The effects of the structure of new carbon fiber bunch heterogeneous unipolar plates on the performance of PEMFC are studied in this thesis. Internal structure of carbon fiber bunches can be modified by embedding different thickness or number of copper plates in the glue bonding area to increase the air permeability of carbon fiber bunches in its soft end. We can add different thickness or amount of coppers at the middle of bonding area, making the carbon fiber bunches soft side to form parallel to the longitudinal fiber bunch with a small flow channel. We can also make a trench at the appropriate place of the soft side of the carbon fiber bunches to form an extra air passage. In order to make the above flow channel, a new process for making the carbon fiber bunches is developed also. This process will be easier to produce a variety of different structures of carbon fiber bunch. Finally, several different experiments are performed to help us to understand the effect of the carbon fiber bunch structure on the performance and find out the best structure of the carbon fiber bunches. The carbon fiber bunch structures of the test cells on the anode side are all the same, but the carbon fiber bunch structures of on cathode side are all different. Experiments show that there are two structures among all test structures displayed better gas permeability. The first one is two 0.2 mm copper plates embedded within both sides of the glue ends of a cathode carbon fiber bunch, so that a small longitudinal flow channel are formed in soft end of the cathode carbon fiber bunch. When the HFC operates at room temperature and by air-breathing, the highest performance of the HFC can reach a value of 185 mW/cm2. The second one is a 0.2 mm copper plate embedded in the center of the glue end of a carbon fiber bunch, and then three 2 mm wide serrated slots are cut on the soft end of the carbon fiber bunch. The highest performance of the HFC can reach a value of 190 mW/cm2. The highest performance of the HFC with no copper plate and no slot structure can only reach a value 160 mW/cm2. The second design can increase the no structure cell performance 18.8%. Therefore, the internal structures of carbon fiber bunches are significant to affect on the fuel cell performance, and its internal design must be considered.

Developmental nicotine exposure (DNE) is known to cause deleterious effects in neonatal mammals through nicotine's actions on nicotinic acetylcholine receptors (nAChRs). In this work, we studied how DNE altered the structure and function of the hypoglossal motoneurons (XIIMNs) over the first few days post-parturition. Previous work in XIIMNs demonstrated an increase in cellular excitability (Pilarski et al., 2011), alterations in synaptic transmission among respiratory-related neurons (Wang et al., 2006; Pilarski et al., 2012; Jaiswal et al., 2013), and a reduction in inspiratory drive currents in DNE animals (Pilarski et al., 2011). Here we show that the effects of DNE extend to alterations in the spike-timing precision and reliability of XIIMNs, as well as spike-frequency adaptation. Additionally, simple morphological analysis of XIIMNs following nicotine exposure in utero has revealed a reduction in soma cross-sectional area. We were interested in studying the complete morphology of XIIMNs following DNE to discern its effects on more complex morphological parameters. We advanced this research using a combination of techniques in thin brainstem slices of neonatal rats, including whole cell patch clamp recordings and immunohistochemistry of intracellularly labeled hypoglossal motoneurons. Furthermore, morphological analysis revealed significant differences in the complexity of the dendritic arborization, showing that neurons from DNE animals had shorter dendrites that branched less often. We also used computational analysis to gain insight into mechanisms that may underlie the changes in spike-timing precision and reliability. In a single cell model of XIIMNs, decreases in potassium-dependent conductances such as the calcium-activated potassium current could potentially replicate the alterations seen in vitro. Finally, we also did a systems-level study of the hyoglossus muscle, a tongue retractor, to determine the relation between tongue retraction force and motor unit discharge characteristics. These experiments utilized adult, anesthetized rats to record single motor units, whole muscle electromyography (EMG) activity and tongue retraction force during spontaneous breathing. We determined that during inspiration-related tongue retractions in low and high force conditions, recruitment of motor units plays a crucial role in the control of tongue force output, whereas rate coding of single motor units is present, but appears to play a lesser role. Overall, this study shows that DNE effects the input-output properties of XIIMNs, potentially through changes in intrinsic channel properties; DNE also alters XIIMN morphology, particularly dendritic arborization; and that organization of a tongue retractor muscle depends primarily on recruitment, but also rate coding, to increase force output.

