Este trabalho apresenta um estudo sobre o escoamento de ar em dutos com múltiplas saídas que são identificados como caixas sopradoras, quando instalados em máquinas desaguadoras de celulose. Estas caixas auxiliam o processo de secagem conduzindo ar aquecido até um conjunto de orifícios que produzem jatos que são impingidos sobre as folhas de celulose fabricadas. É realizada revisão bibliográfica abordando processos e equipamentos de secagem, com foco no escoamento de ar, métodos para solução numérica de escoamentos, seus modelos e parâmetros, e abordagem semi-empírica para fluxos de ar na saída de dutos. O escoamento do ar no interior da caixa sopradora e nos jatos de saída são estudados através de simulação numérica, e de modelo semi-empírico. São propostas duas alternativas de geometria para estes dutos de modo que se garanta a maior uniformidade possível na vazão e na velocidade média do ar que saí através dos orifícios Na primeira alternativa considera-se que a seção transversal da caixa sopradora se mantém constante. Na segunda se considera que a seção transversal seja reduzida de modo uniforme ao longo da caixa sopradora. Um estudo experimental sobre o comportamento do escoamento de ar para caixas sopradoras em escala reduzida apresenta resultados que possibilitam validar um conjunto de valores numéricos obtidos na simulação e também estabelecer características para o escoamento de modo a atender o processo de secagem. Para cada alternativa são adotadas duas condições de vazão de ar. Os resultados obtidos pela da simulação numérica e modelagem semi-empírica validam um perfil geométrico adequado para que a caixa sopradora produza um conjunto de jatos nas suas saídas com valores de velocidade média. Um dos principais resultados foi obtido para a caixa com 275 orificios, na qual as velocidades médias estiveram dentro do intervalo de 32,5 m/s e 33,1 m/s, que representou um ótimo resultado em termos de balanceamento e uniformidade das vazões de ar. / This study presents an analysis about airflow in ducts with multiple outlets that are identified as blow boxes, when installed in pulp dewatering machines. These boxes work in the drying process leading heated air to a set of nozzles that produce air jets that are impinged against the pulp sheet. It is performed literature review about drying processes and equipment, with a focus on air flow, methods for numerical solution of airflows, their models and parameters, and semi-empirical approach about airflow at the outlets of the duct. The airflow inside the blow box and the output jets are studied by numerical simulation, and semi-empirical model. It is proposed two alternative geometries for these ducts in order to guarantee the greatest possible uniformity in flow rate, and in the average velocity of air jets. In the first alternative is considered that the cross section of the blow box remains constant. In the second one it is considered that the cross section is reduced uniformly along the blow box. An experimental study about the behavior of the airflow in blow boxes, using scaled models, presents results that can validate a set of numerical values obtained in the simulation and also establish characteristics for the drying process. For each alternative two conditions of airflow are adopted. The results obtained through numerical simulation and semi-empirical modeling validates an appropriate geometrical profile for the blow box in order to set the values of average speed within the range required by the drying process. One of the principal results, obtained for the case of boxes with 275 holes, was the average speed within the range of 32,5 m/s and 33,1 m/s, this range represents a great result in tterms of balance and uniformity of air flow.

