185 research outputs found
Acondicionamiento del aceite usado de cocina para la producciĂłn de bioetileno
Treballs Finals de MĂ ster d'Enginyeria QuĂmica, Facultat de QuĂmica, Universitat de Barcelona. Curs: 2021-2022. Tutora: Maria Alicia Cardete GarciaThe cracker is the unit where ethylene and polyethylene, among other products, are produced. The conventional cracker unit has had a feed that comes from crude oil, the main raw material being naphtha, but it is a non-renewable source. For this reason, the aim is to reduce the amount of traditional raw material and add one that is recycled and also comes from a renewable source, such as used cooking oil (WCO).
The main disadvantage of using WCO as a raw material is the limitations that the feed has to be processed by the cracker, as the restrictions are aimed at reducing the poisoning of the catalyst present in the cracker, at reducing corrosion, and also at reducing the formation of coke, as if the amount deposited is considerable, the cracker must be stopped.
Therefore, it is necessary to develop a pre-treatment to reduce the components limited by the cracker and for this reason, the present project is developed with the objective of developing a process for the pre-treatment of second-generation vegetable oil (called as WCO, waste cooking oil), so that such raw material fulfils the requirements to be processed without limitations in the cracker unit to produce ethylene.
To achieve the objective, the WCO has been characterised based on a literature search and with the oil characterised, the necessary pre-treatment operations can be selected to meet the specifications for the cracker feed.
The pre-treatment must have operations that remove metals, chlorides, nitrogen, ash and solid particles, free fatty acids, phosphorous, oxygen and water.
The processes selected to remove metals are degumming, bleaching, desalting, membrane extraction, ion exchange, and settling with skimming. The processes selected to remove chlorides are degumming, desalting, membrane extraction and settling with skimming. For the removal of nitrogen, they are deodorization and hydrotreating. For the removal of ash and solid particles, the processes are degumming, desalting, membrane extraction and settling with skimming. Free fatty acids are removed by degumming and deodorization. Phosphorus is removed by degumming, bleaching and desalting. Oxygen is removed by bleaching, deodorization and hydrotreating. Finally, to remove water there are the processes of degumming, deodorization, desalting and settling with skimming.
The future steps for the development are to check experimentally if the proposed pre-treatment is enough to achieve the requirements of the cracker, furthermore, experimentation will give a clearer picture and it is preferable to do this before industrial scale-up.
In addition, an economic study should be carried out to check whether or not the pre-treatment process is viable with the proposed processes. Furthermore, the economic study together with the experimental verification will allow to decide whether all the operations are necessary or not, as the components can be removed by different processes.
On the other hand, the economic viability is favoured by the use of processes that are well known in petroleum refining such as desalting, membrane extraction and hydrotreatment
Providing better care to HIV-infected pregnant women, children and their families in a rural sub-Saharan African clinic
Novel strategies to increase the uptake of prevention of mother-to-child HIV transmission (PMTCT) services are needed in sub-Saharan Africa to reach the goal of elimination of paediatric HIV. In this same region, HIV diagnosis, linkage into care, antiretroviral treatment coverage and treatment outcomes of children need to be improved. Family-centered approaches may facilitate access to HIV care and improve the clinical management.
This thesis was developed mainly as an operational and implementation science research. The main objective of this PhD was to improve maternal and paediatric HIV services in Ifakara, Tanzania, to move towards the UNAIDS goals: 1) elimination of paediatric HIV and 2) “90-90-90” target (i) 90% of children living with HIV know their HIV status, ii) 90% of children with diagnosed HIV receive ART, iii) 90% of children receiving ART are virologically suppressed).
First, we conducted a cross-sectional study to assess the PMTCT services uptake in Ifakara. Second, we designed and implemented a package of measures as a strategy to improve the paediatric and maternal HIV care. Third, we evaluated the impact of the strategy. Forth, we did a prospective study evaluating the PMTCT cascade after the implementation of the package of measures and we compared the results with the initial cross-sectional assessment. Last, we investigated the prevalence and determinants of virological failure and acquired antiretroviral drug resistances in HIV-infected children.
