222 research outputs found
OLPT CONDUCTIVITY IN WOLLASTONITE INLAID NR/SBR TYPE ELASTOMER BASED MATERIAL
The electrical properties of wollastonite inlaid NR/SBR type elastomer based material have been evaluated. Electrical properties of the samples were measured in the temperature range of 303 to 453 K and the frequency range of 100 Hz – 40 MHz. All electrically measured parameters were given anomalies at 385 K. Only one type of dielectric relaxation process have been observed for all measurements. Physical parameters characterizing the dielectric behavior have been obtained by fitting the experimental results in the modified Debye equation. The activation energy which is thermally activated by dielectric relaxation process have been calculated to be 0.58 eV. DC conductivity increasing by temperature has been explained with the help of VFT model whereas the AC one has been clarified by the OLPT model
Investigation of arenesulfonyl-2-imidazolidinones as potent carbonic anhydrase inhibitors
Deanship of Scientific Research at King Saud University [RGP-VPP-163
A combined estimator using TEC and b-value for large earthquake prediction
[EN] Ionospheric anomalies have been shown to occur a few days before several large earthquakes. The published works normally address examples limited in time (a single event or few of them) or space (a particular geographic area), so that a clear method based on these anomalies which consistently yields the place and magnitude of the forthcoming earthquake, anytime and anywhere on earth, has not been presented so far. The current research is aimed at prediction of large earthquakes, that is with magnitude M-w 7 or higher. It uses as data bank all significant earthquakes occurred worldwide in the period from January 1, 2011 to December 31, 2018. The first purpose of the research is to improve the use of ionospheric anomalies in the form of TEC grids for earthquake prediction. A space-time TEC variation estimator especially designed for earthquake prediction will show the advantages with respect to the use of simple TEC values. Further, taking advantage of the well-known predictive abilities of the Gutenberg-Richter law's b-value, a combined estimator based on both TEC anomalies and b-values will be designed and shown to improve prediction performance even more.Baselga Moreno, S. (2020). A combined estimator using TEC and b-value for large earthquake prediction. Acta Geodaetica et Geophysica Hungarica. 55(1):63-82. https://doi.org/10.1007/s40328-019-00281-5S6382551Abordán A, Szabó NP (2018) Metropolis algorithm driven factor analysis for lithological characterization of shallow marine sediments. Acta Geod Geophys 53:189–199. https://doi.org/10.1007/s40328-017-0210-zAkhoondzadeh M, Saradjian MR (2011) TEC variations analysis concerning Haiti (January 12, 2010) and Samoa (September 29, 2009) earthquakes. Adv Space Res 47(1):94–104. https://doi.org/10.1016/j.asr.2010.07.024Asencio-Cortés G, Morales-Esteban A, Shang X, Martínez-Álvarez F (2018) Earthquake prediction in California using regression algorithms and cloud-based big data infrastructure. Comput Geosci 115:198–210. https://doi.org/10.1016/j.cageo.2017.10.011Baselga S (2018) Fibonacci lattices for the evaluation and optimization of map projections. Comput Geosci 117:1–8. https://doi.org/10.1016/j.cageo.2018.04.012Baselga S (2019) TestGrids: evaluating and optimizing map projections. J Surv Eng 144(3):04019004Berényi KA, Barta V, Kis Á (2018) Midlatitude ionospheric F2-layer response to eruptive solar events-caused geomagnetic disturbances over Hungary during the maximum of the solar cycle 24: a case study. 