Search

Electrical Impedance Tomography (EIT) is a clinically used tool for bed-side monitoring of ventilation. Previous work also showed a high potential for lung perfusion monitoring with indicator-enhanced EIT. However, many research questions have yet to be answered before it can be broadly applied in clinical everyday life. The goal of this work is to evaluate a new method to improve EIT perfusion measurements. Pulmonary hemodynamic transfer functions were estimated using regularized deconvolution with Tikhonov regularization to estimate spatial perfusion parameters. The final comparison between EIT images and PET scans showed a median correlation of 0.897 for the images which were reconstructed using the regularized deconvolution. In comparison the previously used maximum slope method led to a median correlation of 0.868.

OBJECTIVE To develop a method based on CT angiography and the maximum slope model (MSM) to measure regional lung perfusion in anesthetized ponies. ANIMALS 6 ponies. PROCEDURES Anesthetized ponies were positioned in dorsal recumbency in the CT gantry. Contrast was injected, and the lungs were imaged while ponies were breathing spontaneously and while they were mechanically ventilated. Two observers delineated regions of interest in aerated and atelectatic lung, and perfusion in those regions was calculated with the MSM. Measurements obtained with a computerized method were compared with manual measurements, and computerized measurements were compared with previously reported measurements obtained with microspheres. RESULTS Perfusion measurements obtained with the MSM were similar to previously reported values obtained with the microsphere method. While ponies were spontaneously breathing, mean ± SD perfusion for aerated and atelectatic lung regions were 4.0 ± 1.9 and 5.0 ± 1.2 mL/min/g of lung tissue, respectively. During mechanical ventilation, values were 4.6 ± 1.2 and 2.7 ± 0.7 mL/min/g of lung tissue at end expiration and 4.1 ± 0.5 and 2.7 ± 0.6 mL/min/g of lung tissue at peak inspiration. Intraobserver agreement was acceptable, but interobserver agreement was lower. Computerized measurements compared well with manual measurements. CLINICAL RELEVANCE Findings showed that CT angiography and the MSM could be used to measure regional lung perfusion in dorsally recumbent anesthetized ponies. Measurements are repeatable, suggesting that the method could be used to determine efficacy of therapeutic interventions to improve ventilation-perfusion matching and for other studies for which measurement of regional lung perfusion is necessary.

This work investigates the fire line evolution in canyon fire spread by analytical and experimental means. The purpose is to understand the mechanism of fire spread acceleration associated with eruptive fire in canyon terrain. A symmetrical model canyon is used for experiments, and in each test the fire is initiated by a point ignition using dead pine needles as the fuels. By experimental observations and data, three distinct types of fire line contour are identified under different central slope angles (the angle between the canyon centerline and the horizontal ground), resulting in different variation modes of rate of spread along the canyon centerline. It is found that the trace of fire head deviates from the line of maximum slope for non-zero central slope angles, and such a deviation increases with increasing central slope angle. The fire spread acceleration associated with eruptive fire occurs when the central slope angle reaches a certain critical value. Experimental data confirm that under higher slope conditions, the significant interaction between the two lateral flame fronts induces marked convective heating ahead of the flame front, which is inferred to be the potential mechanisms of eruptive fire in canyon topography. A model analysis further elucidates how the deflection of the trace of fire head, induced by the fire interaction effect, influences the acceleration of fire spread under higher slope conditions.

Using data from the Sloan Digital Sky Survey Moving Object Catalog, we study color as a function of size for C-complex families in the Main Asteroid Belt to improve our understanding of space weathering of carbonaceous materials. We find two distinct spectral slope trends: Hygiea-type and Themis-type. The Hygiea-type families exhibit a reduction in spectral slope with increasing object size until a minimum slope value is reached and the trend reverses with increasing slope with increasing object size. The Themis family shows an increase in spectral slope with increasing object size until a maximum slope is reached and the spectral slope begins to decrease slightly or plateaus for the largest objects. Most families studied show the Hygiea-type trend. The processes responsible for these distinct changes in spectral slope affect several different taxonomic classes within the C-complex and appear to act quickly to alter the spectral slopes of the family members., Comment: 13 pages, 6 figures, 1 table, to be published in the Astronomical Journal

OBJECTIVE To evaluate the effect of contrast medium injection rate on CT-derived renal perfusion estimates obtained with the maximum slope method in healthy small dogs. ANIMALS 6 healthy sexually intact male purpose-bred Beagles. PROCEDURES All dogs underwent CT perfusion analysis 3 times in a crossover design, receiving a different contrast medium injection rate (1.5, 3.0, and 4.5 mL/s) each time, with a 1-week interval between imaging sessions. All CT images were obtained at the level of the left renal hilus. The time to peak aortic enhancement (TPAE) and time to initial renal venous enhancement (TIRVE) were measured from time-attenuation curves. The renal CT perfusion estimates (blood flow and blood volume) were estimated by use of the maximum slope method, which assumes no venous outflow of contrast medium during CT perfusion analysis. RESULTS The TPAE occurred at or before the TIRVE at all injection rates. Median values of estimated blood flow and blood volume did not differ significantly among injection rates. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that the assumption of no venous outflow of contrast medium during renal CT perfusion analysis with the maximum slope method was satisfied for all 3 contrast medium injection rates in the evaluated dogs. A low injection rate may be more practical than higher injection rates that require large catheters for CT perfusion analysis in small dogs such as Beagles.