The studies included in this thesis show that with an operational approach, real changes can be implemented in a rural Tanzanian setting. The work in Ifakara documents a feasible and scalable model for maternal and paediatric HIV care that if extended to other sub-Saharan African settings can contribute to the goals of zero new HIV infections among children, keep mothers in good health and close the paediatric treatment gap
Regime jurĂdico das contratações de defesa : aspectos gerais : contratação licitada
Monografia (graduação)—Universidade de BrasĂlia, Faculdade de Direito, 2014.Este trabalho procura apresentar os aspectos gerais das contratações do setor de defesa brasileiro com base nas recentes alterações legislativas, especialmente a Lei nÂş 12.598/2012 e o seu regulamento, o Decreto nÂş 7.970/2013. Trata do âmbito de aplica-ção do novo regime, das definições trazidas pela nova lei, analisa a constitucionalidade do instituto da Empresa EstratĂ©gica de Defesa, os procedimentos de catalogação e clas-sificação de produtos de defesa e o credenciamento de empresas de defesa. Analisa a prática de offset, sua definição, metodologia e instrumentos de veiculação jurĂdica. Co-menta as cláusulas especiais aderentes aos contratos de produtos de defesa: continuida-de produtiva, transferĂŞncia de propriedade industrial, poderes administrativos especiais, segregação de áreas reservadas, agregação de conteĂşdo nacional. Suscita questões Ă respeito de Parcerias PĂşblico-Privadas de defesa e aplicação subsidiária da Lei nÂş 8.666/93, do RDC e da modalidade PregĂŁo. Analisa questões relacionadas Ă licitação tais como: financiamento como condição de seleção da proposta, regras especiais de participação nas licitações de defesa, participação de coligadas e empresas com sĂłcios comuns em consĂłrcios distintos. ____________________________________________________________________________ ABSTRACTThis paper intends to present the general aspects of Brazil’s defense procurement sector based on recent legislative changes, especially Law nÂş 12.598/2012 and Decree nÂş. 7.970/2013. The work remarks the scope of the new policy, the definitions established by the law, examines the constitutionality of the Strategic Defense Company institute, the procedures for codification and classification of defense products, and the accredit-ing of defense companies; analyzes the practice of offset, its definition, methodology and tools for legal placement; comments on special clauses adhering to defense con-tracts such as: productive continuity, transfer of industrial property, special administra-tive powers, segregation of reserved areas, adding of local content; raises questions about the Public-Private Partnerships and defense subsidiary application of Law nÂş 8.666 / 93, the RDC and PregĂŁo mode; examines issues related to bidding process such as: financing conditions as selection criterium of proposals, special rules for participa-tion in tenders of defense, and participation of affiliated companies or with common sharers in distinct consortia
Exploring power behaviors and trade-offs of in-situ data analytics
pre-printAs scientific applications target exascale, challenges related to data and energy are becoming dominating concerns. For example, coupled simulation workflows are increasingly adopting in-situ data processing and analysis techniques to address costs and overheads due to data movement and I/O. However it is also critical to understand these overheads and associated trade-offs from an energy perspective. The goal of this paper is exploring data-related energy/performance trade-offs for end-to-end simulation workflows running at scale on current high-end computing systems. Specifically, this paper presents: (1) an analysis of the data-related behaviors of a combustion simulation workflow with an in-situ data analytics pipeline, running on the Titan system at ORNL; (2) a power model based on system power and data exchange patterns, which is empirically validated; and (3) the use of the model to characterize the energy behavior of the workflow and to explore energy/performance tradeoffs on current as well as emerging systems
A Bundle of Services Increased Ascertainment of Tuberculosis among HIV-Infected Individuals Enrolled in a HIV Cohort in Rural Sub-Saharan Africa
OBJECTIVES: To report on trends of tuberculosis ascertainment
among HIV patients in a rural HIV cohort in Tanzania, and
assessing the impact of a bundle of services implemented in
December 2012, consisting of three components:(i)integration of
HIV and tuberculosis services; (ii)GeneXpert for tuberculosis
