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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.
31

Complexity of Air Freight Networks : A Regional focus on Jönköping

Akor, Petrina, Bulic, Zlata January 2011 (has links)
Companies face competition that comes at them from different directions in the current environment of globalization, deregulation and the push for greater mass customization of products, which still can be differentiated from other products and services. A large number of companies have outsourced a large percentage of their non-core activities in order to concentrate on their core competencies with transportation of their goods being one of the aspects that they have outsourced. Companies are faced with shorter lead times, inaccurate forecasts, unexpected delays in production and need to seek out alternative transportation modes in order to get their goods to market on time. Transportation by air ends up being the best choice to handle requirements of time sensitivity and the transportation of high value goods. The purpose of this thesis was to investigate how the air freight supply chain and network that is in place in the Jönkoping region is constructed; in addition to seeking out information in regards to the type of air freight goods being transported into and out of the region; along with the buying behavior and promotion strategies utilized in the promotion of air freight within the region of Jonkoping. The conclusions from this thesis show that there are a number of key actors (integrators and freight forwarders) involved in the air freight network within the Jönköping region. A number of them indicated that the actors they mainly interacted with, in terms of activity links and resource ties, were limited to the airports that were outside of the Jönköping region. There were a few of the actors in terms of integrators that did interact with the Jönköping airport in a capacity that was greater than other actors. In terms of the type of air freight goods that were transported into and out of the region spare parts made up a major portion of the goods transported, followed by clothing and textiles, and other mechanical industry products. The promotion of air freight mostly performed by integrators to their customers is done in terms of emphasizing reliability, punctuality, regularity and security to their customers.
32

Tillsammans är vi starka : en studie om det indirekta exportsamarbetet i en piggybackingprocess

Mared, Sofie, Nordström, Sofia January 2012 (has links)
Vi har i den här studien valt att undersöka problematiken mindre och medelstora företag upplever med en indirekt marknadskontakt. Med hjälp av en kvalitativ forskningsmetod och en flerfallstudie har vi intervjuat fyra företag och på så sätt granskat hur relationerna mellan företagen ser ut med syfte att undersöka företagens möjlighet att säkerställa sin identitet i en piggybackingprocess. Vidare har vi granskat möjligheten till att uppnå ett balanserat beroendeförhållande, förutsättningarna att skapa egna kundrelationer och stärka företagets varumärke, detta för att vidare kunna ge rekommendationer för framtida samarbetens utformande. I den teoretiska referensramen har vi huvudsakligen inriktat oss på etableringsstrategin indirekt export med inriktning på piggybacking. Vidare belyser vi internationaliseringsteorier, kundrelationer samt varumärken. Därefter har vi integrerat samtliga teorier i en teoretisk syntes som legat till grund för vår analys. Det empiriska kapitlet behandlar den information som tillhandahållits genom intervjuer med fallföretagen. I analyskapitlet diskuteras och analyseras den teoretiska referensramen tillsammans med det empiriska utfallet, vidare hålls en diskussion gällande problematiken kring indirekt export och dess utmaningar. Från vår analys framgår det att genom att vara medveten om de svårigheter som uppkommer med indirekt export, piggybacking, finns det möjlighet att reducera riskerna, dock ej utesluta. Vi har således konstaterat att en kundrelation och ett starkt varumärke kan bidra till att företaget kan säkerställa sin identitet. Med utgångspunkt i vår analys kan vi härmed dra slutsatsen att företag som arbetar aktivt med att klargöra sina mål med samarbetet. Genom att arbeta med att förbättra sina kundrelationer och försöka stärka sitt stärka varumärke kan detta bidra till ett ömsesidigt beroendeförhållande och på så vis stärka företagets identitet på en internationell marknad.
33

Swedish CSR with Chinese Characteristics : A case study of four Swedish firms' CSR engagement in their Chinese supply chains

