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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

The potential for using biomonitoring in the Hong Kong marine environment

Yu, Pui-shan., 余珮珊. January 1996 (has links)
published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management
72

香港近岸沉積物中重金屬之化學形態及活動性硏究 =: A study of the chemical speciation and mobility of heavy metals in the Hong Kong near-shore sediments. / Study of the chemical speciation and mobility of heavy metals in the Hong Kong near-shore sediments / Xianggang jin an chen ji wu zhong zhong jin shu zhi hua xue xing tai ji huo dong xing yan jiu =: A study of the chemical speciation and mobility of heavy metals in the Hong Kong near-shore sediments.

January 1993 (has links)
據稿本影印 / 論文(哲學碩士)--香港中文大學硏究院地理學部,1993. / 參考文獻: leaves 212-219 / 郭錦添. / Chapter I. --- 導論 / Chapter A. --- 引言 --- p.1 / Chapter B. --- 研究目的 --- p.1 / Chapter C. --- 研究意義 --- p.3 / Chapter D. --- 理論架構 --- p.4 / Chapter 1. --- 化學形態 --- p.4 / Chapter a. --- 水體中重金屬化學形態分類 --- p.6 / Chapter b. --- 顆粒態重金屬化學形態分類 --- p.7 / Chapter 2. --- 重金屬化學形態與其毒性的關係 --- p.10 / Chapter 3. --- 化學形態分析方法及其困難 --- p.13 / Chapter 4. --- 重金屬在水體與沉積物交接面間的活動 --- p.15 / Chapter 5. --- 重金屬遷移與形態間轉化機制 --- p.17 / Chapter E. --- 香港過往對海港中重金屬的研究 --- p.19 / Chapter II. --- 研究方法 / Chapter A. --- 研究策略 --- p.22 / Chapter B. --- 採樣點分佈 --- p.23 / Chapter C. --- 野外採樣方法 --- p.25 / Chapter D. --- 分析項目及方法 --- p.26 / Chapter 1. --- 重金屬的選擇 --- p.26 / Chapter a. --- 毒性 --- p.26 / Chapter b. --- 濃度 --- p.27 / Chapter c. --- 參考數據 --- p.27 / Chapter 2. --- 分離技術和分析方法 --- p.28 / Chapter a. --- 重金屬分祈法 --- p.28 / Chapter b. --- 水樣分析法 --- p.30 / Chapter c. --- 沉積物樣本分析法 --- p.31 / Chapter d. --- 試劑配備 --- p.32 / Chapter e. --- 選擇以上分析項目的原因 --- p.33 / Chapter f. --- 模擬實驗的設計 --- p.34 / Chapter III. --- 香港近岸沉積物中重金屬含量及其化學形態分佈 / Chapter A. --- 引言 --- p.39 / Chapter B. --- 總濃度分析 --- p.39 / Chapter C. --- 化學形態分析 --- p.40 / Chapter D. --- 總結 --- p.44 / Chapter IV. --- 荃灣個案研究 / Chapter A. --- 研究目的及其重要性 --- p.45 / Chapter B. --- 研究结果 --- p.46 / Chapter 1. --- 水質 --- p.46 / Chapter a. --- 荃灣海域的水文情況 --- p.46 / Chapter b. --- 水污染的空間與時間分佈規律 --- p.48 / Chapter c. --- 水體中重金屬污染物的濃度與存在形態 --- p.49 / Chapter d. --- 小结 --- p.50 / Chapter 2. --- 海底沉積物 --- p.51 / Chapter a. --- 荃灣海域底泥的化學特性 --- p.51 / Chapter b. --- 荃灣海泥中重金屬的存在化學形態 --- p.52 / Chapter C. --- 討論 --- p.54 / Chapter D. --- 從個案研究看全港重金屬污染(沉降)特性 --- p.55 / Chapter V. --- 模擬實驗 / Chapter A. --- 引言 --- p.57 / Chapter B. --- 沉降反應模擬實驗的設計及目的 --- p.57 / Chapter 1. --- 形態轉化模擬 --- p.57 / Chapter 2. --- 沉降模擬 --- p.56 / Chapter 3. --- 渠口反應模擬 --- p.58 / Chapter C. --- 釋放模擬實驗的設計及目的 --- p.59 / Chapter 1. --- 疏浚模擬 --- p.59 / Chapter 2. --- 棄置模擬 --- p.60 / Chapter 3. --- 氧化模擬 --- p.60 / Chapter 4. --- 降雨模擬 --- p.60 / Chapter D. --- 實驗條件 --- p.61 / Chapter E. --- 沉降模擬實驗结果 --- p.66 / Chapter 1. --- 形態轉化模擬實驗结果 --- p.66 / Chapter 2. --- 沉降實驗结果 --- p.68 / Chapter 3. --- 渠口反應模擬實驗结果 --- p.70 / Chapter 4. --- 沉降模擬實驗结論 --- p.79 / Chapter F. --- 釋放模擬實驗结果 --- p.80 / Chapter 1. --- 疏浚模擬實驗结果 --- p.81 / Chapter 2. --- 棄置模擬實驗結果 --- p.82 / Chapter 3. --- 氧化模擬實驗结果 --- p.88 / Chapter 4. --- 降雨模擬實驗结果 --- p.90 / Chapter 5. --- 釋放模擬實驗结論 --- p.91 / Chapter VI. --- 討論 / Chapter A. --- 本港海域的重金屬存在形態與其活動性及毒性的關係 --- p.93 / Chapter B. --- 現存於本港海泥中重金屬形態分佈的形成機制和遷移條件 --- p.95 / Chapter 1. --- 形態分佈的形成機制 --- p.95 / Chapter 2. --- 遷移條件 --- p.96 / Chapter C. --- "環境管理-水質管制,疏浚和填海等工程對底泥中重金屬的影響" --- p.97 / Chapter D. --- 海泥中重金屬污染的空間分佈特性(擴散模型) --- p.98 / Chapter E. --- 總结 --- p.99 / Chapter VII. --- 结論 / Chapter A. --- 總结研究结果 --- p.101 / Chapter B. --- 研究中某些較特別的發現 --- p.104 / Chapter C. --- 研究的局限與展望 --- p.105
73