diagnosis; and (iii)electronic data collection. DESIGN:
Retrospective cohort study of patients enrolled in the Kilombero
Ulanga Antiretroviral Cohort (KIULARCO), Tanzania.). METHODS:
HIV patients without prior history of tuberculosis enrolled in
the KIULARCO cohort between 2005 and 2013 were included.Cox
proportional hazard models were used to estimate rates and
predictors of tuberculosis ascertainment. RESULTS: Of 7114 HIV
positive patients enrolled, 5123(72%) had no history of
tuberculosis. Of these, 66% were female, median age was 38
years, median baseline CD4+ cell count was 243 cells/microl, and
43% had WHO clinical stage 3 or 4. During follow-up, 421
incident tuberculosis cases were notified with an estimated
incidence of 3.6 per 100 person-years(p-y)[95% confidence
interval(CI)3.26-3.97]. The incidence rate varied over time and
increased significantly from 2.96 to 43.98 cases per 100 p-y
after the introduction of the bundle of services in December
2012. Four independent predictors of tuberculosis ascertainment
were identified:poor clinical condition at baseline (Hazard
Ratio (HR) 3.89, 95% CI 2.87-5.28), WHO clinical stage 3 or 4
(HR 2.48, 95% CI 1.88-3.26), being antiretroviralnaive (HR 2.97,
95% CI 2.25-3.94), and registration in 2013(HR 6.07, 95% CI
4.39-8.38). CONCLUSION: The integration of tuberculosis and HIV
services together with comprehensive electronic data collection
and use of GeneXpert increased dramatically the ascertainment of
tuberculosis in this rural African HIV cohort
Experimental study the effect of diesel engine performance fuelled by waste tire oil- dexlite blends
It well known that tire as a waste from vihicles susch as passengger car, truck and trailller. Indonesia country has enough potensial of tire waste, it was produced of about 11 millions ton per years. This phenomena could be serious environmental problem because tire waste was difficult dissolve by environment. It is needs to solve this issue by convert the waste tire to oil fuels. The main focus of this research to evaluate the performance of diesel engine fuelled by waste tire oil-dexlite blends. The physicochemical properties such as viscosity, density, calorific value and cetane number the waste tire fuel and its blends with dexlite were analysed. The experimental methode to determine engine performance by using the CI engine with variation of speed from 1500 rpm to 2100 rpm and waste tire-dexlite blends ratios at 10% (WTO-10), 20% (WTO-20) and 30% (WTO-30) of waste tire oil (WTO) and dexlite were utilized as a fuels. The CI engine with variation of speed from 1500 rpm to 2100 rpm was selected in order to determine the engine performance. The experimental results showed that the blending of waste tire oil with dexlite from 10% to 30% can operate with CI engine without any engine modifications. The results of this study revealed that maximum power and SFC were found to be 2.3 kW and 0.48 kg/kWh, respectively. Moreover, at the engine speed of 1900 rpm and a fuel blend of WTO-10 were found that to be optimal values of power and thermal efficiency which is similarly by using dexlite as fuel
Prevention of mother-to-child transmission of HIV Option B+ cascade in rural Tanzania: The One Stop Clinic model
BACKGROUND: Strategies to improve the uptake of Prevention of
Mother-To-Child Transmission of HIV (PMTCT) are needed. We
integrated HIV and maternal, newborn and child health services
in a One Stop Clinic to improve the PMTCT cascade in a rural
Tanzanian setting. METHODS: The One Stop Clinic of Ifakara
offers integral care to HIV-infected pregnant women and their
families at one single place and time. All pregnant women and
HIV-exposed infants attended during the first year of Option B+
implementation (04/2014-03/2015) were included. PMTCT was
assessed at the antenatal clinic (ANC), HIV care and labour
ward, and compared with the pre-B+ period. We also characterised
HIV-infected pregnant women and evaluated the MTCT rate.
RESULTS: 1,579 women attended the ANC. Seven (0.4%) were known
to be HIV-infected. Of the remainder, 98.5% (1,548/1,572) were
offered an HIV test, 94% (1,456/1,548) accepted and 38 (2.6%)
tested HIV-positive. 51 were re-screened for HIV during late
pregnancy and one had seroconverted. The HIV prevalence at the
ANC was 3.1% (46/1,463). Of the 39 newly diagnosed women, 35
(90%) were linked to care. HIV test was offered to >98% of
ANC clients during both the pre- and post-B+ periods. During the
post-B+ period, test acceptance (94% versus 90.5%, p<0.0001)
and linkage to care (90% versus 26%, p<0.0001) increased. Ten
additional women diagnosed outside the ANC were linked to care.