Populations are locked down during an epidemic to slow down the rate of infection so that epidemic trajectory is "flattened". This helps to keep cases at a manageable level. Given the enormous economic damage and misery caused by a lockdown, it is imperative to keep the lockdown period limited. A lockdown is useful only if it can be ensured that after the lockdown is lifted, the epidemic trajectory does not rise sharply again. We present here the results from a mathematical model of the epidemic which examines how the timing, strength and duration of the lockdown affects the post-lockdown epidemic trajectory. Our results show the following:A early lockdown (imposed when less than 1% of the population has been infected), of any reasonable duration, cannot prevent the return of the epidemic when the lockdown is lifted. The curve starts climbing soon after lifting the lockdown and reaches a peak of the same height as the no-lockdown curveThe post-lockdown trajectory can be flattened only if the lockdown is imposed after about 10% of the population has recovered after infection.The slope of the post-lockdown epidemic curve depends on the level of immunity built up in the population before and during the lockdown period. Application of lockdown around the inflexion point of the epidemic curve (the point of maximum slope of the curve) ensures that the post-lockdown curve is also flattened.

The research location is in the PPSDM Geominerba field campus. The campus is located in Padalarang, West Java that is surrounded by the open-pit mining of limestone and marble. This limestone was formed in Oligo-Miocene of Rajamandala Formation. The research objective was to determine the condition of the slopes around the campus based on geomechanical characteristics. Based on field observations, the slope angle in the area is dominated by steep slopes. The rock hardness level is dominated by hard rock with a hardness ranging from 50-100 MPa. Rock Mass Rating shows that the are a is dominated by good rocks. While the S lope Mass Rating calculation show that the maximum slope angle is between 52-75 ° . L evel of deformation and intensive weathering process will reduce the strength of the rock in the future. Several rock fall occurrences on this research area support this assumption . Yet , some local open pit mining area activity near the toe hill of the area need to be concerned regarding the effect of the local rock fall occurrences.

The Small Punch Test (SPT) is a miniaturized test to characterize the mechanical properties of the materials. The load-displacement curve obtained by this test does not directly provide the material parameters, and linear correlations between data obtained from SPT curve and each mechanical property are necessary. The main difficulty of these correlation methods is the high level of scattering showed when analyzing a wide set of materials in the same study.In this paper, a finite element analysis focused on steel alloys was performed to understand the specimen behavior in the early stages of the SPT. Present methods to correlate the material yield strength with the data obtained from the SPT curve were also analyzed via this FEM study to discover the meaning of the current correlation scattering for this mechanical property. This numerical research also proved the accuracy of the proposed correlation method for the yield strength via the SPT. The maximum slope of zone I (Slopeini) of the SPT curve showed an accurate correlation with this mechanical property.Focusing on steel alloys, experimental tensile tests and SPT's were performed to validate the numerical analysis and to demonstrate the suitability of the proposed Slopeini versus yield strength correlation method. Keywords: Small Punch Test, SPT, Yield strength

The work here presented is focused on defining the geometrical limitations in the manufacturing of metallic parts by the additive manufacturing (AM) technology named Laser Metal Deposition (LMD). AM techniques are often perceived by designers as able to produce parts of any level of complexity. Nevertheless, there exist limitations inherent to all AM processes, and in particular to the LMD, where geometrical distortions and other undesirable factors can be produced, this technique does not provide absolute freedom to fabricate any geometry. Part designers often lack of comprehension about these problems and their effect in the final products. The aim of this work is to approach this lack of knowledge via experimental inspection in order to quantify the geometrical limitations and identify the most common defects of the LMD. To this purpose, the research was focused in the study of inclined walls, experimentally depositing and measuring which is the maximum slope with which an inclined wall can be manufactured by LMD under different conditions

Purpose: To investigate the performance of a new semi-automatic method for analyzing the signal time-intensity curve (TIC) obtained by breast dynamic contrast enhancement (DCE)-MRI. Methods: In the conventional method, a circular region of interest was drawn manually onto the map reflecting the maximum slope of increase (MSI) to delineate the suspicious lesions. The mean TIC was determined subjectively as one of three different wash-out patterns. In the new method, the lesion area was identified semi-automatically. The mean TIC was categorized quantitatively. In addition to the MSI, other quantitative parameters were calculated, including the signal intensity slope (SIslope), initial percentage of enhancement (Einitial), percentage of peak enhancement (Epeak), early signal enhancement ratio (ESER), and second enhancement percentage (SEP). The performances were compared with receiver operating characteristic (ROC) analysis and Wilcoxon's test. Results: For TIC categorization results, the diagnostic accuracy rates were 61.54% with the traditional manual method and 76.92% with the new method. For the mean MSI values from the manual method, the accuracy was 63.41%. For the mean TIC derived using the semi-automatic method, the diagnostic accuracy were 82.05% for SIslope, 67.31% for MSI, 61.53% for Einitial, 64.75% for Epeak, 64.74% for ESER, and 52.56% for SEP, respectively. For the lesion regions identified by the semi-automatic method, the diagnostic accuracy for above mentioned parameters were 80.13%, 69.87%, 61.54%, 63.47%, 64.74% and 55.13%, respectively. Conclusion: With respect to the analysis of TIC from breast DCE-MRI, the results demonstrated that the new method increased the diagnostic accuracy, and should be considered as a supplementary tool for distinguishing benign and malignant lesions.

