Study of the Structure-Property Relationships That Determine the Effects of Latexes and Starch Containing Latex Emulsions on the Performance of the Barrier Coatings (Sub-coat) for Paper

The history of carbonless paper dates back to the 1940s. Before this, a carbon copy sheet was needed between sheets of paper to be able to produce one or more copies simultaneously during writing. The pressure from a pen or typewriter would help deposit the ink of the carbon paper onto the blank sheet of paper under the original written sheet to create a “carbon copy.” This method did however, have its disadvantages. Not only did it produce a limited number of copies, but it was also a messy process. So came the creative process of using microencapsulated dyes to make carbonless paper (Burrell, 2003, pp. 451-456). In this process, microencapsulated dyes are coated onto the back of the original sheet so when pressure is applied to the top sheet, it causes the microcapsules to rupture and form an image on the receiver sheet below. Under this capsule coating is a barrier coat or sub-coat, which is applied to the back of the original written sheet. The coating limits the encapsulated dye from absorbing into the original written sheet and increases the dye transferring onto the copy receiver sheet. In the barrier coating, latexes are used. Different chemical properties within the latex will make the barrier coatings perform differently (Mumford, 2007). The goal of this research study was to test the structure-property relationships that determine the effects of commercial latexes and starch containing latex emulsions (SCEs) on the performance properties of the barrier coating (sub-coat) for paper. The testing of these property changes was performed on the thin film coating of varying pounds per ream on base stock 34lb Domtar paper. Six different latexes with mildly different chemical properties were tested. The rheological techniques used to evaluate the coating slurries include: water retention, viscosity, and pH testing. The performance measurement tests done on the basestock coated samples include: Oil resistance and absorption which were measured through K&N and Croda (Manders Red Drawdown) ink tests and also Sheffield porosity. In conclusion, Typewriter Intensity and Frictional Smudge testing was done to verify the performance results of the barrier coated and CB capsule coated sheets. Through the performance and verification tests, some general conclusions were determined. These include: an increase in coat weight showed an increase in transfer efficiency and a smaller particle size latex created a better film and more sealed base stock sheet. This was shown not only in the porosity values, but also in the ink absorption results. It was also determined that the acrylonitrile containing latexes performed better due to the creation of a softer more flow-able latex. It was determined that DMF 5501, a commercial latex from Styron containing styrene butadiene copolymer with a low level of carboxylic acid groups, a high level of acrylonitrile groups, Tg 15 ̊C, and a particle size of 135nm, had the best performance when targeting the lowest coat weight, at 2lbs per ream. The smaller particle size and presence of both carboxylic acid and acrylonitrile groups proved to aid in this performance. An increase in binder efficiency was shown through testing, it is believed that both of the chemical groups present helped by binding the CB capsule coating to a greater extent to the base stock sheet. The smaller particle size aided in this binding by creating a better flowing more pliable latex which created an evenly formed barrier coat film. The porosity values results determined that DMF 5501 formed a better film, creating a more sealed sheet, hence a showing lower porosity value. The K&N and Croda Ink intensity values also showed that DMF 5501 performed best by showing highest ink intensity values on each base stock sheet. The performance verification tests determined that at only 2 lbs per ream of applied coating, DMF 5501 performed within the required standards set by Appleton Paper Inc., and if chosen, this latex could be used within the current carbonless paper product

The Energy Performance Certification: A tool for smarter cities?

