Thermogravimetric analysis of tobacco combustion assuming DAEM devolatilization and empirical char-burnoff kinetics

Two blends of tobacco (Virginia and Burley) were studied by thermogravimetry at linear and nonlinear heating programs in gas flows containing 2, 4 and 9% oxygen. A kinetic scheme of successive devolatilization and char burn-off reactions was assumed. A distributed activation energy model was assumed for the devolatilization with a Gaussian distribution and a constant pre-exponential factor. The evaluations were also carried out using non-constant pre-exponential factors that depended on the activation energy. The char burn-off was described by first order kinetics and by an empirical model that took into account the change of the reactivity with the conversion of the sample. The dependence of the rate of combustion on the oxygen concentration was approximated by a power function. Series of 15 and 30 experiments were used for the determination of the model parameters by simultaneous least squares evaluation of the experiments. The considerations, methods and results can also be used in the field of biomass gasification and combustion

The Human Right to Water -- Market Allocations and Subsistence in a World of Scarcity

Thesis advisor: David HollenbachMore than one billion people do not have access to an adequate water supply and several billion lack access to basic sanitation, which is the number one cause of diseases linked to water and water contamination. In countries such as Gambia and Haiti, people live on less than 4 liters of water per day. Cholera and dysentery, two of the more deadly water-related diseases, claim around 10 million victims each year, primarily among young children and the elderly; sadly, these diseases are easily preventable. Certain areas of the world are running out of fresh water at an alarming rate, and the global distribution of water is making it increasingly more difficult for poor people to access it. Movements to commodify water and privatize the industries that provide it are, in many cases, exacerbating this situation of scarcity and trapping poor people in a cycle of water poverty. While much research has been done on the problem of water scarcity, there is currently a void in this undertaking regarding the link between scarcity and water as a human right. Therefore, this paper seeks to address the question of whether there exists a human right to water and, if so, what obligations that entails for major market actors, such as: state governments; water corporations; and international lending institutions.Thesis (BA) — Boston College, 2004.Submitted to: Boston College. College of Arts and Sciences.Discipline: International Studies.Discipline: College Honors Program

Tobacco pyrolysis. Kinetic evaluation of thermogravimetric – mass spectrometric experiments.

The thermal decomposition of two tobacco blends was studied by thermogravimetry - mass spectrometry (TGA-MS) at slow heating programs under well defined conditions. The kinetic evaluation was based on a distributed activation energy model (DAEM) which is a suitable tool for complex materials of plant origin. Linear and non-linear (stepwise) heating programs were employed to obtain information for reliable kinetic modeling. Series of experiments were evaluated simultaneously by the method of least squares. Efforts were made to identify and describe kinetically the similarities between two, highly different tobacco samples as well as between the various mass spectrometric intensity curves. This was achieved by evaluating large series of experimental results and assuming several kinetic parameters to be common for both samples and/or a group of mass spectrometric intensities. The methods and considerations outlined in the paper may be helpful in the studies of biomass and other organic samples by a wider variety of experimental techniques including TGA-FTIR and time resolved pyrolysis

Thermal behaviour of selected flavour ingredients and additives under simulated cigarette combustion and tobacco heating conditions