As pesquisas com resinagem de árvores de espécies de pinus têm mostrado o efeito de fatores que afetam a produção e a qualidade da resina, relacionado com as espécies, variabilidade genética, taxa de crescimento, idade, manejo florestal, etc. As práticas de extração da goma-resina, a concentração, freqüência da aplicação de estimulantes químicos, época de abertura dos painéis, etc., têm sido, da mesma forma, analisadas. No entanto, há necessidade do desenvolvimento de pesquisas direcionadas ao estudo da formação e da estrutura do lenho e dos canais de resina das árvores de pinus. Pelo exposto, o presente trabalho teve como objetivos a caracterização da estrutura anatômica do lenho, dos anéis de crescimento e dos canais de resina, através de metodologias de histologia e de densitometria de raios X, de amostras de árvores de Pinus caribaea var. hondurensis resinadas e não resinadas, de três classes de diâmetro. Árvores de pinus, de plantação florestal instalada em 1969, na Estação Ecológica Experimental de Itirapina, do Instituto Florestal do Estado de São Paulo, foram mensuradas e estratificadas em três classes de diâmetro do tronco. As árvores de pinus têm sido resinadas desde 2004, com a abertura de dois painéis simultâneos e opostos. Sessenta amostras do lenho das árvores de pinus foram extraídas do tronco das árvores através de método não destrutivo e, em laboratório, (i) analisada e descrita a estrutura anatômica macro e microscópica do lenho; (ii) caracterizados os anéis de crescimento e determinada a densidade aparente do lenho por densitometria de raios X; (iii) caracterizados e descritos os canais de resina axiais e radiais e sua interconexão. Os resultados das análises evidenciaram que (i) a estrutura anatômica macro e microscópica do lenho e dos anéis de crescimento é característica da espécie; (ii) os anéis de crescimento falsos ocorrem nos lenhos inicial e tardio dos anéis de crescimento anuais devido as variações climáticas; (iii) a análise dos anéis de crescimento demonstrou que as árvores têm 38 anos, comprovada pela data de plantio; (iv) o comprimento e a espessura da parede das traqueídes não diferiram nas três classes de diâmetro do tronco; (v) a largura e o diâmetro do lume das traqueídes mostraram diferenças significativas, com maiores valores na classe de maior diâmetro do tronco; (vi) a densitometria de raios X possibilitou a demarcação dos limites dos anéis de crescimento e a determinação da freqüência dos canais de resina axiais; (vii) a densidade aparente média do lenho mostrou diferença significativa entre as árvores da classe de diâmetro alta em relação as das classes média-baixa; (viii) os canais de resina axiais localizam-se em maior freqüência no lenho tardio e apresentaram maior diâmetro de menor classe de diâmetro; (ix) as características do lenho e dos canais de resina nas faces testemunha e resinada não mostraram diferenças significativas. / The research on resin tapping trees with pine species have shown the effect of factors that affect the production and quality of resin, related with the species, genetic variability, growth rate, age, forest management, etc.. The gum-resin extraction practices, the concentration, frequency of application of chemical stimulants, the time of year that panels are opening, etc., have been in the same manner, discussed. However, there is need for further research directed to study the formation and structure of the wood and resin canals from the pine trees. Therefore, this work aimed to characterize the anatomical structure of wood, the tree rings and resin canals, through methodology of histology and X-ray densitometry, of resin tapped and not resin tapped Pinus caribaea var. hondurensis trees samples, of three diameter classes. Pine trees, in forest plantation established in 1969, in the Ecological Experimental Station of Itirapina, from the Forestry Institute of São Paulo State, were measured and stratified into three classes of diameter of the trunk. The pine trees have been resin tapped since 2004, with the opening of two simultaneous and opposing panels. Sixty samples of pine wood trees were extracted from the tree trunk through a non-destructive method, and in the laboratory, (i) examined and described the macro- and microscopic anatomical structure of wood, (ii) characterized the tree rings and determined the wood apparent density by X-ray densitometry, (iii) characterized and described the ducts for axial and radial resin and its inter-connection. The test results showed that (i) the macro- and microscopic anatomical structure of wood and the tree rings are characteristic of the species, (ii) the false tree rings occur in the early wood and latewood of the tree rings due to climate change (iii) the analysis of tree rings showed that 38 years have proven the date of planting of the trees, (iv) the length and thickness of tracheids wall did not differ in the three diameter classes of the trunk, (v) the tracheids lumen width and diameter showed significant differences, with higher values in the larger diameter class trunk, (vi) the Xray densitometry allowed the demarcation of the tree rings limits and determination of the axial resin canals frequency (vii) the wood apparent density average was significantly different between the trees in high class diameter from the medium-low, (viii) the axial resin canals can be found more frequently in the latewood and had larger diameter in the lowest diameter class, (ix) the wood and resin canals characteristics from the resin tapped and no resin tapped faces did not show significant differences.

