Hausdorff dimension of random limsup sets

We prove bounds for the almost sure value of the Hausdorff dimension of the limsup set of a sequence of balls in $\mathbf{R}^d$ whose centres are independent, identically distributed random variables. The formulas obtained involve the rate of decrease of the radii of the balls and multifractal properties of the measure according to which the balls are distributed, and generalise formulas that are known to hold for particular classes of measures.Comment: 26 pages, 2 figures; v2: Minor correction

On the Fourier dimension and a modification

We give a sufficient condition for the Fourier dimension of a countable union of sets to equal the supremum of the Fourier dimensions of the sets in the union, and show by example that the Fourier dimension is not countably stable in general. A natural approach to finite stability of the Fourier dimension for sets would be to try to prove that the Fourier dimension for measures is finitely stable, but we give an example showing that it is not in general. We also describe some situations where the Fourier dimension for measures is stable or is stable for all but one value of some parameter. Finally we propose a way of modifying the definition of the Fourier dimension so that it becomes countably stable, and show that a measure has modified Fourier dimension greater than or equal to $s$ if and only if it annihilates all sets with modified Fourier dimension less than $s$.Comment: v2: Added some remarks in the introduction and after Example 6. v3: Revised the introduction, strengthened Lemma 6, added Proposition 5 and Example 8. To appear in Journal of Fractal Geometr

Optimering av tanninextraktion

Varje år produceras cirka 1 miljon ton slam i de svenska reningsverken. I slammet ackumuleras oönskade metaller och organiska ämnen. För att avvattna och skilja slammet från avloppsvattnet och effektivisera transporten till deponi eller åkermark som gödsel används ett flocknings-/koaguleringsmedel. Vanligtvis används den syntetiska polymeren polyakrylamid vid slamflockning. Polymeren bryts dock ner långsamt eller inte alls i naturen vilket kan bidra till en ackumulation i marken. Tanniner extraherat från bark har visat liknande egenskaper, kommersiella flockningsprodukter finns men tillverkas utomlands och då främst från akacia. Intresse finns att utvärdera möjligheterna att extrahera tanniner från, inhemska trädslag för senare användning mot avloppsslam och som retentionsmedel inom massaindustrin inom Sverige. Då varje trädslag är unikt krävs olika förhållanden för optimal extraktion, därför behövs en metod som utvärderar vilka faktorer som påverkar tanninutfallet på inhemska trädslag. Syftet med detta examensarbete blir därav att kontrollera vilken inverkan de tre faktorerna temperatur, bark/liter lösningsmedel (TS-halt) och fraktionsstorlek har på extraktionsutfallet på trädslaget tall (Pinus sylvestris). Tanninerna extraherades genom att barken, under omrörning, fick ligga i en 8-procentig natriumkarbonatlösning. De tre faktorernas värden varierade mellan försöken och prover togs efter 4, 8, 16, 32 och 64 minuter. Mängden fenoler kontrollerades med hjälp av en fotospektrometer. Resultatet visade att alla tre faktorerna hade en signifikant inverkan på extraktionsutfallet. Ökad temperatur och bark/liter lösningsmedel hade positiv korrelation med extraktionsutbytet medan ökad fraktionsstorlek visade negativ korrelation. Under studien uppnåddes inget optimalt förhållande för maximerat extraktionsutfall men det visade att framgångsrik extraktion av tanniner från inhemskt trädslag är möjlig.sludge accumulates unwanted metals and organic substances. In order to dewater and separate the sludge from the waste-water and stream-line the transport to landfills or farmland as fertilizer, a flocculation/coagulation agent is used. The most commonly used product in sludge flocculation is the synthetic polymer polyacrylamide. The polymer breaks down slowly or not at all in nature, which can contribute to an accumulation in the soil. Tannins extracted from the bark have similar properties, commercial flocking agents exists but are manufactured abroad, mainly from the bark of the Acacia tree. There is an interest to evaluate the possibilities of extracting tannins from, native tree species for later use against sludge and retention aids in the paper industry in Sweden. As each species is unique, they require different conditions for optimal extraction, therefore a method is needed that evaluates the factors that influence tannin extraction of native tree species. The purpose of this study is hence to evaluate what the impact of the three factors; temperature, bark/liter of solvent and fraction size, has on extraction outcome for the tree species pine (Pinus sylvestris). The tannins was extracted from the bark into an eight percent sodium carbonate solution while stirring. The values of the three factors varied between the trials and samples were taken after 4, 8, 16, 32 and 64 minutes. The amount of phenols was measured using a spectrophotometer. The results showed that all three factors had a significant impact on the extraction outcome. Increased temperature and bark/liter solvent had a positive correlation with the extraction yield while increased fraction size showed a negative correlation. During the study no optimal ratio for maximized outcome was achieved, but showed that the extraction of tannins from indigenous tree species is promising