An experimental method of pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) is proposed to evaluate the fate of selected flavour compounds in low-temperature (300°C) tobacco heating conditions. The thermal behaviour of five flavouring compounds (citronellol, menthol, tartaric acid, cinnamic acid, and guaiacol) was studied under conditions to simulate low-temperature tobacco heating at 300°C, and compared with results obtained using simulated cigarette-combustion conditions with a temperature program up to 900°C. The impact of oxygen and nitrogen atmospheres on the thermal transfer and breakdown patterns was also investigated. It was established that the four flavouring compounds of high volatility (citronellol, menthol, cinnamic acid, and guaiacol) evaporated to a high degree (88-100 %) during the low- and high-temperature experiments, as well. Guaiacol was the most stable compound under the test conditions; only 0.3 % decomposition was detected at 900°C with the oxidative atmosphere. Thermal decomposition reactions were substantially less extensive at the low-temperature heating conditions than with the high-temperature pyrolysis and simulated cigarette combustion. Citronellol and cinnamic acid produced about 1.5 % decomposition products, while menthol produced 0.8 %. In general, dehydrogenation reactions were more pronounced in the oxidative atmosphere, while aromatisation was significant in the nitrogen atmosphere, and at high temperatures. More oxo-compounds and less aromatic hydrocarbons were formed in the oxidative atmosphere. Other types of reactions took place with tartaric acid, due to its low volatility. Extensive formation of light carboxylic acids was observed at the low temperature, and cyclic compounds were also formed in addition to carbon oxides and water under both nitrogen and oxidative atmospheres. Intermolecular reactions are proposed to explain these observations. At high temperatures the pyrolysis products of tartaric acid were the same as at low temperatures, but in the oxidative atmosphere more carboxylic acids and less aldehydes were formed than in pure nitrogen. These results demonstrate the flavour compound’s thermal stability depends strongly on the exact thermal history (heating temperature, heating duration and gas atmosphere) that they are exposed to. The information obtained will be of interests in understanding the thermal behaviour of these and other flavour compounds used in tobacco heating products

Information rigidities and the news-adjusted output gap

A vector-autoregressive model of actual output and expected output obtained from surveys is used to test for information rigidities and to provide a characterisation of output dynamics that accommodates these information structures. News on actual and expected outputs is decomposed to identify innovations understood to have short-lived effects and these are used with the model to derive a ‘news-adjusted output gap׳ measure. The approach is applied to US data over 1970q1–2014q2 and the new gap measure is shown to provide a good leading indicator of inflation

Characterization of Atlantic Cod Spawning Habitat and Behavior in Icelandic Coastal Waters

The physical habitat used during spawning may potentially be an important factor affecting reproductive output of broadcast spawning marine fishes, particularly for species with complex, substrate-oriented mating systems and behaviors, such as Atlantic cod Gadus morhua. We characterized the habitat use and behavior of spawning Atlantic cod at two locations off the coast of southwestern Iceland during a 2-d research cruise (15-16 April 2009). We simultaneously operated two different active hydroacoustic gear types, a split beam echosounder and a dual frequency imaging sonar (DIDSON), as well as a remotely operated underwater vehicle (ROV). A total of five fish species were identified through ROV surveys: including cusk Brosme brosme, Atlantic cod, haddock Melanogrammus aeglefinus, lemon sole Microstomus kitt, and Atlantic redfish Sebastes spp. Of the three habitats identified in the acoustic surveys, the transitional habitat between boulder/lava field and sand habitats was characterized by greater fish density and acoustic target strength compared to that of sand or boulder/lava field habitats independently. Atlantic cod were observed behaving in a manner consistent with published descriptions of spawning. Individuals were observed ascending 1-5 m into the water column from the bottom at an average vertical swimming speed of 0.20-0.25 m s21 and maintained an average spacing of 1.0-1.4 m between individuals. Our results suggest that cod do not choose spawning locations indiscriminately despite the fact that it is a broadcast spawning fish with planktonic eggs that are released well above the seafloor

TRIM21 mediates antibody inhibition of adenovirus-based gene delivery and vaccination

Adenovirus has enormous potential as a gene-therapy vector, but preexisting immunity limits its widespread application. What is responsible for this immune block is unclear because antibodies potently inhibit transgene expression without impeding gene transfer into target cells. Here we show that antibody prevention of adenoviral gene delivery in vivo is mediated by the cytosolic antibody receptor TRIM21. Genetic KO of TRIM21 or a single-antibody point mutation is sufficient to restore transgene expression to near-naïve immune levels. TRIM21 is also responsible for blocking cytotoxic T cell induction by vaccine vectors, preventing a protective response against subsequent influenza infection and an engrafted tumor. Furthermore, adenoviral preexisting immunity can lead to an augmented immune response upon i.v. administration of the vector. Transcriptomic analysis of vector-transduced tissue reveals that TRIM21 is responsible for the specific up-regulation of hundreds of immune genes, the majority of which are components of the intrinsic or innate response. Together, these data define a major mechanism underlying the preimmune block to adenovirus gene therapy and demonstrate that TRIM21 efficiently blocks gene delivery in vivo while simultaneously inducing a rapid program of immune transcription

