have been discussed in the light of recent findings of the field. The findings of the study have significant implications to understand the academic success and adjustment of the students and thus, relevant for teachers, educationists, policy makers and parents. The future directions for the researchers and limitations of the study have also been discussed.

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Authors and Affiliations

Deepika Jain
Gyanesh Kumar Tiwari
Ishdutta Awasthi
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Abstract

Anthracnose disease caused by Colletotrichum lindemuthianum (Sacc. and Magnus) Lams-Scrib is one of the most devastating seed-borne diseases of common bean (Phaseolus vulgaris L.). In the present study, we evaluated the antifungal activity of Bunium persicum essential oil (EO) and its main constituents on mycelial growth, sporulation and spore germination inhibition of C. lindemuthianum. The main objective of this study was to investigate the effect of EO and its main constituents on decreasing the activity of cell wall degrading enzymes (CWDEs) produced by C. lindemuthianum, which are associated with disease progress. Also, the effects of seed treatment and foliar application of EO and its main constituent, cuminaldehyde, on anthracnose disease severity was investigated. The essential oil of B. persicum, was obtained by using a clevenger apparatus and its major constituents were identified by gas chromatography-mass spectrometry (GC-MS). The EO was characterized by the presence of major compounds such as cuminaldehyde (37.7%), γ-terpinene (17.1%) and β-pinene (15.4%), which indicated antifungal effects against C. lindemuthianum. This pathogen did not grow in the presence of EO, cuminaldehyde and γ-terpinene, β-pinene at 1,500; 1,010 and 1,835 ppm concentrations, respectively. Also, sporulation and spore germination of C. lindemuthianum was completely inhibited by EO and cuminaldehyde. Synergistic effects of the main constituents showed that combing γ-terpinene with cuminaldehyde induced a synergistic activity against C. lindemuthianum and in combination with β-pinene caused an additive effect. Activities of pectinase, cellulase and xylanase, as main CWDEs, were decreased by EO and its main constituents at low concentration without affecting mycelial growth. Seed treatment and foliar application of peppermint EO and/or cuminaldehyde significantly reduced the development of bean anthracnose. We introduced B. persicum EO and constituents, cuminaldehyde and γ-terpinene, as possible control agents for bean anthracnose.

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Authors and Affiliations

Nima Khaledi
Farshid Hassani
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Abstract

Electric arc is a complex phenomenon occurring during the current interruption process in the power system. Therefore performing digital simulations is often necessary to analyse transient conditions in power system during switching operations. This paper deals with the electric arc modelling and its implementation in simulation software for transient analyses during switching conditions in power system. Cassie, Cassie-Mayr as well as Schwarz-Avdonin equations describing the behaviour of the electric arc during the current interruption process have been implemented in EMTP-ATP simulation software and presented in this paper. The models developed have been used for transient simulations to analyse impact of the particular model and its parameters on Transient Recovery Voltage in different switching scenarios: during shunt reactor switching-off as well as during capacitor bank current switching-off. The selected simulation cases represent typical practical scenarios for inductive and capacitive currents breaking, respectively.

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Authors and Affiliations

Piotr Oramus
Tomasz Chmielewski
Tomasz Kuczek
Wojciech Piasecki
Marcin Szewczyk
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Abstract

Feasibility of a model of gas bubble break-up and coalescence in an air-lift column enabling determination of bubble size distributions in a mixer with a self-aspirating impeller has been attempted in this paper. According to velocity measurements made by the PIV method with a self-aspirating impeller and Smagorinski’s model, the spatial distribution of turbulent energy dissipation rate close to the impeller was determined. This allowed to positively verify the dependence of gas bubble velocity used in the model, in relation to turbulent energy dissipation rate. Furthermore, the range of the eddy sizes capable of breaking up the gas bubbles was determined. The verified model was found to be greatly useful, but because of the simplifying assumptions some discrepancies of experimental and model results were observed.

