Effect of particle morphology on the mechanical and thermo-mechanical behavior of polymer composites

Fiber reinforced polymer composites have been used in many applications, such as in automobile, aerospace and naval industries, due basically to their high strength-to-weight and modulus-to-weight, among other properties. Even though particles are usually not able to lead to the level of reinforcement of fibers, particle reinforced polymer composites have been proposed for many new applications due to their low cost, easy fabrication and isotropic properties. In this work, polymer composites were prepared by incorporating glass particles of different morphologies on poly(aryl sulfones) matrices. Particles with aspect ratios equal to 1, 2.5 and 10 were used. The prepared composites were characterized using electron microscopy and thermal analysis. Mechanical properties of the composites were evaluated using a four-point bending test. The thermo-mechanical behavior of the obtained composites was also investigated. The results showed that the morphology of the particles alter significantly the mechanical properties of composites. Particles with larger values of aspect ratio led to large elastic modulus but low levels of strain at failure. This result was explained by modeling the thermo-mechanical behavior of the composites using a viscoelastic model. Parameters of the model, obtained from a Cole-Cole type of plot, demonstrated that interactions at the polymer-reinforcing agent interface were higher for composites with large aspect ratio particles. Higher levels of interactions at interfaces can lead to higher degrees of stress transfer and, consequently, to composites with large elastic modulus, as experimentally observed.

Use of fiber-reinforced composite framework and thermochromic pigment in maxillofacial prostheses

The purpose of this investigation was to evaluate the possibility to enhance certain qualities of facial prostheses. Polymethyl methacrylate is still being used as base mate¬rial or clip carrier material, but it is hard and heavy, and debonding of the silicone from the acrylic base material is a frequent problem. This thesis aims to evaluate the use of fiber-reinforced composite (FRC) as framework material for maxillofacial silicone prostheses. FRC has been used as reinforcement in removable and fixed partial dentures since the 1990s. This material is lightweight and can be fabricated to compress the margins of the prosthesis slightly, to keep it tightly against the skin during jaw movements and facial expressions. Additionally, the use of a thermochromic pigment, colorless in room temperature and red in a cold environment, was studied in order to evaluate the possibility of using this color changing pigment in facial prostheses to mimic the color change of facial skin in cold weather. The tensile bond strength between pre-impregnated, unidirectional FRC and maxillofacial silicone elastomer was studied. Three different bonding agents or primers were compared. Bond strength was improved by one of the primers and by roughening the surface. The effect of a skin compressing glass fiber-reinforced composite framework on facial skin blood flow was studied by using a face mask, constructed with a compression pad corresponding to the outer margin of a glass fiber-reinforced framework beam of a facial prosthesis. The skin blood flow of ten healthy volunteers, aged 23-25 years, was measured during touch, light, and moderate compression of the skin, by using laser Doppler imaging technique. None of the compressions showed any marked effects on local skin blood flow. There were no significant differences between blood flow during compression and at baseline. Maxillofacial silicone elastomer was colored intrinsically with conventional color pigments: a control group containing only conventional pigments was compared to two test groups with 0.2 wt% and 0.6 wt% thermochromic pigment added. The color of the material was measured with a spectrophotometer in room temperature and after storage in a freezer. The color stability of the maxillofacial silicone elastomer colored with thermo¬chromic pigment was evaluated by artificial aging. The color dif¬ference of the L* (lightness) and a* values (redness), comparing color after the samples were stored at room temperature and in a freezer (-19°C), was statistically significant for both 0.2 wt% and 0.6 wt% thermo¬chromic pigment groups. The differences in the b* values (yellowness) were statistically significant for the 0.6 wt% group. Exposure to ultraviolet (UV) radiation led to visually noticeable and statistically signifi¬cant color changes (ΔE) in all color values in both test groups. The specimens containing thermochromic pigment were very sensitive to UV radiation. In conclusion, a framework of fiber-reinforced composite can successfully be bonded to maxillofacial silicone elastomer, and a framework beam, compressing the facial skin, did not remarkably alter the skin blood flow on healthy, young adults. The thermochromic pigment showed color change in maxillofacial silicone elastomer. However, artificial aging showed that it was too sensitive to UV radiation to be used, as such, in maxillofacial prostheses.