Current epigenetic aspects the clinical kidney researcher should embrace

Chronic kidney disease (CKD), affecting 10-12% of the world's adult population, is associated with a considerably elevated risk of serious comorbidities, in particular, premature vascular disease and death. Although a wide spectrum of causative factors has been identified and/or suggested, there is still a large gap of knowledge regarding the underlying mechanisms and the complexity of the CKD phenotype. Epigenetic factors, which calibrate the genetic code, are emerging as important players in the CKD-associated pathophysiology. In this article, we review some of the current knowledge on epigenetic modifications and aspects on their role in the perturbed uraemic milieu, as well as the prospect of applying epigenotype-based diagnostics and preventive and therapeutic tools of clinical relevance to CKD patients. The practical realization of such a paradigm will require that researchers apply a holistic approach, including the full spectrum of the epigenetic landscape as well as the variability between and within tissues in the uraemic milieu

Två höjdtilldelningsmetoder för trädhöjder

Detta kandidatarbete avsåg att utvärdera två metoder för höjdtilldelning av enskilda träd och hur dessa påverkade kvalitén på skattningar av grundytevägd medelhöjd gjord med hjälp av laserdata. De metoder som utvärderades var Söderbergs funktioner och en ny metod som Riksskogstaxeringen nyligen tagit fram. Studien skedde i tre delar, först en jämförelse mellan de värden för varje provyta som tilldelats enligt Söderbergs funktioner respektive Riksskogstaxeringens metod, sedan en regressionsanalys av mängden värden från respektive metod och laserdata, och slutligen en granskning av regressionsfunktionernas noggrannhet gentemot fältinventerade provytor som inte användes i framtagandet av funktionerna. För att göra dessa analyser användes Riksskogstaxeringens provytor, Lantmäteriets laserdata samt provytor tillhandahållna av Bergvik Skog.Resultatet visade på att den nya metoden gav systematiskt högre skattningar än Söderbergs funktioner. Skattningar gjorda utifrån laserdata baserade på den nya metoden hamnade närmare det fältinventerade värdet, jämfört med skattningar grundade på Söderbergs funktioner.The aim of this bachelors degree thesis was to analyze how estimations of basal area weighted mean height made with airborne laser scanning (ALS) data is affected by the tree wise height estimation method used for the plots before regression analysis. The methods compared are Söderberg’s functions and a new method produced by the Swedish National Forest Inventory (NFI). This study was performed in three parts. First an initial comparison between the values assigned to every plot was made. Then a regression analysis between these values and laser data was completed. Finally an evaluation of estimations made with the computed functions versus third party inventoried values was performed. To make this analysis, data was used that came from the NFI, Lantmäteriet’s (the Swedish national land survey) national laser scanning, and Bergvik Skog. The result showed that the new method developed by the NFI systematically produced a higher value than Söderberg’s functions. It was found that the estimates, made with ALS data, based on the new height estimation method showed better agreement with the evaluation data from Bergvik Skog than the estimates based on Söderberg’s functions