L’objectif de cette thèse est de modéliser en temps réel la propagation d’un incendie dans des ensembles comportant un grand nombre de locaux. Un modèle semi-physique de réseau polydisperse amorphe prenant en compte les connexions à courte et longue distances entre sites, est proposé. Les phénomènes physiques liés au développement du feu dans un local et à sa transmission entre locaux par les parois sont simulés par des lois normales de probabilité. Les durées moyennes de transmission par les parois sont déterminées à l’aide d’un modèle à zones prenant en compte les spécificités du local en feu. Des expérimentations spécifiques dans un caisson en acier, représentatif d’un local de la Marine Nationale, ont permis de valider le modèle à zones. Un exemple détaillé du calcul par le modèle de réseau de la propagation d’un feu dans une maquette de navire à échelle un est ensuite décrit et analysé pour différents scénarios. Une analyse de sensibilité utilisant un plan factoriel complet à deux niveaux permet de hiérarchiser les paramètres du modèle et d’étudier la sensibilité de la solution aux variations de ces paramètres. Une étude statistique est conduite afin d’établir une cartographie du risque incendie à bord du navire. La transmission du feu par les gaines de ventilation est simulée par une loi normale de probabilité où la durée moyenne de transmission est déterminée à l’aide d’un code à champ unidimensionnel. Après avoir validé ce code sur des mesures obtenues par DGA dans une conduite cylindrique différentiellement chauffée, l’influence de ce mode de transmission sur la propagation du feu dans le navire est analysée. / This thesis work is devoted to the development of a semi-physical network model to predict real-time fire spread in polydisperse amorphous massively multi-compartmented spaces. This model takes into account short-range and long-range connections between adjacent and remote network sites. The physical phenomena of fire ignition and flashover, and of fire transmissions through the walls are simulated using time-dependent normal probability distributions. Mean durations of transmission though the walls are determined by a two-zone model which takes into account the fuel load, the room size and the thermal properties of walls. Specific experiments were conducted in a steel room, representative of a naval vessel compartment, in order to validate the zone model. Then a proof of concept is developed by applying the network model to different fire scenarios in a full-scale vessel mockup. A sensitivity analysis using a two-level full factorial design is performed to identify the most influential model parameters and to evaluate the sensitivity of the solution to variations of these parameters. A statistical study is conducted to produce fire risk maps. Finally, a special emphasis is put on the fire transmission by the ventilation ducts. This phenomenon is simulated using a time-dependent normal probability distribution where the mean duration is determined by means of a one-dimensional CFD model. This model is first validated using data obtained by DGA in a differentially heated duct and second, the influence of fire transmission through ventilation duct on its propagation throughout the vessel is investigated.

The development of checkpoint immunotherapy has been a paradigm shift in the treatment of cancer, leading to dramatic improvement in treatment outcomes across a broad range of tumor types. Nevertheless, our current understanding of the tumor immune microenvironment and mediators of resistance to therapy are limited. The recent development of high-throughput single-cell RNA-Sequencing (scRNA-Seq) technology has opened up an unprecedented window into the transcriptional states of distinct tumor-infiltrating immune and stromal cells. However, even this technology has its biological limitations, with very high levels of data dropout induced by low total mRNA molecules and capture efficiency. This thesis explores the application of a transcriptional regulatory protein activity inference approach to single-cell data in order to resolve gene dropout and more deeply characterize upstream drivers of cell state within the micro-environment of several distinct tumor types. To this end, algorithms for inference of protein activity, drug sensitivity, and cell-cell interaction have been adapted to scRNA-Seq data, along with an approach for querying enrichment of single-cell-derived population marker gene sets patient-by-patient in larger bulk-RNA-Seq cohorts. By applying these tools systematically, we have identified distinct cellular sub-populations associated with clinical outcome in different tumor types, including a novel population of C1Q+/TREM2+/APOE+ macrophages associated with post-surgical tumor recurrence in clear cell renal carcinoma, a sub-population of fibroblasts associated with improved response to immunotherapy in head and neck squamous cell carcinoma, tumor cell subpopulations with distinct inferred drug sensitivities in cholangiocarcinoma and prostate cancer, as well as tumor-specific regulatory T-cells (Tregs), active as a mechanism of immunotherapy resistance across a range of tumor types. In ongoing clinical trials from both primary and metastatic prostate cancer as well as clear cell renal carcinoma, we are able to assess which of these populations are enriched in non-responders to checkpoint immunotherapy. The proteomic master regulators of each of these single-cell types have direct utility as potential biomarkers for treatment response, but they may also be therapeutically modulated as novel targets for combination immunotherapy, potentially improving treatment response rates and treatment outcomes in future clinical trials. Finally, this thesis also presents a discovery-to-validation platform to accelerate micro-environment-directed drug repurposing in the context of immunotherapy resistance and rapid CRISPRko validation of novel therapeutic targets. This platform has been developed specifically to validate newly identified master regulators of tumor-specific immunosuppressive regulatory T-cells (Tregs), resulting in discovery of low-dose gemcitabine as a tumor-specific Treg-modulating drug synergistic with anti-PD1 checkpoint immunotherapy and TRPS1 as a proteomic master regulator with clinically significant effect on tumor Treg-infiltrating and tumor growth rate. However, the platform itself may be readily extended in future work to prioritize agents against immunosuppressive macrophage and fibroblast populations for clinical development and trials. As we have discovered, different cancers have different populations of cells driving therapy response and resistance. Taken together, the analytical and validation tools presented in this thesis represent an opportunity to tailor future immuno-therapies at the single-cell level to particular tumor types and to individual patients.