Brändin hallinta ja uudistaminen: Case SM-liiga

Tapaustutkimus SM-liigan brändiuudistuksesta

Improving the usability of extruded wood-plastic composites by using modification technology

Using cellulosic reinforcement to produce plastic composites is a globally growing trend. One of such materials are wood-plastic composites, which are an extensively studied group of materials for which the global industry is looking for new applications. Issues such as bondability, durability and fire resistance still require development to improve the usability of the wood-plastic composite material. Improvement of the usability of wood-plastic composites is studied in this thesis through the effects of using selected modification technology in wood and plastic industry. The applied modification methods are surface by mechanical abrasion and plasma, chemical impregnation of wood flour, and structural modification by the co-extrusion process. The study shows that the properties of WPC can be influenced by the selected modification methods. The selected methods are also found to be able to result as improvement in the properties of the material. The may also affect other than just the targeted properties of the end-product, either in a positive or a negative manner. Therefore modification as performance improvement should be considered as a caseby- case study. Introducing WPC materials for new applications can be done by using modification technology. Structuralmodification can possibly be used to reduce material costs of the modified WPC material.

Comparison of Pavlovian serial conditional discrimination in rats and hamsters in the same experimental situation

The present study compares behavioral changes between two distinct rodent groups, hamsters (Mesocricetus auratus) and Wistar rats, when submitted in the same homogeneous experimental situations to a serial conditional discrimination procedure which involves water deprivation and the processing of temporal variables. Both hamsters and rats acquired serial positive conditional discrimination as indicated by higher frequencies of magazine-oriented behavior during the tone followed by reinforcement (T+) and preceded by the feature stimulus light (L) and during the empty interval, than during the tone alone not followed by reinforcement (T-). Rats' frequencies of magazine-oriented behavior were high during T+ and T-, initially during training, and decreased during T- as the training progressed. However, the hamsters' frequencies of magazine-oriented behavior started very low and increased only during T+ as the training progressed. Comparison of the frequencies of magazine-oriented behavior during the empty interval in relation to the frequencies during the preceding L period showed that rats' frequencies remained very high and hamsters' frequencies increased during training. These results suggest that rats and hamsters have different behavioral strategies for the acquisition of a conditional discrimination. The results of the comparisons made in these experiments support the view of the importance of an ecological psychology approach to the understanding of complex learning in animals.

Food system transition towards sustainability: Inside thoughts of pioneers

The objective of this Master’s Thesis is to find individuals’ inducements that assist innovation adoption in the framework of sustainable food system. The purpose of the thesis is to examine the reasons why individuals adopt sustainable approaches, and furthermore, to see by what means the transition to the more sustainable food system could be accelerated. The study’s focal point is on the micro level, even if the wider purpose is to accelerate the holistic change of food system in the near future. The study consists of a literature review and a qualitative research, which is actualized with semi-structured interviews. The results indicate that individuals adopt innovations based on their strong intrinsic motivation. The main inducements were environment-related and health-related aspects, and individual’s deep connection to the countryside. The effect of social circle and doing good actions with the consuming behavior were also highlighted. Strongest barriers to innovation adoption seem to be price sensitivity, lack of easiness, and lack of interest in food. The findings indicate also that the most significant means that could ease the individuals’ decision to adopt an innovation are health-related aspects, educating and learning, environmental aspects, and decreasing the prices. Although the theoretical part of the study highlights the effect of positive reinforcement, the empirical part neglects it.