82% (37/45) of these newly-enrolled women started antiretroviral
treatment (ART). After a median time of 17 months, 27% (12/45)
were lost to follow-up. 79 women under HIV care became pregnant
and all received ART. After a median follow-up time of 19
months, 6% (5/79) had been lost. 5,727 women delivered at the
hospital, 20% (1,155/5,727) had unknown HIV serostatus. Of
these, 30% (345/1,155) were tested for HIV, and 18/345 (5.2%)
were HIV-positive. Compared to the pre-B+ period more women were
tested during labour (30% versus 2.4%, p<0.0001). During the
study, the MTCT rate was 2.2%. CONCLUSIONS: The implementation
of Option B+ through an integrated service delivery model
resulted in universal HIV testing in the ANC, high rates of
linkage to care, and MTCT below the elimination threshold.
However, HIV testing in late pregnancy and labour, and retention
during early ART need to be improved
Practical scalable consensus for pseudo-synchronous distributed systems
The ability to consistently handle faults in a distributed en-vironment requires, among a small set of basic routines, an agreement algorithm allowing surviving entities to reach a consensual decision between a bounded set of volatile re-sources. This paper presents an algorithm that implements an Early Returning Agreement (ERA) in pseudo-synchronous systems, which optimistically allows a process to resume its activity while guaranteeing strong progress. We prove the correctness of our ERA algorithm, and expose its logarith-mic behavior, which is an extremely desirable property for any algorithm which targets future exascale platforms. We detail a practical implementation of this consensus algorithm in the context of an MPI library, and evaluate both its effi-ciency and scalability through a set of benchmarks and two fault tolerant scientific applications. CCS Concepts •Computing methodologies → Distributed algorithms; •Computer systems organization→Reliability; Fault-tolerant network topologies; •Software and its engi-neering → Software fault tolerance
A decade of HIV care in rural Tanzania: Trends in clinical outcomes and impact of clinic optimisation in an open, prospective cohort
OBJECTIVES: Our objectives were to describe trends in enrolment
and clinical outcomes in the open, prospective Kilombero and
Ulanga Antiretroviral Cohort (KIULARCO) in the Morogoro region
of southern Tanzania, and identify strengths and areas for
improvement in the care of HIV-positive individuals in rural
Tanzania. METHODS: We included adults (>/=15 years) and
children (<15 years) enrolled in the cohort in 2005-2014. The
cohort underwent significant changes from autumn 2012 to
optimise care. We evaluated mortality and loss to follow-up
(LTFU) using competing risks methods, ART usage, opportunistic
infections (OI), co-infections and laboratory abnormalities.
RESULTS: Overall, 7010 adults and 680 children were enrolled;
enrolment peaked in 2008 but has increased steadily since 2011.
Among adults (65% female; median age 37 [interquartile range
31-45] years), the proportion referred from hospital wards
quadrupled in 2013-14 versus earlier years. 653 (9%) adults died
and 2648 (38%) were LTFU; the five-year cumulative probabilities
of death and LTFU were 10.3% and 44.0%, respectively. Among
children, 69 (10%) died and 225 (33%) were LTFU. The
corresponding five-year probabilities were 12.1% and 39.6%.
Adult ART use (regardless of eligibility) increased from 5% in
2005 to 89% in 2014 (similarly among children), with 9% on
second-line therapy in 2014 (17% of children). OI diagnoses
increased over time; tuberculosis prevalence at enrolment
quadrupled from 6% in 2011 to 26% in 2014. The proportion of
newly-enrolled participants assessed for laboratory
abnormalities peaked at nearly 100% in 2014 (from a minimum of
24%), yet abnormality prevalences remained fairly constant.
CONCLUSIONS: In this cohort, ART usage improved dramatically and
is approaching targets of 90%. Improved screening led to
increases in detection of OIs and laboratory abnormalities,
suggesting that a large number of these co-morbidities
previously went undetected and untreated. Further work will
address the high LTFU rates and implications for mortality
estimates, and the management and outcomes of co-morbidities
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