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Pure appl Geophys 117:1025–1044. https://doi.org/10.1007/BF00876083Dogan U, Ergintav S, Skone S, Arslan N, Oz D (2011) Monitoring of the ionosphere TEC variations during the 17th August 1999 Izmit earthquake using GPS data. Earth Planets Space 63(12):1183–1192. https://doi.org/10.5047/eps.2011.07.020Florido E, Martínez-Álvarez F, Morales-Esteban A, Reyes J, Aznarte-Mellado JL (2015) Detecting precursory patterns to enhance earthquake prediction in Chile. Comput Geosci 76:112–120. https://doi.org/10.1016/j.cageo.2014.12.002Florido E, Asencio-Cortés G, Aznarte JL, Rubio-Escudero C, Martínez-Álvarez F (2018) A novel tree-based algorithm to discover seismic patterns in earthquake catalogs. Comput Geosci 115:96–104. https://doi.org/10.1016/j.cageo.2018.03.005Freund FT, Kulahci IG, Cyr G, Ling J, Winnick M, Tregloan-Reed J, Freund MM (2009) Air ionization at rock surfaces and pre-earthquake signals. J Atmos Sol Terr Phys 71(17–18):1824–1834. https://doi.org/10.1016/j.jastp.2009.07.013Gopinath S, Prince PR (2018) Nonextensive and distance-based entropy analysis on the influence of sunspot variability in magnetospheric dynamics. Acta Geod Geophys 53:639–659. https://doi.org/10.1007/s40328-018-0235-yGrant RA, Halliday T (2010) Predicting the unpredictable; evidence of pre-seismic anticipatory behaviour in the common toad. J Zool 281:263–271. https://doi.org/10.1111/j.1469-7998.2010.00700.xGrant RA, Halliday T, Balderer WP, Leuenberger F, Newcomer M, Cyr G, Freund FT (2011) Ground water chemistry changes before major earthquakes and possible effects on animals. Int J Environ Res Public Health 8:1936–1956. https://doi.org/10.3390/ijerph8061936Guo J, Yu H, Li W, Liu X, Kong Q, Zhao C (2017) Total electron content anomalies before Mw 6.0 + earthquakes in the seismic zone of southwest China between 2001 and 2013. J Test Eval 45(1):131–139. https://doi.org/10.1520/JTE20160032International GNSS Service (2019) IGS products. https://www.igs.org/products. Accessed 5 May 2019Kane RP (2005) Ionospheric foF2 anomalies during some intense geomagnetic storms. Ann Geophys 23:2487–2499. https://doi.org/10.5194/angeo-23-2487-2005Kulhanek O, Persson L, Nuannin P (2018) Variations of b-values preceding large earthquakes in the shallow subduction zones of Cocos and Nazca plates. J South Am Earth Sci 82:207–214. https://doi.org/10.1016/j.jsames.2018.01.005Lin JW (2010) Ionospheric total electron content (TEC) anomalies associated with earthquakes through Karhunen–Loéve Transform (KLT). Terr Atmos Ocean Sci 21(2):253–265. https://doi.org/10.3319/TAO.2009.06.11.01(T)Lin JW (2011) Latitude-time total electron content anomalies as precursors to Japan’s large earthquakes associated with principal component analysis. Int J Geophys. https://doi.org/10.1155/2011/763527Liu JY, Chen YI, Chuo YJ, Chen CS (2006) A statistical investigation of preearthquake ionospheric anomaly. J Geophys Res 111:A05304. https://doi.org/10.1029/2005JA011333Liu JY, Chen YI, Chen CH, Liu CY, Chen CY, Nishihashi M, Li JZ, Xia YQ, Oyama KI, Hattori K, Lin CH (2009) Seismoionospheric GPS total electron content anomalies observed before the 12 May 2008 Mw7.9 Wenchuan earthquake. J Geophys Res 114:A04320. https://doi.org/10.1029/2008JA013698Nuannin P, Kulhanek O, Persson L (2005) Spatial and temporal b value anomalies preceding the devastating off coast of NW Sumatra earthquake of December 26, 2004. Geophys Res Lett 32:L11307. https://doi.org/10.1029/2005GL022679Pardalos PM, Romeijn HE (eds) (2002) Handbook of global optimization, vols. 1 & 2. Kluwer, DordretchPaul B, De BK, Guha A (2018) Latitudinal variation of F-region ionospheric response during three strongest geomagnetic storms of 2015. Acta Geod Geophys 53:579–606. https://doi.org/10.1007/s40328-018-0221-4Pulinets S, Boyarchuk K (2004) Ionospheric precursors of earthquakes. Springer, BerlinPulinets SA, Legen’ka AD, Gaivoronskaya TV, Depuev VKh (2003) Main phenomenological features of ionospheric precursors of strong earthquakes. J Atmos Sol Terr Phys 65:1337–1347. https://doi.org/10.1016/j.jastp.2003.07.011Reyes J, Morales-Esteban A, Martínez-Álvarez F (2013) Neural networks to predict earthquakes in Chile. Appl Soft Comput 13:1314–1328. https://doi.org/10.1016/j.asoc.2012.10.014Şentürk E, Çepni MS (2018a) A statistical analysis of seismo ionospheric TEC anomalies before 63 Mw ≥ 5.0 earthquakes in Turkey during 2003–2016. Acta Geophys 