Målen med denna uppsats var att studera två aspekter av temperatur inducerade spänningar med referens till kärnkraftsanläggningen Forsmark F1. Ena aspekten inkluderade den termiska kyleffekten av de ventilerade spännkabelrören i cylinderväggen. Det var av intresse att studera om den termiska kyleffekten av de ventilerade spännkabelrören hade en positiv global effekt som var relevant att beakta i globala tredimensionella modeller. Den andra aspekten inkluderade inverkan av ingjutet stål i den övreringplattan. Med syftet att studera om ingjutet stål var en aspekt som ansågs nödvändigt att beakta i transienta analyser.   Huvudanalyseringsverktyg var finita element metoden (FEM), genom användning av det kommersiellt tillgängliga finita element programmet SOLVIA.   Inverkan av den termiska kyleffekten av de ventilerade spännkabelrören indikerade en spännings reducerande effekt, med reducerade zoner av sprucken betong i cylinderväggen vid förhöjda temperaturer. Inverkan av ingjutet stål indikerade ökade temperaturskillnader mellan det ingjutna stålet och den omgivande betongen, med sprucken betong lokalt mellan stålet och betongen vid förhöjda temperaturer. Den termiska kyleffekten av de ventilerade spännkabelrören ansågs relevant att beakta i globala tredimensionella modeller. Ingjutet stål ansågs vara nödvändigt att inkludera i transienta analyser. / The aims of this thesis were to study two aspects of temperature induced stresses with reference to the nuclear power plant Forsmark F1. One aspect included the thermal cooling effect of the ventilated tendon ducts in the cylinder wall. It was of interest to study if the thermal cooling effect of the ventilated tendon ducts had a positive global effect which was relevant to consider in global three-dimensional models. The other aspect included the influence of embedded steel in the upper ring slab. With the purpose to study if embedded steel was an aspect that was considered necessary to include in transient analyses.   The used main analysis tool was the finite element method (FEM), through the use of the commercially available finite element program SOLVIA.   The influence of the thermal cooling effect of the ventilated tendon ducts indicated a stress reducing effect, with reduced cracked concrete in the cylinder wall at elevated temperatures. The influence of embedded steel indicated increased temperature differences between the embedded steel and the surrounding concrete, with cracked concrete locally between the steel and the concrete at elevated temperatures. The thermal cooling effect of the ventilated tendon ducts was considered relevant to consider in global three-dimensional models. Embedded steel was considered necessary to include in transient analyses.

No description available.

The objective of this doctoral thesis is to study three different innovative noise control techniques in ducts namely: acoustic metamaterials, porous absorbers and microperforates. There has been a lot of research done on all these three topics in the context of duct acoustics. This research will assess the potential of the acoustic metamaterial technique and compare to the use of conventional methods using microperforated plates and/or porous materials.  The objective of the metamaterials part is to develop a physical approach to model and synthesize bulk moduli and densities to feasibly control the wave propagation pattern, creating quiet zones in the targeted fluid domain. This is achieved using an array of locally resonant metallic patches. In addition to this, a novel thin slow sound material is also proposed in the acoustic metamaterial part of this thesis. This slow sound material is a quasi-labyrinthine structure flush mounted to a duct, comprising of coplanar quarter wavelength resonators that aims to slow the speed of sound at selective resonance frequencies. A good agreement between theoretical analysis and experimental measurements is demonstrated. The second technique is based on acoustic porous foam and it is about modeling and characterization of a novel porous metallic foam absorber inside ducts. This material proved to be a similar or better sound absorber compared to the conventional porous absorbers, but with robust and less degradable properties. Material characterization of this porous absorber from a simple transfer matrix measurement is proposed.The last part of this research is focused on impedance of perforates with grazing flow on both sides. Modeling of the double sided grazing flow impedance is done using a modified version of an inverse semi-analytical technique. A minimization scheme is used to find the liner impedance value in the complex plane to match the calculated sound field to the measured one at the microphone positions. / <p>QC 20160923</p>