Magnusson, Frida, Pettersson, Kristoffer January 2011 (has links)
ABSTRACT The purpose of this thesis is to analyze, describe, and explain how Swedish firms implement CSR in their Chinese supply chains. In order to reach the intention of the thesis a case study of four Swedish firms operating in China has been conducted which involved personal interviews in the field. The theoretical framework contains a description of the stakeholder theory, the legitimacy theory, the CSR pyramid, the ARA-analysis, and theory on business relations which all are relevant to the phenomenon studied and the research questions. The empirical findings include the case firms view on stakeholder pressure, their CSR related activities in their supply chains, and how supplier relations are managed. In the analysis the theoretical framework is connected to the empirical findings. The analysis consist of how the case firms deal with stakeholder pressure, to what extent they take social responsibility in their Chinese supply chains, and how their supplier relations are managed concerning CSR. Our analysis shows that the firms perceive their customers to be the main pressure to engage in CSR. However, the analysis further demonstrates that the case firms find it difficult to comply with the responsibilities demanded by their customers in the Chinese context. Moreover, the analysis will touch upon how supplier relations are managed when implementing CSR. The conclusion of the thesis shows that Swedish companies implement CSR in their Chinese supply chains by adding Chinese characteristics, meaning adapting the expected responsibilities to the Chinese context. The thesis will end with recommendations for further research in the field of CSR in firms’ supply chains in emerging economies.
34

The Utility of Digital Aerial Surveys in Censusing Dipteryx Panamensis, the Key Food and Nesting Tree of the Endangered Great Green Macaw (Ara Ambigua) in Costa Rica

Chun, Sara Lai Ming 31 October 2008 (has links)
<p>Remote sensing technologies offer an innovative way to study tropical forests and complement research from forest inventory plots. From a logistic standpoint, remote sensing mitigates some of the physical, political, and economic challenges that complicate terrestrial studies of tropical forests. From a biological standpoint, remotely sensed data can elucidate ecological phenomena and dynamics of tropical forests that may be challenging to observe on the ground. I conducted a digital aerial survey during the peak blooming period for <em>Dipteryx panamensis</em>. <em>D. panamensis</em> is a canopy emergent, keystone tree species within the lowland Atlantic forests of Costa Rica. The aerial survey occurred over Maquenque National Wildlife Refuge, which is situated in the proposed San Juan-La Selva Biological Corridor. Maquenque was decreed in 2005 to protect the last breeding habitat for the endangered Great Green Macaw (<em>Ara ambigua</em>) in Costa Rica. The Great Green Macaw depends on <em>D. panamensis</em> as its primary food and nesting resource. However, because of Costa Rica's complex deforestation history, the Great Green Macaw remains imperiled due to habitat fragmentation, degradation, and loss. Only 25 to 35 breeding pairs and 250 individuals likely persist in the country. My research had three main objectives. First, I evaluated a classification technique that capitalized on the unique spectral signature of blooming <em>D. panamensis</em> in order to detect this species using a pattern recognition approach. Second, I determined the landscape density and distribution of this tree species using results from the aerial survey and classification. I also noted environmental factors predicting potential <em>D. panamensis</em> habitat using a classification and regression tree (CART) model, and I subsequently calculated how much potential habitat exists in Costa Rica. Third, I identified environmental conditions that indicate potential breeding habitat for the Great Green Macaw using a CART model, and I calculated how much potential breeding habitat exists in Costa Rica. Results of the classification work indicate that <em>D. panamensis</em> can be identified based on its unique spectral signature. In particular, the IHS (intensity, hue, saturation) color space was effective at resolving this tree. Results of the density analysis suggest that canopy emergent <em>D. panamensis</em> trees occur at densities as high as 2 trees/hectare. This work demonstrates that <em>D. panamensis</em> exists in denser patches than previously determined from forest inventory plots. Environmental conditions that will support high densities of <em>D. panamensis</em> habitat occur between 45 and 125 meters in elevation and on soil with an acid and clay profile. Nearly 240,000 hectares could support high density patches of <em>D. panamensis</em> in Costa Rica. Potential Great Green Macaw breeding habitat is defined by the density of <em>D. panamensis</em> trees within its 550-hectare breeding territory. Approximately 67,000 hectares of Great Green Macaw breeding territory exist in Costa Rica. Ultimately, the conservation of both <em>D. panamensis</em> and the Great Green Macaw in Costa Rica may require a multinational partnership between Costa Rica and Nicaragua.</p> / Dissertation
35

Payair – Reaching for critical mass

Kock, Gustav, Rådelius, Max January 2014 (has links)
The mobile payments industry has in recent years experienced large growth and rapid changes. Several different actors are trying to capture the market, to get enough users of their system to reach critical mass. This study investigates how a small Swedish mobile payments company have utilized its business network in their strive to reach critical mass, both in their domestic market and internationally.  The study intends to describe how the company has developed its network and which stages of the network development that have been the most important.  We utilize the ARA-model to analyze the business network and the Uppsala Model and born global theory to define how the company has internationalized.  Our main results indicate that our case company has the mindset of a born global but the particulars of the industry have forced it to internationalize following the Uppsala Model. The development of the business network have to a large part been dependent of the initial activities since this builds the credibility needed to work with large actors.  Moreover the business network is found to not only help the company, but to be essential for their plans on reaching critical mass.
36