Objectives: Temperature dependent chemical shifts of important brain metabolites measured by localised 1H MRS were investigated to test how the use of incorrect prior knowledge on chemical shifts impairs the quantication of metabolite concentrations. Materials and methods: Phantom measurements on solutions containing 11 metabolites were performed on a 7 T scanner between 1 and 43 °C. The temperature dependence of the chemical shift differences was fitted by a linear model. Spectra were simulated for di erent temperatures and analysed by the AQSES program (jMRUI 5.2) using model functions with chemical shift values for 37 °C. Results: Large differences in the temperature dependence of the chemical shift differences were determined with a maximum slope of about ±7.5 × 10−4 ppm/K. For 32–40 °C, only minor quantification errors resulted from using incorrect chemical shifts, with the exception of Cr and PCr. For 1–10 °C considerable quantification errors occurred if the temperature dependence of the chemical shifts was neglected. Conclusion: If 1H MRS measurements are not performed at 37 °C, for which the published chemical shift values have been determined, the temperature dependence of chemical shifts should be considered to avoid systematic quantification errors, particularly for measurements on animal models at lower temperatures.

Analytical relations to describe experimentally measured traction-separation laws are often expressed in dimensionless quantities. The traction and the separation are commonly normalized using the cohesive strength and a length measure, respectively. The ratio between the fracture energy and the cohesive strength is often used as a length measure. An alternative length measure is the ratio between the cohesive strength and the maximum slope of the traction-separation law. A relation between these two length measures are established. To illustrate the implications on cohesive laws, three existing cohesive laws are rewritten using the alternative normalization. As a result it is shown that the number of unknown material parameters can be reduced. One of the derived dimensionless cohesive law is validated against experimental uniaxial tension and compression load-deformation data of different sample sizes and different quasi-brittle materials, i.e. concrete and paperboard. A good fit of the cohesive law is shown to all the investigated data. These findings indicate that the derived normalized cohesive law is independent of material directions, moisture contents and sample size.

Producción Científica, Debris cones are a very common landform in temperate high mountains. They are the most representative examples of the periglacial and nival processes. This work studies the dynamic behavior of two debris cones (Cone A and Cone B) in the Picos de Europa, in the north of the Iberian Peninsula. Their evolution was measured uninterruptedly throughout each August for 10 years (2009–2018) using the Terrestrial Laser Scanning (TLS) technique. The observations and calculations of the two debris cones were treated independently, but both showed the same behavior. Therefore, if these results are extrapolated to other debris cones in similar environments (temperate high mountain), they should show behavior similar to that of the two debris cones analyzed. Material falls onto the cones from the walls, and transfer of sediments follows linear trajectories according to the maximum slope. In order to understand the linear evolution of the two debris cones, profiles were created along the maximum slope lines of the Digital Elevation Model (DEM) of 2009, and these profile lines were extrapolated to the remaining years of measurement. In order to determine volumetric surface behavior in the DEMs, each year for the period 2009–2018 was compared. In addition, the statistical predictive value for position (Z) in year 2018 was calculated for the same planimetric position (X,Y) throughout the profiles of maximum slopes. To do so, the real field data from 2009–2017 were interpolated and used to form a sample of curves. These curves are interpreted as the realization of a functional random variable that can be predicted using statistical techniques. The predictive curve obtained was compared with the 2018 field data. The results of both coordinates (Z), the real field data, and the statistical data are coherent within the margin of error of the data collection., Fondo Europeo de Desarrollo Regional - Agencia Estatal de Investigación (grant TIN2016-76843-C4-2-R), Ministerio de Economía, Industria y Competitividad - Fondo Europeo de Desarrollo Regional (grant CGL2015-68144-R)

Pulse Transition Time (PTT) is being increasingly used for estimating blood pressure unobtrusively aiming at continuous assessment of cardiovascular diseases (CVD) and illness monitoring using portable and low-cost equipment. Several methods are available for PTT estimation, each one accepting its own constraints and physical parameters' assumptions, besides the panoply of definitions attributed to PTT calculus. Defining PTT as the time difference between the time instant were peak R occurred in an electrocardiogram (ECG) cardiac cycle and the time instant were the photoplestimography (PPG) signal of correspondent cardiac cycle presents the inflexion point of its maximum slope, a method of PTT estimation based on measured ECG and PPG signals during several cardiac cycles is proposed. This method was tested on ECG and PPG data collected from 7 individuals for periods ranging from 30 min to 8 h. For the sake of PTT algorithm performance evaluation, ECG and PPG signals were collected with a commercial system, together with the PTT signals provided by the same equipment resultant from automatic computation with unknown algorithm. Preliminary results so far obtained encourage the use of the proposed PTT estimation algorithm on future internet of things (IoT) e-health system development aiming at elderly blood pressure estimation and CVD assessment. Accuracy of the proposed algorithm (0.9 correlation with reference signal) may be improved by further studies on raw data filtering parametrizations. Fundacao para a Ciencia e TecnologiaPortuguese Foundation for Science and TechnologyEuropean Commission [SFRH/BSAB/142998/2018, SFRH/BSAB/142997/2018] Junta de Comunidades de Castilla La ManchaJunta de Comunidades de Castilla-La Mancha [SBPLY/17/180501/000392] info:eu-repo/semantics/publishedVersion

Internal fixation is a method of healing fractures by connecting them using metal called pen. Pen metal in the body isn’t permanent, when the bone was strong the pen must be removed to avoid infection. In finding the pen, X-Ray are usually used. But X-Ray has bad effect, so not everyone is allowed to use it. The solution given by make prototype to detect pen location using B-Mode ultrasonic scanning method, it uses 5MHz single transducerultrasonic. Objects measurement is the animal bones connected with metals placed in the jelly with different heights. From the two transducers, the concave surface transducer has a better result and smaller percentage error than the flat surface transducer. The concave surface transducer has a focal length area 1.94cm above the transducer surface. The maximum slope angle of the object is 20o, which more than that makes the echo signal unreadable the object.The measurement results of objects displayed in the B-Mode 1 dimensional on PC that displays the structure of the bottom surface of an object, based on comparison between the actual object and the B-Mode display an error less than 6%, meaning B-Mode can represent the surface structure bottom of the actual object.