Reduction of aldehydes and hydrogen cyanide yields in mainstream cigarette smoke using an amine functionalised ion exchange resin

<p>Abstract</p> <p>Background</p> <p>Cigarette smoking is a well recognized cause of diseases such as lung cancer, chronic obstructive pulmonary disease and cardiovascular disease. Of the more than 5000 identified species in cigarette smoke, at least 150 have toxicological activity. For example, formaldehyde and acetaldehyde have been assigned as Group 1 and Group 2B carcinogens by IARC, and hydrogen cyanide has been identified as a respiratory and cardiovascular toxicant. Active carbon has been shown to be an effective material for the physical adsorption of many of the smoke volatile species. However, physical adsorption of acetaldehyde, formaldehyde and also hydrogen cyanide from smoke is less effective using carbon. Alternative methods for the removal of these species from cigarette smoke are therefore of interest. A macroporous, polystyrene based ion-exchange resin (Diaion^®CR20) with surface amine group functionality has been investigated for its ability to react with aldehydes and HCN in an aerosol stream, and thus selectively reduce the yields of these compounds (in particular formaldehyde) in mainstream cigarette smoke.</p> <p>Results</p> <p>Resin surface chemistry was characterized using vapour sorption, XPS, TOF-SIMS and ¹⁵N NMR. Diaion^®CR20 was found to have structural characteristics indicating weak physisorption properties, but sufficient surface functionalities to selectively remove aldehydes and HCN from cigarette smoke. Using 60 mg of Diaion^®CR20 in a cigarette cavity filter gave reductions in smoke formaldehyde greater than 50% (estimated to be equivalent to >80% of the formaldehyde present in the smoke vapour phase) independent of a range of flow rates. Substantial removal of HCN (>80%) and acetaldehyde (>60%) was also observed. The performance of Diaion^®CR20 was found to be consistent over a test period of 6 months. The overall adsorption for the majority of smoke compounds measured appeared to follow a pseudo-first order approximation to second order kinetics.</p> <p>Conclusions</p> <p>This study has shown that Diaion^®CR20 is a highly selective and efficient adsorbent for formaldehyde, acetaldehyde and HCN in cigarette smoke. The reductions for these compounds were greater than those achieved using an active carbon. The results also demonstrate that chemisorption can be an effective mechanism for the removal of certain vapour phase toxicants from cigarette smoke.</p

Randomised, open-label, phase II study of Gemcitabine with and without IMM-101 for advanced pancreatic cancer

Background: Immune Modulation and Gemcitabine Evaluation-1, a randomised, open-label, phase II, first-line, proof of concept study (NCT01303172), explored safety and tolerability of IMM-101 (heat-killed Mycobacterium obuense; NCTC 13365) with gemcitabine (GEM) in advanced pancreatic ductal adenocarcinoma. Methods: Patients were randomised (2 : 1) to IMM-101 (10 mg ml−l intradermally)+GEM (1000 mg m−2 intravenously; n=75), or GEM alone (n=35). Safety was assessed on frequency and incidence of adverse events (AEs). Overall survival (OS), progression-free survival (PFS) and overall response rate (ORR) were collected. Results: IMM-101 was well tolerated with a similar rate of AE and serious adverse event reporting in both groups after allowance for exposure. Median OS in the intent-to-treat population was 6.7 months for IMM-101+GEM v 5.6 months for GEM; while not significant, the hazard ratio (HR) numerically favoured IMM-101+GEM (HR, 0.68 (95% CI, 0.44–1.04, P=0.074). In a pre-defined metastatic subgroup (84%), OS was significantly improved from 4.4 to 7.0 months in favour of IMM-101+GEM (HR, 0.54, 95% CI 0.33–0.87, P=0.01). Conclusions: IMM-101 with GEM was as safe and well tolerated as GEM alone, and there was a suggestion of a beneficial effect on survival in patients with metastatic disease. This warrants further evaluation in an adequately powered confirmatory study