Using satellite imageries in marine water quality monitoring: a case of Hong Kong.

January 1994 (has links)
by Siu, Wai Lok. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leaves 213-218). / ABSTRACT --- p.i -ii / ACKNOWLEDGEMENTS --- p.iii / TABLE OF CONTENTS --- p.iv -vi / LIST OF FIGURES --- p.vi -viii / LIST OF PLATES --- p.ix / LIST OF TABLES --- p.x -xii / Chapter CHAPTER I --- INTRODUCTION --- p.1 / Chapter 1.1 --- Problem Statement --- p.1 / Chapter 1.2 --- Study Area --- p.3 / Chapter 1.3 --- Research Objectives --- p.4 / Chapter 1.4 --- Rationale --- p.9 / Chapter 1.5 --- Organization of the Thesis --- p.10 / Chapter CHAPTER II --- LITERATURE REVIEW --- p.12 / Chapter 2.1 --- Introduction --- p.12 / Chapter 2.2 --- Optical Properties of Sea Water --- p.12 / Chapter 2.3 --- Water Quality Modeling Algorithms --- p.18 / Chapter 2.3.1 --- Suspended Sediment Models --- p.22 / Chapter 2.3.2 --- Chlorophyll Models --- p.29 / Chapter 2.3.3 --- Sea Surface Temperature Models --- p.30 / Chapter 2.3.4 --- Salinity Models --- p.33 / Chapter 2.3.5 --- Total Phosphorus Models --- p.34 / Chapter 2.4 --- Use of Chromaticity Technique --- p.35 / Chapter 2.5 --- Principal Component Transformation --- p.37 / Chapter 2.6 --- Remote Sensing Water Quality in Hong Kong --- p.37 / Chapter 2.7 --- Summary --- p.38 / Chapter CHAPTER III --- METHODOLOGY --- p.40 / Chapter 3.1 --- Data Set --- p.40 / Chapter 3.1.1 --- Water Sampling and Water Quality Parameters --- p.40 / Chapter 3.1.2 --- Satellite Data --- p.45 / Chapter 3.1.2.1 --- Image Preprocessing --- p.45 / Chapter 3.1.2.1.1 --- Radiometric Correction --- p.45 / Chapter 3.1.2.1.2 --- Atmospheric Correction --- p.49 / Chapter 3.1.2.1.3 --- Geometirc Correction --- p.53 / Chapter 3.1.2.2 --- Data Extraction --- p.55 / Chapter 3.1.2.3 --- Spectral Data Transformation --- p.56 / Chapter 3.2 --- Statistical Water Quality Models --- p.59 / Chapter 3.3 --- Water Quality Mapping --- p.61 / Chapter CHAPTER IV --- EXPERIMENTAL SET-UP --- p.63 / Chapter 4.1 --- Introduction --- p.63 / Chapter 4.2 --- Water Quality Samples --- p.63 / Chapter 4.2.1 --- Sample Data for TM Experiment --- p.63 / Chapter 4.2.2 --- Sample Data for SPOT Experiment --- p.68 / Chapter 4.2.3 --- Correlations Among Parameters --- p.76 / Chapter 4.3 --- Image Preprocessing --- p.81 / Chapter 4.3.1 --- Image Destriping --- p.83 / Chapter 4.3.2 --- Atmospheric Correction --- p.85 / Chapter 4.3.3 --- Geometric Correction --- p.88 / Chapter 4.4 --- Data Extraction --- p.89 / Chapter 4.4.1 --- Descriptive Statistics of the Spectral Data Samples --- p.89 / Chapter 4.4.2 --- Data Transformation --- p.100 / Chapter 4.4.3 --- Correlations Among Spectral Variables --- p.103 / Chapter 4.5 --- Summary --- p.107 / Chapter CHAPTER V --- ANALYSIS OF WATER QUALITY MODELS …… --- p.113 / Chapter 5.1 --- Introduction --- p.113 / Chapter 5.2 --- Criteria for Assessing Water Quality Models --- p.113 / Chapter 5.3 --- Models Derived from TM Data --- p.116 / Chapter 5.3.1 --- Models of Various Water Quality Paramters --- p.116 / Chapter 5.3.2 --- Summary --- p.142 / Chapter 5.4 --- Models Derived from SPOT Data --- p.145 / Chapter 5.4.1 --- Models of Various Water Quality Parameters --- p.145 / Chapter 5.4.2 --- Summary --- p.169 / Chapter 5.5 --- Comparisons Among Models --- p.171 / Chapter 5.5.1 --- Comparisons Among Models Derived from TM and SPOT Data --- p.171 / Chapter 5.5.2 --- Comparisons with Past Models --- p.172 / Chapter 5.6 --- Conclusion --- p.173 / Chapter CHAPTER VI --- WATER QUALITY MAPPING --- p.175 / Chapter 6.1 --- Introduction --- p.175 / Chapter 6.2 --- Classification Schemes for Various Water Quality Paramters --- p.175 / Chapter 6.3 --- Water Quality Maps --- p.180 / Chapter 6.3.1 --- Water Quality Mapping Using TM Data --- p.180 / Chapter 6.3.2 --- Water Quality Mapping Using SPOT Data --- p.190 / Chapter 6.4 --- Difficulties Encountered in Water Quality Mapping --- p.202 / Chapter 6.5 --- Summary --- p.204 / Chapter CHAPTER VII --- CONCLUSION --- p.206 / Chapter 7.1 --- Summary of Findings --- p.206 / Chapter 7.1.1 --- Summary on Water Quality Modeling --- p.206 / Chapter 7.1.2 --- Summary on Water Quality Mapping --- p.208 / Chapter 7.2 --- Limitations of the Study --- p.209 / Chapter 7.3 --- Recommendations for Further Studies --- p.210 / BIBLIOGRAPHY --- p.213
74