One of the existing tools that could help creating smart cities is the Energy Performance Certification (EPC) of residential buildings, by introducing energy efficiency as a comparative criterion for real-estate purchase choices, influencing real-estate market value, stimulating energy saving investments, moving the housing market towards greater energy efficiency and creating comprehensive databases which are fundamental for shaping smart strategies on urban, regional and national levels. The impact on potential buyers or tenants is crucial in order to reach these goals but EPC’s results, in their actual form, do not help raise people awareness: often distant from reality, overestimating consumption, they usually result is a general misunderstanding and misuse of the document. This study aims at verifying that the actual calculation method used in certification could approach real building consumption, by using additional data on occupant behaviour and household characteristics. It first presents the concepts behind smart cities, then an overview of the uncertainties that weight on the Belgian certification calculation method parameters. It also presents variations that could be applied to the EPC calculation method in order to add behavioural parameters… inspired from case studies of buildings.Etude du facteur humain dans l’évaluation des performances énergétiques des stratégies de rénovation résidentiell

GABAC Receptors in the Lateral Amygdala: A Possible Novel Target for the Treatment of Fear and Anxiety Disorders?

Activation of GABAARs in the lateral nucleus of the amygdala (LA), a key site of plasticity underlying fear learning, impairs fear learning. The role of GABACRs in the LA and other brain areas is poorly understood. GABACRs could be an important novel target for pharmacological treatments of anxiety-related disorders since, unlike GABAARs, GABACRs do not desensitize. To detect functional GABACRs in the LA we performed whole cell patch clamp recordings in vitro. We found that GABAARs and GABABRs blockade lead to a reduction of evoked inhibition and an increase increment of excitation, but activation of GABACRs caused elevations of evoked excitation, while blocking GABACRs reduced evoked excitation. Based on this evidence we tested whether GABACRs in LA contribute to fear learning in vivo. It is established that activation of GABAARs leads to blockage of fear learning. Application of GABAC drugs had a very different effect; fear learning was enhanced by activating and attenuated by blocking GABACRs in the LA. Our results suggest that GABAC and GABAARs play opposing roles in modulation of associative plasticity in LA neurons of rats. This novel role of GABACRs furthers our understanding of GABA receptors in fear memory acquisition and storage and suggests a possible novel target for the treatment of fear and anxiety disorders

Métabolisme énergétique cardiaque fœtal dans un modèle de restriction de croissance intra-utérine chez le rat

Une diète faible en sodium donnée à des rates lors de la dernière semaine de gestation induit une diminution de l’expansion volumique, du diamètre des artères utérines et du poids des placentas comparativement à des rates témoins. Ces perturbations suggèrent une diminution de la perfusion placentaire affectant l’apport foetal en nutriments. Les ratons naissent avec une restriction de croissance intra-utérine (RCIU). Chez le foetus, le substrat énergétique cardiaque principal est le glucose via la glycolyse. À la naissance, la source principale d’énergie est l’utilisation des acides gras par la β-oxydation. Nous émettons l’hypothèse que dans ce modèle de RCIU, le coeur foetal répond à la diminution d’apport nutritionnel due à une atteinte maternelle en adaptant son métabolisme énergétique cardiaque à la baisse. Les rates gestantes (témoins et recevant la diète faible en sodium) sont sacrifiées au jour 22 de gestation (sur 23). Les coeurs foetaux sont prélevés afin de caractériser les protéines dites « limitantes » in vitro des voies de la glycolyse et de la β-oxydation. Les expressions protéiques de GLUT1, GLUT4, HK1, HK2, CPT2, CPT1β, cytochrome c, PFK1, PKM1/2, mesurées par immunobuvardage de type Western, sont similaires entre les coeurs des foetus RCIU et témoins, mâles et femelles. L’expression protéique de CPT1α est diminuée dans les coeurs des femelles RCIU seulement. Il n’existe aucune différence significative entre les différents groupes quant à l’activité enzymatique de PKM1/2. Nos résultats dressent un profil métabolique général suggérant que le sexe du foetus peut avoir un effet sur la réponse cardiaque foetale à une atteinte du volume sanguin maternel causée par la diète restreinte en sodium. Ce profil métabolique semble démontrer une atteinte du catabolisme des lipides. Afin de bien caractériser cette réponse du mécanisme énergétique, l’activité enzymatique des autres enzymes principales de la glycolyse (HK1, HK2, PFK1), le flux intra-mitochondrial d’acyl CoA à travers les CPTs ainsi que la quantité totale d’acétyl CoA devront être quantifiés.A low sodium diet was given to pregnant rats during the last week of gestation. This diet diminished the maternal expansion of blood volume, the uterine arteries diameter, and placental weight, when compared to their controls. Together, these results suggest a lower placenta perfusion and a decreased output of nutrients to the fetus. The offspring of these pregnant rats were born with an intra-uterine growth retardation (IUGR). The fetal heart utilizes glucose through glycolysis as the major cardiac energy substrate. At birth, the principal source of energy switches to the oxidation of fatty acids, through β-oxydation. We hypothesized that within our IUGR model, the fetal heart could respond to a diminished nutritional intake due to the maternal input when a decreased cardiac energy metabolism was present. The pregnant rats of both groups (controls and on the low sodium diet) were sacrificed on day 22 of a 23 day gestation. The fetal hearts were then analyzed looking for signs of the limiting proteins glycolysis and β-oxidation. The GLUT1, GLUT4, HK1, HK2, CPT2, CPT1β, cytochrome c, PFK1, PKM1/2 proteins obtained through a Western immunoblot method were similar between the hearts of the IUGR and their control fetuses, whether they were male or female. The protein expression of CPT1α was lower only in female IUGR fetal hearts. There was no significant difference between the groups with respect to the enzymatic activity of PKM1/2. Our results suggest that the metabolic profile changes with regards to the fetus gender and could affect the fetal cardiac metabolism, due to a lower maternal blood flow caused by a sodium controlled diet, by diminishing its lipid metabolism and sparing glucose metabolism. To characterize the energy metabolism, the enzymatic activity of the other principal limiting enzymes glycolysis (HK1, HK2, PFK1), the intra-mitochondrial flux of acyl CoA through the CPTs and the total quantity of acetyl CoA must also be analyzed

