京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第19504号 / 理博第4164号 / 新制||理||1598(附属図書館) / 32540 / 京都大学大学院理学研究科地球惑星科学専攻 / (主査)教授 田口 聡, 教授 家森 俊彦, 教授 余田 成男 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

In preparation for a Climate Action Plan, this policy and practice audit provides an overview of current city policies and practices with the potential to impact greenhouse gas (GHG) emissions reduction goals. The audit builds upon information previously collected in a GHG emissions inventory report to identify policies that are consistent or inconsistent with emissions reductions goals. Preliminary GHG emissions reductions recommendations address policy gaps and opportunity areas in suggesting strategies to achieve GHG emissions reductions.

The objective of the research is to reduce the volatile organic compounds (VOCs) emitted during kiln drying of southern yellow pine (SYP) lumber. Three treatment methods were explored to determine their effect on VOC emissions. The three methods were configured at the air exhaust of a pilot-scale dry kiln. 1) A steel reactor containing copper tubing heated to 100°, 200°, and 240° Celsius was evaluated. Temperature did not statistically affect VOC emissions (p-value = 0.1674). The average reduction of VOCs at 240° C was seven percent. 2) The use of hydrogen peroxide and ultra-violet (UV) light did not reduce VOCs emitted during kiln drying. 3) The use of Fenton?s reagent, with hydrogen peroxide and ferrous sulfate, also did not reduce VOCs emitted during kiln drying. 4) It is recommended that future studies with copper heated to temperatures above 240° C be performed.

No description available.

No description available.

Noise exposure is one of the most prevalent causes of irreversible occupational disease in Sweden and in many other countries. In hearing conservation programs, aimed at preventing noise-induced hearing loss, audiometry is an important instrument to highlight the risks and to assess the effectiveness of the program. A hazardous working environment and persons affected by it can be identified by monitoring the hearing thresholds of individual employees or groups of employees over time. However, in order to evaluate the prevalence of occupational noise-induced hearing loss, relevant reference data of unexposed subjects is needed. The first part of this dissertation concerns the changes in hearing thresholds over three decades in two occupational environments with high noise levels in the province of Östergötland, Sweden: the mechanical and the wood processing industries. The results show a positive trend, with improving median hearing thresholds from the 1970s into the 1990s. However, the hearing loss present also in the best period, during the 1990s, was probably greater than if the occupational noise exposure had not occurred. This study made clear the need for a valid reference data base, representing the statistical distribution of hearing threshold levels in a population not exposed to occupational noise but otherwise comparable to the group under study. In the second part of the dissertation, reference data for hearing threshold levels in women and men aged from 20 to 79 years are presented, based on measurements of 603 randomly selected individuals in Östergötland. A mathematical model is introduced, based on the hyperbolic tangent function, describing the hearing threshold levels as functions of age. The results show an age-related gender difference, with poorer hearing for men in age groups above 50 years. The prevalence of different degree of hearing loss and tinnitus is described for the same population in the third part of the dissertation. The overall prevalence of mild, moderate, severe or profound hearing loss was 20.9% collectively for women and 25.0% collectively for men. Tinnitus was reported by 8.9% of the women and 17.6% of the men. Approximately 2.4% of the subjects under study had been provided with hearing aids. However, about 7.7% were estimated to potentially benefit from hearing aids as estimated from their degree of hearing loss. Noise-induced hearing loss primarily causes damage to the outer hair cells of the inner ear. The fourth and last part of the dissertation evaluates the outer hair cell function, using otoacoustic emission measurements (OAE). Prevalence results from three different measuring techniques are presented: spontaneous otoacoustic emissions (SOAE), transient evoked otoacoustic emissions (TEOAE) and distortion product otoacoustic emissions (DPOAE). Gender and age effects on the recorded emission levels were also investigated. Women showed higher emission levels compared to men and for both women and men the emission levels decreased with increasing age. The results from the OAE recordings were shown to be somewhat affected by the state of the middle ear. The study included tympanometry, and the relation of the outcome ofthis test to the otoacoustic emissions is described, where high middle ear compliance resulted in low emission level. Reference data for the tympanometric measurements are also presented. The results of this project form an essential part of the important work against noiseinduced hearing loss, which needs continuous monitoring. The reference data presented here will provide a valid and reliable data base for the future assessment of hearing tests performed by occupational health centres in Sweden. This data base will in turn prove useful for comparison studies for Sweden as a responsible fellow EU member country setting high standards for work force safety. The statistical distribution of hearing threshold levels as a function of age for men and women in tabulated form is available on the Swedish Work Environment Authority (Arbetsmiljöverket) web site: http://www.av.se/publikationer/bocker/fysiskt/h293.shtm.

