bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Significance of a Crack Growth Law for a C(T) Fracture Specimen Undergoing Stable Crack Extension
Authors: Donoso Juan R. , Vasquez Katherine , Landes John D. 
Published: November 2008

Abstract
A new method of construction of the J-R curve has been proposed recently that makes use of a postulated crack growth law relating stable crack extension, Δa, to plastic displacement, vpl. An analytical treatment of both the J-Δa curve and the force-displacement, P-v, curve, is now possible even under circumstances in which the sole inputs are the P-v curve and the initial and final crack size values. Based upon this crack growth law concept, and on the common and the concise format equations of Donoso and Landes, an alternative way of estimating the amount of stable crack growth is presented. This alternative method, which allows for the evaluation of the crack size at any value of force or displacement along the P-v curve, has been applied to some examples of C(T) fracture test specimens that have crack extension values obtained by the unloading compliance method. The results are quite encouraging, and the method is extended here to cases in which there are no crack extension measurements available.
Use of Ground Clay Brick as a Pozzolanic Material in Concrete
Authors: Bektas F. , Wang K. , Ceylan H. 
Published: November 2008

Abstract
This study investigates the suitability of using ground clay brick (GCB) as a pozzolanic material in concrete. Crushed clay brick originating from demolished masonry was ground in the laboratory and used as a cement replacement in paste and concrete. Hydration characteristics of paste mixtures were investigated for a better understanding in concrete application. The effect of ground brick replacement for cement on concrete’s mechanical properties and chloride ion penetration resistance, as a measure of durability, were also studied. Two replacement levels, 15 % and 25 %, were compared with the control (0 % GCB). The study on the cementitious pastes showed that the ground brick slightly increased the water demand for normal consistency, delayed the time of setting, reduced the temperature rise during hydration, and decreased the calcium hydroxide (Ca(OH)2) content. The tests on concrete showed that the mechanical properties (i.e., compressive, flexural and splitting tensile strengths, and modulus of elasticity) of concrete containing ground brick were comparable to those of the concrete without GCB. Furthermore, the GCB increased the resistance of concrete to chloride ion penetration. The study undertaken proved that, when it is finely ground, clay brick obtained from demolished masonry can be recycled as a pozzolanic cementitious material in concrete.
Field Calibration of an Analytical Model for Pavement Friction Testing Applications
Authors: Seneviratne H. N. , Rajapakshe M. P. N. , Gunaratne M. 
Published: November 2008

Abstract
Regular evaluation and maintenance of skid resistance (friction) of highway and runway pavements is an essential task in improving transportation safety. Various measuring devices operating under different mechanisms have been developed for friction evaluation. Generally, there is a significant variation of friction measurements provided by different devices on the same surface, requiring reliable guidelines for comparison of devices. This paper presents the results of a study conducted to verify whether the LuGre model, an existing dynamic friction model composed of physically significant parameters, would satisfy the above need. A revised formulation which would enhance the applicability of the average lumped version of the LuGre model to model real-world dynamic friction problems is also presented. The original LuGre model was applied to two widely used pavement friction measuring devices; the locked wheel skid trailer and the dynamic friction tester (DFT). In the work presented here the characteristic equations for each device have been formulated based on the LuGre model. In addition an analytical treatment of the kinetics of the DFT is performed to facilitate the application of the LuGre model to the DFT. For each device, the LuGre model parameters were tuned to match a part of the field data collected during a field test carried out by the authors. It was seen that the obtained parameters are reasonably comparable with those reported in the literature. Moreover, the calibrated model equations were seen to predict the observed data that were not used in model fitting, with acceptable accuracy. The results obtained in this study clearly show that the LuGre model can be utilized as an efficient physically intuitive tool with possible applications in: (1) predicting the three-dimensional variation of friction (with wheel slip and traveling speed) as measured by selected friction measuring devices, (2) providing physical interpretations to friction data from different devices, (3) regular self-calibration of friction devices, and (4) comparing pavement friction measurements from different devices.
Clinical impact of two different intraoperative parathyroid hormone assays in primary and renal hyperparathyroidism
Authors: Meyer Sonja-Kerstin , Zorn Markus , Frank-Raue Karin , Büchler Markus W , Nawroth Peter , Weber Theresia 
Published: November 2008