Regulation, control and prevention of marine pollution in South Africa : a comparative analysis between national and international legal frameworks

Bapela, Mpho Paulos January 2021 (has links)
Thesis (LLD.) -- University of Limpopo, 2021 / This thesis, “Regulation, control and prevention of marine pollution in South Africa: A Comparative analysis between national and international legal framework” focuses on the existing laws, conventions, treaties and policies on the control and prevention of marine pollution. Various laws have been enacted in South Africa to prevent and control marine pollution. However, marine pollution continues to increase at a rapid rate. This study aims to establish a basic approach that is aimed at combating marine pollution through examining the regulation, prevention and control of marine pollution in South Africa, with a specific focus on the comparative analysis of national and international framework. To this end, a comparison is made between South Africa and other jurisdictions in Africa, Europe, Asia and Latin America. The reason for employing a comparative approach is to learn best practices and finding solutions to the problem of marine pollution. Thus, the international legal framework, regional framework and operations of intergovernmental bodies and non-governmental bodies on the effort of combatting marine pollution were analysed. The objectives of this study were to examine how marine pollution is prevented through the existing legal framework; to identify the reason for the increasing rate of marine pollution despite the existing legal framework promulgated to curb marine pollution; to determine the effectiveness of the newly created IMOrg, juxtaposing it with similar organisations in other jurisdictions and to propose amendments to legislation that prevent and control marine pollution to ensure effective protection of the marine environment. This study was guided by questions such as the following: Do the existing legal frameworks adequately protect and control marine pollution? What is the reason for the increase in marine pollution despite the existing legal framework regulating marine pollution? How effective is the IMOrg in ensuring that South Africa address marine pollution? Is there a need to promulgate more effective legislation preventing and controlling marine pollution? x The study adopted a non-empirical qualitative research design that does not include data collection, questionnaire, systematic data analysis, observations and/or interviews. The study relied on the library materials that include but are not limited to textbooks, reports, legislations, regulations, charters, policies, amendments to the legislation, journals or academic journals, government gazette, constitution, national and international journals. From the materials consulted, the study revealed the existence of a relationship between the national and international legal framework. However, such an existing relationship is not good enough to effectively prevent the marine environment from harm. This is because a plethora of national legislations that regulate the marine environment comprise less stringent measures to deter future contravention. The study recommends amendments to legislations that regulate marine pollution to impose penalties that have a deterrent value on parties. The study advises against the repealing of these legislations.
75

Επιπλέοντα (floating) απορρίμματα σε θαλάσσιες περιοχές της δυτικής Ελλάδος

Δημητρίου, Ευφροσύνη 17 July 2014 (has links)
Στη παρούσα εργασία παρουσιάζονται τα αποτελέσματα της καταγραφής των επιπλεόντων απορριμμάτων σε δύο θαλάσσιες περιοχές της Δυτικής Ελλάδος: (α) το δυτικό Κορινθιακό κόλπο και (β) το βόρειο τμήμα του Στενού Κέρκυρας Ηγουμενίτσας. Ο δυτικός Κορινθιακός κόλπος χαρακτηρίζεται από ισχυρή συμβολή χερσαίων πηγών ρύπανσης (ποταμοί) ενώ οι ναυσιπλοϊακές γραμμές συνιστούν μια αξιοσημείωτη θαλάσσια πηγή ρύπανσης. Η περιοχή του βόρειου στενού Κέρκυρας-Ηγουμενίτσας ελέγχεται κυρίως από θαλάσσιες πηγές ρύπανσης (ναυσιπλοΐα). Το πλαστικό διαπιστώνεται ότι είναι το κυρίαρχο υλικό και στις δύο περιοχές (83%-82%) ενώ οι γενικές συσκευασίες (23%-21%) και οι συσκευασίες ποτών/αναψυκτικών (32%-22%) οι κυρίαρχες χρήσεις τους. Αναπτύχθηκαν μέθοδοι για τον υπολογισμό και την παρουσίαση της επιφανειακής πυκνότητας των απορριμμάτων και οι μετρήσεις αυτές ερμηνεύτηκαν με βάση τις κυρίαρχες πηγές ρύπανσης. Μέθοδοι στατιστικής ανάλυσης εφαρμόστηκαν για την σύγκριση της σύστασης (υλικό) των επιπλεόντων απορριμμάτων. / In this study, the results of the recording of floating litter in two maritime regions of West Greece are presented: (a) in the west Corinthian gulf and (b) in the north part of the narrow region between Corfu and Igoumenitsa. The west Corinthian gulf is characterized by powerful contribution of overland polluted sources (rivers) while the navigational lines institute one notable maritime source of pollution. The region of the north narrow region between Corfu and Igoumenitsa is controlled mainly from maritime sources of pollution (navigation). It is concluded that the plastic is the predominant material in both regions (83%-82%) while the general packaging (23%-21%) and the beverage packaging (32%-22%) their main uses. Methods have beendeveloped for the calculation and the presentation of the surface density of the litter and these measurements have been interpreted according to the predominant sources of pollution. Methods of statistical analysis have been implemented for the comparison of the consistency (material) of the floating litter.
76