A trapped air pocket can cause a partial air lock in the top of a hump pipe zone. It increases the resistance and decreases the hydraulic cross section, as well as the capacity of the water supply pipeline. A hydraulic model experiment is conducted to observe the deflection and movement of the trapped air pocket in the hump pipe zone. For various pipe flow velocities and air volumes, the head losses and the equilibrium slope angles are measured. The extra head losses are also obtained by reference to the original flow without the trapped air pocket. Accordingly, the equivalent sphere model is proposed to simplify the drag coefficients and estimate the critical slope angles. To predict the possibility and reduce the risk of a hump air lock, an empirical criterion is established using dimensional analysis and experimental fitting. Results show that the extra head losses increase with the increase of the flow velocity and air volume. Meanwhile, the central angle changes significantly with the flow velocity but only slightly with the air volume. An air lock in a hump zone can be prevented and removed by increasing the pipe flow velocity or decreasing the maximum slope of the pipe.

The aim objective: to improve the methods, protocol specification and assessment of the possibilities of the complex magnetic resonance imaging in the diagnosis of ovarian lesions. Materials and methods. From 2011 to 2015 256 patients with 289 ovarian lesions underwent pelvic and abdominal (if necessary) MRI results compared with histological data, obtained intraoperatively, or verification is made on the basis of dynamic observation for at least 6 months. Results. Quantitative estimation showed that the amplitude of the accumulation of the contrast agent was significantly higher in malignant tumors – 167% (115.2-212.5%), than benign – 61.2% (41.2-99.0%; P

Here we developed a novel wavelength-switchable visible continuous-wave (CW) Pr3+:YLF laser around 670 nm. In single-wavelength laser operations, the maximum output powers of 2.60 W, 1.26 W, and 0.21 W, the maximum slope efficiencies of 34.7%, 27.3%, and 12.3% were achieved with good beam qualities (M2 < 1.6) at 670.4 nm, 674.2 nm, and 678.9 nm, respectively. Record-high output power (2.6 W) and record-high slope efficiency (34.7%) were achieved for the Pr3+:YLF laser operation at 670.4 nm. This is also the first demonstration of longer-wavelength peaks beyond 670 nm in the 3P1→3F3 transition of Pr3+:YLF. In multi-wavelength laser operations, the dual-wavelength lasings, including 670.1/674.8 nm, 670.1/679.1 nm, and 675.0/679.4 nm, were obtained by fine adjustment of one/two etalons within the cavity. Furthermore, the triple-wavelength lasings, e.g. 672.2/674.2/678.6 nm and 670.4/674.8/679.4 nm, were successfully demonstrated. Moreover, both the first-order vortex lasers (LG0+1 and LG0-1 modes) at 670.4 nm were obtained by off-axis pumping.

The aim of the current study was to develop a semi-automatic and quantitative method for the analysis of a time-intensity curve (TIC) from breast dynamic contrast-enhanced magnetic resonance imaging. The performance of the proposed method, based on the level set segmentation algorithm, was evaluated by comparison with the traditional method. In the traditional method, the lesion area is delineated manually and the corresponding mean TIC is classified subjectively as one of three washout patterns. In addition, only one quantitative parameter, the maximum slope of increase (MSI), is calculated. In the proposed method, the lesion region was determined semi-automatically and the corresponding mean TIC was categorized quantitatively. In addition to MSI, a number of quantitative parameters were derived from the mean TIC and lesion area, including signal intensity slope (SI(slope)), initial percentage of enhancement (E(initial)), percentage of peak enhancement (E(peak)), early signal enhancement ratio (ESER) and second enhancement percentage (SEP). Wilcoxon signed-rank test and receiver operating characteristic analyses were performed for statistical analysis. For TIC categorization the accuracy was 61.54% for the traditional method and 82.05% for the proposed method. Using the proposed method, mean curve accuracies were 84.0% for SI(slope), 66.7% for MSI, 66.0% for E(initial), 66.0% for E(peak), 68.0% for ESER and 44.9% for SEP. In the lesion region, the accuracies for the aforementioned parameters were 80.8, 65.4, 66.7, 62.2, 69.2 and 57.1%, respectively. Accuracy of the MSI value derived from the traditional method was 63.4%. Compared with the traditional method, the proposed semi-automatic method in the current study may provide results with a higher accuracy to differentiate benign and malignant lesions. Therefore, the proposed method should be considered as a supplementary tool for the diagnosis of breast lesions.

