Magister Artium (Development Studies) - MA(DVS) / This thesis examines how recent South African government fisheries policies have affected the livelihoods and food security of small-scale fishers, using the Kalk Bay fishing community in Cape Town, South Africa, as a case study. Fish has for generations provided food security for the fishers of Kalk Bay and their families. This food security has been both through catching fish for direct consumption and selling fish for income. Fish is an excellent source of nutrition, supplying easily digestible protein, as well as vital macro and micro nutrients essential for development and growth, thereby providing nutritional security. In South Africa, the right to food has been identified by the South African government as a primary policy objective. The Constitution of South Africa also guarantees access to food for citizens of the country primarily through providing access to food sources and livelihoods. This mini-thesis argues that despite the stated objectives of the government, the development and implementation of policy in the fisheries sector has not supported the right to food. Research was conducted through in-depth interviews with government representatives, fishing activists and fishers with a direct interest in Kalk Bay, as well as a survey completed in the Kalk Bay fishing community. The findings were examined through a sustainable livelihoods perspective, with a focus on access rights as a necessity to access livelihoods. The results clearly indicate that households in Kalk Bay who have traditionally pursued livelihoods and food security through fishing are often no longer able to do so. Small-scale fishers were completely omitted from the Marine Living Resources Act of 1998. This has resulted in the removal of access rights to marine resources which has led to these traditional fishers no longer being able to access their historical livelihoods and provide food security. These fishers have experienced further disenfranchisement from policies that were promised to empower the citizens of South Africa at the beginning of the new democracy in South Africa. As a result of a loss of access to livelihoods, small-scale fishers in South Africa launched a class action against the government. This legal action was won by the fishers and a judgement was given that the government was to amend the Marine Living Resources Act (1998), and a fisheries policy ensuring the inclusion of small-scale fishers was to be written. This thesis also addresses the attitudes towards and challenges of the newly adopted “Policy for small-scale fisheries in South Africa” of the fishing community of Kalk Bay. The evidence suggests that although small-scale fishers are now included, there are still notable challenges that could derail its successful implementation. A key challenge is the uncertainty by any parties about the quantity and value of marine resources to be allocated to the small-scale sector. It is unclear how much, if any, of the allocation is coming from the large scale industrial sector. This could result in continued challenges to the small-scale sector in terms of being able to access livelihoods and maintain food security.

I denna studie har kalkbruks styrkeförändring över tid undersökts.  Inom kulturmiljövården finns det vid restaureringar ett behov av att använda hållbara kalkbruk. En efterfråga finns också på beräkningsbara kalkmurbruk för att kunna räkna på konstruktionslaster i murverk. Reparationsbruk måste vara kompatibla med såväl underliggande material som befintligt bruk. De bör ha samma hållfasthet som de äldre kalkbruken samt hellre underordna sig i styrka än tvärtom. Hållfasthetsbestämning på murbruk ska enligt standard utföras på gjutna provkroppar efter 28 dygn. Eftersom kalkbruk karbonatiserar långsamt behövs mycket längre tid innan full styrka uppnåtts. Det finns inga hållfasthetskrav på luftkalkbruk, däremot finns hållfasthetskrav för hydraulisk kalk. Hållfastheten som anges på dessa är då mätta enligt standard efter 28 dygn. Styrketillväxten därefter kan bli avsevärt högre än vad som är önskvärt. Genom laboratorieundersökningar har förändringar av styrkan i kalkbruk fastställts. De standardiserade metoderna har använts men provtillfällena har utökats till att förutom att göras efter 28 dygn också utföras efter 90 och 180 dygn. Bruk har blandats av traditionellt tillverkad svensk kalk samt industriellt framställd hydraulisk kalk. Blandningsförhållandet 1:1,5 (kalk:sand) har valts då det är ett rimligt blandningsförhållande med avseende på historisk autencitet. Den standardiserade provningsmetoden behövde justeras något gällande härdningsklimat på grund av problem med bruk innehållandes luftkalk. Studien visar att hållfastheten hållfastheten många gånger nästan fördubblas mellan 28 och 180 dygn. På denna tid har inte provkropparna hunnit genomkarbonatiseras och hållfastheten förväntas att öka ytterligare. Att standarden varken i fråga om tidpunkt för bestämmande prov eller i fråga om härdningsklimat passar luftkalk har medfört att en parallell studie gjorts. Där har tidigare metoder för hållfasthetsbestämning kartlagts samt jämförts. / In this study, the change in strength of lime mortar over time was investigated. There is a need to use sustainable lime mortars during the restoration and protection of cultural heritage structures. Repair mortars must be compatible with both the underlying material and the existing mortar. There is additionally a demand for calculations regarding the final strength of limestone mortars as the strength of the repair mortar should be the same as or less than the older lime mortar. According to existing standards, strength determination of mortar must be carried out on cast specimens after 28 days. Since lime carbonates slowly, a much longer time is needed before full strength is achieved. There are no strength requirements for air lime mortar, but there are for hydraulic lime. The reported strengths of these materials are measured according to the standard after 28 days. Strength increases thereafter can become considerably higher than desirable. Through laboratory experiments, changes in the strength of lime mortar were investigated using standardized methods. The number of tests were extended so that, in addition to being performed after 28 days, they were also carried out after 90 and 180 days. The mortars were mixed with traditionally produced Swedish lime and industrially produced hydraulic lime. A mixing ratio of 1:1.5 (lime:sand) was chosen as it is reasonable with regard to historical authenticity. A mapping and comparison of previous Swedish methods and standards for strength determination was also performed. The results show how the strength of the different mortars increases between 28 and 180 days.

