TGA/FTIR study of the pyrolysis of diammonium hydrogen phosphate–tobacco mixtures

Diammonium hydrogen phosphate (DAP) is commonly used as a flavor ingredient of commercial cigarettes. In addition, among its other uses, it is employed to expand the tobacco volume, to manufacture reconstituted tobacco sheet, and to denicotinize tobacco. However, the use of DAP as a cigarette ingredient is a controversial issue. Some authors have stated that ammonium compounds added to tobacco increase smoke ammonia and “smoke pH”, resulting in more free nicotine available in the smoke. On the other hand, other researchers have reported that the larger ammonium content of a cigarette blend due to the presence of DAP was not reflected in increased smoke ammonia. In this work, the thermal behavior of DAP, tobacco and DAP-tobacco mixtures has been studied by TGA/FTIR. The chemical processes involved in the different pyrolysis steps of DAP have been suggested. Marked changes in the pyrolytic behavior of both, tobacco and DAP have been detected when analyzing the behavior of the mixtures. A displacement of the decomposition steps mainly related to the glycerol and lignin from tobacco toward lower temperatures has been observed, whereas that associated with cellulose is displaced toward higher temperature. Additionally, no peak corresponding to the phosphorous oxides decomposition has been detected in the curves relating to the DAP-tobacco mixtures. All these features are indicative of the strong interactions between DAP and tobacco. The FTIR spectra show no significant qualitative differences between the qualitative overall composition of the gases evolved from the pyrolysis of tobacco in the absence and in the presence of DAP. Nevertheless, depending on the temperature considered, the addition of DAP contributes to a decrease in the generation of hydrocarbons and an increase in the formation of CO, CO2 and oxygenated compounds in terms of amount generated per mass of pyrolysed tobacco.

In vitro-in vivo Pharmacokinetic correlation model for quality assurance of antiretroviral drugs

Introduction: The In vitro-in vivo pharmacokinetic correlation models (IVIVC) are a fundamental part of the drug discovery and development process. The ability to accurately predict the in vivo pharmacokinetic profile of a drug based on in vitro observations can have several applications during a successful development process. Objective: To develop a comprehensive model to predict the in vivo absorption of antiretroviral drugs based on permeability studies, in vitro and in vivo solubility and demonstrate its correlation with the pharmacokinetic profile in humans. Methods: Analytical tools to test the biopharmaceutical properties of stavudine, lamivudine y zidovudine were developed. The kinetics of dissolution, permeability in caco-2 cells and pharmacokinetics of absorption in rabbits and healthy volunteers were evaluated. Results: The cumulative areas under the curve (AUC) obtained in the permeability study with Caco-2 cells, the dissolution study and the pharmacokinetics in rabbits correlated with the cumulative AUC values in humans. These results demonstrated a direct relation between in vitro data and absorption, both in humans and in the in vivo model. Conclusions: The analytical methods and procedures applied to the development of an IVIVC model showed a strong correlation among themselves. These IVIVC models are proposed as alternative and cost/effective methods to evaluate the biopharmaceutical properties that determine the bioavailability of a drug and their application includes the development process, quality assurance, bioequivalence studies and pharmacosurveillance.

A Model for Continuous Measurement of Drilled Shaft Diameter During Construction

Non-Destructive Testing (NDT) of deep foundations has become an integral part of the industry’s standard manufacturing processes. It is not unusual for the evaluation of the integrity of the concrete to include the measurement of ultrasonic wave speeds. Numerous methods have been proposed that use the propagation speed of ultrasonic waves to check the integrity of concrete for drilled shaft foundations. All such methods evaluate the integrity of the concrete inside the cage and between the access tubes. The integrity of the concrete outside the cage remains to be considered to determine the location of the border between the concrete and the soil in order to obtain the diameter of the drilled shaft. It is also economic to devise a methodology to obtain the diameter of the drilled shaft using the Cross-Hole Sonic Logging system (CSL). Performing such a methodology using the CSL and following the CSL tests is performed and used to check the integrity of the inside concrete, thus allowing the determination of the drilled shaft diameter without having to set up another NDT device. This proposed new method is based on the installation of galvanized tubes outside the shaft across from each inside tube, and performing the CSL test between the inside and outside tubes. From the performed experimental work a model is developed to evaluate the relationship between the thickness of concrete and the ultrasonic wave properties using signal processing. The experimental results show that there is a direct correlation between concrete thicknesses outside the cage and maximum amplitude of the received signal obtained from frequency domain data. This study demonstrates how this new method to measuring the diameter of drilled shafts during construction using a NDT method overcomes the limitations of currently-used methods. In the other part of study, a new method is proposed to visualize and quantify the extent and location of the defects. It is based on a color change in the frequency amplitude of the signal recorded by the receiver probe in the location of defects and it is called Frequency Tomography Analysis (FTA). Time-domain data is transferred to frequency-domain data of the signals propagated between tubes using Fast Fourier Transform (FFT). Then, distribution of the FTA will be evaluated. This method is employed after CSL has determined the high probability of an anomaly in a given area and is applied to improve location accuracy and to further characterize the feature. The technique has a very good resolution and clarifies the exact depth location of any void or defect through the length of the drilled shaft for the voids inside the cage. The last part of study also evaluates the effect of voids inside and outside the reinforcement cage and corrosion in the longitudinal bars on the strength and axial load capacity of drilled shafts. The objective is to quantify the extent of loss in axial strength and stiffness of drilled shafts due to presence of different types of symmetric voids and corrosion throughout their lengths.

