Gas phase biofilters are used for controlling odors from animal facilities. Some characteristics can affect their performance and moisture content is one very important. A methodology for controlling and measuring moisture content is required to optimize these systems. An experiment was conducted to determine the appropriate placement of a set of soaker hoses 1.2 m in length for water application. It was found that the soaker hose installed in the lower region of the biofilter coupled with appropriate and timely application of water was able to minimize drying of the compost. Thermal conductance proved to be a reliable indicator for measuring the moisture content. Biofilters using the soaker hoses together with the thermal conductance as a media moisture sensor were able to maintain moisture content above 30% w.b. which provided sufficient water for microbial activity and ammonia abatement. A characterization of the ammonia and nitrous oxide concentrations was performed in order to compare the behavior of the gases when water was applied versus no water addition. These analyses revealed that the overall performance was not significantly different between treatments. But a more detailed assessment inside the biofilter media is performed; it is possible to identify different processes taking place.

This thesis focuses on the chemical concept of conjugation, i.e., electron delocalization, and the effect it has on electronic and optical properties of molecules. The emphasis is on electron delocalization across a saturated σ-bonded segment, and in our studies these segments are either inserted between π-conjugated moieties or joined together to form longer chains. The electronic and optical properties of these compounds are probed and compared to those of traditionally π-conjugated compounds. The investigations utilize a combination of qualitative chemical bonding theories, quantum chemical calculations, chemical syntheses and different spectroscopic methods. Herein, it is revealed that a saturated σ-bonded segment inserted between two π-systems can have optical and electronic properties similar to a cross-conjugated compound when substituents with heavy Group 14 elements (Si, Ge or Sn) are attached to the central atom. We coined the terminology cross-hyperconjugation for this interaction, and have shown it by both computational and spectroscopic means. This similarity is also found in cyclic compounds, for example in the 1,4-disilacyclohexa-2,5-dienes, as we reveal that there is a cyclic aspect of cross-hyperconjugation. Cross-hyperconjugation can further also be found in smaller rings such as siloles and cyclopentadienes, and we show on the similarities between these and their cross-π-conjugated analogues, the fulvenes. Here, this concept is combined with that of excited state aromaticity and the electronic properties of these systems are rationalized in terms of “aromatic chameleon” effects. We show that the optical properties of these systems can be rationally tuned and predicted through the choice of substituents and knowledge about the aromaticity rules in both ground and excited states. We computationally examine the relation between conjugation and conductance and reveal that oligomers of 1,4-disilacyclohexa-2,5-dienes and related analogues can display molecular cord properties. The conductance through several σ-conjugated silicon compounds were also examined and show that mixed silicon and carbon bicyclo[2.2.2]octane compounds do not provide significant benefits over the open-chain oligosilanes. However, cyclohexasilanes, a synthetic precursor to the bicyclic compounds, displayed conformer-dependent electronic structure variations that were not seen for cyclohexanes. This allowed for computational design of a mechanically activated conductance switch.

Cerebrospinal fluid (CSF) infusion tests can be used to estimate the dynamic properties of the CSF system. Idiopathic normal pressure hydrocephalus (INPH) is a syndrome signified by a disturbance to the CSF system, where the cause is unknown and the diagnosis is difficult to determine. As an aid in identifying patients with INPH who will improve after shunt surgery, infusion tests are commonly used to determine the outflow conductance (Cout), or outflow resistance (Rout=1/Cout), of the CSF system. The tests are also used to determine shunt function in vivo. The general aim of this thesis was to develop and validate CSF infusion methods, to investigate the dynamics of the CSF system. The methods should be applicable to patients with INPH, to aid in the quest to further improve the diagnosis and management of this syndrome. An existing mathematical model describing the dynamics of the CSF system was further developed. The characteristics of the model were verified and the effect of expanding intracranial air on the intracranial pressure (ICP) was simulated. The simulations supported the recommendation to maintain sea-level pressure during air ambulance transportation of patients with suspected intracranial air. A recently developed infusion apparatus was evaluated, on an experimental model as well as on a patient material. The repetitiveness in estimating Cout was found to be good. A statistically significant difference was found between the repeated Cout estimations in the patient group, indicating that there might have been a small physiological change introduced during the infusion test. A parameter, ∆Cout, was proposed and evaluated. It proved to reflect the reliability of individual Cout investigations in a clinically useful way, as well as to provide easily interpreted information. An adaptive algorithm for assessment of Cout was developed and evaluated on a patient group. The new algorithm was shown to reduce the investigation time, from 60 minutes, by 14.3 ± 5.9 minutes (mean ± SD), p<0.01, without reducing the reliability of the estimated Cout below clinically relevant levels. The relationship between ICP and CSF outflow was studied in a group of patients investigated for INPH. It was found that in the range of moderate increase from baseline pressure, the assumption of a pressure independent Rout was confirmed (p=0.5). However, at larger pressure increments, the relationship had a non-linear tendency (p<0.05). This indicates that the traditional view of a pressure independent Rout might have to be questioned in the region where ICP exceeds baseline pressure too much. Infusion tests can be performed in different ways, where three main categories may be distinguished. The bolus infusion method was compared to the constant pressure and constant flow infusion methods, on an experimental model as well as on a patient material. When physiological pressure fluctuations were added to the model, significant differences were found in the determination of Cout in the range of clinical importance, i.e. low Cout (p<0.05). The finding was supported by the patient investigations, the difference was however not significant. With the application of the new methods developed in this thesis, and the increased knowledge concerning relationships between CSF dynamic parameters, the CSF infusion test was further improved with the ability to increase measurement reliability in a reduced time. This constitutes a good basis to perform a large multi-centre study with the main goal to determine the predictive value of the parameter Cout.