Cardiac arrest survival rate is strongly associated with high quality cardiopulmonary resuscitation (CPR), which includes chest compression (CC) rates above 100 min−1. Currently, defibrillator monitors use external hardware such as CPR assist pads to monitor CC rate and give feedback to the rescuer. The photoplethysmogram (PPG) provides information about the level of oxygen saturation in blood and can be easily recorded by a pulse oximeter in the fingertip. The aim of this study was to analyze the feasibility of using the finger PPG to monitor the presence and rate of CCs in out-of-hospital cardiac arrest (OHCA). The dataset used in the study consisted of 112 segments from 46 OHCA patients, with a total duration of 256 min and 27667 CCs. The method is based on the power spectral density analysis of 10 s segments of the PPG. CC presence was determined through thresholding, and CC rate was computed applying a maximum slope criterion. The dataset was divided patient-wise intro training (60%) and testing (40%) sets. For the test set the algorithm presented a sensitivity and a positive predictive value of 85.2% and 98.1% respectively for CC detection, a CC rate error of 2.8 (6.8)min−1 and 3.4% of the values with an error above 10%.

Background To explore the value of parameters of multiphase dynamic contrast-enhanced magnetic resonance imaging (MDCE-MRI) in the qualitative diagnosis of hepatic masses. Methods Eighty patients with hepatic masses were retrospectively analyzed. All the patients underwent MDCE-MRI at 3.0 T MR before treatment. Mean enhancement time (MET), positive enhancement integral (PEI), a maximum slope of increase (MSI), and a maximum slope of decrease (MSD) were measured. Results There were significant differences between benign and malignant hepatic masses with respect to MET, PEI, and MSI values. The PEI and MSI values between hemangiomas, hepatocellular carcinomas (HCCs), cholangiocarcinomas, and metastatic tumors had significant differences. The MSD value between metastatic tumors, HCCs, and hemangiomas were significantly different. The area under the curve (AUC) values of the receiver operator characteristic curves for MET, PEI, and MSI were 0.70, 0.72, and 0.80, respectively. The specificity of MET, PEI, and MSI were all 77%, and the sensitivities of MSI was the highest, of which was 82.40%. Logistic regression analysis showed the regression equation to be P = 1/[1 + e0.008 × 1 + 0.007 × 2–6.707], and taking the Youden index maximum points as a diagnostic point was 0.2946. Conclusion Some parameters of MDCE-MRI have significant roles in differentiating hepatic masses.

El riego por melgas es la modalidad de riego por superficie que se adapta mejor a los cultivos forrajeros en siembra directa, pero las condiciones de alta pendiente y baja velocidad de infiltración de la mayoría de los suelos del sur de Uruguay hacen difícil su adaptación cuando se pretende aplicar las recomendaciones de la bibliografía internacional. El objetivo del estudio fue determinar indicadores de desempeño del riego por melgas para los suelos del sur del Uruguay y plantear escenarios de optimización para identificar estrategias de manejo. Se instaló un ensayo de riego por melgas orientadas en el sentido de la máxima pendiente, variando la dirección entre grupo de melgas para minimizar la pendiente transversal. La buena conformación de los bordos de las melgas favoreció las medidas de los indicadores de desempeño. Para poder evaluar situaciones diferentes a las ensayadas a campo se planteó el uso del modelo WinSRFR. Los caudales con mejor desempeño fueron más bajos que los recomendados por la bibliografía internacional. Para el suelo evaluado y largo de ladera de 50-60 m el caudal 0,2 L/s/m tuvo la mejor respuesta a la optimización por tiempo de corte. El caudal 0,5 L/s/m alcanzó las mejores eficiencias con largos en el entorno de 170 m. El caudal 0,33 L/s/m podría ser la mejor solución en zonas donde la ladera tiene longitud variable, permitiendo alcanzar alta eficiencia de aplicación mediante la modificación del tiempo de riego. El modelo predijo muy bien el volumen infiltrado y escurrido.

To evaluate postexercise heart rate recovery (HRR) in adults born preterm.We studied the association between preterm birth and postexercise HRR in 545 adults (267 women) at 23.3 years of age (range 19.9-26.3 years). One hundred three participants were born early preterm (34 completed weeks), 178 late preterm (34-36), and 264 were full term (control group). HRR was calculated as change in heart rate (HR) 30 seconds and 60 seconds after cessation of submaximal step test and maximum HR slope during the first minute after.Mean peak HR was 159.5 bpm in the early preterm (P = .16 with controls), 157.8 bpm in the late preterm (P = .56), and 157.0 bpm in the control group. Mean HRR 30 seconds after exercise was 3.2 bpm (95% CI 1.1-5.2) lower in the early preterm group and 2.1 bpm (0.3-3.8) lower in the late preterm group than the full term controls. Mean 60s HRR was 2.5 (-0.1 to 5.1) lower in the early preterm group and 2.8 bpm (0.6-4.9) lower in the late preterm group. Mean maximum slope after exercise was 0.10 beats/s (0.02-0.17) lower in the early preterm group and 0.06 beats/s (0.00-0.12) lower in the late preterm group.Our results suggest reduced HRR after exercise in adults born preterm, including those born late preterm. This suggests altered reactivation of the parasympathetic nervous system, which may contribute to cardiovascular risk among adults born preterm.