An evaluation of HTV-SR insulators with different creepage lengths under AC and bipolar DC in marine polluted service conditions

Elombo, Andreas Iyambo 03 1900 (has links)
Thesis (MScEng)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: The use of high voltage direct current (HVDC) applications has gained enormous popularity for long distance power transmission. This is due to the lucrative benefits offered by this type of power transmission technology when compared to the traditional high voltage alternative current (HVAC). This new shift in the paradigm of power system design has led to the increased interest in the research that focuses on issues relating to the reliability of power supply associated with HVDC. Amongst such issues, insulation coordination has increasingly become a challenging task that continues to receive renewed research focus. It has been convincingly demonstrated, both from field experience and laboratory research, that insulator contamination constitutes a multifaceted phenomenon, especially when transmission voltages ramp up into high operating voltage levels. More so, this is particularly interesting with reference to the increasing applications of high voltage direct current (HVDC). The recently commissioned HVDC power-line in Namibia is one of the major motivations upon which NamPower (Namibia‟s national power utility) has committed financial resources to research on insulator pollution performance. This project was a part of NamPower‟s research initiative – seeking to investigate the phenomena associated with insulator pollution performance under natural pollution environments when energized under both AC and DC excitation voltage types. The significance of this research is especially crucial for HVDC applications given the paucity of research conducted on the DC performance of insulators, under natural pollution environments. This study was conducted at the Koeberg Insulator Pollution Test Station (KIPTS) on the west coast of Cape Town in the Western Cape province of South Africa. KIPTS is an internationally recognized insulator pollution test facility, which is widely used by both insulator manufacturers and academic researchers from many parts of the world. STRI and ABB, both Swedish-based companies, are good examples of international subscribers to the KIPTS research facility. The first objective of this research was to design a suitable DC excitation voltage system for both DC+ and DC- to be used at KIPTS. This apparatus was designed and built at the University of Stellenbosch. The second objective was to conduct a comparative evaluation of the performance of high temperature vulcanized silicone rubber (HTV-SR) power line insulators under AC, DC+ and DC- when subjected to natural pollution conditions at KIPTS. All test insulators were made from the same material and sourced from the same manufacturer – having different creepage lengths. Five different creepage lengths were considered for each excitation voltage – summing up to fifteen HTV-SR test samples. A standard DC glass disc insulator was also installed on each excitation voltage as a control sample. It was therefore envisaged that this study would give rise to new research questions, leading to future explorations on the subject. With reference to weather monitoring and leakage current measurements (using an online leakage current monitoring device - OLCA), a correlation was found to exist between the variations in climatic conditions and the corresponding occurrence of leakage current on the insulator surfaces. High leakage current levels were recorded in summer due to the high pollution levels that were measured in that season (using the equivalent salt deposit density (ESDD) approach). Winter, in contrast, had lower levels of leakage current recorded. This corresponds to a high prevalence of rainfall in winter, which caused occasional natural washing of the insulator surfaces. The leakage current levels for the HTV-SR insulators were of a similar order of magnitude for AC and DC+ and lower for DC-. The harshest pollutants (with high conductivities, as measured with the directional dust deposit gauges (DDDG)) were found to have emanated largely from the south. As a result, most instances of erosion were observed in the southward direction on the test insulators. The electrical discharge activity observations, conducted at night, had revealed that dryband corona (DBC) and dryband discharge (DBD) prominently occurred on the terminating sheaths (both live and ground ends) and bottom side of HTV-SR and glass disc insulators, respectively. This justifies the dominance of erosion that was observed on the terminating sheaths and bottom side of HTV-SR and glass disc insulators, respectively. Flashover events were recorded on the shortest HTV-SR insulator installed on DC+ and the glass disc insulator installed on DC-. All flashover events occurred in summer (the harshest season at KIPTS). Two interesting observations, albeit unexplained, were observed: star-shaped erosion on the shed