Gotland has a very long tradition of lime burning. Traces of lime burning on Gotland stretch back to the 12th century. An inventory of all the lime kilns in Gotland was made in 1942. Since then the market, the use and the tradition of lime burning have changed significantly. By the start of WW2 a shortage of black coal occurred. This meant that the large, traditional lime kilns could no longer be operated with the same capacity. The small, wood-burning kilns were the only furnaces that survived. With the cement's entry the demand for lime mortar got heavily reduced, which in turn meant the end for the last lime kilns. The cement quickly proved inadequate in many situations, especially in the field of monument care​​, and the demand for traditional lime mortar increased again already in the 1960s. Since then, three lime kilns were taken into use on Gotland; two smaller, traditional lime kilns and one large, industrial kiln. This thesis intends to follow up on the inventory that was made in 1942 in order to create a basis for further discussion of the historical values the lime kilns possesses and how these values can be cared for. In order to ensure the being of cultural heritage of the traditional lime industry, it requires popular demand, care and knowledge of the furnace, its use and production and its product. / Gotland har en mycket lång tradition av kalkbränning. Spår av kalkbränning sträcker sig på ön tillbaks till 1100-talet. En inventering av samtliga kalkugnar och kalkmilor på Gotland gjordes år 1942. Sedan dess har marknaden, användningen och traditionen av kalkbränning förändrats kraftigt. Vid andra världskrigets början uppstod en bristsituation på stenkol. Detta medförde att de stora, traditionella kalkugnarna inte längre kunde drivas med samma kapacitet. De mindre, vedeldade ugnarna var de enda ugnarna som överlevde. Med cementens intåg minskade även efterfrågan på kalkbruk, vilket i sin tur betydde slutet för de sista kalkugnarna. Cementen visade sig snabbt vara bristfällig i flera situationer, särskilt inom kulturvårdens praktik, och efterfrågan på traditionellt kalkbruk ökade igen redan på 1960-talet. Sedan dess har tre kalkugnar tagits i bruk på Gotland; två mindre, traditionella kalkugnar och en stor, industriell ugn. Uppsatsen ämnar följa upp inventeringen som gjordes 1942 för att skapa ett underlag för att vidare resonera kring de kulturhistoriska värden kalkugnarna besitter och hur dessa tas till vara. För att kunna vårda kulturarvet från den traditionella kalkindustrins dagar fordras efterfrågan på kalk, vård och kunskap om ugnarna, dess användning och produktion och dess produkt.