Made available in DSpace on 2019-10-06T02:14:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-05-28 Coffee farms have been adopting the microterraces system, a technique that reduces the effect of the slope by moving the soil between the crop lines. In this way, all the mechanized operations can be carried out normally, except for harvesting, due to the work limitation of the harvesters, who work in areas with a maximum slope of 20%. One option is to use unilateral harvesters, which crop one side at a time; however, there has been no research on these microterrace machines to evaluate their performance and to compare it with those of the other harvesting methods in those regions. This study aimed to compare the mechanized harvest performance in the microterraces with the manual and semimechanized harvesting methods. The study was carried out in an agricultural area of the municipality of Ouro Fino / MG, Brazil, in a crop production site where the microterraces were built six years before the experiment. The treatments were assigned to a split-block design with seven repetitions and consisted of mechanized harvest-unilateral harvester with bag storage; manual harvest-regionally experienced workers; and semimechanized harvest-with portable breakers. Through an analysis of the times and movements, the operational efficiency and operational and effective field capabilities were measured. The adoption of microterraces allows the efficient mechanization of areas previously impossible to mechanize. The unilateral harvester is a potential tool for the partial replacement of manual labor in the harvest, performing a service equivalent to that of 23.68 manual workers and 10.55 manual workers in the semimechanized system. Sao Paulo State Univ, Lab Agr Machinery & Mechanizat, Dept Agr Engn, Jaboticabal, SP, Brazil Sao Paulo State Univ, Lab Agr Machinery & Mechanizat, Dept Agr Engn, Jaboticabal, SP, Brazil

Spectroscopic properties of Er : LiLuF4 and Er : LiYF4 crystals in the spectral region near 1.5 μm and the lasing characteristics of these crystals under in-band pumping at a wavelength of 1522 nm are studied. With the Er : LiLuF4 crystal, the maximum slope efficiency with respect to the absorbed pump power was 44% at a wavelength of 1609 nm. Continuous-wave operation of an inband pumped Er : LiYF4 laser is obtained for the first time. The output power at a wavelength of 1606 nm was 58 mW with a slope efficiency of 21%.

Leadon, M., 2015. Beach slope and sediment-grain-size trends as a basis for input parameters for the SBEACH erosion model. Results from Storm-induced BEAch CHange (SBEACH) model calibration studies have provided new techniques and support for selection of model input parameters and interpretation of model output results. Beach and dune erosion analyses using the SBEACH erosion model in St. Johns County, Florida, demonstrated sensitivity of simulated erosion to changes of two model input parameters: sediment grain size and maximum slope prior to avalanching (MSPA). The MSPA parameter corresponds with the seaward slope of the dune or beach-berm erosion escarpment at the landward limit of the storm-induced erosion. Model calibration work demonstrated trends of these two model input parameters and of the sediment-transport rate coefficient K in relation to changes in beach slope. Evaluation of beach-slope values computed from county-wide topographic survey data in relation to the available mean sedim...

A common representation of a three dimensional object in computer applications, such as graphics and design, is in the form of a triangular mesh. In many instances, individual or groups of triangles in such representation need to satisfy spatial constraints that are imposed either by observation from the real world, or by concrete design specifications of the object. As these problems tend to be of large scale, choosing a mathematical optimization approach can be particularly challenging. In this paper, we model various geometric constraints as convex sets in Euclidean spaces, and find the corresponding projections in closed forms. We also present an interesting idea to successfully maneuver around some important nonconvex constraints while still preserving the intrinsic nature of the original design problem. We then use these constructions in modern first-order splitting methods to find optimal solutions.

OBJECTIVE: To use the patient outcome endpoints overall survival and progression-free survival to evaluate functional parameters derived from dynamic contrast-enhanced computed tomography (DCE-CT). METHODS: 69 patients with metastatic renal cell carcinoma (mRCC) had DCE-CT scans at baseline and after 5 and 10 weeks of treatment. Blood volume, blood flow and standardized perfusion values were calculated using deconvolution (BVdeconv, BFdeconv and SPVdeconv), blood flow and standardized perfusion values using maximum slope (BFmax and SPVmax), and blood volume and permeability surface area product using the Patlak model (BVpatlak and PS). Histogram data for each was extracted and associated to patient outcomes. Correlations and agreements were also assessed. RESULTS: The strongest associations were observed between patient outcome and medians and modes for BVdeconv, BVpatlak, and BFdeconv at baseline and during the early on-treatment period (p

application/pdf, 論文(Article)