Approved for public release; distribution in unlimited. / This is a study of abnormal refractive layer occurrence over the Amazon region and possible effects on radar and ESM systems, ground or airborne based. Climatologic data from three stations in that region are analyzed using computations from the Global Tropospheric Experiment (GTE), soundings and satellite imagery. The GTE data provide monthly occurrences and seasonality of atmospheric ducts and superrefractive layers. Further, individual soundings from the March-June 2003 period and the Advanced Refractive Effects Prediction Systems (AREPS) 2.1 software are used in a case study that analyzed these layers and, in addition, subrefractive and multiple layers. Selected soundings were used in simulations to explain the effects of different types of abnormal layers on the electromagnetic propagation. Although abnormal layers did not affect ground systems, airborne ones were. For radar, a region with low or no detection is created when an abnormal layer refracts the electromagnetic energy upwards or downwards. Some combinations of multiple layers may cause effects even stronger. It is concluded that knowledge of the abnormal layers occurrence is important for operations in the Amazon region. Further, airborne radar platforms should measure local refractive conditions, if possible. A comprehensive study in time and space is recommended to provide forecasting. / Lieutenant Colonel, Brazilian Air Force

O controle de emissões em veículos pesados está em foco desde a década de 90, com a criação de regulamentações nacionais e internacionais que impõe limites cada vez mais rígidos para as concentrações de poluentes emitidos por estes veículos. O desenvolvimento de novas tecnologias possui papel fundamental neste processo, buscando redução nos níveis de emissões com mínimo impacto negativo no desempenho e no consumo do veículo. Para tanto, o presente trabalho visa avaliar a influência da posição dos dutos de admissão de ar de cabeçotes de motores a combustão interna, especificamente em motores de ignição por compressão (MIC) de 4 válvulas, no escoamento de ar dentro do cilindro. O escoamento do ar e o movimento de swirl são fatores importantes para a mistura e distribuição do combustível injetado, e quando otimizados para uma queima melhor distribuída, contribuem para redução nos níveis de emissões. Procura-se investigar quais direções características dos dutos são determinantes para o escoamento e para o comportamento de swirl do motor através de simulações em fluidodinâmica computacional (Computational Fluid Dynamics - CFD) utilizando o programa CD-adapco STAR-CCM+®. Os resultados de alguns dos cenários simulados são comparados a resultados de testes experimentais realizados em bancada de medição de swirl, no âmbito de outro trabalho sendo desenvolvido no mesmo grupo de projeto. / The emissions control in heavy-duty vehicles has been in focus since the 1990\'s, with the creation of national and international regulations which impose strict limits for pollutant concentrations released by these vehicles. The development of new technologies has a fundamental role in this process, aiming the reduction of emission levels with minimum impact on the performance and fuel consumption of the vehicle. Therefore, the present study aims to evaluate the influence of the position of intake ports in cylinder heads from internal combustion engines, specifically 4-valves compression-ignition (CI) engines, in the in-cylinder air flow. The air flow and swirl motion are important factors for the mixture and distribution of injected fuel, and when optimized for a better distributed combustion, contribute for the reduction of emission levels. This study investigates the characteristic directions of ports which are determinant for the air flow and swirl behaviour of the engine through Computational Fluid Dynamics (CFD) simulations using CD-adapco software STAR-CCM+®. The results from a group of simulated cases are compared to experimental test results from another project, developed on the same project group, performed in a swirl meter test rig.