O agro andino, um outro desenvolvimento e a sustentabilidade

Olarte Calsina, Saul January 2017 (has links)
A realidade andina, e particularmente a realidade agraria andina, desde a migração ilegal e intrusa do k´arusuyu (europeu), se tem manifestado distante às ações, políticas ou visões de desenvolvimento pensadas fora de seu espaço, aspecto que derivou na busca do próprio desenvolvimento: Sumak Kawsay, esse próprio, contextualizado no Etnodesenvolvimento. O estudo argumentou respostas a esse real diferente, aprofundado desde outro olhar, o pensar próprio, desde Guaman Poma de Ayala (1615) e Santa Cruz Pachacuti (1613), ambos, plasmam nas sus imagens a relação entre seres de distintos espaços, uma relação Ser-Ser, o não ser não, elemento que pervive desde uma complexidade no real atual. Nesse contexto, para entender a realidade agraria andina, se considerou dois espaços de realidades não isoladas das dinâmicas totais: os distritos de Orurillo e Sicuani, no Qollasuyo; utilizando como método o Teqsimuyuq Kawsaynin – Hinantin Suyupi (TK-HS): convivência com tudo, em todo lugar. Os resultados mostram que, as realidades andinas perviven com outra própria visão do eruivalente ao “desenvolvimento”, refletida nas tecnologias, saberes, ciencias, pensares, infraestruturas, etc., que vem desde antes e até o Tahuantinsuyo, transitando logo a o Andino, caminhando dentro do bom governo como em tempos do Inca, ao não governo do k´arusuyu, seguido logo pelo musoqk´ara, até a atualidade. Nesse entender, a realidade agraria andina reflete continuação do Tahuantinsuyo, desde seus próprios pensares, o próprio termo andino é referente. O próprio desenvolvimento desde um pensar andino, é a relacao de convivencia com o agro, parte da co-existência, relacao total não encaixada no ritual ou cerimonial só. O agro não é atividade, recursos, etapa a superar, nem é inferior, é um igual com que se convive, assim se chega à convivencia equilibrada, Sumak Kawsay, o desejo do desenvolvimento sustentável: emergencia do “desenvolvimento” ocidental. Nesse entender o agro andino representa o desejo u objetivo da agricultura sustentavel, sendo que, esta ultima requer reconstruir suas bases epistemológicas se quer converter-se em realidade. / The Andean reality, and particularly the Andean agrarian reality, since the illegal and intrusive migration of the k'arusuyu (European), has manifested itself far from the actions, policies or visions of development thought outside of its space, an aspect that led to the search of the own development: Sumak Kawsay, this very one, contextualized in Ethnodevelopment. Guaman Poma de Ayala (1615) and Santa Cruz Pachacuti (1613), both of them, portray in their images the relation between beings of different spaces, a relation Being-Being, not being not exist, element that survives from a complexity in the current real. In this context, to understand the Andean agrarian reality, two spaces of realities not isolated from the total dynamics were considered: the districts of Orurillo and Sicuani, in Qollasuyo; using as method the Teqsimuyuq Kawsaynin - Hinantin Suyupi (TK-HS): coexistence with everything, everywhere. The results, show that the Andean realities survive with another vision of the erudent to the "development", reflected in the technologies, knowledge, sciences, thought, infrastructures, etc., that comes from before and until Tahuantinsuyo. Transiting soon to the Andean, walking within the good government as in times of the Inca; to the non-government of k'arusuyu, followed later by the musoqk'ara, until the present time. In this understanding, the Andean agrarian reality reflects the continuation of the Tahuantinsuyo, from its own thoughts; the Andean term itself is referent. The development itself from an Andean thinking, is the relation of coexistence with the agro, part of the co-existence, total relation not fit in the ritual or only ceremonial. Agro is not activity, resources, stage to be overcome, nor is it inferior, it is an equal with which it coexists, thus comes to a balanced coexistence, Sumak Kawsay, the desire for sustainable development: emergence of Western "development". In this understanding, the Andean agriculture represents the goal of sustainable agriculture, and the latter requires reconstructing its epistemological basis if it is to become a reality.
37