BackgroundIntraoperative parathyroid hormone (PTH) monitoring predicts successful surgery for primary hyperparathyroidism (pHPT). In renal HPT, intraoperative PTH assays can define whether parathyroid resection is adequate.MethodsIntraoperative PTH was measured with two different immunometric assays (Immulite Turbo DPC and ADVIA Centaur assay) in 91 patients undergoing parathyroidectomy for primary (n=57) and renal (n=34) hyperparathyroidism. PTH was monitored preoperatively, 10, 20, and 30 min after parathyroidectomy and 24 h postoperatively.ResultsTen minutes after parathyroidectomy, intraoperative PTH dropped into the normal range (<7.6 pmol/l) in 84% of patients with pHPT and tertiary HPT as measured with the ADVIA Centaur assay (PTH-A), compared with 100% of the samples measured with the Immulite Turbo DPC assay (PTH-I; P=0.0082). Twenty minutes after parathyroidectomy for secondary HPT, intraoperative PTH decreased to the normal range in 100% measured with PTH-I compared with 50% measured with PTH-A (P=0.009). Then, 24 h postoperatively, PTH-I and PTH-A levels were within the normal range in all of the successfully treated patients. Both assays correctly identified six patients with persistent disease and another patient with a double adenoma in pHPT.ConclusionsIn patients undergoing parathyroidectomy for primary or renal HPT, PTH levels decreasing to the normal range indicated successful surgery in all of the patients as measured with the PTH-I assay. Comparing the two assays, PTH-I was able to quantify the intraoperative PTH decay more quickly than PTH-A.
The daily rhythm of heart attack morbidity and mortality may be influenced by the time of sunrise
Authors: Kriszbacher Ildikó , Csoboth Ildikó , Boncz Imre , Bódis József 
Published: November 2008

A myocardialis infarctus morbiditásának, mortalitásának időpontja szezonális és napi ritmust is mutat, amely ingadozásra a napkelte és a napfényes órák száma is hatással lehet.
A vizsgálat célja:
Tanulmányozni kívánjuk, hogy a napkelte időpontja és a napfényes órák száma befolyásolja-e a szívinfarktus morbiditásának és mortalitásának szezonalitását, és hatással van-e diurnalis ritmusára.
Módszer:
Magyarországon retrospektív elemzést végeztünk 2004–2005-ben a klinikákra és a kórházi osztályokra felvett, akut szívinfarktuson átesett betegek (
n
= 32329) és szívinfarktusban elhalálozottak (
n
= 5142) vonatkozásában. Az Országos Egészségbiztosítási Pénztár adatbázisából a betegségek nemzetközi osztályozása szerint gyűjtöttük össze az adatokat.
Eredmények:
A napkelte és a myocardialis infarctus előfordulása és az utóbbi által okozott mortalitás között egyaránt pozitív korrelációt (
p
< 0,01) találtunk szezonális és diurnalis ritmus vonatkozásában. A napfényes órák száma és a szívinfarktus szezonális előfordulása között negatív korrelációt (
r
= –0,107,
p
< 0,05) találtunk. A napfényes órák száma és az infarktus mortalitásának szezonális előfordulása között szintén negatív korrelációt (
r
= –0,105,
p
< 0,05) tapasztaltunk.
Következtetés:
Adataink szerint a napkelte és a napfényes órák száma összefüggésbe hozható a szívinfarktus morbiditásának és mortalitásának gyakoriságával, de más tényezők is szerepet játszanak.
Health behaviour survey among medical students
Authors: Bíró Éva , Balajti Ilona , Ádány Róza , Kósa Karolina 
Published: November 2008

