603 research outputs found

    Predicting the Friction Coefficient of High-Friction Surface Treatment Application Aggregates using the Aggregates\u27 Characteristics

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    Providing Sufficient Pavement Surface Friction (I.e., Skid Resistance) between Vehicle Tires and Pavement Surface throughout the Pavement Service Life is Considered to Be One of the Main Objectives of Highway Design. Moreover, Vehicle Safety, the Amount of Consumed Fuel, and the Wearing Rate of Vehicle Tires Generally Are Influenced by Pavement Surface Friction. in This Study, a Comprehensive Experimental Testing Program Was Conducted on Different Aggregate Sources, Including Calcined Bauxite and Five Alternative Local Sources, to Assess their Friction Characteristics. the Testing Program Included a British Pendulum Tester (BPT) and a Dynamic Friction Tester (DFT), Which Were Used to Evaluate the Friction Characteristics of the Proposed Aggregates, Along with Basic and Durability Properties Tests. the Aggregate Imaging Measurement System (AIMS) Technique Was Applied to Evaluate the Aggregate Characteristics Due to Micro-Deval Degradation. This Study Provides Two Empirical Models for the Friction Characteristics of High-Friction Surface Treatment (HFST)-Application Aggregates based on the Experimental Results. the First Model Correlates the Friction Coefficient at 20 Km/h (DFC20) with the British Pendulum Number (BPN). the Second Model Expresses DFC20 as a Function of Polishing Resistance of Aggregates, Which is Represented by the Initial and Terminal Aggregate Texture and Angularity Values Measured using the AIMS Device with an overall Coefficient of Determination (R2) of 0.949. the Aggregate Characteristics (I.e., Particle Angularity and Surface Texture) Align Well with the Microtexture Characteristics of the Investigated Sources

    Is spinopelvic sagittal alignment correlated with pain level, functional disability and frontal plane projection angle in women with patellofemoral pain syndrome? A cross-sectional study

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    There is a growing interest concerning the understanding of measurements of spinal and leg alignment in patients with patellofemoral pain syndrome (PFPS). However, evaluating spinopelvic alignment in the sagittal plane with pain level, functional disability and frontal plane projection angle (FPPA) in PFPS has not been adequately addressed. The aim of the study was to identify the correlation of spinopelvic parameters with pain level, functional disability and frontal plane projection angle in women with PFPS. This was a cross–sectional study involving sixty female patients diagnosed with PEPS, with a mean age of 32±6.47. The measurements used in the study included: radiographic parameters (X-Ray), the numeric pain rating scale (NPRS), the Arabic anterior knee pain scale (AAKP/Kujala) and the 2D-FPPA. Spearman correlation analysis was conducted to evaluate the relationship between these parameters. The results of our study demonstrated a strong positive correlation of lumbar lordosis (LL) with pain level and FPPA (r=0.825, r=0.812, p=0.0001). Also, a strong positive correlation of sacral slope (SS) with pain level (r = 0.0.820) and FPPA (r= 0.783). Pelvic tilt (PT) showed a moderate correlation with pain level (r = 0.0.614) and FPPA (r= 0.605), while a weak negative correlation was found between LL, SS and PT and functional disability score (r=-0.397, r=-0.385 and, r=-0.215 p=0.002). It was concluded that LL, SS and PT were significantly related to the pain level, functional disability and frontal plane projection angle in women with PFPS. These spinal alignments should be considered in clinical evaluation of knee-related disorders associated with PFPS

    S1 gene sequence analysis of a nephropathogenic strain of avian infectious bronchitis virus in Egypt

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    BACKGROUND: Infectious bronchitis is highly contagious and constitutes one of the most common and difficult poultry diseases to control. IBV is endemic in probably all countries that raise chickens. It exists as dozens of serotypes/genotypes. Only a few amino acid differences in the S1 protein of vaccine and challenge strains of IBV may result in poor protection. Tropism of IBV includes the respiratory tract tissues, proventriculus and caecal tonsils of the alimentary tract, the oviduct and the kidney. RESULTS: Infectious bronchitis virus (IBV) strain closely related to Massachusetts (Mass) serotype was isolated from broiler chickens suffering from severe renal and respiratory distresses. The isolate was serologically identified by Dot-ELISA and further characterized by RT-PCR then genotyped using S1 gene sequence analysis. Alignment of the S1 sequence of the isolate with 16 IBV strains revealed high homology to isolates related to Mass serotype. Inoculation with the strain reproduced the disease in experimental 1-day-old chickens and resulted in 20% mortality, severe renal and moderate respiratory distresses. Marked histopathological changes in both kidney and trachea were observed in experimentally infected chickens. A protection study using the H120 live attenuated vaccine showed low protection rate in spite of high S1 sequence homology (97%). Protection based criteria were: virus re-isolation attempts from trachea, tracheal and renal histopathology as well as IBV antigens detection by immunofluorescent antibody technique in kidney sections. CONCLUSION: Periodical evaluation of cross-protective capabilities of IBV vaccine(s) versus recently recovered field isolates should be performed to ensure optimum control of IBV