Kentucky’s Upper Green River Basin has received significant attention due to the area’s high biodiversity and spectacular karst development. While carbonate bedrock is present throughout the watershed, it is more extensive and homogenous along the river between Greensburg and Munfordville than upstream from Greensburg where the geology is more heterogeneous. This research quantitatively evaluated how lithological differences between the two catchment areas impact hydrochemistry and inorganic carbon cycling. This first required correcting catchment boundaries on previous US Geological Survey Hydrologic Unit Maps to account for areas where the boundaries cross sinkhole plains. Basin boundaries using existing Kentucky Division of Water dye trace data differed from the earlier versions by as much as three kilometers. The river at the downstream site is more strongly influenced by carbonate mineral dissolution, reflected in higher specific conductance (SpC) and pH. The SpC at Munfordville ranges from 0.9 to 4.8 times that at Greensburg, averaging 2.0 times higher. Although rainfall is impacted by sulfuric acid from coal burning, river pH is buffered at both sites. The pH is higher at Munfordville 91% of the time, by an average of 0.28 units. Diurnal, photosynthetic pH variations are damped out downstream suggesting interactions between geologic and biological influences on river chemistry. River temperature differences between the two sites are at least 4oC higher at Greensburg under warm season conditions, but there is a clear trend of temperature differences diminishing as the river cools through the fall and winter. This results from a relatively stable temperature at Munfordville, impacted by large spring inputs of groundwater within the karst region downstream. Although weak statistical relationships between SpC and HCO3 - create uncertainties in high resolution carbon flux calculations, measurement of these fluxes is more highly impacted by discharge variations than concentration variations, which resulted in average daily atmospheric flux estimates within 34% between the two basins using weekly concentration data (3.3x108 vs. 2.2x108 gkm-2 d-1, where km2 is the outcrop area of carbonate rocks), and within only 12% using 15-minute concentration data from regressions (2.6x108 vs. 2.3x108 gkm-2 d-1) for Greensburg and Munfordville, respectively.

A self-terminated electrochemical method was used to fabricate microscopic-scale contacts between two Au electrodes in a microfluidic channel. The conductance of contacts varies in a stepwise fashion showing quantization near the integer multiples of the conductance quantum ( ). The mechanism works by a pressure-driven flow parallel to a pair of Au electrodes with a gap on the order of micron in an electrolyte of HCl. When applying a bias voltage between two electrodes, metal atoms are etched off the anode and dissolved into the electrolyte as metal ions, which are then deposited onto the cathode. Consequently, the gap decreases to the atomic scale and then completely closes as the two electrodes form a contact. The electrochemical fabrication approach introduces large variance in the formation and location of individual junctions. Understanding and controlling this process will enable the precise positioning of reproducible geometries into nano-electronic devices.

The adaptations of vessel diameter represented by vascular conductance (VC), muscle blood flow (MBF) and oxygen delivery (DO2est) were investigated during rest and exercise using the effects of gravity to manipulate muscle perfusion pressure (MPP) by placing the heart above (head-up tilt) and below (head-down tilt) the level of the muscle. This experimental paradigm was used to explore VC and MBF regulation and related control mechanisms during rest and exercise. Study 1 tested the repeatability of Doppler ultra- sound measurements of muscle blood flow velocity (MBV), arterial diameter, MBF and VC. The adaptations in VC and MBF (Study 2) and changes in anterograde and retro- grade MBV patterns (Study 3) were investigated during postural challenges at rest. Study 4, determined the peak VC and its fractional recruitment during transitions from rest to lower (LPO) and higher power output (HPO) calf muscle exercise in HDT and HUT. Study 5 investigated the combined effects of altered MPP and hypoxia during exercise. During rest-HDT, increases in VC compensated for the MPP reduction to maintain MBF, while in rest-HUT, MBF was reduced. Following the start of LPO and HPO exercises, MBF and VC responses were delayed in HDT and accelerated in HUT. During LPO, MBF steady- state was reduced in HUT compared to horizontal (HOR), while the greater increase in VC during HDT maintained MBF at a similar level as HUT. Post-exercise MBF recovered rapidly in all positions after LPO exercise but did not after HPOHDT. During HPOHDT, MBF was reduced despite the increase in VC, while in HPOHUT MBF was similar to that in HPOHOR. The hypoxic challenge added in exercise was met during LPOHDT by in- creased VC to compensate reduced MPP and O2 availability such that MBF maintained DO2est. However, during HPOHDT in hypoxia, VC reached maximal vasodilatory capacity, compromising MBF and DO2est. Together, these findings indicate that LPOHDT in nor- moxia or hypoxia VC increased to maintain MBF and DO2est, but during HPO functional limitation for recruitment of VC constrained MBF and DO2 in normoxia and hypoxia. Elevated muscle electromyograpic signals in HPOHDT were consistent with challenged aer- obic metabolism. MPP reduction in HDT caused slower adaptation of MBF limiting O2 availability would result in a greater O2 deficit that could contribute to an increase in the relative stress of the exercise challenge and advance the onset of muscle fatigue.

