NMR study of styrene-butadiene rubber (SBR) and TiO2 nanocomposites

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Sperimentazione di tecniche SBR nel trattamento "on site delle acque domestiche" per nuclei isolati e case sparse.

Scopo di questo lavoro di tesi è quello di sperimentare “sul campo’’ la validità e l'efficacia di tecniche SBR per il trattamento delle acque domestiche per case sparse e nuclei isolati. Tuttavia quella SBR, pur essendo una tecnica impiantistica, può soddisfare queste esigenze. Grazie alla presenza di un adeguato volume d'accumulo ed al funzionamento ciclico dell'impianto sono annullati tutti i problemi determinati, nei normali impianti in continuo, dalla discontinuità dell'afflusso di reflui (picchi di portata). L'impianto è studiato per ridurre la necessità di manutenzione al minimo: tutte le apparecchiature tecniche sono collocate in un armadio esterno all'impianto ed in vasca ci sono solo le tubazioni. Ciò esclude ogni presenza interna al serbatoio di apparecchiature elettriche e di parti in movimento soggette a usura. Il vantaggio è evidente nella semplificazione delle operazioni di gestione/controllo/manutenzione dell’impianto che non richiedono, di norma, lo svuotamento della cisterna e consentono operazioni più agevoli e sicure.Tutti i movimenti di processo sono supportati da tre sistemi Air Lift azionati da un unico compressore che provvede anche all'immissione dell'ossigeno attraverso l'aeratore tubolare a membrana nella vasca SBR. Il compressore si caratterizza per lunga vita operativa e assoluta silenziosità di funzionamento. Per verificare l’efficacia del processo depurativo indotto dall’impianto SBR installato dalla GreenSolar abbiamo fatto dei prelievi sul liquame in entrata alla camera SBR e su quello in uscita da essa. I campioni così prelevati sono stati analizzati da un laboratorio autorizzato.I valori limite imposti dal DGR n. 1053 sono ampiamente rispettati, tuttavia i risultati ottenuti non sono soddisfacenti relativamente alle potenzialità dell'impianto.

Obtenção e identificação de grânulos de polihidroxialcanoatos (PHA) presentes em biomassa de um reator descontínuo sequencial (SBR) com tratamento de águas residuais

As implicações ambientais dos plásticos convencionais, produzidos através de combustíveis fósseis, não permitem a sua utilização de forma sustentável pela sociedade devido aos seus problemas de degradabilidade e à sua dependência de matérias-primas não renováveis. Surgem então os polihidroxialcanoatos (PHA) como uma alternativa ambientalmente sustentável, já que conseguem reproduzir grande parte das aplicações dos plásticos ditos normais, tendo as grandes vantagens de serem biodegradáveis e produzidos a partir de uma fonte de carbono renovável. Mais recentemente, de forma a tornar a produção do PHA mais sustentável, tem-se desenvolvido o conceito de associar a produção destes polímeros ao tratamento de efluentes líquidos através do processo de lamas ativadas. Apesar destas vantagens todo o processo que envolve a produção do PHA é ainda dispendioso. Esta dissertação insere-se na estratégia de tentar minorar esses custos. Uma das formas de o fazer será na otimização de técnicas de quantificação do PHA em culturas mistas. Neste trabalho o principal objetivo reside na avaliação da capacidade da metodologia de análise de imagem, acoplada a microscopia de fluorescência, como método de quantificação de PHA. Pretende-se também explorar a produção de PHA a partir da simulação de um sistema de tratamento de águas residuais implementado num reator descontínuo sequencial (SBR) em regimes cíclicos de feast/famine, aliando assim a função de tratamento de efluentes líquidos com a produção de um produto de valor acrescentado como é o PHA. Deste modo, foi montada uma instalação com um sistema de lamas ativadas num SBR cujo principal objetivo era produzir PHA. Este objetivo de produzir PHA através do regime de alimentação dinâmica aeróbia com uma alimentação com acetato como fonte de carbono, e sem controlo do pH foi conseguido, atingindo-se um máximo de concentração mássica de 0,37 mg PHA/mg SST e de concentração volumétrica de 1785 mg PHA/L. Em relação à capacidade de tratamento, comprovou-se a adequabilidade do sistema utilizado para a remoção da carga orgânica devido a uma elevada captação de nutrientes do afluente pela biomassa. Foram encontradas algumas limitações na metodologia de análise de imagem ao nível da transformação da bidimensionalidade da área projetada dos grânulos de PHA nas imagens para a sua tridimensionalidade real, na gama de concentração de PHA na qual a metodologia é válida e na amostragem relativamente curta. Contudo, foi possível comprovar a potencialidade deste método obtendo-se um R2 de 0,80 para o modelo de previsão da concentração mássica de PHA. Deste modo, pode-se concluir que esta é uma metodologia promissora para quantificar PHA em amostras de licor misto.