Pyrolysis of rice husk and corn stalk in auger reactor:Part 1. Characterization of char and gas at various temperatures

In this study, rice husk and corn stalk have been pyrolyzed in an auger pyrolysis reactor at pyrolysis temperatures of 350, 400, 450, 500, 550, and 600 °C in order to investigate the effect of the pyrolysis temperature on the pyrolysis performance of the reactor and physicochemical properties of pyrolysis products (this paper focuses on char and gas). The results have shown that the pyrolysis temperature significantly affects the mass yields and properties of the pyrolysis products. The mass yields of pyrolysis liquid and char are comparable to those reported for the same feedstocks processed in fluidized bed reactors. With the increase of the pyrolysis temperature, the pyrolysis liquid yield shows a peak at 500 °C, the char yield decreases, and the gas yield increases for both feedstocks. The higher heating value (HHV) and volatile matter content of char increase as the pyrolysis temperature increases from 350 to 600 °C. The gases obtained from the pyrolysis of rice husk and corn stalk mainly contain CO2, CO, CH4, H2, and other light hydrocarbons; the molar fractions of combustible gases increase and therefore their HHVs subsequently increase with the increase of the pyrolysis temperature.

Health beliefs affect the correct replacement of daily disposable contact lenses:predicting compliance with the Health Belief Model and the Theory of Planned Behaviour

Purpose: To assess the compliance of Daily Disposable Contact Lenses (DDCLs) wearers with replacing lenses at a manufacturer-recommended replacement frequency. To evaluate the ability of two different Health Behavioural Theories (HBT), The Health Belief Model (HBM) and The Theory of Planned Behaviour (TPB), in predicting compliance. Method: A multi-centre survey was conducted using a questionnaire completed anonymously by contact lens wearers during the purchase of DDCLs. Results: Three hundred and fifty-four questionnaires were returned. The survey comprised 58.5% females and 41.5% males (mean age 34. ±. 12. years). Twenty-three percent of respondents were non-compliant with manufacturer-recommended replacement frequency (re-using DDCLs at least once). The main reason for re-using DDCLs was "to save money" (35%). Predictions of compliance behaviour (past behaviour or future intentions) on the basis of the two HBT was investigated through logistic regression analysis: both TPB factors (subjective norms and perceived behavioural control) were significant (p. <. 0.01); HBM was less predictive with only the severity (past behaviour and future intentions) and perceived benefit (only for past behaviour) as significant factors (p. <. 0.05). Conclusions: Non-compliance with DDCLs replacement is widespread, affecting 1 out of 4 Italian wearers. Results from the TPB model show that the involvement of persons socially close to the wearers (subjective norms) and the improvement of the procedure of behavioural control of daily replacement (behavioural control) are of paramount importance in improving compliance. With reference to the HBM, it is important to warn DDCLs wearers of the severity of a contact-lens-related eye infection, and to underline the possibility of its prevention.

Development of an antigen-driven colitis model to study presentation of antigens by antigen presenting cells to T cells

Inflammatory bowel disease (IBD) is a chronic inflammation which affects the gastrointestinal tract (GIT). One of the best ways to study the immunological mechanisms involved during the disease is the T cell transfer model of colitis. In this model, immunodeficient mice (RAG-/-recipients) are reconstituted with naive CD4+ T cells from healthy wild type hosts. This model allows examination of the earliest immunological events leading to disease and chronic inflammation, when the gut inflammation perpetuates but does not depend on a defined antigen. To study the potential role of antigen presenting cells (APCs) in the disease process, it is helpful to have an antigen-driven disease model, in which a defined commensal-derived antigen leads to colitis. An antigen driven-colitis model has hence been developed. In this model OT-II CD4+ T cells, that can recognize only specific epitopes in the OVA protein, are transferred into RAG-/- hosts challenged with CFP-OVA-expressing E. coli. This model allows the examination of interactions between APCs and T cells in the lamina propria.