bottoms of the HTV-SR insulators installed on DC+ and material peel-off at the shed-to-sheath bonding interface of the HTV-SR insulators installed on DC-. These observations therefore require further investigation in order to establish possible explanations. / AFRIKAANSE OPSOMMING: Die gebruik van hoë gelykspanning (HSGS) het baie gewild geword vir kragtransmissie oor lang afstande. Dit is as gevolg van die uitstekende voordele wat hierdie tipe tegnologie teenoor die tradisionele hoë wisselspanning (HSWS) bied. Hierdie paradigmaskuif in die ontwerp van kragstelsels het tot verhoogde belangstelling in navorsing gelei wat betrekking het op aspekte wat verband hou met die betroubaarheid van kragvoorsiening deur HSGS. Van hierdie aspekte word isolasiekoördinasie toenemend ʼn uitdagende taak en navorsing word tans daarop toegespits. Daar bestaan oortuigende bewyse, gebaseer op laboratorium- en veldtoetse dat isolatorbesoedeling ʼn verskynsel met vele fasette is, veral wanneer hoër spannings gebruik word. Dit is in „n meerdere mate van belang met verwysing na toepassings van HSGS. Die onlangs inbedryfgestelde HSGS kraglyn in Namibië is een van die hoofmotiverings vir die verskaffing van geldelike steun deur NamPower (Namibië se nasionale kragvoorsiener) vir navorsing oor die besoedelingsprestasie van isolators. Hierdie projek is deel van NamPower se navorsingsinisiatief om verskynsels betreffende die besoedelingsprestasie van isolators in natuurlik-besoedelde omgewings te ondersoek, onder WS en GS-bekragtiging. Die betekenis van hierdie navorsing is veral belangrik vir die HSGS-toepassings in die lig van die skaarsheid van navorsing oor die GS-prestasie van isolators in natuurlik-besoedelde omgewings. Hierdie studie is gedoen by die Koeberg isolatorbesoedelingstoetsstasie (KIPTS) aan die weskus van die Wes-Kaap. KIPTS is 'n internasionaal-erkende toetsfasiliteit en word algemeen gebruik deur beide isolatorvervaardigers en akademiese navorsers uit baie dele van die wêreld. STRI en ABB, albei Sweeds-gebaseerde maatskappye, is die goeie voorbeelde van die internasionale gebruikers van die KIPTS navorsingsfasiliteit. Die oogmerk van hierdie navorsing was om eerstens 'n geskikte GS-kragbron vir beide die GS+ en die GS- vir gebruik by KIPTS te ontwerp. Hierdie apparaat is ontwerp en gebou deur die Universiteit van Stellenbosch. Tweedens is 'n vergelykende evaluering van die prestasie hoë temperatuur gevulkaniseerde silikoon (HTV-SR) kraglynisolators onder WS, GS+ en GS– onder natuurlike besoedeling by die KIPTS uitgevoer. Alle toetsisolators is van dieselfde materiaal gemaak en is afkomstig van dieselfde vervaardiger, maar het verskillende kruipafstande. Vyf verskillende kruipafstande is gebruik vir elke tipe spanning  'n totaal van vyftien HTV-SR toets monsters. 'n Standaard GS glasisolatorskyf is ook vir elke spanning as' n kontrolemonster geïnstalleer. Dit kan dus verwag word dat hierdie studie aanleiding sal gee tot nuwe navorsingsvrae, wat kan lei tot verdere toekomstige ondersoeke oor die onderwerp. Met verwysing na die monitering van die weer en die lekstroommetings (met behulp van 'n aanlyn-lekstroommoniteringstoestel - OLCA), is 'n korrelasie gevind tussen die variasie in klimaatstoestande en die ooreenstemmende voorkoms van lekstroom op die isolator- oppervlaktes. Hoë lekstroomvlakke is waargeneem in die somer, as gevolg van die hoë besoedelingsvlakke wat in daardie seisoen gemeet is (met behulp van die ekwivalente soutneerslag-digtheid (ESDD) metode). In die winter, in teenstelling, is die laagste vlakke van lekstroom aangeteken. Dit stem ooreen met 'n hoë voorkoms van reënval in die winter, wat die isolatoroppervlaktes van tyd tot tyd natuurlik gewas het. Die lekstroomvlakke op die HTV-SR isolators was van soortgelyke ordegrootte vir WS en GS+ maar laer vir GS-. Dit is bevind dat die ergste besoedelingstowwe, met 'n hoë geleiding, soos gemeet met die rigtingsensitiewe stofneerslagsmeters (DDDG), hoofsaaklik uit ʼn suidelike rigting kom. As gevolg hiervan, is die meeste gevalle van erosie aan die suidekant van die toetsisolators waargeneem. Die waarneming van elektriese ontladingsaktiwiteit in die nag, het aan die lig gebring dat droëbandkorona (DBC) en droëbandontladings (DBD) prominent voorgekom het op die skedes aan die uiteindes (beide lewende en grond kante) en onderste kant van HTV-SR en glasskywe, onderskeidelik. Oorvonkings is waargeneem op die kortste HTV-SR isolator op GS+ en op die glasisolator op GS-. Al die oorvonkings het in die somer (die ergste seisoen by KIPTS) voorgekom. Twee interessante, dog onverklaarbare, verskynsels is waargeneem: stervormige erosie aan die onderkante van die skerms van die HTV-SR isolators op GS+ en material-afskilfering by die skerm-skede tussenvlak van die HTV-SR isolators op GS-. Hierdie verskynsels vereis verdere ondersoek ten einde moontlike verklarings vas te stel.
77

Um Sistema de Vigilância Marítima Aplicado à Poluição Marinha por Petróleo no Brasil / A Maritime Surveillance System Applied to Marine Pollution by Oil in Brazil