66:1495–1507. https://doi.org/10.1007/s11600-018-0214-2Şentürk E, Çepni MS (2018b) Ionospheric temporal variations over the region of Turkey: a study based on long-time TEC observations. Acta Geod Geophys 53:623–637. https://doi.org/10.1007/s40328-018-0233-0Şentürk E, Çepni MS (2019) Performance of different weighting and surface fitting techniques on station-wise TEC calculation and modified sine weighting supported by the sun effect. J Spat Sci 64(2):209–220. https://doi.org/10.1080/14498596.2017.1417169Şentürk E, Livaoğlu H, Çepni MS (2019) A comprehensive analysis of ionospheric anomalies before the mw 7.1 Van earthquake on 23 October 2011. J Navig 72(3):702–720. https://doi.org/10.1017/S0373463318000826Shiuly A, Roy N (2018) A generalized VS–N correlation using various regression analysis and genetic algorithm. Acta Geod Geophys 53:479–502. https://doi.org/10.1007/s40328-018-0220-5U.S. Geological Survey (2019) Earthquake catalog. https://earthquake.usgs.gov/earthquakes/search/. Accessed 5 May 2019Warwick JW, Stoker C, Meyer TR (1982) Radio emission associated with rock fracture: possible application to the Great Chilean Earthquake of May 22, 1960. J Geophys Res Solid Earth 87:2851–2859. https://doi.org/10.1029/JB087iB04p02851Yao Y, Chen P, Wu H, Zhang S, Peng W (2012) Analysis of ionospheric anomalies before the 2011 M w 9.0 Japan earthquake. Chin Sci Bull 57(5):500–510. https://doi.org/10.1007/s11434-011-4851-yZakharenkova IE, Shagimuratov II, Krankowski A (2007a) Features of the ionosphere behavior before the Kythira 2006 earthquake. Acta Geophys 55(4):524–534. https://doi.org/10.2478/s11600-007-0031-5Zakharenkova IE, Shagimuratov II, Krankowski A, Lagovsky AF (2007b) Precursory phenomena observed in the total electron content measurements before great Hokkaido earthquake of September 25, 2003 (M = 8.3). Stud Geophys Geod 51(2):267–278. https://doi.org/10.1007/s11200-007-0014-
Validity and reliability of velocity and power measures provided by the Vitruve linear position transducer
This study aimed to determine the validity and between-day reliability of the mean velocity (MV), peak velocity (PV), mean power (MP), and peak power (PP) provided by the Vitruve linear position transducer at different submaximal loads in the free-weight and Smith machine back squat using GymAware as a reference point. Fourteen male sports science students (free-weight back squat one-repetition maximum [1RM]: 132.5 ± 28.5 kg, Smith machine back squat 1RM: 163.9 ± 30.4 kg) performed six experimental sessions, twice per week with 72 hours of rest. The first two included the assessment of the 1RM of both exercises. In the four remaining, both linear position transducers were simultaneously used to record MV, PV, MP, PP of each repetition during an incremental load test (i.e., 20, 40, 60, 80, 90% 1RM) with three minutes of rest between sets. Vitruve displayed both fixed and proportional bias for certain relative loads across all variables. Vitruve did not meet the validity criteria for all (MV, PP) or at least two (MP, PV) relative loads (Coefficient of variation [CV] > 10%; Pearson correlation < 0.70; Effect size > 0.60). MV, PV, MP, and PP recorded by Vitruve displayed acceptable reliability (CV < 10%) with superior reliability observed during a Smith Machine compared to free-weight back squat, and for velocity compared to power variables. Considering GymAware as a reference point, Vitruve was not valid for measuring velocity and power outcomes. Acceptable validity was observed only for PV in the Smith machine back squat, while the other variables—regardless of relative loads and exercise modes—were mostly inaccurate. All variables demonstrated acceptable reliability, with greater reliability noted in the Smith machine compared to the free-weight back squat exercise mod
The examination of protective effects of gallic acid against damage of oxidative stress during induced-experimental renal ischemia-reperfusion in experiment
Aim: In this study, probable effects of gallic acid were investigated in experimentally induced renal I/R injury in rats.