Application of an equivalent frame model for the analysis of typical Dutch masonry structures

A partire dal 1986, nell’Olanda settentrionale si sta verificando un incremento di fenomeni sismici superficiali di medio-bassa intensità. Siccome la zona è considerata a basso rischio sismico, tali fenomeni sono legati all’estrazione di gas nella regione Groningen situata a nord-est del paese, la quale rappresenta il più grande giacimento d’Europa. Di conseguenza, si sono verificati danni ingenti sulle strutture che sorgono in zona, che di fatto non erano state progettate per resistere a forze orizzontali legate all’accelerazione del suolo. Ricercatori, aziende e università sono stati coinvolti nel progetto di ricerca finalizzato alla valutazione della vulnerabilità sismica delle costruzioni esistenti, in modo da poter avviare interventi di miglioramento o adeguamento sismico. A questo scopo, presso l’università tecnica di Delft sono stati svolti diversi test sperimentali e analitici su murature non rinforzate tipiche olandesi, che rappresentano la tipologia costruttiva più diffusa e si distinguono per la presenza di maschi murari snelli, grandi aperture e inadeguatezza delle connessioni tra gli elementi strutturali. Lo scopo della tesi è verificare l’adeguatezza del modello a telaio equivalente implementato nel software 3Muri per la modellazione di due tipiche case a schiera in muratura non rinforzata. Tali case, precedentemente ricostruite e testate in laboratorio attraverso un’analisi pushover, differiscono per metodologia costruttiva ed i materiali utilizzati.

Development of a porcine lactation model for the evaluation of mammary transfer of exogenous molecules - A contribution from the conception project

Around 5 million women give birth each year in Europe and, while breastfeeding, the majority of them may need to take medications, either occasionally or continuously. Unfortunately, there is often scarce evidence of trustworthy information about how a specific molecule might affect the physiology of lactation. This is the reason that brought a European public-private partnership to fund the development of a reliable platform to provide women and health-care professionals a helpful instrument to reduce uncertainty about the effects of medication used during breastfeeding. On April 1st 2019, the ConcePTION project (Grant Agreement n°821520) started to develop such envisaged platform. The 3rd Work Package was in charge of the validation of in vitro, in vivo and in silico lactation models. Between the numerous species currently used in preclinical studies, pigs’ similarities with humans’ anatomy, physiology and genomics make them extremely useful as translational models, when proper veterinary expertise is applied. The ASA team from the University of Bologna, went first to characterize the translational lactation model using the swine species, chosen upon literature review. The aim of this work was to lay the foundations of a porcine lactation model that could be suitable for application within pharmaceutical tests, to study drug transfer through milk prior approval and commercialization. The obtained results highlighted both strengths and critical points of the study design, allowing a significant improvement in the knowledge of pharmacokinetic physiology in lactating mammals. Lastly, this project allowed the assessment of microbial changes in gut resident bacteria of newborns through an innovative in vitro colonic model. Indeed, even if there were no evident adverse effects determined by drug residues in milk, possible alterations in the delicate microbial ecology of newborns’ gastrointestinal tract was considered pivotal, giving its possible impact on the individual health and growth.

Soluble carbon in oxisol under the effect of organic residue rates

The application of organic residues to the soil can increase soluble organic carbon (SOC) and affect the pH and electrolytic conductivity (EC) of the soil. However, the magnitude of these changes depends on the type of residue and the applied dose. This study aimed to evaluate the effect of increasing C rates contained in organic residue on the pH, EC, water-extractable total carbon (WETC), water-extractable organic carbon (WEOC), and water-extractable inorganic carbon (WEIC) in soil treated with manure (chicken, swine, and quail), sawdust, coffee husk, and sewage sludge. The levels of total C (TC- KH2PO4), organic carbon (OC- KH2PO4), and inorganic C (IC- KH2PO4) extractable by a 0.1 mol L-1 KH2PO4 solution were also quantified in soil under the effect of increasing rates of chicken and quail manures. The following rates of organic residue C were applied to a dystrophic Red Latosol (Oxisol) sample: 0, 2,000, 5,000, 10,000, and 20,000 mg kg-1. The addition of organic residues to the soil increased pH, except in the case of sewage sludge, which acidified the soil. The acidity correction potential of chicken and quail manure was highest, dependent on the manure rate applied; regardless of the dose used, sawdust barely alters the soil pH. At all tested rates, the EC of the soil treated with swine manure, coffee husk, and sawdust remained below 2.0 dS m-1, which is a critical level for salinity-sensitive crops. However, the application of chicken or quail manure and sewage sludge at certain rates increased the EC to values above this threshold level. Highest levels of WETC, WEOC, and WEIC were obtained when chicken and quail manure and coffee husk were applied to the Oxisol. The quantities of SOC extracted by KH2PO4 were higher than the quantities extracted by water, demonstrating the ability of soil to adsorb C into its colloids.