Vzorn ̌dt̕ko; sbr̕ka bs̀n ̕pro d¿m a ¿kolu s tendenc ̕vychovatelskou.

Mode of access: Internet.

Efficient and stable nitritation and denitritation of ammonium-rich sludge dewatering liquor using an SBR with continuous loading

Separate treatment of dewatering liquor from anaerobic sludge digestion significantly reduces the nitrogen load of the main stream and improves overall nitrogen elimination. Such ammonium-rich wastewater is particularly suited to be treated by high rate processes which achieve a rapid elimination of nitrogen with a minimal COD requirement. Processes whereby ammonium is oxidised to nitrite only (nitritation) followed by denitritation with carbon addition can achieve this. Nitrogen removal by nitritation/denitritation was optimised using a novel SBR operation with continuous dewatering liquor addition. Efficient and robust nitrogen elimination was obtained at a total hydraulic retention time of 1 day via the nitrite pathway. Around 85-90% nitrogen removal was achieved at an ammonium loading rate of 1.2 g NH4+-N m(-3) d(-1). Ethanol was used as electron donor for denitritation at a ratio of 2.2gCODg(-1) N removed. Conventional nitritation/denitritation with rapid addition of the dewatering liquor at the beginning of the cycle often resulted in considerable nitric oxide (NO) accumulation during the anoxic phase possibly leading to unstable denitritation. Some NO production was still observed in the novel continuous mode, but denitritation was never seriously affected. Thus, process stability can be increased and the high specific reaction rates as well as the continuous feeding result in decreased reactor size for full-scale operation. (c) 2006 Elsevier Ltd. All rights reserved.

Impianti di depurazione delle acque: SBR

In questo elaborato è stato discusso il tema della depurazione delle acque reflue, in particolar modo il sistema SBR. L'SBR (Sequencing Batch Reactors) è un sistema di impianti di depurazione composto da una vasca di raccolta del liquame e una o più vasche in parallelo, i reattori, che consistono nel vero e proprio cure dell'impianto. Di fatto le fasi del processo depurativo restano immutate rispetto ad un impianto tradizionale, ma l'SBR introduce come nuovo parametro dimensionale il tempo. infatti, tutti i trattamenti depurativi sono svolti sequenzialmente nel reattore. Un programma gestisce le varie fasi del trattamento esclusivamente sulla base della loro durata (stabilita relativamente alla natura del refluo e quindi ai trattamenti da svolgere in maniera più o meno intensiva). Questa caratteristica rende l'intero impianto molto versatile nel caso di variazioni dei dati in ingresso. Per questo motivo gli impianti SBR sono ottimi per la piccola media impresa, in quanto sono facilmente adattabili alle variazioni stagionali di produzione. Sono inoltre possibili realizzazioni di impianti per il trattamento di ingenti portate, o elevate concentrazioni, ponendo più reattori in parallelo alimentati dalle stessa vasca di accumulo. In questo modo è possibile svolgere un maggiore numero di cicli depurativi al giorno e quindi rispettare i valori normativi in uscita dell'impianto. In conclusione questa tipologia d'impianto presenta notevoli vantaggi fra i quali anche quello di avere bassi costi operativi. La motivazione di ciò sta nel fatto che l'impianto lavora solo se ha effettivamente una portata, per cui se non vi è presenza di refluo il reattore non lavora e quindi non comporta costi.