Luporini, Guido 17 December 1996 (has links)
O principal objetivo deste trabalho é fazer uma análise exploratória a partir da bibliograa disponível, sobre o problema da poluição marinha no Brasil, em particular, da causada por derramamento de óleo. Analisando as principais fontes de poluição, no mundo e no Brasil, seus respectivos impactos ambientais e as metodologias de prevenção, controle, e de resposta adotadas, foi proposto um sistema de vigilância marítimo, capaz de vigiar grandes áreas independentemente das condições de luminosidade e de tempo. São apresentadas duas propostas, ambas baseadas em técnicas de sensoriamento remoto por radar, mas que se diferem principalmente pelas técnicas de aquisição de imagens e de processamento dos dados. Uma já consagrada mundialmente, a RAR (Real Aperture Radar ), e, a outra, a SAR (Synthetic Aperture Radar), que além de operar sob as condições adversas acima mencionadas, é capaz também de obter ótima resolução espacial independentemente da distância do sensor e do alvo. Este estudo demonstra a ineficiência das metodologias adotadas aqui no Brasil, para detectar, avaliar e combater óleo no mar e alerta para as vantagens de se utilizar técnicas modernas de vigilância marítima. / The main objectives of this work are to make a exploratory analysis from the available readings, about the maritime pollution problem in Brazil, particulary that from oil spills. Analyzing the main sources of oil pollution around the world and in Brazil; their environmental impacts, and prevention, control and response methods adopted, a radar maritime surveillance system was proposed to investigate large areas, under rain or sun, at day and night time, agaist oil spills. It is presented two kind of sensor: the first one is RAR (Real Aperture Radar) wich is well known world wide, and the other one is the SAR (Synthetic Aperture Radar), wich is well suited to have good spacial resolution at any distance from the target. This work shows the needs to solve those problems related to maritime pollution in Brazil and the advantages to have a modem system to patrol the sea.
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Contaminação e toxicidade de microplásticos em uma área de proteção marinha costeira / Microplastics contamination and toxicity in a coastal marine protected area

Silva, Pablo Pena Gandara e 23 August 2016 (has links)
Os plásticos têm trazido grandes benefícios aos humanos, sendo utilizados em diversas atividades como em aplicações médicas, entretenimento e na indústria de alimento. O uso crescente de plástico e seu descarte não adequado têm contribuído para o acúmulo deste detrito no meio ambiente, em especial nos oceanos onde tendem a acumular. Dentre os detritos de plástico de maior importância atualmente estão os microplásticos, que são partículas de plástico de tamanho entre 1 μm e 5 mm. Os principais riscos que os microplásticos oferecem são sua grande capacidade de persistência e dispersão no ambiente marinho, sua grande afinidade por poluentes persistentes orgânicos, sua a ingestão pela biota e a transferência para a teia trófica marinha. Dentre os ambientes marinhos mais impactados por microplásticos, estão as praias arenosas, onde estas partículas tendem a acumular após encalharem ao serem trazidas pelo mar. Este estudo teve como objetivo avaliar a contaminação por microplásticos em uma praia de uma área de proteção marinha costeira e avaliar a toxicidade de pellets virgens e coletados nesta praia no desenvolvimento embriolarval de mexilhão marrom Perna perna. Foram realizadas coletas de microplásticos entre o período de fevereiro de 2014 a fevereiro de 2015 na praia de Paranapuã em duas regiões do perfil da praia (linha de maré alta e supralitoral). As partículas foram analisadas individualmente em laboratório e quanto a composição de seu polímero por Espectrofotômetro de Infravermelho por Transformada de Fourier (FT-IR). Os resultados sugerem que a poluição por microplásticos na praia de Paranapuã ocorre ao longo do ano inteiro, porém variando em concentração ao longo do tempo e com um padrão de distribuição espacial irregular na praia. A concentração de microplásticos está aparentemente relacionada com a direção do vento, tendendo a ser maior quando a direção do vento é a favor da praia. A concentração de microplásticos na praia de Paranapuã (4,72 microplásticos/m²) é próxima àquela encontrada em outras praias no mundo e da região. Os experimentos de toxicidade demonstraram que tanto pellets de plástico virgens como aqueles coletados na praia inibem o desenvolvimento embriolarval de mexilhão marrom. Entretanto, os pellets coletados na praia mostraram uma alta toxicidade que resultou numa porcentagem de larvas anormais ou mortas de 100%, significativamente superior aos pellets virgens que foi de 23,5%. Acredita-se que a diferença de toxicidade entre os pellets virgens e coletados na praia pode ser causada por contaminantes adsorvidos na superfície dos pellets coletados no campo. Os resultados deste estudo sugerem que praias de áreas de proteção marinha costeira próximas a zonas urbanas e regiões portuárias apresentam risco de contaminação por plásticos. Apesar de terem acesso restrito a humanos, os microplásticos entram nestas praias através do ambiente marinho, podendo causar efeitos adversos na fauna destes ambientes. As informações deste trabalho contribuem para a melhor compreensão dos efeitos da contaminação de ambientes costeiros por microplásticos, fornecendo informações básicas para o desenvolvimento de políticas públicas voltadas para uma gestão deste tipo de poluição em áreas de proteção ambiental. / Plastics have great benefits to humans, used in various activities such as medical applications, entertainment and food industry. The increasing use of plastic and your inappropriate disposal have contributed to the accumulation of this debris in the environment, particularly in the oceans where they tend to accumulate. Among the most important plastic waste are the microplastic which are plastic particles of size between 1 μm and 5 mm. The main risks that microplastics offer are your large capacity persistence and dispersal in the marine environment, your great affinity for persistent organic pollutants and their ingestion by biota and transfer to the marine food web. Among the marine environments most impacted by microplastics are sandy beaches where these particles tend to accumulate after carried by sea. This study evaluate the contamination by microplastics on a beach of a coastal marine protected area, and assess the virgin pellets toxicity and collected on this beach in embryo-larval development of brown mussel Perna perna. Microplastics samples were collected in the period from February 2014 to February 2015 on the beach of Paranapuã in two regions of the beach (high tide line and supralittoral). The particles were analyzed individually in the laboratory and the composition of your polymer was identified for Fourier Transform infrared spectroscopy (FT-IR). The results suggest that pollution microplastics in Paranapuã beach is continuous in entire year, but varying in concentration over time and with a pattern irregular of spatial distribution on the beach. The microplastics concentration is apparently related to the wind direction, tends to be higher when the wind direction is downwind. The concentration of microplastics on the beach Paranapuã (4.72 microplastics/m²) is similar to other beaches in the world. The toxicity experiments showed that both virgin plastic pellets as those collected on the beach inhibit embryo-larval development of brown mussels. However, the pellets collected at the beach showed high toxicity resulting in abnormal or percentage of dead larvae 100%, significantly higher than for virgin pellets, which was 23.5%. It is believed that the difference in toxicity between the virgin pellets and collected on the beach can be caused by high concentration of adsorbed contaminants on the surface of the pellets collected in the field. The results of this study suggest that beaches areas of coastal marine protection near urban areas and port areas have high risk of contamination by plastics. Although this beach has access restricted to humans, microplastics enter these beaches through the marine environment, potentially causing adverse effects on the local fauna of these environments due to your high toxicity. The information from this study contribute to a better understanding of the effects of contamination of coastal environments by microplastics, providing basic information for the development of public policies for management of this type of pollution in the areas of environmental protection.
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\"Estudo hidrogeoquímico, sedimentológico e de foraminíferos em áreas da Baixada Santista, SP, submetidas a disposição oceânica de esgotos\" / \"Study hydrogeochemical, sedimentological and of foraminifers in regions of the Baixada Santista, SP, submitted to oceanic sewage disposal\"