Proteinograma sérico e parâmetros hematológicos de papagaios-verdadeiro (Amazona aestiva) e araras-canindé (Ara ararauna) de cativeiro

Proença, Laila Maftoum [UNESP] 07 November 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:31:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-11-07Bitstream added on 2014-06-13T20:01:48Z : No. of bitstreams: 1 proenca_lm_dr_jabo.pdf: 902738 bytes, checksum: 24e7df923f783deb867689e53ad7c409 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Os Psittaciformes representam uma das ordens de aves mais comumente criadas como animais de companhia. A identificação de doenças em aves de companhia pode respresentar um desafio diagnóstico. A carência de dados a respeito de perfis normais para psitacídeos, como hemograma e perfil bioquímico sérico, são notórias no país. Pesquisas dessa natureza podem contribuir no diagnóstico e prognóstico de importantes doenças de aves criadas em cativeiro e de vida livre, dentre elas a clamidiose, zoonose de alta prevalência e com diagnóstico definitivo relativamente difícil, devido à complexa fisiopatogenia da infecção causada por Chlamydophila psittaci. Este estudo objetivou a realização do hemograma e o perfil bioquímico, inclusive as concentrações de imunoglobulinas e de proteínas de fase aguda, pela técnica de eletroforese em gel de poliacrilamida contendo dodecil sulfato de sódio - SDS-PAGE, de papagaios-verdadeiro (Amazona aestiva) e araras-canindé (Ara ararauna), de cativeiro, clinicamente saudáveis e o proteinograma em SDS-PAGE de papagaios-verdadeiro e araras-canindé de cativeiro positivos ou negativos para Chlamydophila psittaci. Os valores hematológicos, incluindo o hemograma e bioquímica sérica, foram determinados para ambas as espécies, demonstrando estar entre os intervalos de referência para as mesmas. O proteinograma sérico em SDS-PAGE permitiu a detecção de até 33 proteínas no traçado eletroforético de papagaios-verdadeiro sadios, e até 29 proteínas no traçado eletroforético de araras-canindé sadias. O proteinograma permitiu visualizar diferenças biologicamente importantes nas concentrações das proteínas de fase aguda e imunoglobulinas de papagaios-verdadeiro e araras-canindé positivos e negativos para C. psittaci, principalmente quanto a evidência da proteína de peso molecular 21 kDa, presente somente em papagaios-verdadeiro positivos... / Psittaciformes represent one of the most common orders of birds bred as pets. Disease identification in birds can represent a diagnostic challenge. The lack of data about normal ranges for psittacines, like hemogram and serum biochemistry are notorious in this country. Research regarding this subject can contribute to the diagnosis and prognosis of important diseases in captive and free-range birds. One of these diseases is clamidiosis, a zoonotic disease with high prevalence and with definitive diagnosis relatively difficult, because of the complex fisiopatogeny of the infection caused by Chlamydophila psittaci. The objective of this study was to determine the hemogram and serum biochemistry, including serum acute phase proteins and imunoglobulins using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), of clinically healthy, adult, captive blue fronted amazon parrots (Amazona aestiva) and blue and gold macaws (Ara ararauna) and the SDS-PAGE proteinograma of blue fronted amazon parrots and blue and gold macaws testing positive and negative for clamidiosis. The hematological values, including hemogram and serum biochemistry, were determined for both species, showing to be between the normal reference ranges. The SDS-PAGE proteinogram allowed visualization of up to 33 proteins of healthy blue fronted amazon and up to 29 proteins of healthy blue and gold macaws. The proteinogram allowed visualization of important biological differences in the concentrations of acute phase proteins and imunoglobulins of blue fronted amazon parrots and blue and gold macaws, testing positive and negative for clamidiosis. Present only in parrots positive for clamidiosis was the molecular weight 21 kDa protein
38

Prospecção de locos microssatélite e análise da variabilidade genética em uma população do Mato Grosso do Sul, visando a conservação da Arara Vermelha, Ara chloroptera (Psittacidae, Aves)