Desenvolvimento de pastas de cimento flexíveis para poços de petróleo submetidos à injeção de vapor utilizando látex do tipo SBR

Novel cementing materials formulations containing flexible polymeric admixtures have been studied aiming at improving the mechanical behavior of oil well cement slurries submitted to steam injection. However, research activities in this sector are still under development. The steam injected directly into the well causes casing dilation, which after a reduction in temperature, tends to return to its original dimensions, resulting in crack formation and hydraulic isolation loss of the well, which will result in shortening of well life. In this scenario, the objective of the present study was to evaluate the mechanical behavior of Portland-based slurries containing SBR latex, applied in oil well cementing of wells submitted to steam injection. Were formulated slurries with densities of 1.797 g/cm3 (15.0 lb/Gal) and 1.869 g/cm3 (15.6 lb/Gal), containing admixtures with a latex concentration of 0; 66.88; 133.76; 200.64 and 267.52 L/m3 (0, 0.5, 1.0, 1.5 and 2.0 gpc). Tests including rheology, fluid loss control, thickening time, API compressive strength and splitting tensile strength, beyond steam injection simulation. Microstrutural characteristics of the slurries were also performed (XRD, TG, FTIR and SEM). The results showed that increasing the polymer concentration increased in the rheological properties and fluid loss, and a decrease in the elasticity modulus of the cement slurries. The results obtained showed that the slurries can be applied in cementing operations of oil wells submitted to steam injection.

Hush-a-by mummy : interactions between co-sleeping and maternal sleep disturbance

Childbirth is an extraordinary, everyday experience; in 2011, 301 617 infants were born in Australia [1], resulting in countless potential occurrences of sleep disturbance and subsequent daytime sleepiness. While the relationship between sleep and sleepiness has been heavily investigated in the vulnerable sub-populations of shift workers and patients with sleep disorders, comparatively postpartum women have been overlooked. Previous research has reported slower reaction times to the Psychomotor Vigilance Task [2] and shorter sleep onset in the multiple sleep latency test [3] in new mothers compared with control women. However little is known about change in sleep and sleepiness over time or potential interactions with infant care behaviour choices, such as co-sleeping (mother and infant sharing a bed). This study aims to investigate change in new mothers sleep quantity, sleep quality and resulting daytime sleepiness over postpartum weeks 6, 12 and 18, while evaluating the impact of co-sleeping.

Management of over-the-counter insomnia complaints in Australian community pharmacies: A standardized patient study

Objective To evaluate the current management of over-the-counter (OTC) insomnia complaints in Australian community pharmacies using standardized patient methodology. Methods Trained standardized patients visited a sample of 100 randomly selected South East Queensland community pharmacies in June 2011. The standardized patients enacted two OTC insomnia scenarios: a direct product request (DPR) (n = 50) and a symptom-based request (SBR) (n = 50). Results of the interactions were documented immediately after each visit and evaluated using the Pharmaceutical Society of Australia's WHAT STOP GO protocol as a standard comparison. Key findings Of all DPRs, 30% were handled entirely by the pharmacist, 70% of staff enquired about specific symptoms and 28% investigated the cause of insomnia. No staff investigated the frequency of product use. The DPR scenario resulted in a 92% supply of the requested doxylamine product (Restavit). In the SBR scenario, 18% of requests were handled entirely by the pharmacist, 58% of staff enquired about specific symptoms and 44% investigated the cause of insomnia. Staff recommended medicated products (38%), or herbal (78%) or non-drug techniques (18%). Investigation into smoking and alcohol intake was not undertaken in DPR or SBR interactions, while questioning on caffeine intake was undertaken in 2 and 14% of cases respectively. There were no significant differences found in the handling of sleep requests by pharmacists compared to pharmacy assistants. Conclusion The standardized patient methodology was a successful way to assess the community pharmacy counselling provided with OTC sleep requests and suboptimal staff responses were found when compared with recommended practice standards.