A leendő orvosok vélemény- és attitűdformáló hatása, példaképszerepe az egészséggel kapcsolatos ismeretek és szemlélet formálásában nemcsak a betegek, hanem rajtuk keresztül a hozzátartozók, a tágabb népesség körében is érvényesül. Azért fontos megismerni már tanulmányaik során egészségmagatartásukat és az arra ható tényezőket, hogy azt szükség esetén formálni lehessen.
Célkitűzések és módszer:
A jelen vizsgálat az orvostanhallgatók egészségi állapotának és egészségmagatartásának felmérése céljából történt a Debreceni Egyetem Orvos- és Egészségtudományi Centruma Általános Orvostudományi Karának I–V. évfolyamain magyar nyelven tanuló orvostanhallgatók körében, kérdőíves adatfelvétellel. A kérdőív a demográfiai adatokon túl az egészségi állapotra és az egészségmagatartásra vonatkozó kérdéseket tartalmazott.
Eredmények:
A debreceni orvostanhallgatók közel háromnegyede jónak, illetve nagyon jónak ítéli egészségi állapotát; csaknem mindannyian úgy vélekednek, hogy sokat, illetve nagyon sokat tehetnek az egészségükért. A hallgatók csaknem kétharmada soha nem dohányzott; 15%-uk napi rendszerességgel szív cigarettát. Alkoholt a hallgatók több mint négyötöde fogyaszt, de leginkább csak alkalmanként. Egynegyedük kipróbált már valamilyen kábítószert, a leggyakrabban marihuánát, illetve altatót és nyugtatót orvosi javaslat nélkül. A debreceni orvostanhallgatók adatait az átlagnépesség azonos korosztályával összehasonlítva elmondható, hogy az orvostanhallgatók közül kevesebben dohányoznak, és a naponta dohányzók aránya is kisebb; közel 50% a heti rendszerességgel italozók aránya.
Következtetések:
Az orvostanhallgatók közt korábban történt felmérések és a jelen vizsgálat eredményeit összehasonlítva a szerhasználat gyakorisága nem emelkedett lényegesen. Aggasztó azonban, hogy a hallgatók körében szignifikánsan magasabb a lelki egészség zavarára utaló pontszám átlaga, mint a hasonló korú átlagnépesség körében.
Report on erythroderma and scabies infection in connection with two cases of scabies norvegica
Authors: Jenei Márta , Veres Imre , Schmidt Emese , Varga Imre , Remenyik Éva 
Published: November 2008

Az erythroderma a testfelszín csaknem egészét érintő bőrgyulladás, amelyet hyperaemia, bőrmegvastagodás, hámlás jellemez. A testfelület nagy részére lokalizálódó gyulladás az etiológiai tényezőtől függetlenül önmagában is előidézhet életveszélyes állapotot. Parazitafertőzés az erythroderma hátterében extrém ritka. A scabieses megbetegedésért (közismerten rühesség) egy, az atkák családjába tartozó élősködő, aSarcoptes scabieivar.hoministehető felelőssé. Míg a „klasszikus” scabies prevalenciája világviszonylatban magas, addig a súlyosabb, veszélyesebb formával – a scabies norvegicával, más néven crustosus scabiesszel – jóval ritkábban találkozhat a klinikus, felismerése és kezelése epidemiológiai szempontból kiemelkedően fontos. A szerzők scabies norvegica két esete kapcsán ismertetik az erythroderma és a scabies differenciáldiagnosztikai problémáit és a fertőzés epidemiológiai jelentőségét.
Hemodynamic effects of N-acetylcystein and ischemic preconditioning in a liver ischemia-reperfusion model
Authors: Ghosh Subhamay , †Baumann János , Falusi Boglárka , Bogár Lajos , Rőth Erzsébet , Gál János 
Published: November 2008

Tanulmányunk célja volt megvizsgálni, hogy az ismételt ischaemiás prekondicionálás, illetve az N-acetilcisztein-terápia befolyásolják-e kedvező hemodinamikai hatásuk révén az ischaemiás-reperfúziós sérülést kutyamájban.Módszer:A kontrollcsoport (n= 10) 60 perc májischaemián esett át, majd ezt követően 180 perc reperfúzióban részesült. Az N-acetilcisztein-csoport (n= 5) intravénásan 150 mg kg–1N-acetilciszteint kapott az ischaemia megkezdése előtt. A prekondicionált csoportba tartozó kísérleti állatok (n = 5) ischaemiás prekondicionálásban részesültek (10 perc ischaemiás periódus után 10 perc reperfúzió, ismételve háromszor) a portalis triász lefogása előtt.Eredmények:Tizennyolc kísérleti állat élte túl a vizsgálati időszakot. Az N-acetilcisztein-csoportba tartozó kísérleti állatok közül egy kutya elhalt inotrop kezelésre nem reagáló keringési elégtelenség következében. A szívindex és az intrathoracicus vér volumenindexe szignifikánsan magasabb volt a prekondicionált csoportban a kontrollcsoporthoz viszonyítva, végig a vizsgálati periódus során.Következtetések:A kapott adatok arra engednek következtetni, hogy az ismételt ischaemiás prekondicionálás javíthat a hemodinamikai paramétereken, mindamellett az N-acetilcisztein-kezeléssel kapcsolatban nem tudtunk szignifikáns különbséget kimutatni.
A kinetic approach to evaluate the association of acid volatile sulfide and simultaneously extracted metals in aquatic sediments
Authors: Poot Anton , Meerman Eric , Gillissen Frits , Koelmans Albert A. 
Published: November 2008