Martins, Julia Mara 30 November 2007 (has links)
Made available in DSpace on 2016-06-02T20:21:21Z (GMT). No. of bitstreams: 1 2146.pdf: 1671091 bytes, checksum: f97eeea1da741ae03253f4c73616f003 (MD5) Previous issue date: 2007-11-30 / Universidade Federal de Minas Gerais / Several Psittacidae species, as those of Ara genus, have biological characteristics frequently associate with extinction risk. These include corporal size, specialized food preferences, low rate of population growth, restricted habitat and geographic dispersal. Genetic studies are important tools because they provide helpfulness for the conservation of those species with high extinction risks. Microsatellite markers are frequently used in population and conservation studies, and are usually isolated from the genome of the targeted species or of the related species. The main goal of this study was evaluate the genetic variation of Ara chloroptera inhabiting a touristic area, named Buraco das Araras, in Mato Grosso do Sul. For such way, six microsatellite loci were isolated and characterized and were useful to assess the genetic variation of Ara chloroptera and presented also a good value to study other Neotropical parrot. The studied population showed a genetic variation value comparable to that previously observed in a non endangered congeneric species. A significant Hardy-Weinberg disequilibrium was detected, probably related to migrants. It was hypothesized the occurrence a throughout of the years alternation of visiting individuals. The Buraco das Araras constitutes a favorable and helpful environment for reproduction and food of the red-and-green macaw and species conservation. / Certas espécies de psitacídeos possuem uma série de características normalmente associadas ao risco de extinção, como grande tamanho corporal, pequena diversidade de itens alimentares, alta especificidade de hábitat, pequena taxa de crescimento populacional e distribuição geográfica restrita, como o gênero Ara. Estudos genéticos são importantes ferramentas para auxiliar a conservação de espécies sob risco de extinção. Um dos marcadores moleculares mais utilizados é o microssatélite, o qual deve ser isolado da própria espécie ou de espécies correlatas. O objetivo principal desse estudo foi avaliar a variação genética de uma população de Ara chloroptera que habita uma região turística do Mato Grosso de Sul, conhecida por Buraco das Araras. Para tanto foram identificados e caracterizados seis locos de microssatélites na espécie, os quais foram úteis para acessar a variação genética e também apresentaram potencial para utilização em estudos com outros psitacídeos neotropicais. A população estudada apresentou uma variabilidade genética comparável a observada em uma espécie congenérica não ameaçada. Mostrouse significativamente em desequilíbrio de Hardy-Weinberg, provavelmente devido aos imigrantes detectados. Foi hipotetizada a ocorrência de alternância de indivíduos visitantes ao através dos anos. O Buraco das Araras proporciona um ambiente favorável para reprodução e alimentação da arara vermelha, ajudando na conservação da espécie.
39

Diagnóstico em BPM: uma investigação longitudinal sobre os resultados da aplicação da árvore da realidade atual em uma UPC / BPM diagnostic: a longitudinal reserch on the application of the current reality tree in a CRU

Elisa França Leôncio Alves 28 August 2017 (has links)
Dentre as fases do ciclo de vida do Gerenciamento de Processos de Negócios (BPM - Business Process Management), a fase de diagnóstico de processos pode facilitar a mudança de modo a fundamentar futuros esforços de aumento de produtividade, padronização da execução do trabalho e criação de uma rotina de trabalho mais eficiente. Como técnica de diagnóstico, a ARA (Árvore da Realidade Atual) é mais ampla pois demonstra a visão geral da situação da empresa. A pergunta de pesquisa que se pretende responder com este trabalho é: como o diagnóstico da Árvore da Realidade Atual pode promover melhorias em uma Unidade de Pesquisa Clínica (UPC)? O objetivo é analisar o relacionamento entre a aplicação do diagnóstico da ARA e as melhorias realizadas em uma UPC. Para tanto, foi utilizado como método um estudo de caso em uma UPC que utilizou ARA como técnica de diagnóstico precursora da implementação de melhorias organizacionais. Nos resultados deste estudo é apresentado o diagnóstico da ARA em uma UPC e são descritas as melhorias que ocorreram na organização a partir da aplicação desta técnica. Além disso, são identificados quais fatores de sucesso do BPM contribuíram para a aplicação da ARA. Conclui-se que a utilização da ARA como técnica de diagnóstico, além de fornecer uma análise que contempla as necessidades reais da organização, pode ser relacionada com o sucesso da implementação de melhorias. Este estudo deve fornecer subsídios aos gestores de UPCs em relação à efetividade das práticas administrativas passíveis a serem adotadas, além de ser importante para pesquisadores que atuam com diagnóstico de processos e BPM ao apresentar a efetividade da utilização da ARA como técnica e relacionar as melhorias obtidas com os fatores críticos de BPM. / Among the phases of the Business Process Management (BPM) lifecycle, the process diagnostics phase can facilitate the change in order to support future efforts to increase productivity, standardize the execution of work and create a more efficient work routine. As a diagnostic technique, CRT (Current Reality Tree) is broader because it demonstrates the overall picture of the company\'s situation. The research question that intends to answer with this work is: how the diagnosis of the Current Reality Tree can promote improvements in a Clinical Research Unit (CRU)? The objective is to analyze the relationship between the application of CTR diagnosis and the improvements performed in a UPC. For that, a case study was used as a method in a UPC that used CRT as diagnostic tool for the implementation of organizational improvements. The results of this study present the diagnosis of CRT in a CRU and describe the improvements that occurred in the organization from the application of this technique. In addition, it is identified which BPM success factors contributed to the application of ARA. It is concluded that the use of ARA as a diagnostic technique, besides providing an analysis that considers the real needs of the organization, can be related to the success of the implementation of improvements. This study should provide support to UPC managers concerning to the effectiveness of the administrative practices that may be adopted, and it is important for researchers working with process and BPM diagnoses to introduce the effectiveness of the use of ARA as a technique and to relate the improvements obtained with the critical BPM factors.
40