Models showing the anthropogenic and natural flows of two sustainability indicators; carbon based GHG and energy (as work energy) have been made for the Swedish region Jämtland. The methodology used was inspired by the study sustainability analysis conducted on the small Danish island Samsø using the above two indicators. The aim was to upscale the methodology used for Samsø and make necessary adaptations for Jämtland in order to be able to evaluate sustainability in terms of global warming. We also wanted to study the linkages between research, education and regional sustainability initiatives. Working at a regional level has advantages compared to working at a national or global level, as socio-ecological processes can be covered more extensively to reach a deeper understanding of practical aspects. In parallel to this we have also been participating in local and regional sustainability activities to increase our understanding of practical approaches and human behaviour. Studies of the energy flows in Jämtland show that 46,000 TJ (88% renewable) flows into the region and about 31,000 TJ is exported. The remaining 15,000 TJ (63% renewable) drives ‘the machine Jämtland’. Added to this is about 4000TJ as matter. The total global warming potential (GWP20) impact of Jämtland (as carbon dioxide equivalents, CO 2eq ) indicating influence on the global mean temperature as radiative forcing) is an annual uptake of 2.4 Mton. The total regional emissions, as CO 2eq, from anthropogenic activities, including consumption, are 1500 kton. The region has large emissions of methane, 80kton (6700 kton CO 2eq ), mainly from mires, lakes and animals but also large uptakes of CO2 from assimilation in woody biomass. Jämtland can be regarded as relatively sustainable from several perspectives, but taking the large forests and a population of only 127,000 inhabitants into consideration, the total uptake of CO 2eq is not very large and of the 15,000 TJ driving Jämtland, 37% comes from non-renewable sources. From a national (and global) perspective Jämtland needs to perform better, in view of its considerable reserves of natural resources. How to increase long-term sustainability in the region is a complex issue that requires penetration from many perspectives. Modelling results presented here needs to be interpreted in a broader sustainability context, together with regional stakeholders, to serve as a base for future knowledge development and sustainability activities. / Två modeller har utvecklats för att studera antropogena och naturliga flöden av energi (exergi) och kolbaserade växthusgasflöden i Jämtland. Metodiken har inspirerats av en metodik för att göra hållbarhetsanalyser som genomförts för den lilla danska ön Samsø utifrån dessa båda indikatorer. Att arbeta på regional nivå har fördelar gentemot att arbeta på en nationell eller global nivå eftersom man har större möjligheter att gå ned på djupet både gällande samhälleliga processer och ekologiska processer. Kopplingen mellan siffror och faktiska skeenden blir tydligare. Parallellt med arbetet med de regionala modellerna har vi också deltagit i lokalt och regionalt arbete för att förståelsen omkring praktiska angreppssätt och mänskligt beteende. Studien av energiflöden i Jämtland visar att 46.000 TJ (varav 88% förnyelsebart) flödar in i regionen och 31.000 TJ exporteras ut och att resterande 15.000 TJ (varav 63% förnyelsebart) driver maskineriet Jämtland. Till detta kommer omkring 4000 TJ i form av material. Den totala GWP20-påverkan från Jämtland är ’kylande’ och motsvarar ett upptag av koldioxid-ekvivalenter årligen på 2.4 Mton, vilket ungefär motsvarar emissionen från225.000 genomsnittssvenskar. De totala antropogena emissionerna av CO 2eq , inklusive konsumtion, är 1500 kton. Regionen uppvisar betydande emissioner av metan, 80 kton (motsvarande 6700 kton CO 2eq ) från sjöar, myrar och våtmarker samt djur. Jämtland kan ur flera perspektiv betraktas som relativt hållbart, men tar man de enorma skogsarealerna och den i ett internationellt perspektiv blygsamma befolkningen på 127 000 personer i beaktande är hållbarheten mindre övertygande. Vidare är 37% av den energi som driver Jämtland faktiskt icke-förnyelsebar. Sett ur ett globalt perspektiv och med hänvisning till Jämtlands enorma naturresurser behöver Jämtland prestera bättre. Hur man skall kunna öka den långsiktiga hållbarheten är en komplex fråga som kräver belysning från flera olika perspektiv. Resultat som de som presenteras här måste tolkas tillsammans med regionala intressenter i ett bredare hållbarhetssammanhang för att kunna utarbeta lämpliga implementeringsstrategier. / <p>Vid tidpunkten för framläggningen av avhandlingen var följande delarbete opublicerat: delarbete 4 (manuskript).</p><p>At the time of the defence the following paper was unpublished: paper 4 (manuscript).</p>

No description available.

Methane (CH4) is a potent greenhouse gas contributing to the warming of Earth's atmosphere. Lakes are a natural source of CH4, where CH4 generally is produced in oxygen depleted sediments. Ebullitive CH4 is regulated naturally in the oxic-anoxic interface of lakes by methane oxidizing bacteria, methanotrophs uses CH4 as a substrate when O2 is present. Lakes in boreal regions are among the largest sources of CH4 emissions, CH4 oxidation can mitigate some of the CH4 emissions from lakes. Gaps in knowledge and data remain regarding net fluxes of CH4, indicating that there are processes unaccounted for. Previous research highlights the variability of CH4 emissions and oxidations rates in lakes, there is lacking knowledge on what drives the variability of oxidation rates and total emissions. It’s been suggested that availability of phosphorus (P) has a positive relationship with increased oxidation rates. Moreover, availability of trace elements has been suggested to affect aerobic CH4 oxidation, but there is a lack of knowledge on these factors in natural lake waters. In this study incubations with lake water from two different lakes, Gårasjön and Kisasjön, were prepared with different treatments of P and/or trace elements. We investigate how this can affect the rate of CH4 oxidation when incubated in specific conditions. Our results indicate that treatments with added P had a greater tendency to exhibit higher rates of methane oxidation in both lakes, while treatments with trace elements and P had varied oxidation rates depending on the lake. This suggests that when there are no limitations of the substrates CH4 and O2, the oxidations rates in lakes might be limited by the availability of P and the specific lake conditions can influence CH4 oxidation.

Bevölkerungswachstum, Klimawandel und steigende Umweltbelastung durch Emission von Schadstoffen zählen zu den größten Herausforderungen dieses Jahrhunderts. In dieser Arbeit sollen daher die CO2-Emissionen untersucht werden, welche durch und an unterschiedlichen Knotenpunkten entstehen. Für diese Untersuchungen sollen daher für drei verschiedene Knotenpunktarten, drei verschiedene Verkehrsstärken und vier verschiedene Fahrzeugtypen die CO2-Emissionen berechnet werden.