Material and methods: For this purpose, each group consisted of 7 Sprague dawley male albino rats. Groups were defined as follows; Group I: control group; Group II: I/R group; Group III, IV and V: I/R+Gallic acid (50, 100 and 200 mg.kg(-1) respectively-i.p.). Left kidney was removed by nephrectomy except for Group I. I/R was induced in the other kidney. Gallic acid was given 15 mins before ischemia induction. SOD, CAT and Gpx activities were determined by electrophoresis. MDA, MPO levels were determined spectrophotometrically. Histopathological investigations were also performed in kidney tissues. BUN and Creatinine levels in serum were determined.
Results: BUN, Creatinine and MDA levels were statistically significant but MPO level was not statistically significantly increased in Group II. For SOD, CAT, Gpx activities in Group II, an increase was determined with respect to Group I. Histopathological investigations revealed widespread hyperemia in glomerulus, expansion of the structure between tubules and cell disruptions in Group II. In Group V (200 mg.kg-1 gallic acid), in terms of biochemical parameters, in spite of the significant decrease in BUN, Creatinine and MDA levels; a decrease was determined in SOD, CAT and Gpx isoenzyme activities. Group V showed histologically that I/R injury had been prevented to a greater extent and appearances were close to the control.
Conclusion: As a result, in terms of our study, evaluations regarding kidney functions and histopathology have shown that gallic acid has protective effects in renal I/R injury (Tab. 2, Fig. 5, Ref. 36). Text in PDF www.elis.sk
Using velocity recordings to predict squat repetitions to failure in high‐level wrestlers
The aim of this study was to assess whether lifting velocity (MV) can provide accurate estimations of the maximum number of repetitions that can be performed to failure (RTF) during the parallel back‐squat exercise performed in a Smith machine. Thirty male wrestlers from the Turkey Olympic preparation center (age = 22.6 ± 2.2 years) completed four testing sessions: a session to determine the back‐squat one‐repetition maximum [1RM], two sessions consisting of single sets to failure against three loads (90%‐80%‐70%1RM), and one session consisting of four sets to failure against the 75%1RM. The goodness‐of‐fit of the generalized RTF‐MV relationship was strong (r2 = 0.838), but the individualized RTF‐MV relationships were stronger (r2 = 0.957 ± 0.058). Only 3 out of 60 individualized RTF‐MV relationships revealed a r2 lower than the r2 of the generalized RTF‐MV relationship (r2 = 0.685, 0.779 and 0.810). The reliability of the fastest MV associated with each RTF ranged from acceptable (4 out of 15 RTFs) to high (11 out of 15 RTFs). The raw and absolute errors in the prediction of RTF did not increase under fatigue and were comparable for both generalized (raw errors: −1.0–0.3 repetitions; absolute errors: 1.1–1.7 repetitions) and individualized (raw errors: −0.8 to 0.1 repetitions; absolute errors: 1.2–1.8 repetitions) RTF‐MV relationships. These results indicate that RTF can be predicted with acceptable precision from MV recordings in resistance‐trained skilled wrestlers during the parallel back‐squat exercise performed in a Smith machine
Aortic distensibility and coronary artery bypass graft patency
<p>Abstract</p> <p>Background</p> <p>Aortic distensibility is an elasticity index of the aorta, and reflects aortic stiffness. Coronary artery disease has been found to be substantially associated with increased aortic stiffness. In this study we aimed to retrospectively analyze the association of angiographically determined aortic distensibility with the patency rates of coronary bypass grafts</p> <p>Methods</p> <p>The study was conducted in the Cardiology department of the Applied Research Centre for Health of Uludağ University. The coronary angiograms of 53 consecutive coronary bypass patients were analysed retrospectively. Aortic distensibility was calculated using the formula: 2 × (change in aortic diameter)/(diastolic aortic diameter) × (change in aortic pressure). The number of stenosed and patent bypass grafts and the patient characteristics like age, risk factors were noted.