Zugl.: Dortmund, Techn. Univ., Diss., 2009

Zugl.: Giessen, Univ., Diss., 2009

Stabilization of subgrade is an internationally common technique to improve the characteristics of a soft soil. Improving the stiffness and bearing capacity of the subgrade enables the pavement to be designed with reduced depths of subbase and basecourse aggregates. This makes the stabilization technique both economically and environmentally interesting. Both natural and stabilized soils have high inherent property variability that should be considered when the characteristic value is derived. By analyzing the spatial variability in stabilized and natural subgrades it is possible get the parameters needed for reliability–based modeling of soil properties. I order to do so, three statistical parameters need to be evaluated, i.e. the mean, the variance and the scale of fluctuation, which is the distance within which soil properties show relatively strong correlation. The objective of this thesis is to study different devises for determining the elastic modulus of subgrade and to study the spatial variability of the elastic modulus. With knowledge of this it is possible to optimize the testing. The different devises used in the field investigations was the light weight deflectometer (LWD), surface seismic and static plate loading. The different devices were used because they take measurements at different load- and strain levels. Another aim was to investigate correlations between moduli determined by the different devices. This thesis is a part of a research project at Skanska about subgrade stabilization. The field studies were performed in Tygelsjö, south of Malmö, and the soil type was claytill. Two test areas, each 7x15 m, were stabilized with 6 % respective 4 % hydrated lime and two test areas, each 4x15 m, were left unstabilized. Totally 133 test points were investigated with the LWD and surface seismic and 11 static plate load tests were performed. With geostatistical analyses of the experimental results the scale of fluctuation with respect to the elastic modulus has been evaluated to approximately 1,3 m. That means only points within 1,3 m reveal relative strong correlation. In practice this means that subsidence due to less stiffness in the stabilized subgrade will not be extensive in the surface. Therefore it’s not economically rational to design the pavement with respect to small areas with low stiffness in the subgrade. Comparison between the LWD and the static plate load test showed that ELWD is on average 2 times greater than EV2. No correlations with the surface seismic were found. One influencing factor on the LWD measurements was the drop height. ELWD decreased with increasing drop height but only on the unstabilized subgrade. This thesis also shows how the characteristic value of the elastic modulus could be evaluated with statistical methods where the evaluation will depend on the number of measurements, the variability of the measurements and the variance reduction factor which in turn depends on the scale of fluctuation and the size of the mechanical system. This type of evaluation could be used as basis for reliability based design and design according to the observational method according to Eurocode 7. / <p>QC 20100706</p>