The results of measuring maximum loads on different slopes when skidding uphill with WOO DY 110 cable skidder and adapted 4WD agricultural tractor AGT 835 are described in the article. Both tractors are very different and were chosen for the purpose of finding the limits of uphill skidding. Besides the slope, the pre-designated loads of different sizes and log orientation (butt-end or top-end forward) have been main variables. The trial was conducted on two concave shaped test skid trails in the forest. On the lower altitudes, the skid trails had small inclination, which slowly increased to 42% on the track where WOODY 110 was tested, and 27% where AGT 835 was measured. First the loads were skidded uphill with butt-end and then with top-end forward. The purpose was to choose too heavy loads, as we wished to stop tractors due to overload, but on different slopes. The proper load formation (butt-end forward if possible) in uphill skidding is most important on steeper skid trails. The dependency between maximum load and slope is linear. The calculated theoretical maximum load on horizontal surface enables us to make similar assessment for any other tractor weighing between 2 and 7 tons. For this purpose, John Deere 6220 and LIMB 80 LUXS adapted agricultural tractors for forest use were chosen and compared. The ratio between the tractor load on different slopes and tractor weight was calculated for all four tractors included in our comparison. Apart from the weight, tractor's engine torque (power) has the decisive influence on the load size. Maximum loads on different slope categories were calculated according to different engine powers. Članek obravnava rezultate meritev spravila navzgor z gozdarskim traktorjem WOODY 110 in prilagojenim kmetijskim traktorjem s pogonom na štiri kolesa AGT 835 z mehanskim in hidrostatsko-mehanskim pogonom. Namen analize je bilo ugotavljanje maksimalnih bremen. Oba traktorja sta zelo različna in sta bila izbrana zato, da bi ocenili zmogljivosti traktorjev pri spravilu lesa navzgor. Poleg naklona vlake so bile spremenljivke še vnaprej določene velikosti bremen in njihove orientacije (z debelim oz. tanjšim koncem naprej). Meritve so bile opravljene v gozdu na dveh testnih vlakah konkavne oblike. Vlake so imele v spodnjem delu majhen naklon, ki se je pri vlaki za WOODY 110 povzpel na 42 % in na 27 % na vlaki, kjer je bil merjen AGT 835. Bremena so bila vlečena navzgor z debelim in v drugem poskusu s tankim koncem pri traktorju. Namen je bil izbrati pretežka bremena za takšne naklone, da bi se traktor zaradi preobremenitve zaustavil pri nekem naklonu vlake. Pokazalo se je, da je pri spravilu navzgor pravilno oblikovanje bremena (če je mogoče, z debelim koncem naprej) najpomembnejše na zelo strmih vlakah. Odvisnost največjega bremena in naklona vlake je linearna. Izračunano teoretično, največje breme na horizontalni podlagi omogoča oceno za katerikoli traktor, ki tehta med 2 in 7 tonami. V ta namen smo izbrali za spravilo lesa prilagojena kmetijska traktorja John Deere 6220 in LIMB 80 LUXS. Za vse štiri traktorje smo izračunali razmerje med največjim bremenom in težo traktorja. Na velikost največjega bremena poleg teže traktorja odločilno vpliva navor (in moč) motorja, zato je za različne kategorije terena izračunana odvisnost med največjim bremenom in močjo motorja.

We report laser operation of two Tb3+-activated gain media, Tb:LiYF4 and LiTbF4, in yellow or/and green spectral region. A record-high slope efficiency of 63% among Tb3+-lasers and maximum output power of 1.17 W (incident power of 2.79 W) at around 544 nm were obtained with a c-cut 15%Tb:LiYF4 crystal. The yellow laser characteristics in σ-polarization were studied. A slope efficiency of 21% at 582 nm was achieved. More importantly, we succeeded in laser operation of LiTbF4 for the first time to the best of our knowledge. Laser oscillation at around 544 nm yielded a maximum slope efficiency of 45%. This points toward the possibility of producing high-energy pulsed lasers using LiTbF4, which features a high active-ion concentration as well as relatively long lifetime.

We report laser operation of Pr:YAlO3 pumped by a frequency-doubled optically pumped semiconductor laser. Continuous-wave laser oscillations at around 622 nm, 662 nm, and 747 nm were demonstrated in plano-concave or/and plano-plano cavities. The maximum slope efficiencies were found to be 37%, 35%, and 59%, respectively, which are record-high values for Pr:YAlO3 lasers. Furthermore, lasing at 622 nm was demonstrated at room temperature for the first time to the best of our knowledge.

Two methods for digital mapping and analysis of topographic surfaces of moderate relief, such as erosional surfaces, are introduced and discussed in this paper. The surface fit method uses least squares to solve the problem of finding the best surface fit to the data, whereas the region grow method uses the surface slope and a set of properties (e.g. maximum slope between adjacent pixels) to generate surfaces from single seed GPS-positions. In both methods the analysed surface was identified from field controlled geological maps. The surface fit method is applicable to landscapes with great topographic varieties, whereas the region grow method is most applicable to relatively flat areas. Both methods were used to identify the sub-Cambrian peneplain (SCP). The result suggests that the SCP occurs across significant parts of the Hardangervidda area, with a greater lateral extent in the central part of the area compared to the northern part. This can be attributed to more extensive faulting of the SCP in the northern part.

The problems and issues that arise during the mechanical method of separating the monolith from the array are considered. For example, at what angle to drill or cut the vertical plane of the monolith, which take the optimal size of the monolith, what mechanisms or tool to use in the separation of the monolith from the array. In all cases, the need to move the monolith or upset, it is this specific problem discussed in our publication. The length of the monolith takes 2 m in all cases, the volume of the monolith with decreasing trench increased. The publication efforts that are necessary for monolith tipping or moving away from the monolithic array, depending on the angle of drilling or cutting the monolith back are calculated. The optimal drill angling the monolith back to the maximum slope of the capital trench is defined.

In a valley sheltered from strong synoptic effects, the dynamics of the valley atmosphere at night is dominated by katabatic winds. In a stably stratified atmosphere, these winds undergo temporal oscillations, whose frequency is given by $$N \sin {\alpha }$$ for an infinitely long slope of constant slope angle $$\alpha $$ , $$N$$ being the buoyancy frequency. Such an unsteady flow in a stably stratified atmosphere may also generate internal gravity waves (IGWs). The numerical study by Chemel et al. (Meteorol Atmos Phys 203:187–194, 2009) showed that, in the stable atmosphere of a deep valley, the oscillatory motions associated with the IGWs generated by katabatic winds are distinct from those of the katabatic winds. The IGW frequency was found to be independent of $$\alpha $$ and about $$0.8N$$ . Their study did not consider the effects of the background stratification and valley geometry on these results. The present work extends this study by investigating those effects for a wide range of stratifications and slope angles, through numerical simulations for a deep valley. The two oscillatory systems are reproduced in the simulations. The frequency of the oscillations of the katabatic winds is found to be equal to $$N$$ times the sine of the maximum slope angle. Remarkably, the IGW frequency is found to also vary as $$C_\mathrm{w}N$$ , with $$C_\mathrm{w}$$ in the range $$0.7$$ – $$0.95$$ . These values for $$C_\mathrm{w}$$ are similar to those reported for IGWs radiated by any turbulent field with no dominant frequency component. Results suggest that the IGW wavelength is controlled by the valley depth.