AbstractThe acid volatile sulfide (AVS) and simultaneously extracted metals (ΣSEM) method is widely used for evaluating potential bioavailability of heavy metals in soil and sediment. It is also criticized, because the requirement that AVS and SEM metals (i.e., Cd, Cu, Ni, Pb, and Zn) are associated in the same phase is not always met. Here, we propose a dissolution-kinetics-based approach to assess whether AVS and ΣSEM originate from the same phase, as a prescreening tool for ΣSEM-AVS-based risk assessment or site characterization. Acid volatile sulfide and SEM metals from the same phase are assumed to yield equal dissolution rates. Therefore, dissolution rates for AVS and SEM metals were measured using a modified purge-and-trap method. Results were interpreted in terms of a shrinking particle model and a first-order model, which performed equally well. Of the SEM metals, only Cu showed reaction kinetics similar to those of AVS. Extraction of Fe and SEM-Zn (which constituted more than 90% of ΣSEM) was much faster than AVS and did not fit to the models. This suggests that they are not associated with AVS but also that AVS is probably not present as sulfide minerals. These data illustrate that the ΣSEM-AVS risk assessment concept would not be applicable for the studied sediments.
Biogas production from mono-digestion of maize silage–long-term process stability and requirements
Authors: Lebuhn M. , Liu F. , Heuwinkel H. , Gronauer A. 
Published: November 2008

Biogas production from mono-digestion of maize silage was studied for more than one year in six continuously stirred, daily fed 36 L fermenters. Chemical and microbiological parameters were analysed concomitantly. The reactors acidified already after 8 months of operation at a low organic loading rate (OLR) of 2 g VS*(L*d)−1. The TVA/TAC ratio was the most reliable parameter to indicate early process instabilities leading to acidification. A TVA/TAC threshold of 0.5 should not be exceeded. After acidification and recovery of the fermenters, propionic acid was no reliable parameter anymore to indicate process failure, since values far below the threshold of 1 g*L−1 were obtained although the process had collapsed.
The acidified reactors recovered better, showed greatly improved stability and allowed a higher OLR when a trace element (TE) cocktail was supplemented. Hydrolysis was obviously not process-limiting, results indicated that methanogens were affected. The most limiting element in long-term mono-digestion of maize silage turned out to be cobalt, but data obtained suggest that molybdenum and selenium should also be provided. TE supplementation should be designed specifically in order to meet the actual needs. TE availability for the biocenosis appears to be a key issue in biogas production, not only in mono-but also in co-digestion processes.
A simple method to evaluate the short-term biogas yield in anaerobic codigestion of WAS and organic wastes
Authors: Scaglione D. , Caffaz S. , Ficara E. , Malpei F. , Lubello C. 
Published: November 2008

The present study was aimed at setting and applying a procedure to measure the anaerobic degradability of different organic substrates by short-term tests (2–7 days) carried out at lab-scale with a low food to biomass (F/M) ratio. All tests were carried out using an acclimated sludge taken from a pilot-plant anaerobic digester (200 L). Trials were performed with a manometric system.
The experimental reliability of the device in measuring the anaerobic degradability was assessed by several preliminary tests carried out using acetate and glucose as reference substrates. The average conversion to methane was 99% for acetate and of 83% for glucose. The results of tests in triplicate showed the high repeatability of the method with an average coefficient of variation lower than 2%.
Then, the lab-scale procedure was applied to study the short-term anaerobic degradability of complex organic substrates: thickened waste activated sludge, two kinds of organic fraction of municipal solid waste (a kitchen waste and a fruit and vegetable waste collected at the wholesale market of Florence), olive mill wastewater and freshly harvested grass. Results indicated that organic fraction of municipal solid waste, olive mill wastewater and grass were characterized by a much higher anaerobic degradability if compared to the thickened activated sludge, well in agreement with literature data.
The limits and ultimate possibilities of technology of the activated sludge process
Authors: van Nieuwenhuijzen A. F. , van Bentem A. G. N. , Buunnen A. , Reitsma B. A. , Uijterlinde C. A. 
Published: November 2008