Teodoro, Andreia Cristiane 30 March 2006 (has links)
O presente estudo analisou a influência do emissário submarino de esgoto sobre as associações de foraminíferos, regionalmente (macroescala) e localmente (microescala), na Enseada do Guarujá e Baía de Santos. Foram analisadas, em macroescala, 26 amostras coletadas na Enseada do Guarujá e 24 na Baía de Santos. As amostras foram obtidas no inverno de 1997 e verão de 1998. Em microescala foram coletadas 10 amostras próximo aos difusores do emissário de Santos em abril de 2004. Em cada estação foram obtidos dados hidrográficos e sedimentológicos. Foi analisada a composição das associações de foraminíferos, descrevendo as variações espaciais e temporais em relação as variáveis ambientais. Em macroescala, a influência da disposição oceânica não foi conclusiva, devido à baixa densidade da biocenose. Entretanto, análises das tanatocenoses (tafonômicas e morfométricas) e dos dados sedimentológicos possibilitaram distinguir dois setores morfossedimentares na Enseada do Guarujá e na Baía de Santos. O primeiro setor localizado na porção oeste possui sedimentos arenosos, com baixos teores de C e N, baixa densidade e riqueza de foraminíferos. O segundo localiza-se nas porções central-leste e apresenta predominância de lama, com altos teores de C e N e elevada densidade e riqueza de foraminíferos. Os resultados das razões C/S permitiram detectar sedimentos anóxicos próximo ao emissário da Enseada do Guarujá no inverno, e na Baía de Santos no inverno e verão. Em microescala, os dados hidrogeoquímicos e sedimentológicos indicaram que a área circunjacente aos difusores está hipereutrofizada, apresentando altos teores de C, N, P e S tanto na água como nos sedimentos. As baixas razões C/S indicaram presença de ambiente com características fortemente redutoras. Em microescala, a análise da composição e distribuição das biocenoses indicou que as características ambientais da Baía de Santos estão influenciando diretamente as associações de foraminíferos, diminuindo os valores de densidade e riqueza. Desse modo conclui-se que o pré-tratamento dos efluentes de Santos é precário, tornando a região dos difusores mais um grande foco de poluição na baía. / The present study analyzed the influence of submarine sewage outfall upon foraminifera assemblages on a regional (macro scale) and local (micro scale), in Guarujá and Santos Bay. Fifty samples were analyzed at the macro scale, twenty six from Guarujá and twenty four from Santos Bay. The samples were collected in winter 1997 and summer 1998. At the micro scale, ten samples were collected close to sewage outfall diffusers in Santos Bay in April 2004. At each station hydrographic and sedimentological data were obtained. Spatial and seasonal variations in the composition of foraminifera assemblages were related to environmental variables. Analysis of the influence of oceanic sewage disposal at the macro scale was inconclusive due to the low density of live foraminifera. Thanatocenosis (taphonomic and morphometric analyses) and sedimentological analyses revealed two morphosedimentary sectors in Guarujá and Santos Bay, one in the western portion of the study area with sandy sediments, low C and N, low density and low richness of foraminifera, and the other, in the east-central portion, with predominance of mud, higher C and N, higher density and richness of foraminifera. C/S ratios permitted detection of anoxic sediments near sewage outfall in Guarujá in the winter, and in Santos Bay in both the winter and summer. At the micro scale, hydrogeochemical and sedimentological data indicated that area close to the diffusers is highly eutrofized, with high contents of C, N, P and S in both the water and the sediment. The low C/S ratios of the sediment indicated highly reducing conditions. At the micro scale the biocenosis composition and distribution indicated that environmental characteristics of Santos Bay directly influence the foraminifera assemblages. The results also suggest that the (pre) treatment of Santos sewage is inefficient, transforming the area of the diffusers into one more major focus of pollution in the bay.
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Efeitos de microplástico na fisiologia do mexilhão Perna perna (Bivalvia: Mytilidae) / Microplastics effects on the physiology of the Mussel Perna perna (Bivalvia:Mytilidae)