Cut marks on bones provide crucial information about tools used and their mode of application, both in archaeological and forensic contexts. Despite a substantial amount of research on cut mark analysis and the influence of fire on bones (shrinkage, fracture pattern, recrystallisation), there is still a lack of knowledge in cut mark analysis on burnt remains. This study provides information about heat alteration of cut marks and whether consistent features can be observed that allow direct interpretation of the implemented tools used. In a controlled experiment, cut marks (n=25) were inflicted on pig ribs (n=7) with a kitchen knife and examined using micro-CT and digital microscopy. The methods were compared in terms of their efficacy in recording cut marks on native and heat-treated bones. Statistical analysis demonstrates that floor angles and the maximum slope height of cuts undergo significant alteration, whereas width, depth, floor radius, slope, and opening angle remain stable. Micro-CT and digital microscopy are both suitable methods for cut mark analysis. However, significant differences in measurements were detected between both methods, as micro-CT is less accurate due to the lower resolution. Moreover, stabbing led to micro-fissures surrounding the cuts, which might also influence the alteration of cut marks.

Based on the 3107 working face of a mine in Shanxi province, using the theoretical calculation and field measurement methods, explored a coal mining technology by combining use of the caving method and the roadway filling method, to solve the coal mining problems under the highway, under the premise that not change the mining layout of the coal mine. The results show that it is feasible to solve the problem of coal mining under the highway by using the combined mining technology. The surface subsidence can be controlled at the range of 282 to 312mm and 278 ~ 85mm, in parallel to and vertical to the working face direction, respectively, by using this technology; and the maximum slope of the surface deformation was controlled at 1.52mm/m, and all of the deformation variables are controlled under the requirement of the regulation

Output parameters of microchip lasers based on Yb:Er co-doped phosphate glasses have been numerically calculated using a simplified 4-level model in order to optimize the Yb and Er concentrations and active medium length. It was shown that active media with Yb concentration ~2·1027 m–3 and length of the order of 1 mm were most appropriate to obtain the practically maximum slope efficiency and minimum threshold power. Simulation results indicated that the Er concentration could be much lower than those currently used in practice. The obtained results were in good agreement with available experimental data.

The volume and depth of a lake are basic properties that greatly affect a wide array of its physical, chemical, and biological properties. Nevertheless, volume and depth data are scarce in lake-rich regions of the world. We coupled the Swedish lake register to GIS-derived geographical and topographical parameters, attempting to predict the volume and depth of 6943 lakes from map-derived parameters only. Lake area and the maximum slope in a 50 m wide zone outside of the lake shoreline were the most important predictors of both lake volume and depth, explaining 92% of the variance in lake volume but ˂40% of the variance in both maximum and mean depth. Regression parameters of regional submodels of lake volume were similar across geographically and topographically different regions, indicating that the model probably is applicable for glacially formed lakes in general. Despite the high degree of explanation for lake volume, the uncertainty in predicted volume for a single lake is considerable (relative standard deviation, ±57%). However, the mean or cumulative lake volume of catchments containing several lakes (n > 15) is predictable from map-derived parameters with a greatly reduced uncertainty.

El uso de las tisanas es bastante difundido a nivel de Latinoamérica, generando grandes ganancias a las empresas dedicadas a este negocio. El presente trabajo ha buscado estudiar las condiciones de elaboración y optimizar las materias primas utilizadas. Para esta investigación se ha empleado un total de 22 hierbas aromáticas que conforman la tisana, para estudiarlas en una primara etapa se ha utilizado un diseño de Plackett-Burman. Las muestras generadas fueron evaluadas por un panel de catación conformado por 30 personas; las respuestas de la valoración sensorial han sido estudiadas mediante funciones de utilidad para favorecer respuestas agradables y penalizar las indeseables. Se ha identificado que únicamente resultan importantes 2 variables, mientas que otras se las puede mantener constantes. Estas dos variables se han optimizado en tres etapas sucesivas aplicando la metodología de máxima pendiente, observándose que no existen variaciones por parte del panel de cata, indicando que se encuentran alrededor del máximo, el cual brinda las condiciones de optimalidad para el producto.

It has been well documented in many literature that porous media and nanofluid can augment heat transfer in many engineering system. However the combined usage of these two media has not been given much attention in literature. The objective of the present work is to experimentally investigate porous media heat exchanger using Al2O3/water nanofluids. The heat transfer characteristics is determined using transient testing method wherein, only one fluid stream flows steadily throughthe test core, then a transient perturbation in the inlet fluid temperature is induced and the outletfluid temperature variation is measured continuously. The measured data is evaluated using the maximum slope method to obtain the heat transfer characteristics. The results show an increase in Nusselt number values with the use of nanofluids in porous media heat exchanger compared to water