Adsorbents a partir de fangs biològics excedents de depuradora mitjançant l'aplicació de microones: estudi d'obtenció, caracterització i aplicació en fase líquida

El fang biològic es produeix en les plantes de tractament d'aigües residuals urbanes i industrials. El tractament i la gestió dels fangs és un dels problemes més importants en el camp del tractament de les aigües residuals. Aquesta situació es preveu que es veurà agreujada en el futur, per un increment del volum de fang produït associat a l'exigència de nivells més alts de depuració i per l'augment dels nombre d'estacions depuradores en funcionament. D'altre banda, les limitacions que presenten les opcions tradicionals de gestió dels fangs, fa necessari buscar solucions innovadores i efectives per a solucionar el problema que suposa la gestió d'aquests fangs biològics. Els fangs biològics són de naturalesa carbonosa i amb un alt contingut de matèria orgànica. Aquestes característiques, permeten la conversió del fang en un sòlid adsorbent de tipus carbonós. Aquesta conversió ofereix el doble benefici de reduir el volum de fang que ha de ser gestionat i alhora produir un adsorbent amb un cost inferior a la dels adsorbents convencionals (carbons actius comercials). Fins el moment, els tractaments alta temperatura han demostrat la seva efectivitat per du a terme el procés de transformació dels excedents de fang biològic en un sòlid adsorbent carbonós (carbó actiu). Com a alternativa a aquests processos a alta temperatura, es proposa un nou procés d'obtenció d'un sòlid adsorbent carbonós a partir dels excedents de fangs biològics, mitjançant un tractament a baixa temperatura, combinant el tractament per microones amb l'addició d'un reactiu químic (H2SO4). La present tesi analitza el tractament dels excedents de fangs biològics utilitzant un tractament mitjançant microones i l'addició d'àcid sulfúric (H2SO4), al mateix temps analitza la possibilitat d'utilitzar els sòlids adsorbents obtinguts per a millorar la qualitat de les aigües residuals. Paràmetres d'operació com poden ser la quantitat d'àcid sulfúric addicionada al fang, el nivell de potència del forn microones i el temps de tractament, es modificaran per tal de determinar la influència que poden tenir sobre la qualitat del sòlid adsorbent. Un cop determinada la qualitat dels diferent sòlids adsorbents s'avalua la seva capacitat per a l'eliminació de colorant i metalls en fase líquida. Els resultats obtinguts es comparen amb els obtinguts per un carbó actiu derivat de fangs i un carbó actiu comercial.

Procesos secuenciales de adsorción/oxidación con H2O2 para la eliminación de compuestos orgánicos volátiles

Volatile Organic Compounds (VOCs) are one of the main groups of odour causing compounds in Waste Water Treatment Plants (WWTP). Adsorption technology is already established, in recent years the interest for the optimization of the costs associated with this technique has grown significantly. In particular, there are different options, from the use of low cost adsorbents, to reducing costs associated with carbon regeneration process. In this thesis, the adsorption of the three VOCs on sewage sludge based adsorbents was studied. It was proved that adsorbents obtained by chemical activation of sewage sludge with alkaline hydroxides are comparable to commercial activated carbons (ACs). Likewise, the adsorption of multicomponent gaseous streams was also studied. Related to the ACs regeneration, it was proposed a regeneration treatment of VOC saturated ACs with H2O2 based on advanced oxidation processes (AOP). The influence of the surface chemistry of ACs in this regeneration process was also studied.