Kvėpavimas yra kūno egzistencijos ir gyvastingumo pagrindas, kuris padeda palaikyti dujų apykaita tarp organizmo ir aplinkos (Adaškevičienė, 2008). Grinienė, Vaitkauskas (2009), Kriščiūnas (2009), Andžiulis ir kt. (1999) savo knygose kvėpavimo pratimus išskiria kaip itin veiksmingą būdą, gydant kvėpavimo takų ligas. Bakalauro darbe, analizuojama specialių kvėpavimo pratimų programos poveikis vaikams, sergantiems bronchitu. Tyrimo tikslas: atskleisti specialių kvėpavimo pratimų programos poveikį 14-17 metų vaikams, sergantiems bronchitu. Tyrimui atskleisti buvo iškelti šie tikslai: apžvelgti kvėpavimo pratimų svarbą vaikams sergantiems bronchitu, remiantis mokslinės literatūros analize, taikant Štangės, Henšo ir krūtinės ląstos paslankumo testus ištirti ir palyginti eksperimentinės ir kontrolinės grupės vaikų plaučių funkcinį pajėgumą prieš ir po kineziterapijos taikymo, ištirti ir palyginti vaikų eksperimentines ir kontrolines grupes, ištestuoti ir įvertinti pilvo bei liemens šonų raumenų jėgą prieš ir po specialių kvėpavimo pratimų programos taikymo, taip nustatant eksperimento poveikį bei naudą vaikams. Tyrime dalyvavo trisdešimt Palangos vaikų reabilitacijos sanatorijos ,,Palangos Gintaras‘‘ 14-17 metų vaikai, sergantys bronchitu. Sudarytos dvi grupės - eksperimentinė ir kontrolinė, kuriose vaikų skaičius paskirstytas vienodai. Eksperimentinėje grupėje reikėjo išsiaiškinti specialių kvėpavimo pratimų poveikį pilvo, liemens šonų raumenų jėgą, plaučių... [toliau žr. visą tekstą] / Breathing is bodily existence’s and vitality basis. The aim of the work is to disclose specific breathing exercise program’s effects to 14-17 years - old children who are sick with bronchitis. To reveal the research goals were risen: to review breathing exercises importance to adolescent who have bronchitis basing on scientific literature analysis; applying Štangės, Henšo and thorax flexibility tests to examine and compare experimental and control group children’s lung functional capacity before and after physiotherapy application; to test and rate stomach and torso side muscles strength before and after specific breathing exercises program’s application in that way setting experiment’s effect and benefits for children. In this research thirty Palangos rehabilitation sanatorium “Palangos Gintaras” patients participated. It was 14-17 years’ old teenagers, who are sick with bronchitis. There was made two kind of groups: experimental and control in which the numbers of kids were the same. In experimental group it was needed to reveal specific breathing exercises effects on stomach, torso side muscles strength, lungs functional possibilities, thorax flexibility. In experimental group breathing exercises has been adapted two times per day. In control group ordinary physiotherapy activities happened. Research results revealed experiment effect statistically processed results were clearly seen, of the respiratory exercise program had a... [to full text]

This study addressed slowed, paced, diaphragmatic breathing as an adaptive technique for persons in stressful life circumstances. Ninety-six U.S. Army National Guard and Reserve trainees on active duty voluntarily participated over 12 days according to one of three conditions: (1) The treatment group (n=35) was instructed in and given four 10 minute sessions of slowed, diaphragmatic breathing paced to the flashing of two lights (one red and one green) which cued a 4 second inspiration and a 4 second exhalation; (2) The attention control group (n=31) counted flashes on an identical light apparatus for four 10 minute sessions; (3) The no treatment control group (n=30), was given four 10 minute breaks during concurrent periods. All subjects were pretested and posttested with the A-State form of the StateTrait Anxiety Inventory and the Mooney Problem Checklist. These scores were the two dependent variables. Analysis ofvariance of pretest scores indicated no significant differences among group means. Two univariate analyses were used to test the hypotheses. Null hypothesis 1, that there would be no difference among posttest means for A-State Anxiety, was rejected. Null hypothesis 2, that there would be no difference among posttest means for Mooney Total, was upheld. Post hoc comparisons (Sheffe) between groups on the A-State measure revealed that the treatment group reported significantly less anxiety than the attention control group. But no significant difference was found between the treatment group and the no treatment group. Similar findings were reported by Holmes, et al. (1978). Procedural and nonspecific effects on the outcome and implications for future research were discussed.

When spontaneous breathing (SB) is allowed during mechanical ventilation (MV), atelectatic lung areas are recruited and oxygenation improves thereby. Whether unsupported SB at its natural pattern (without PEEP and at low pressure/small tidal volume) equally recruits and improves oxygenation, and if so by which mechanism, has not been studied. A porcine lung collapse model was designed to study this question. The cardiac output dependency of the pulmonary shunt was investigated with healthy lungs and with major shunt (during one-lung ventilation) and with SB, MV and continuous positive airway pressure (CPAP). The hypoxic pulmonary vasoconstriction (HPV) was blocked with sodium nitroprusside (SNP) to see whether HPV is the only mechanism available for ventilation/perfusion (VA/Q) matching during MV and SB. In all experiments, respiratory rate and tidal volume during MV were matched to SB. Oxygenation was assessed by serial blood gas measurements, recruitment by thoracic CTs; pulmonary shunt was assessed by multiple inert gas elimination or venous admixture. SB attained better oxygenation and lower pulmonary shunt compared with MV, although it did not recruit collapsed lung. Pulmonary shunt did not correlate with cardiac output during SB, whereas a correlation was found during MV and CPAP. With blocked HPV, pulmonary shunt was considerably lower during SB than MV. In conclusion, SB improves VA/Q matching as compared with MV, even when no recruitment occurs. In contrast to MV and CPAP, cardiac output has no major effect on pulmonary shunt during SB. The improved VA/Q matching during SB despite a blocked HPV might indicate the presence of a SB-specific mechanism that improves pulmonary blood flow redistribution towards ventilated lung regions independent of or supplementary to HPV.

Thesis (Ph. D.)--University of Western Sydney, 2002. / A thesis submitted in fulfillment of the requirement for the degree of Doctor of Philosophy at the University of Western Sydney, College of Science, Technology and Environment, 2002. Includes bibliographical references (p. 352-370).

Thesis (Honors)--Liberty University Honors Program, 2007.

Thesis (M.S.)--University of Michigan, 1968.

Thesis (M.S.)--University of Michigan, 1968.

Thesis (M.S.)--University of Wisconsin--Madison, 1980. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 201-205).