https://repositorio.ufba.br/handle/ufba/556 2026-05-19T22:51:30Z https://repositorio.ufba.br/handle/ri/44503 Obtenção de biocombustíveis líquidos por pirólise e hidropirólise rápida catalítica da microalga Halamphora coffeaeformis. Fonseca, Noyala Souza Cerqueira Sales, Emerson Andrade Microalgae biomass has shown great potential for biofuel production. These microorganisms, in various culture media, synthesize compounds that are renewable raw materials for generating green hydrocarbons, used as an alternative to fossil fuels in the energy transition. Microalgae have phytoextractive capacity for certain metals, which can stimulate fatty acid production by the cells. Fast pyrolysis (PY) and fast hydropyrolysis (H2PY), with the aid of catalysts, are technological routes currently used in converting microalgae into green hydrocarbons. In this work, the diatom Halamphora coffeaeformis, the metal ion Ni2+, at 3 ppm, in two Conway culture media were selected. Associated with PY in the production of drop-in biofuels in biogasoline, biojet fuel, and green diesel, alumina (γ-Al2O3) was used at 600°C for 15 seconds. In P. E and H2PY, a synthesized catalyst was also used: nickel and cerium oxide supported on alumina (NiO-CeO2/Al2O3) at 450°C under 1 atm H2 pressure for 2 minutes. Biomass production reached 1 g/L in 30 days, and the highest percentage of free fatty acids was achieved in the condition with the Ni2+ ion in the traditional Conway medium. The biomass was mainly characterized by thermogravimetry (TGA), scanning electron microscopy (SEM), and by fast (thermal) pyrolysis coupled with gas chromatography-mass spectrometry (PY-GC-MS). Fatty acids C14:0, C15:0, C16:0, C16:1, and C18:0 were quantified, representing about 7.8% (w/w), with C16:0 and C16:1 being the most abundant. In the conversions, the deoxygenation effect and hydrocarbon (HC) production were investigated. The presence of a catalyst increased the conversion and selectivity to hydrocarbons, mainly olefinic, paraffinic, and aromatic medium-chain hydrocarbons in PY, obtaining 58.1% of hydrocarbons in the carbon range of C4 to C18. In H2PY, with NiO-CeO2/ Al2O3, 84% of hydrocarbons ranging from C7 to C23 were obtained. This catalyst was more selective to paraffin production compared to Al2O3, with an α/n (olefin/paraffin) ratio of 1.4, while with γ- Al2O3 it was 2.4. In the different reaction processes, hydrocarbons compatible with the desired liquid fuels were obtained. In PY, higher conversion to higher quality biogasoline was achieved, while in H2PY, the production of bio-kerosene and green diesel was maximized, demonstrating the potential of microalgae as a raw material for biorefining in obtaining biofuels, contributing to the energy transition without major technological changes to engines and turbines. UNIVERSIDADE FEDERAL DA BAHIA Tese 2026-03-23T00:00:00Z https://repositorio.ufba.br/handle/ri/44483 Integração dos princípios do lean office e lean 4.0 na gestão acadêmico-administrativa: uma análise da percepção de valor dos estudantes de pós-graduação Pereira, Tatiane dos Reis Silva Woytysiak Barbosa, Ava Santana The main objective of this study is to investigate how the integration of Lean Office principles and Industry 4.0 digital technologies can contribute to improving the quality and efficiency of academic and administrative management at higher education institutions, focusing on graduate students' perceptions of value. The research is based on the premise that the student experience is influenced by value attributes that can be optimized through lean practices and digital technologies. The methodology adopted is both qualitative and quantitative, involving a focus group followed by the administration of structured questionnaires and multivariate statistical analysis, highlighting the use of Principal Component Analysis to identify the latent structure of perceived value attributes. The data collected allowed us to map relevant dimensions of the academic and administrative experience, such as agility, reliability, accessibility, and personalized services. The results reveal that incorporating Lean 4.0 practices can promote significant gains in institutional efficiency, academic sustainability, and student satisfaction. Universidade Federal da Bahia Dissertação 2025-11-06T00:00:00Z https://repositorio.ufba.br/handle/ri/44286 Bioprospecção de uma cianobactéria isolada no rio Joanes/BA para síntese de produtos visando aplicações biotecnológicas Pinheiro, Maria Teresa Araujo Sales, Emerson Andrade Cyanobacteria represent the most diverse group of photosynthetic organisms on the planet and hold high potential for the discovery of novel bioactive compounds. Their pigments have well-established applications in food and nutraceutical