Origin and variability of the late Precambrian-Cambrian Athel Silicilyte, South Oman Salt Basin

Al Rajaibi, Ibrahim Mohamed amur January 2011 (has links)
The Precambrian-Cambrian Athel Silicilyte is an enigmatic chert unit of up to 390 m thick found as slabs (each slab typically 2 × 6 km across) entrapped within salt domes at a depth of 4-5 km in the South Oman Salt Basin. This formation is a prolific self-charged reservoir with high porosity (up to 34 %) and high oil saturation (80 %). Despite its economic value, the origin and the variability of this formation are not fully understood. This study therefore aims to investigate the variability and the origin (silica source and precipitation mechanism) of the Athel Silicilyte. Data obtained from core, wireline log and petrographical analysis were employed to establish the vertical and the lateral variability and, with the assistance of geochemical data, the likely source and precipitation mechanism of silica was determined.The Athel Silicilyte is only present in the deepest parts of the South Oman Salt Basin within the fault-bounded Athel Basin, bounded by two silt-rich mudstone units. Six lithofacies were recognised in the Athel Silicilyte that reflect variability in detrital material contents (three silica-rich facies), sediment remobilisation (slumped and brecciated lithofacies) and diagenetic modification (carbonate-bearing lithofacies), with the silica-rich facies being the most abundant (> 97 % of the total thickness). The Athel Silicilyte exhibits wavy discontinuous lamination and it is predominately (silica-rich facies average = 80 wt. %) composed of connected-networks of microcrystalline quartz (1-5 µm). Other constituent components are detrital quartz (3 wt. %), illite (10 wt. %), pyrite (4 wt. %) and organic carbon (TOC = 3 wt. %). The detrital contents increase towards the Upper Athel Silicilyte and towards the basin margins (ranging from 3 to 30 wt. %). The wavy laminations are interpreted to have a microbial origin. The homogeneity, loose packing of detrital grains and preservation of 390 m thick laminated fabric suggest that the Athel Silicilyte precipitated syndepositionally in microbial layers during low detrital input. The intense detrital input during bounding mudstones sedimentation inhibited Athel Silicilyte precipitation as a result of the rapid burial of microbial layers. The Athel Silicilyte shows strong enrichments of redox-sensitive elements (U, V and Mo), Mn-depletion, positive Ce anomalies, and small framboidal pyrites (3.6-4.0 µm), suggesting that the water column was euxinic during precipitation.Based on the petrographical evidence for the Athel Silicilyte forming as a syndepositional precipitate alongside seawater-like rare earth element (REE) characteristics, silica is interpreted to have been sourced directly from seawater. Mass balance calculations support this interpretation, indicating that silica-rich Precambrian seawater provided the significant silica mass in the Athel Silicilyte. The ability of dissolved silica to form hydrogen bonds with the functional groups (e.g. carboxyl and hydroxyl) in microbial layers was the key for Athel Silicilyte precipitation. The formation of hydrogen bonds was made possible under euxinic conditions, where the pH values were probably lower (< 7) than for the normal seawater as a result of HS- and H+ production by sulphate reducing bacteria and HS- oxidation at the redox boundary by sulphur oxidising bacteria. Consequently, dissolved silica was concentrated in microbial layer microenvironemnts, resulting in silica nucleation and polymerisation.

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