Introdução: O acesso biliar ecoguiado é um método de drenagem alternativo à drenagem percutânea transhepática (DPTH) e à cirurgia em pacientes com obstrução biliar distal incurável que falharam drenagem por Colangiopancreatografia Endoscópica Retrógrada (CPRE). Nos casos em que a drenagem ecoguiada anterógrada transpapilar (ou transanastomótica) e o rendez-vous ecoguiado não podem ser realizados como primeira opção, a coledocoduodenostomia (CDT) e a hepaticogastrostomia (HPG) ainda podem ser realizadas em pacientes selecionados. Estas duas vias de drenagem não anatômicas criam uma fístula entra a via biliar e o estômago ou duodeno. Não há dados na literatura que determinem superioridade de uma ou outra técnica. Objetivo: Comparar o sucesso técnico, sucesso clínico e fatores associados entre as duas vias de drenagem em pacientes com obstrução da via biliar distal maligna incurável que não lograram sucesso na drenagem por CPRE ou rendez-vous ecoguiado. Métodos: Entre abril de 2010 e dezembro de 2013, 49 pacientes com obstrução biliar distal maligna incurável que falharam CPRE e rendez-vous ecoguiado foram randomizados para CDT ou HPG. Dados referentes ao sucesso técnico, sucesso clínico, tempo de procedimento, complicações, qualidade de vida e sobrevida foram coletados até três meses após o procedimento. Todos os procedimentos foram realizados em um centro terciário de endoscopia pelo mesmo endoscopista. Próteses biliares parcialmente recobertas (Boston Scientific, Wallflex, 10 mm, 8 cm ou 6 cm) foram utilizadas em todos os pacientes com sucesso técnico. Nos casos de HPG a punção ecoguiada foi intra-hepática no ducto hepático esquerdo. Nos casos de CDT a punção foi extra-hepática no segmento distal não obstruído do colédoco. Após a punção foi realizada colangiografia com introdução de um fio guia hidrofílico de 0,035 polegada. Dilatação com cateter e um dispositivo de needle knife foi realizada para permitir introdução do sistema de disparo da prótese biliar com 8,5 Fr. Resultados: Quarenta e nove procedimentos foram realizados (25 HPG e 24 CDT). Todos os pacientes tinham dilatação da via biliar intra e extra-hepática. A taxa de sucesso técnico foi de 96 % para HPG e de 91% para CDT (p = 0,609). A taxa de sucesso clínico foi de 91% para o grupo HPG e de 77% para o grupo CDT (p = 0,234). No grupo da HPG 5 pacientes (20%) tiveram complicações (3 sangramentos, 2 biliomas e uma bacteremia). No grupo da CDT 3 pacientes (12,5%) tiveram complicações (1 bilioma, 1 sangramento e 1 perfuração). Somente o caso da perfuração necessitou tratamento cirúrgico. As outras complicações foram tratadas clinicamente. O tempo de procedimento médio foi de 47,83 min para a HPG e de 48,88 min para a CDT (p = 0,843). Conclusão: O presente estudo não demonstrou diferença estatisticamente significante em relação ao sucesso técnico, sucesso clínico, complicações e tempo de procedimento entre os dois grupos estudados. Mais estudos são necessários para elucidar o papel de cada via de drenagem / Background: EUS-guided biliary access is an alternative for percutaneous access or surgery in patients with malignant unresectable distal biliary obstruction and failed ERCP. When rendezvous or anterograde transpapillary/transanastomotic intervention fails as primary drainage options, a Choledochoduodenostomy (CDT) or a Hepaticogastrostomy (HGT) can still be performed in selected patients. This procedure creates a new \" \" y I w one route or the other should be recommended. Aim: To compare technical and clinical success and possible associated factors between the two different drainage routes CDT and HGT in patients with distal unresectable malignant biliary obstruction that failed standard ERCP and EUS-guided rendez vouz (RV) maneuver. Methods: Between April/2010 and December/2013 49 consecutive jaundiced patients with distal unresectable malignant biliary obstruction that failed previous ERCP and EUS-guided RV maneuver were elected randomly to undergo either EUS-guided CDT or HGT. Data including indications, clinical and technical success, procedural times and complications with a three-month follow-up were prospectively collected in a database. All procedures were performed in a tertiary center by the same endoscopist. A partially covered SEMS (Boston Scientific, Wallflex, 10 mm, 8 cm or 6 cm) was used in all technically successful procedures. After puncture of left hepatic duct in case of HGT or the distal unobstructed segment of common bile duct in case of CDT a cholangiogram was obtained followed by advancement of a 0,035-inch guide wire into the biliary system. Bougies and wire-guided needle-knife were used to perform track dilation to allow passage of an 8.5 Fr stent delivery system. Results: Forty-nine cases (25 HGT and 24 CDT) were performed. All patients had intra and extra hepatic biliary dilation. Technical success rate was 96 % for HGT and 91% for CDT (p = 0.609). Clinical success rate was 91% for HPG and 77% for CDT (p = 0.234). In the HGT group five patients (20%) had complications (3 bleeding, 2 bilomas and 1 bacteremia). In the CDT group 3 patients (12.5%) had complications (1 biloma, 1 bleeding and 1 perforation). Only the perforation patient required surgery. All other complications were managed clinically. The median procedural time was 47.83 min for HGT and 48.88 min for CDT (p = 0.843). Conclusion: No significant difference was found in regards to technical or clinical success, complications and procedure time between the two drainage routes. More studies are needed to clarify situations in which the CDT or the HGT should be advocated