Identification of salt- resistant tree species and genotypes is needed for rehabilitation of lands affected by salinity in Mexico. This dissertation consists of four studies for analyzing the responses of Pinus leiophylla seedlings to salt. In the first study, resistance to salt stress was studied in six-month-old seedlings from eight different sources of seed collected from the areas with contrasting precipitation levels. Plants from the xeric areas were shorter and had smaller stem diameters but were less sensitive to salt stress and recovered faster from salt injury compared with the plants from mesic sites, suggesting that morphological and physiological adaptations to drought were helpful with salt stress resistance. In the second study, fascicle needle production and tissue ion accumulation were examined in NaCl-treated three-month-old seedlings from two populations of the xeric origin and two populations from the mesic areas. Seedlings from the xeric population of San Felipe developed fewer fascicles and had shorter needles compared with seedlings from the remaining three populations. NaCl treatment delayed the emergence of fascicles and reduced the fascicle needle production and needle length. However, the extent of needle injury and ion accumulation in shoots were lower in the San Felipe seedlings compared with the other studied populations. In the third study, the effects of branch pruning and seedling size on total transpiration and accumulation of Na+ and Cl- in tissues were examined. Total plant transpiration, as affected by plant size and branch pruning, was correlated with Na+ and Cl- needle concentrations and needle necrosis. Branch pruning reduced ion accumulation in the shoots and needle necrosis levels in short seedlings but not in the tall seedlings. In the fourth study, sprouting and physiological responses of 16 month-old-seedling to salt were examined. NaCl treatment concentrations of 100, 150, and 200 mM reduced gas exchange and root hydraulic conductance, caused needle injury and triggered sprouting of adventitious shoots. Sprouting from the upper parts of the main stem and lateral branches was three times greater with 100 and 150 mM NaCl compared with 200 mM NaCl treatment but, at the base of the stem, sprout numbers were similar for all NaCl treatments.

主催：JST/CREST，Vrije University, ALTERRA, IBPC

No description available.

This thesis deals with electron correlation effects within low-dimensional, mesoscopic systems. We study phenomena within two different types of system in which correlations play an important role. The first involves the spectra and spin structure of small symmetric quantum dots, or &quoteartificial atoms&quote. The second is the &quote0.7 structure&quote, a well-known but mysterious anomalous conductance plateau which occurs in the conductance profile of a quantum point contact. Artificial atoms are manufactured mesoscopic devices: quantum dots which resemble real atoms in that their symmetry gives them a &quoteshell structure&quote. We examine two-dimensional circular artificial atoms numerically, using restricted and unrestricted Hartree-Fock simulation. We go beyond the mean-field approximation by direct calculation of second-order correlation terms; a method which works well for real atoms but to our knowledge has not been used before for quantum dots. We examine the spectra and spin structure of such dots and find, contrary to previous theoretical mean-field studies, that Hund's rule is not followed. We also find, in agreement with previous numerical studies, that the shell structure is fragile with respect to a simple elliptical deformation. The 0.7 structure appears in the conductance of a quantum point contact. The conductance through a ballistic quantum point contact is quantised in units of 2e^2/h. On the lowest conductance step, an anomalous narrow conductance plateau at about G = 0.7 x 2e^2/h is known to exist, which cannot be explained in the non-interacting picture. Based on suggestive numerical results, we model conductance through the lowest channel of a quantum point contact analytically. The model is based on the screening of the electron-electron interaction outside the QPC, and our observation that the wavefunctions at the Fermi level are peaked within the QPC. We use a kinetic equation approach, with perturbative account of electron-electron backscattering, to demonstrate that these simple features lead to the existence of a 0.7-like structure in the conductance. The behaviour of this structure reproduces experimentally observed features of the 0.7 structure, including the temperature dependence and the behaviour under applied in-plane magnetic fields.