    CHARACTERIZATION OF A NEW BIOTYPE Moringa OF SAUDI ARABIA USING RAPD AND ISSR MARKERS

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    Moringa peregrina and M. oleifera are the only Moringa (Kelor) species found in Saudi Arabia. Both species are drought resistant and have very high nutritional and medicinal properties. Detection of genetic diversity is of great value for the improvement of nutritional and medicinal value of these plants. The aim of the present study was to characterize a new biotype Moringa observed in Al Bahah Region, Saudi Arabia. We used 11 RAPD and 15 ISSR primers to characterize and compare the new biotype with M. peregrina and M. oleifera. Level of polymorphism generated by each marker was calculated. We also calculate Nei’s coefficient to measure the genetic distance between the studied species. Level of polymorphism generated by RAPD and ISSR was 59.7% and 75%, respectively. RAPD and ISSR primers revealed that the new biotype shared 53 amplicons (43.44%) with both M. peregrina and M. oleifera, 29 amplicons with M. peregrina (2377%), 22 amplicons (18.03%) with M. oleifera, and displayed 18 unshared amplicons (14.75%). Based on RAPD data, genetic distance between M. oleifera and M. peregrina was 0.59, whereas genetic distance between the new biotype and M. oleifera and M. peregrina was 0.41 and 0.54, respectively. For ISSR data, genetic distance between M. oleifera and M. peregrina was 0.98, whereas genetic distance between the new biotype and M. oleifera and M. peregrina was 0.59 and 0.56, respectively

    Photo-identification of Dugongs in Marsa Alam and Wadi El Gemal National Park, Egypt

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    1351-1358Using photo-identification techniques, 30 dugongs were recorded at the southern Egyptian Red Sea coast between December 2015 and October 2017, 16 at Marsa Alam and 14 at Wadi El Gemal National Park (WGNP). Males were recorded seven times more frequently than females and calves were also recorded. A Photo ID catalogue was prepared for the dugongs with records of their occurrence among sites. We confirmed the presence of particular dugong specific sites. Long- and short-distance movements within the study sites were recorded for eight different dugongs. This is the first study to document the number of dugongs in inshore areas of the Egyptian Red Sea coast. Further studies are recommended for offshore sites in WGNP for better documentation of this group of animals

    Photo-identification of Dugongs in Marsa Alam and Wadi El Gemal National Park, Egypt

    Get PDF
    1351-1358Using photo-identification techniques, 30 dugongs were recorded at the southern Egyptian Red Sea coast between December 2015 and October 2017, 16 at Marsa Alam and 14 at Wadi El Gemal National Park (WGNP). Males were recorded seven times more frequently than females and calves were also recorded. A Photo ID catalogue was prepared for the dugongs with records of their occurrence among sites. We confirmed the presence of particular dugong specific sites. Long- and short-distance movements within the study sites were recorded for eight different dugongs. This is the first study to document the number of dugongs in inshore areas of the Egyptian Red Sea coast. Further studies are recommended for offshore sites in WGNP for better documentation of this group of animals

    Characterization of a New Biotype Moringa of Saudi Arabia Using Rapd and Issr Markers

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    Moringa peregrina and M. oleifera are the only Moringa species found in Saudi Arabia. Both species are drought resistant and have very high nutritional and medicinal properties. Detection of genetic diversity is of great value for the improvement of nutritional and medicinal value of these plants. The aim of the present study was to characterize a new biotype Moringa observed in Al Bahah Region, Saudi Arabia. We used 11 RAPD and 15 ISSR primers to characterize and compare the new biotype with M. peregrina and M. oleifera. Level of polymorphism generated by each marker was calculated. We also calculate Nei and Li\u27s coefficient to measure the genetic distance between the studied species. Level of polymorphism generated by RAPD and ISSR was 46% and 57%, respectively. RAPD and ISSR primers revealed that the new biotype shared 55 amplicons (45.08%) with both M. peregrina and M. oleifera, 28 amplicons with M. peregrina (22.95%), 21 amplicons (17.21%) with M. oleifera, and displayed 18 unshared amplicons (14.75%). Based on RAPD data, genetic distance between M. oleifera and M. peregrina was 0.32, whereas genetic distance between the new biotype and M. oleifera and M. peregrina was 0.21 and 0.29, respectively. For ISSR data, genetic distance between M. oleifera and M. peregrina was 0.5, whereas genetic distance between the new biotype and M. oleifera and M. peregrina was 0.36 and 0.34, respectively. Based on these results we suggested that the new biotype is a hybrid crossbred between M. peregrina and M. oleifera

    Effect of Wiper Edge Geometry on Machining Performance While Turning AISI 1045 Steel in Dry Conditions Using the VIKOR-ML Approach

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    AISI 1045 can be machined well in all machining operations, namely drilling, milling, turning, broaching and grinding. It has many applications, such as crankshafts, rollers, spindles, shafts, and gears. Wiper geometry has a great influence on cutting forces (Fr, Ff, Fc and R), temperature, material removal rate (MRR) and surface roughness (Ra). Wiper inserts are used to achieve good surface quality and avoid the need to buy a grinding machine. In this paper, an optimization-based investigation into previously reported results for Taguchi’s based L27 orthogonal array experimentations was conducted to further examine effect of the edge geometry on the turning performance of AISI 1045 steel in dry conditions. Three input parameters used in current research include the cutting speed (Vc), feed (f) and depth of cut (ap), while performance measures in this research were Ra, Fr, Ff, Fc, R, temperature (temp) and MRR. The Vise Kriterijumska Optimizacija Kompromisno Resenje (VIKOR) method was used to normalize and convert all the performance measures to a single response known as the VIKOR-based performance index (Vi). The machine learning (ML) approach was used for the prediction and optimization of the input variables. A correlation plot is developed between the input variable and Vi using the ML approach. The optimized setting suggested by Vi-ML is Vc: 160 m/min; ap: 1 mm and f: 0.135 mm/rev, and the corresponding value of Vi was 0.2883, while the predicted values of Ra, Fr, Ff, Fc, R, temp and MRR were 2.111 µm, 43.85 N, 159.33 N, 288.13 N, 332,16 N, 554.4 °C and 21,600 mm3/min, respectively
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