Strategic management of non-point source pollution from sewage sludge

In the UK, the recycling of sewage sludge to land is expected to double by 2006 but the security of this route is threatened by environmental concerns and health scares. Strategic investment is needed to ensure sustainable and secure sludge recycling outlets. At present, the security of this landbank for sludge recycling is determined by legislation relating to nutrient rather than potentially toxic elements (PTEs) applications to land - especially the environmental risk linked to soil phosphorus (P) saturation. We believe that not all land has an equal risk of contributing nutrients derived from applications to land to receiving waters. We are currently investigating whether it is possible to minimise nutrient loss by applying sludge to land outside Critical Source Areas (CSAs) regardless of soil P Index status. Research is underway to develop a predictive and spatially-sensitive, semi-distributed model of critical thresholds for sludge application that goes beyond traditional 'end-of-pipe" or "edge-of-field" modelling, to include hydrological flow paths and delivery mechanisms to receiving waters from non-point sources at the catchment scale.

Estudo da viabilidade da utilização de cinza de lodo de esgoto como adição em argamassa de cimento Portland

The use of sewage sludge as a raw material falls within the waste recycling key in the current process model environmental sustainability .Waste recycling has been consolidated as a sustainable environmentally sound technical solution, and. Despite showing very variable composition and characteristics, sewage sludge, can be considered as a residue with a high recycling potential in the building sector. In this paper the feasibility of using sewage sludge ash was studied in addition to Portland cement mortar in 1:3 mass considered the standard dash. This gray additions were studied in proportions of 5%, 10 %, 15 %, 20 %, 25% and 30% by mass of cement. The methodology was focused on the characterization of materials by physical, chemical , mechanical , environmental and morphological followed by the production of mortar tests ,and finalized by the characterization tests of mortar in the fresh state, through the consistency index, content of entrained air, bulk density and water retention, and in the hardened state by bulk density, water absorption by capillarity capillarity coefficient, compressive strength, tensile strength in bending ,tensile bond strength and microstructural analysis for percentages of 0 to 20%. After comparing with the standard mortar mortars with addition of ash, it is concluded that the ash of sewage sludge did not impair the integrity and properties of mortars with addition, including increasing resistance to compression and tension, being 20% more indicated percentage. Thus, it becomes feasible the addition of sewage sludge ash in Portland cement mortar for the trait studied

Evaluation of biochemical and redox parameters in rats fed with corn grown in soil amended with urban sewage sludge

The increased production of urban sewage sludge requires alternative methods for final disposal. A very promising choice is the use of sewage sludge as a fertilizer in agriculture, since it is rich in organic matter, macro and micronutrients. However, urban sewage sludge may contain toxic substances that may cause deleterious effects on the biota, water and soil, and consequently on humans. There is a lack of studies evaluating how safe the consumption of food cultivated in soils containing urban sewage sludge is. Thus, the aim of this paper was to evaluate biochemical and redox parameters in rats fed with corn produced in a soil treated with urban sewage sludge for a long term. For these experiments, maize plants were grown in soil amended with sewage sludge (rates of 5, 10 and 20. t/ha) or not (control). Four different diets were prepared with the corn grains produced in the field experiment, and rats were fed with these diets for 1, 2, 4, 8 and 12 weeks. Biochemical parameters (glucose, total cholesterol and fractions, triglycerides, aspartate aminotransferase and alanine aminotransferase) as well the redox state biomarkers such as reduced glutathione (GSH), malondialdehyde (MDA), catalase, glutathione peroxidase and butyrylcholinesterase (BuChE) were assessed. Our results show no differences in the biomarkers over 1 or 2 weeks. However, at 4 weeks BuChE activity was inhibited in rats fed with corn grown in soil amended with sewage sludge (5, 10 and 20. t/ha), while MDA levels increased. Furthermore, prolonged exposure to corn cultivated in the highest amount per hectare of sewage sludge (8 and 12 weeks) was associated with an increase in MDA levels and a decrease in GSH levels, respectively. Our findings add new evidence of the risks of consuming food grown with urban sewage sludge. However, considering that the amount and type of toxic substances present in urban sewage sludge varies considerably among different sampling areas, further studies are needed to evaluate sludge samples collected from different sources and/or undergoing different types of treatment. © 2013 Elsevier Inc.

Study of the thermal decomposition of petrochemical sludge in a pilot plant reactor

The pyrolysis of a sludge produced in the waste water treatment plant of an oil refinery was studied in a pilot plant reactor provided with a system for condensation of semivolatile matter. The study comprises experiments at 350, 400, 470 and 530 °C in nitrogen atmosphere. Analysis of all the products obtained (gases, liquids and chars) are presented, with a thermogravimetric study of the char produced and analysis of main components of the liquid. In the temperature range studied, the composition of the gas fraction does not appreciably vary. In the liquids, the light hidrocarbon yield increases with increasing temperature, whereas the aromatic compounds diminish. The decomposition of the solid fraction has been analysed, finding a material that reacts rapidly with oxygen regardless of the conditions it is formed.