products and also serve as valuable sources of proteins and other biomolecules. These characteristics broaden their potential use in sectors such as biofuels, food, animal feed, and, more recently, in the emerging field of phyconanotechnology. In this context, the aim of this study was to isolate a cyanobacterial strain from a river located in northeastern Brazil, analyze its potential for cyanotoxin production, and evaluate its application potential for obtaining bioproducts such as phycocyanin and carotenoids, as well as for the synthesis of carbon dots from laboratory-cultivated biomass and post-extraction residual biomass. The strain was isolated using a thermal method. Identification was carried out through a polyphasic approach, and cyanotoxin production potential was assessed by molecular and chemical methods (PCR and LC-MS²). Cultivation and growth kinetics were conducted under controlled temperature and light conditions to produce biomass, which was subsequently used for phycocyanin extraction, carotenoid identification, and carbon dot synthesis from residual biomass after bioactive extraction. The isolated and laboratory-cultivated strain was identified as Leptolyngbya boryana and was non-toxigenic. Phycocyanin extraction followed a protocol combining different solvents with freeze–thaw cycles. The most efficient extraction method employed calcium lactate at pH 9.47, yielding the highest phycocyanin content (153.24 mg/g of biomass). HPLC analysis revealed the presence of echinenone and chlorophyll a homologs in the biomass. Additionally, carbon dots were synthesized via a hydrothermal process from the cultivated species’ biomass (both before and after bioactive extraction), as well as from Chlorella vulgaris for comparison. Characterization of the carbon dot nanomaterials showed high fluorescence, photostability, and consistent performance in potential applications such as bioimaging, fluorescent sensors, and optoelectronic devices. Overall, the results indicate that the identified L. boryana strain possesses significant biotechnological potential, both for the production of phycocyanin and carotenoids and for the generation of nanomaterials of interest, highlighting the prospects for valorizing biomass into high-value products and commercial applications. Universidade Federal da Bahia Tese 2026-03-06T00:00:00Z https://repositorio.ufba.br/handle/ri/44099 Estudo do estágio de maturidade da cultura de segurança de uma rede de revendas de GLP em Salvador - Bahia Mendes, Allen Greyson Gomes Gonçalves Filho, Anastácio Pinto The Liquefied Petroleum Gas (LPG) distribution industry in Brazil faces significant challenges regarding operational safety, particularly within reseller networks. Despite the product’s importance for the national energy matrix and both residential and commercial supply, incidents related to inadequate handling, lack of standardized procedures, and the low maturity level of safety culture are still recurrent in part of the sector. In this context, the present study aimed to study the maturity stage of the safety culture in an LPG reseller network located in Salvador, Bahia. The research is grounded in well-established theoretical models that conceptualize safety culture as a set of values, practices, and collective behaviors that evolve through maturity stages. A mixed-methods approach was employed, combining quantitative and qualitative techniques. Data collection involved questionnaires covering six dimensions (leadership, commitment, involvement, information, communication, and organizational learning), along with a documentary evidence checklist. The sample consisted of 289 workers from 82 reseller companies. Results indicated an intermediate stage of safety culture maturity, between the reactive and bureaucratic stages, with significant variations across sociodemographic and organizational profiles. Positive correlations were identified between safety culture maturity and education level, age, and length of employment. Smaller resellers demonstrated higher levels of safety culture maturity. The findings suggest that advancing the maturity of safety culture within resellers depends on consolidating clear policies, implementing continuous training programs, and strengthening safety-oriented leadership. Furthermore, the development of monitoring tools and performance indicators is recommended to systematically track safety culture progress. This study contributes to the understanding of the current panorama of safety culture in the LPG distribution sector and provides practical insights for managers seeking to enhance operational reliability and reduce risks associated with reseller activities. Universidade Federal da Bahia Dissertação 0004-02-01T00:00:00Z