ANALISIS PENERAPAN TOTAL PRODUCTIVE MAINTENANCE (TPM) DI PT CHANDRA ASRI PETROCHEMICAL TBK

PT Chandra Asri Petrochemical Tbk merupakan perusahaan terbesar dan terintegrasi di Indonesia yang menghasilkan produk biji plastik. Dalam dunia industri petrokimia, kondisi dan kinerja alat dan mesin menjadi salah satu penentu pencapaian target produksi yang ditetapkan. Kondisi mesin dan peralatan harus dijaga agar selalu dalam kondisi prima dan siap digunakan seoptimum mungkin dengan cara pemeliharaan dan perbaikan (maintenance). Dari hasil laporan data tahunan yang dimiliki perusahaan diketahui adanya permasalahan yang sering terjadi di mesin Product Discharge System pada train 2 sehingga sering terjadi breakdown. Salah satu metode yang dapat mengetahui pengaruh breakdown terhadap jumlah produksi yaitu dengan menggunakan metode Overall Equipment Effectiveness (OEE), di mana breakdown menjadi salah satu indikator yang digunakan dalam perhitungan OEE yaitu Availability. Dengan perhitungan yang ada, maka akan didapatkan hasil nilai Overall Equipment Effectiveness dan dilanjutkan dengan proses analisis six big losses untuk menentukan kerugian mana saja yang paling berpengaruh. Hasil dari penelitian yaitu didapatnya hasil rata-rata Overall Equipment Effectiveness yaitu sebesar 85,4% dengan losses terbesar ditemukan pada Equipment Failure Losses dengan persentase paling besar yaitu 47,65% dari keenam losses lainnya. Dari hasil Equipment Failure Losses ini dapat diketahui bahwa yang mempengaruhi besarnya nilai dari hasil tersebut dikarenakan angka kerusakan pada valve Product Discharge System yang cukup tinggi serta waktu untuk setup dan adjustment yang lama. Berdasarkan hasil tersebut serta konsultasi dengan pihak perusahaan, maka didapatkan beberapa solusi yang dapat diimplementasikan perusahaan untuk perbaikan ke depannya yang lebih baik

Alterations in the neuropeptide galanin system in major depressive disorder involve levels of transcripts, methylation, and peptide

Major depressive disorder (MDD) is a substantial burden to patients, families, and society, but many patients cannot be treated adequately. Rodent experiments suggest that the neuropeptide galanin (GAL) and its three G protein-coupled receptors, GAL1–3, are involved in mood regulation. To explore the translational potential of these results, we assessed the transcript levels (by quantitative PCR), DNA methylation status (by bisulfite pyrosequencing), and GAL peptide by RIA of the GAL system in postmortem brains from depressed persons who had committed suicide and controls. Transcripts for all four members were detected and showed marked regional variations, GAL and galanin receptor 1 (GALR1) being most abundant. Striking increases in GAL and GALR3 mRNA levels, especially in the noradrenergic locus coeruleus and the dorsal raphe nucleus, in parallel with decreased DNA methylation, were found in both male and female suicide subjects as compared with controls. In contrast, GAL and GALR3 transcript levels were decreased, GALR1 was increased, and DNA methylation was increased in the dorsolateral prefrontal cortex of male suicide subjects, however, there were no changes in the anterior cingulate cortex. Thus, GAL and its receptor GALR3 are differentially methylated and expressed in brains of MDD subjects in a region- and sex- specific manner. Such an epigenetic modification in GALR3, a hyperpolarizing receptor, might contribute to the dysregulation of noradrenergic and serotonergic neurons implicated in the pathogenesis of MDD. Thus, one may speculate that a GAL3 antagonist could have antidepressant properties by disinhibiting the firing of these neurons, resulting in increased release of noradrenaline and serotonin in forebrain areas involved in mood regulation