A new method has been developed to objectively determine green-up dates for the National Fire Danger Rating System (NFDRS). This method has applications for the current point-data NFDRS and for ...possible future calculations of fire danger at higher spatial resolutions. The objectives of this thesis are to propose two features of a live fuel moisture model for NFDRS in the 21st century. The first feature is a method to determine in “real time” the green-up date at 1-km spatial and 1-week temporal resolutions using Normalized Difference Vegetation Index (NDVI) from NOAA Advanced Very High Resolution Radar. The second feature is a process to determine historical green-up dates for historical analysis purposes. The proposed method is the integration of area under a smoothed curve of NDVI from the curve minimum until the climatological green-up threshold is achieved. (Abstract shortened by UMI.)
Extra-alveolar air (EAA) developed in 38 patients during mechanical ventilation. High ventilatory pressures and destructive lung disease predispose to EAA. Pneumoretroperitoneum and pneumoperitoneum ...are more common forms of ventilator-induced EAA in adults than generally realized; an associated pneumomediastinum was always identified when one of the two disorders above resulted from ventilation. Retroperitoneal air was located laterally along the liver and in the flanks, and changed little with change in patient position. Early detection of EAA may allow life-saving changes in therapy to be implemented.
Twenty patients requiring ventilation for acute respiratory failure were studied to determine whether intrapulmonary shunt fraction (Qs/Qt) measured at an inspired oxygen concentration (FIO2) of 1.0 ...differs from Qs/Qt measured at the clinically indicated FIO2 and, if so, the mechanism by which this occurs. Qs/Qt increased from 15.5 +/- 1.8 per cent (mean +/- SE) at the clinically indicated inspired oxygen fraction (FIO2 0.3-0.6) to 21.7 +/- 2.1 per cent after 20 minutes at FIO2 1.0. Functional residual capacity (FRC) decreased by 6 +/- 6 per cent and total compliance (CT) by 10 +/- 6 per cent. Mean pulmonary arterial pressure fell from 21 +/- 2 to 17 +/- 2 mm Hg, whereas pulmonary capillary wedge pressure (PCWP) and cardiac output remained unchanged. Mixed venous oxygen tension increased from 37 +/- 1 to 45 +/- 2 mm Hg with 100 per cent oxygen. At 90 per cent oxygen, Qs/Qt increased from the value at low FIO2, but FRC and CT did not change. Simultaneous application of 100 per cent oxygen and a positive end-expiratory pressure (6 cm H2O) increased FRC, CT and Qs/Qt. Patients with increased PCWP showed smaller increases in Qs/Qt with 100 per cent oxygen. These findings suggest two mechanisms responsible for the increase in Qs/Qt: 1) redistribution of blood flow to nonventilated areas, resulting from the vasodilating effect of an increased oxygen tension in the vessels of hypoxic lung segments; 2) resorption atelectasis. Of the total change in Qs/Qt observed during ventilation with oxygen, 63 per cent was calculated to be due to factors other than a decrease in FRC. (Key words: Ventilation, positive end-expiratory pressure; Oxygen, pulmonary shunt and; Lung, compliance; Lung, shunts.)
Simulation and measurement of the solder bumps with a plastic core Schlobohm, J.; Weide-Zaage, K.; Rongen, R. ...
2013 14th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE),
2013-April
Conference Proceeding
With the aim to miniaturize and to reduce the cost, the increasing demand, regarding to advanced 3D-packages as well as high performance applications, accelerates the development of 3D-silicon ...integrated circuits. The trend to smaller and lighter electronics has highlighted many efforts towards size reduction and increased performance in electronic products. RF performances are limited by parasitic effects due to the RLC network between the wirebond from the dies to the leadframe. The use of flip-chip bonding technology for very fine pitch packaging allows high integration and limits parasitic inductances. Electromigration (EM) and thermomigration (TM) may have serious reliability issues for fine-pitch Pb-free solder bumps in the flip-chip technology used in consumer electronic products. A possibility to extend the reliability is the use of plastic ball in the solder bumps. Bumps containing a plastic solder balls have an excellent reliability. Using a plastic ball with a low Young modulus, the solder hardness is moderated and the stress on a ball is relaxed. Due to this the stress doesn't concentrate on the solder joint which prolongs the lifetime. In this investigation the thermal-electrical-mechanical influence of electromigration on bumps containing a plastic solder is investigated.
End-expiratory pressure is often used to improve arterial oxygenation and prevent atelectasis in intubated spontaneously breathing patients. To compare the effect of extubation from low levels of ...expiratory positive airway pressure (EPAP) of extubation from ambient airway pressure, functional residual capacity (FRC) and arterial blood oxygen tension (Pao2) were measured in 12 spontaneously breathing patients during three conditions in the peri-extubation period: 1) intubated at 5 cm H2O EPAP (EPAP 5); 2) intubated at ambient airway pressure (EPAP 0); and 3) within one hour after extubation. During EPAP 5, mean +/- SE values for FRC (1864 +/- 230 ml) and Pao2 (114 +/- 8 torr) were the same as those obtained after extubation (FRC = 1794 +/- 159 ml, Pao2 = 117 +/- 5 torr). However, both FRC (1600 +/- 186 ml) and Pao2 (106 +/- 8 torr) were lower during EPAP 0 than after extubation or EPAP 5 (P less than 0.01-0.05). The magnitude of increase in FRC and Pao2 on extubation from EPAP 0 varied inversely with the patient's lung thorax compliance (r = -0.84, P less than 0.005). It was concluded that a period of EPAP 0 is not necessary in the weaning period, and that it may be deleterious in patients with compromised lung thorax mechanics.
To assess the change in venous admixture during breathing of 100 per cent oxygen (FIO2 1.0), shunt fraction (Qs/Qt) was calculated at a maintenance FIO2 (FIO2m:0.27--0.70) and at FIO2 1.0 in 40 ...studies of 34 patients with acute respiratory failure. At FIO2 1.0 Qs/Qt increased in 26 studies, but did not increase in 14 studies. Patients in whom Qs/Qt increased during breathing of oxygen and mild respiratory failure, as indicated by low Qs/Qt values at FI02m and a low incidence of diffuse parenchymal infiltrates on chest roentgenograms. All patients who had recently had cardiovascular surgical procedures were in this group. Respiratory failure was more severe in those in whom Qs/Qt decreased with oxygen, as indicated by high Qs/Qt values at FIO2m, evidence of diffuse pulmonary disease by roentgenography, and signs of adult respiratory distress syndrome. The authors conclude that changes in Qs/Qt in response to FIO2 1.0 in acute respiratory failure are related to the severity of respiratory insufficiency.