NUCLEAR FUEL ASSEMBLY TRANSFER PROJECT

The spent nuclear fuel assembly transfer process is complicated and has several important constraints. Continuity of Knowledge (COK) must be maintained throughout the process while also keeping the fuel underwater and away from workers to assure safety and security. The conveyance is mechanical in nature and must provide for worker access for repair/maintenance. Reliability, safety, and safeguards requirements must be met for the entire expected life span of the nuclear facility. This paper describes a new engineering design for enhanced safety and reliability for transfer of spent fuel assemblies from the reactor building to the fuel storage building. The new design is compliant with U.S. Nuclear Regulatory Commission (NRC) and the International Atomic Energy Agency guidelines, requirements, and regulations. This project was sponsored by Los Alamos National Laboratory at the University of Rhode Island and performed by faculty and students in the mechanical and nuclear engineering program. A physical scaled prototype of the system has been manufactured is currently going through functional non-nuclear testing for mechanical performance. The fuel transfer system begins with the fuel assembly being lowered into a Fuel Assembly Transport Vessel (FATV). The FATV is equipped with side mounted wheels designed for horizontal movement through the transport tunnel via a rail system. An industrial roller chain conveyor with vertical attachments runs between the rails and makes contact with the FATV. The new design includes gears, axles, and a safely-positioned dry and above water surface motor that drives the chain laterally in either direction. Thus the FATV containing the spent fuel assembly is safely and securely moved in the connecting water tunnel. Engineering analyses were performed on the various facets of the design to validate the merit of the system’s purpose and the adherence to reliability, safeguards, and safety factors set for a system undergoing 50+ years of service life in a radioactive environment. Each individual fuel transfer system will be modified in accordance to the needs of each corresponding nuclear reactor plant. Our design addresses constraints pertaining to that of the transference of spent nuclear fuel assemblies while meeting of the design criteria, safety, and safeguards standards set by the IAEA and the NRC. A scaled physical model of the design has been built to demonstrate the mechanical systems functionality