I Sverige förekommer det sura sulfatjordar som är resultatet av när sulfidrika sediment, som avsattes för 4000 – 7000 år sedan, introduceras i en oxisk miljö. Sedimenten avsattes i botten av Litorinahavet främst längs östkusten samt Mälardalen i anaeroba förhållanden där sulfider kunde bildas. När dessa sulfider kommer i kontakt med syret i atmosfären vittar sulfiderna och medför en pH sänkning. Detta påskyndas av en antropogen påverkan samt en pågående landhöjning som förekommer i Sverige. Ett lågt pH medför att toxiska metaller kan bli mobila och utlakas till miljöer där de kan medföra stora konsekvenser. I anläggningsprojekt deponeras stora volymer sulfidjordsmassor varje år, som ett resultat att de är försurande samt har en hög sättningsbenägenhet. Detta medför flera kostnader i byggprojekt för deponi, transport och nytt utfyllnadsmaterial. Som en följd motverkar detta ett cirkulärt samhälle när jordens resurser deponeras istället för att återvinnas och återanvändas. Skanska har beslutat om ett mål, att samtliga verksamhetsgrenar ska uppnå s.k. klimatneutralitet vid år 2045. Att framtida kunna återvinna och återanvända sulfidjord kan vara ett bidrag för Skanska att uppnå detta mål genom minskade transporter och återanvändande istället för att deponera sulfidjord och vid anläggningsarbeten tillföra jungfruligt material. För att neutralisera sulfidjord kan olika material användas som förhöjer jordens alkalinitet och motverkar försurningen från oxidationen. Två sådana material är bränd kalk och bioaska som är de två material som jämförs i detta arbete, för att se hur kvalitén på porvattnet samt växtetableringen påverkas av respektive tillsats. För att kontrollera sammansättningen av provattnet samt växtetableringen utfördes flera laborationer, kontroll av torrsubstans, glödförlust, lakförsök, bestämning av mängd buffert, kontroll av vattenhållningskapacitet, återväxtförsök, ämnes analys av porvatten och en beräkning för att uppskatta hur länge den behandlade sulfidjorden bör kunna buffra systemet mot syror.   Vanlig planteringsjord tillät bäst växtetablering och den obehandlade sulfidjorden var den jord som medförde sämst växtetablering. Porvattnet hade högre pH, kring neutralt, än initialt pH för den obehandlade sulfidjorden som var kring pH 4,5. Flera ämnen återfanns i lägre halter i porvattnet för sulfidjorden som har behandlats jämfört med den obehandlade, med vissa variationer. Porvattnet i sulfidjorden som behandlats med bioaska hade högre halter av flera ämnen jämfört med sulfidjorden som behandlats med bränd kalk, framförallt höga nivåer av arsenik samt svavel. Slutsatsen är att båda sulfidjordsblandningarna uppskattas kunna buffra systemet i mer än 10 000 år. Tillsammans med halterna i porvattnet förespråkar resultatet att det finns goda förutsättningar till att behandla sulfidjord och återanvända i olika projekt. Vidare forskning krävs till att optimera ett förhållande mellan mängd tillsatser samt mängd sulfidjord. Skanska bedöms ha goda förutsättningar till att arbeta vidare och kunna etablera en eller flera återvinningsanläggningar i landet för sulfidjord. / In Sweden there are acid sulphate soils that are the result of when sulphide rich sediments, deposited 4000 – 7000 years ago, enters an oxic environment. The sediments deposited at the bottom of the Littorina sea mainly along the east coast as well as Mälardalen in anaerobic conditions where the sulphide could precipitate. When these sulphides get in contact with the oxygen in the atmosphere weathering occurs where the reaction lowers the pH. The rate is increased due to anthropogenic actions along with land rise which occurs in Sweden. Low pH contributes the toxic metals can become mobile and leach to other environments where they could do significant damage. In construction projects, large volumes of sulphide soils are deposited at landfills annually, due to the soil being acidifying as well as the soil often have a high tendency to settle. This entails several costs in constructions projects for landfill, transport and new filling material. As a result, this offsets a circular society when natural resources are landfilled rather than reused. Skanska has decided on a goal, that all branches in their network should achieve climate neutrality by 2045. Recycling and reusage of the sulphide soil would help Skanska to achieve this goal by reduced transport and reusage of the soil instead of outsourcing for virgin material. To neutralize sulphide soils, various materials can be used as buffers that increases the alkalinity of the soil and counteract the acidification from the oxidation. Two possible materials that could achieve this is quicklime and bio-ash, which are the two materials that are compared in this work to see how the porewater quality and plant establishment are affected by the additive. In order to analyse the difference in porewater quality and plant establishment between the two additives, several laboratory works were conducted. Control of dry matter, loss of ignition, batch leaching test, determination of the amount of buffer needed to buffer the soil mixture, control of water holding capacity, growth rate test, analysis of porewater and estimation of buffer capacity. Ordinary topsoil allowed the best plant establishment and the untreated sulphide soil had the worst plant establishment. The porewater from the treated sulphide soil mixtures had a higher pH, around neutral, than the initial pH of the untreated sulphide soil, which was around pH 4,5. Several substances in the porewater had lower concentrations in the treated sulphide soil compared to the untreated, with some variation. The porewater from the soil mixture with the additive bio-ash had higher concentrations for several substances than the sulphide soil that have been treated with quicklime, especially high levels of arsenic and sulphur. The conclusions are that both sulphide soil mixtures have been estimated to be able to buffer the system for over 10 000 years. Together with the porewater properties it suggests that there are great prerequisites to treat and reuse sulphide soil. Although, a more optimum recipe for the ratio of sulphide soil, buffer and stabilizer is required. Skanska is considered to have excellent prerequisites to establish recycling facilities for sulphide soil.

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