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Authors and Affiliations

Jacek Stelmach
Czesław Kuncewicz
Radosław Musoski
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Abstract

Orthogonal frequency division multiple access (OFDMA) in Long Term Evolution (LTE) can effectively eliminate intra-cell interferences between the subcarriers in a single serving cell. But, there is more critical issue that, OFDMA cannot accomplish to decrease the inter-cell interference. In our proposed method, we aimed to increase signal to interference plus noise ratio (SINR) by dividing the cells as cell center and cell edge. While decreasing the interference between cells, we also aimed to increase overall system throughput. For this reason, we proposed a dynamic resource allocation technique that is called Experience-Based Dynamic Soft Frequency Reuse (EBDSFR). We compared our proposed scheme with different resource allocation schemes that are Dynamic Inter-cellular Bandwidth Fair Sharing FFR (FFRDIBFS) and Dynamic Inter-cellular Bandwidth Fair Sharing Reuse-3 (Reuse3DIBFS). Simulation results indicate that, proposed EBDSFR benefits from overall cell throughput and obtains higher user fairness than the reference schemes.

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Authors and Affiliations

Mert Yağcıoğlu
Oğuz Bayat
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Abstract

Advanced metallic material processes (titanium) are used or developed for the production of heavily loaded flying components (in fan blade construction). The article presents one process for diagnosing the blade interior by means of laser ultrasonography. The inspection of these parts, which are mainly made of titanium, requires the determination of the percentage of bonded grain sizes from around 10 to 30 μm. This is primarily due to the advantages of a high signal-to-noise ratio and good detection sensitivity. The results of the research into the internal blade structure are attached.

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Authors and Affiliations

Paweł Swornowski
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Abstract

A correlation measuring tool for an endogenous pulsed neutron source experiment is developed in this work. Paroxysmal pulses generated by a bursts of neutron chains are detected by a 10-kbit embedded shift register with a time resolution of 100 ns. The system is implemented on a single reprogrammable device making it a compact, cost-effective instrument, easily adaptable for any case study. The system was verified experimentally in the Esfahan heavy-water zero power reactor (EHWZPR). The results obtained by the measuring tool are validated by the Feynman-α experiment, and a good agreement is seen within the boundaries of statistical uncertainties. The theory of the methods is briefly initiated in the text. Also, the system structure is described, the experimental results and their uncertainties are discussed, and neutron statistics in EHWZPR is examined experimentally.

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Authors and Affiliations

Mohammad Arkani
Hossein Khalafi
Naser Vosoughi
Samad Khakshournia
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Abstract

The micro-Particle Image Velocimetry (micro-PIV) was used to measure flow velocities in micro-channels

in two passive micromixers: a microfluidic Venturi mixer and a microfluidic spiral mixer, both preceded

by standard “Y” micromixers. The micro-devices were made of borosilicate glass, with micro-engineering

techniques dedicated to micro-PIV measurements. The obtained velocity profiles show differences in the

flow structure in both cases. The micro-PIV enables understanding the micro-flow phenomena and can help

to increase reproducibility of micromixers in mass production.

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Authors and Affiliations

Dariusz Witkowski
Wojciech Kubicki
Jan A. Dziuban
Darina Jašíková
Anna Karczemska
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Abstract

Perinatal calf mortality in dairy herds has been reported worldwide. The etiology of stillbirth is multifactorial, and can be caused by various species of bacteria and environmental factors. Among them some potential pathogens from the Mollicutes class such as Mycoplasma (M.) spp. and Ureaplasma (U.) diversum can be isolated from the bovine genital tract and other organs of the suspected cattle. The aim of this study was to evaluate if the bacteria belonging to the Molli- cutes class i.e. M. bovis, M. bovigenitalium, M. canadense, M. canis, M. arginini, M. bovirhinis, M. dispar, M. alkalescens and U. diversum could have an impact on perinatal calf mortality in selected Polish dairy farms. The material was: 121 stillborn calves (SB), 21 live born calves (C) and 131 cows (dams) from 30 Polish Holstein-Friesian herds. Samples were examined from all the SB calves’ and six control euthanized calves’ abomasal contents and lung samples collected during necropsy, and from the dams’ serum and placenta. In dams the serological ELISA, and in calves and placenta samples molecular PCR/denaturing gradient gel electrophoresis, methods were used. Screening of dams’ sera for antibodies to M. bovis (ELISA) showed seven dams positive for M. bovis, whereas none of the nine examined Mollicutes microorganisms were detected in the placenta and calves.

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Authors and Affiliations

E. Szacawa
P. Jawor
K. Dudek
D. Bednarek
T. Stefaniak

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