Ascer, Liv Goldstein 18 November 2015 (has links)
Dentre as diferentes poluições presentes nos oceanos, o plástico é provavelmente, aquele que leva aos maiores impactos ambientais, sendo encontrado de praias e manguezais à giros no meio dos oceanos. Os macroplásticos, cujo tamanho é superior a 5mm, são maiores em volume e provocam um impacto socioambiental importante, porém os microplásticos, fragmentos menores que 5mm, estão em maior quantidade e podem provocar danos em organismos marinhos filtradores como mexilhões e ostras. Apesar da sua grande presença nos oceanos, ainda não se estabeleceu com clareza se causam efeitos somente físicos, por um aumento de material particulado não orgânico ingerido, ou se seus efeitos podem ser de origem química, devido à quantidade de contaminantes que possuem. Para estudar o impacto que essas partículas têm em organismos filtradores, o mexilhão Perna perna, espécie bioindicadora abundante na costa brasileira, foi exposto a partículas de polietileno encontradas em cosméticos nacionais. O microplástico foi adquirido diretamente da indústria e precisou ser identificado. A análise de FT−IR mostrou que o plástico era polietileno de baixa densidade. Os organismos então foram expostos ao polietileno, virgem ou lixiviado, em duas concentrações (0,5 g⁄L e 2,5 g⁄L) por diferentes períodos (12,24,48,96 e 144 horas). Após os experimentos, os mexilhões foram coletados e dissecados e a resposta de seis biomarcadores foi analisada: O Tempo de Retenção do Vermelho Neutro nos hemócitos, Danos ao DNA e Lipoperoxidação nas brânquias e os níveis de três proteínas de estresse (AIF−1, pP38−MAPK e HSP−70) nas glândulas digestivas. Todos os biomarcadores foram afetados pela exposição ao polietileno, porém um padrão no resultado não pôde ser observado. Os fatores de exposição analisados (Concentração, Período e Tratamento do Plástico) individualmente, ou combinados, levaram a respostas diferentes e até mesmo opostas em alguns casos. A coleta de indivíduos de P. perna in situ na região do Porto de Santos mostrou que todos os bancos naturais possuem organismos contaminados. Os resultados deste trabalho mostram que a fisiologia do mexilhão P. perna é modificada após a exposição aguda ao polietileno. Um maior número de biomarcadores deve ser analisado futuramente para elucidar quais vias estão efetivamente sendo ativadas ou inibidas. O alto nível de contaminação dos mexilhões da região do porto de Santos é um fator alarmante que deve ser discutido pela sociedade com o intuito de se criar soluções para o problema da poluição por plástico nos oceanos antes que este afete a saúde humana. / Among all different pollutants, plastic debris is one of the main environmental impacts, being found from beaches and mangrove to gyres in the middle of the oceans. Macroplastics, with size above 5mm, are larger in volume and are an important social and environmental problem, but microplastics, fragments less than 5mm can be most harmful for filter feeding animals such as mussels and oysters. However, it is still debatable if its effects are physical, due to the increase in indigestible material; or chemical, due to plastic additives such as phthalates or PCBs. To study the impact that these particles can have in those animals, the brown mussel Perna perna (Bivalvia) an abundant and an organism easy to maintain in the laboratory, was exposed to virgin or leached polyethylene (PE) microbeads, used as abrasives in Brazilian cosmetics. Polyethylene was acquired directly from the industry and therefore needed to be identified. Analysis of FT−IR showed that the plastic was Low Density Polyethylene. The microplastic exposure had two concentrations (0.5 and 2.5g⁄l) and different periods of time (12, 24, 48, 96 and 144 hours). After the experiment, the organisms were dissected and the levels of six biomarkers were analyzed: Neutral Red Retention Time by the Hemocytes, Lipid Peroxidation and DNA Damages in the Gills and the response levels of three stress proteins (pP38−MAPK, AIF−1 and HSP−70) in the Digestive Glands. All biomarkers were affected by the PE exposure, but the results did not follow a pattern. The exposure factors analyzed (Concentration, Period of Time and Plastic Treatment), alone or combined, led to different and sometimes opposite responses. In Situ collected samples in the Santos Harbour area showed that all natural mussel\'s beds analyzed had microplastics contaminated mussels. The results of this work showed that microplastics acute exposure in P. perna modifies its physiology. More biomarkers should be used to clarify which pathways are being activated or inhibited. The high levels of contamination of important commercial mussel\'s beds in the Santos Harbour area, is an alarming sign for the community, that should start working together to solve the plastic pollution problem in our oceans before starts to affect human health.

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