</p> <p>Results</p> <p>There were 44 male (83%) and 9 female (17%) cases. Eighteen cases had only one saphenous vein grafting. The number of cases with two, three and four saphenous grafting were 18, 11 and 1; respectively. In the control angiograms the number of cases with one, two, three and four saphenous vein graft obstruction were 15 (31.3%), 7 (14.6%), 1 (2.1%) and 1 (2.1%) respectively. The aortic distensibility did not differ in cases with and without saphenous graft occlusion (p > 0.05). Also left internal mammary artery (LIMA) graft patency was not related to the distensibility of the aorta (p > 0.05). We also evaluated the data for cut-off values of 50 and 70 mmHg of pulse pressure and did not see any significant difference between the groups in terms of saphenous or LIMA grafts.</p> <p>Conclusion</p> <p>In this study we failed to show association of angiographically determined aortic distensibility with coronary bypass graft patency in consecutive 53 patients with coronary artery bypass graft surgery (CABG).</p
Postresectional lung injury in thoracic surgery pre and intraoperative risk factors: a retrospective clinical study of a hundred forty-three cases
<p>Abstract</p> <p>Introduction</p> <p>Acute respiratory dysfunction syndrome (ARDS), defined as acute hypoxemia accompanied by radiographic pulmonary infiltrates without a clearly identifiable cause, is a major cause of morbidity and mortality after pulmonary resection. The aim of the study was to determine the pre and intraoperative factors associated with ARDS after pulmonary resection retrospectively.</p> <p>Methods</p> <p>Patients undergoing elective pulmonary resection at Adnan Menderes University Medical Faculty Thoracic Surgery Department from January 2005 to February 2010 were included in this retrospective study. The authors collected data on demographics, relevant co-morbidities, the American Society of Anesthesiologists (ASA) Physical Status classification score, pulmonary function tests, type of operation, duration of surgery and intraoperative fluid administration (fluid therapy and blood products). The primary outcome measure was postoperative ARDS, defined as the need for continuation of mechanical ventilation for greater than 48-hours postoperatively or the need for reinstitution of mechanical ventilation after extubation. Statistical analysis was performed with Fisher exact test for categorical variables and logistic regression analysis for continuous variables.</p> <p>Results</p> <p>Of one hundred forty-three pulmonary resection patients, 11 (7.5%) developed postoperative ARDS. Alcohol abuse (p = 0.01, OR = 39.6), ASA score (p = 0.001, OR: 1257.3), resection type (p = 0.032, OR = 28.6) and fresh frozen plasma (FFP)(p = 0.027, OR = 1.4) were the factors found to be statistically significant.</p> <p>Conclusion</p> <p>In the light of the current study, lung injury after lung resection has a high mortality. Preoperative and postoperative risk factor were significant predictors of postoperative lung injury.</p
VERITAS: Status and Highlights
The VERITAS telescope array has been operating smoothly since 2007, and has
detected gamma-ray emission above 100 GeV from 40 astrophysical sources. These
include blazars, pulsar wind nebulae, supernova remnants, gamma-ray binary
systems, a starburst galaxy, a radio galaxy, the Crab pulsar, and gamma-ray
sources whose origin remains unidentified. In 2009, the array was reconfigured,
greatly improving the sensitivity. We summarize the current status of the
observatory, describe some of the scientific highlights since 2009, and outline
plans for the future.Comment: Presented at the 32nd ICRC, Beijing, 201
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