Thermal stability and decomposition kinetics of styrene-butadiene rubber nanocomposites filled with different particle sized kaolinites

A series of styrene-butadiene rubber (SBR) nanocomposites filledwith different particle sized kaolinites are prepared via a latex blending method. The thermal stabilities of these clay polymer nanocomposites (CPN) are characterized by a range of techniques including thermogravimetry (TG), digital photos, scanning electron microscopy (SEM) and Raman spectroscopy. These CPN show some remarkable improvement in thermal stability compared to that of the pure SBR. With the increase of kaolinite particle size, the residual char content and the average activation energy of kaolinite SBR nanocomposites all decrease; the pyrolysis residues become porous; the crystal carbon in the pyrolysis residues decrease significantly from 58.23% to 44.41%. The above results prove that the increase of kaolinite particle size is not beneficial in improving the thermal stability of kaolinite SBR nanocomposites.

Standard business reporting in Australia : efficiency, effectiveness, or both?

The benefits of using eXtensible Business Reporting Language (XBRL) as a business reporting standard have been widely canvassed in the extant literature, in particular, as the enabling technology for standard business reporting tools. One of the key benefits noted is the ability of standard business reporting to create significant efficiencies in the regulatory reporting process. Efficiency-driven cost reductions are highly desirable by data and report producers. However, they may not have the same potential to create long-term firm value as improved effectiveness of decision making. This study assesses the perceptions of Australian business stakeholders in relation to the benefits of the Australian standard business reporting instantiation (SBR) for financial reporting. These perceptions were drawn from interviews of persons knowledgeable in XBRL-based standard business reporting and submissions to Treasury relative to SBR reporting options. The combination of interviews and submissions permit insights into the views of various groups of stakeholders in relation to the potential benefits. In line with predictions based on a transaction-cost economics perspective, interviewees who primarily came from a data and report-producer background mentioned benefits that centre largely on asset specificity and efficiency. The interviewees who principally came from a data and report-consumer background mentioned benefits that centre on reducing decision-making uncertainty and decision-making effectiveness. The data and report consumers also took a broader view of the benefits of SBR to the financial reporting supply chain. Our research suggests that advocates of SBR have successfully promoted its efficiency benefits to potential users. However, the effectiveness benefits of SBR, for example, the decision-making benefits offered to investors via standardised reports, while becoming more broadly acknowledged, remain not a priority for all stakeholders.

Quantitative characterization of kaolinite dispersibility in styrene–butadiene rubber composites by fractal dimension

A fractal method was introduced to quantitatively characterize the dispersibility of modified kaolinite (MK) and precipitated silica (PS) in styrene–butadiene rubber (SBR) matrix based on the lower magnification transmission electron microscopic images. The fractal dimension (FD) is greater, and the dispersion is worse. The fractal results showed that the dispersibility of MK in the latex blending sample is better than that in the mill blending samples. With the increase of kaolinite content, the FD increases from 1.713 to 1.800, and the dispersibility of kaolinite gradually decreases. There is a negative correlation between the dispersibility and loading content. With the decrease of MK and increase of PS, the FD significantly decreases from 1.735 to 1.496 and the dipersibility of kaolinite remarkably increases. The hybridization can improve the dispersibility of fillers in polymer matrix. The FD can be used to quantitatively characterize the aggregation and dispersion of kaolinite sheets in rubber matrix.