The (low loaded) biological nutrient removing activated sludge process is the generally accepted and applied municipal wastewater treatment method in the Netherlands. The hydraulical and biological flexibility, robustness and cost efficiency of the process for advanced removal of nutrients like nitrogen and phosphorus without (too much) chemicals results in a wide application of the activated sludge process within Dutch waterboards.
Presumably, wastewater treatment plants will have to contribute to the improvement of the quality of the receiving surface waters by producing cleaner effluent. In this perspective, the Dutch research organisation STOWA initiated a research project entitled “The Boundaries of the Activated Sludge Process” to investigate the possibilities and limitations of activated sludge processes to improve the effluent quality.
It is concluded that the activated sludge process as applied and operated at WWTP's in the Netherlands has the potential to perform even better than the current effluent discharge standards (10 mg Ntotal/l and 1 mg Ptotal/l). Reaching the B-quality effluent (&lt;5mg Ntotal/l and &lt;0.3 mg Ptotal/l) will be possible at almost all WWTPs without major adjustments under the conditions that:
the sludge load is below 0.06 kg BOD/kg TSS.d
the internal recirculation is above 20
the BOD/N ratio of the influent is above 3.
Complying with the A-quality effluent (&lt;2.2 Ntotal/l and &lt;0.15 mg Ptotal/l) seems to be difficult (but not impossible) and requires more attention and insight into the activated sludge process. Optimisation measures to reach the A-quality effluent are more thorough and are mostly only achievable by additional construction works (addition of activated sludge volume, increasing recirculation capacity, etc.).
It is furthermore concluded that the static HSA-results are comparable to the dynamic ASM-results. So, for fast determinations of the limits of technology of different activated sludge processes static modelling seems to by sufficient.
Electromagnetic plane-wave scattering from a sectorial groove in a perfectly conducting plane
Authors: Tsaur Deng-How , Chang Kao-Hao 
Published: November 2008

Abstract
Scattering characteristics of plane waves by a sectorial groove in a perfectly conducting plane are investigated. Both the transverse magnetic (TM) and transverse electric (TE) polarizations of the incident wave are considered. Judicious use of the region-matching technique provides a rigorous series solution to the problem. The analyzed region is separated into two sub-regions by choosing a semi-circular auxiliary boundary. Thefield in each sub-region is expanded as a summationof proper wave functions with unknown coefficients. Enforcing the matching of conditions on the auxiliary boundary and of boundary condition on the circular-arc surface of the groove leads to a linear set of equations and the unknown coefficients are then determined. Numerical results demonstrate the influence of central angles of the sectorial groove on echo width, far-field pattern and near-field distribution. The presented geometry is easily applicable to the design and fabrication of a grating structure for optical switches and tunable filters.
Controlling chaos by developing spiral wave from heterogeneity in excitable medium
Authors: Chen Jiang-Xing , Xu Jiang-Rong , Zhang Xiang-Peng , Zhang Ju-Wang , Zhang Xiao-Wei 
Published: November 2008

Abstract
We study pattern formation induced by a spiral wave developing from heterogeneities in an excitable medium. Turbulence can be suppressed by a spiral wave from the heterogeneity, forming multiple coexistent systems of regular geometrical patterns. We find that the types of these patterns depend critically on the degree of heterogeneity. The underlying mechanism is due to dispersion relation which is characterized by excitability.
Shoulder dystocia related fetal neurological injuries: the role of diabetic control
Authors: Iffy Leslie , Brimacombe Michael , Varadi Valeria , Raghuwanshi Maya , Ganesh Vijaya , Raju Vijaya 
Published: November 2008

Abstract
The study explores the roles of routine prenatal diabetic screening and control in the occurrence of neurological birth injuries associated with shoulder dystocia. The investigation involved retrospective review of 226 medical records that contained information about the antenatal events in cases that resulted in permanent neonatal injuries following arrest of the shoulders at delivery. Close attention was paid to diabetic screening and management of mothers with evidence of glucose intolerance. Analysis of the records revealed that one-third of all women, including those with predisposing factors, received no diabetic screening during pregnancy. The majority of confirmed diabetic patients were not treated adequately. Among babies of diabetic women, birth weights exceeding 4500 g were about 30-fold more frequent than among those with normal glucose tolerance. The data suggest that universal screening and rigid diabetic control, including mothers with borderline glucose tolerance, are effective measures for the prevention of excessive fetal growth and intrapartum complications deriving from it. If ignored, impaired maternal glucose tolerance may become a major predisposing factor for neurological birth injuries. It appears therefore that with routine screening for diabetic predisposition and effective control of gestational diabetes the risk of fetal damage can be reduced substantially.