Digitaalisen valmistuksen vaikutus hitsatun rakenteen väsymiskestävyyteen

Tässä työssä tutkittiin kuinka eri tavoin rakenteen mallintaminen vaikuttaa laskettuun väsy-misikään. Työssä tutkittavana rakenteena toimi Sandvik Mining and Construction OY:n las-tauskoneen nostovarsi. Nostovarrelle väsytyskokeet suoritettiin Lappeenrannan teknillisen yliopiston teräsrakenteiden laboratoriossa. Työn tavoitteena oli tutkia miten eri digitaalinen valmistuksen tasot vaikuttavat hitsatulle rakenteelle saatuun kestoikään. Työssä tutkittiin myös miten todellista geometriaa voidaan hyödyntää rakenteen kestoiän arvioinnissa. Väsytyskoejärjestely mallinnettiin FE-menetelmällä, ja järjestelystä tehtiin useita malleja käyttäen solidi- ja laattaelementtejä. Malleista laskettiin väsymisiät hot spot- ja tehollisen lovijännityksen menetelmällä, ja saatuja tuloksia vertailtiin toisiinsa ja väsytyskokeen tulok-siin. Väsytyskokeessa vaurioituneista kohdista tarkemman tutkimuksen kohteena oli nosto-varren palstalevyn kärki. Hot spot-menetelmällä saadut kestoiät vaihtelivat paikoin melko paljon eri mallien välillä. Tehollisen lovijännityksen menetelmällä saaduissa tuloksissa erot olivat pienempiä mallien välillä. FE-mallin ja venymäliuskojen jännitykset poikkesivat toisistaan paikoin melko pal-jon. Todellisen hitsatun rakenteen kestoikään vaikuttaa moni asia, ja täten FE-menetelmällä las-kettu kestoikä voi poiketa huomattavasti todellisesta kestoiästä. Varsinkin hot spot-menetel-mällä tulokset voivat poiketa hyvinkin paljon todellisuudesta, mikäli jännitystila tutkitta-vassa kohdassa on moniaksiaalinen. Todellisen geometrian mallintaminen vaatii tarkkuutta, ja alkuperäisdatan tulee olla mahdollisimman tarkkaa ja riittävän suurelta alueelta, jotta malli vastaa tarpeeksi todellista.

Operant serial feature-positive conditional discrimination with composite features and different topography responses

In a serial feature-positive conditional discrimination procedure the properties of a target stimulus A are defined by the presence or not of a feature stimulus X preceding it. In the present experiment, composite features preceded targets associated with two different topography operant responses (right and left bar pressing); matching and non-matching-to-sample arrangements were also used. Five water-deprived Wistar rats were trained in 6 different trials: X-R®Ar and X-L®Al, in which X and A were same modality visual stimuli and the reinforcement was contingent to pressing either the right (r) or left (l) bar that had the light on during the feature (matching-to-sample); Y-R®Bl and Y-L®Br, in which Y and B were same modality auditory stimuli and the reinforcement was contingent to pressing the bar that had the light off during the feature (non-matching-to-sample); A- and B- alone. After 100 training sessions, the animals were submitted to transfer tests with the targets used plus a new one (auditory click). Average percentages of stimuli with a response were measured. Acquisition occurred completely only for Y-L®Br+; however, complex associations were established along training. Transfer was not complete during the tests since concurrent effects of extinction and response generalization also occurred. Results suggest the use of both simple conditioning and configurational strategies, favoring the most recent theories of conditional discrimination learning. The implications of the use of complex arrangements for discussing these theories are considered.

Missale (C.ö.IV.9, Oripään missale II)

A (mainly votive) missal consisting of seven distinct parts. Put together in several stages, somewhat haphazardly. Parts II and III are probably the oldest parts. The final stage in the composition of the book is probably the addition of part VII. Part II belongs in the same liturgical tradition as C.ö.IV.7 (Oripään Missale I), probably that of Diocese of Linköping. Part III, a votive missal, is an informal copy of a book that would most probably have been used close to a Swedish cathedral (Linköping?). How the present book found its way to Oripää chapel is not known.

Brändin vahvistaminen ja uudistaminen kiinteistönvälitysalalla

Tutkimus keskittyy brändin luomiseen ja brändin kokonaisvaltaisen hallinnan keinoihin kiinteistönvälitysalalla. Tutkielman tavoitteena on selvittää miten yritykset hyödyntävät brändipääomiaan brändiä vahvistettaessa ja uudistettaessa. Tätä kysymystä pyritään tarkastelemaan erityisesti kahden case-yhtiön näkökulmasta, jotka molemmat toimivat kiinteistönvälitysalalla. Tutkimuksen pääongelmaksi muodostui kysymys: ”Mitä tekijöitä tulisi huomioida brändipääoman vahvistamisessa ja uudistamisessa kiinteistönvälitysalalla toimivissa yrityksissä?”. Tutkimus on luonteeltaan laadullinen eli kvalitatiivinen tutkimus. Laadullinen tutkimus pohjaa läheisesti teorian ja empirian väliseen vuorovaikutukseen ja sen lähtökohtana on pyrkiä kuvaamaan tutkimuskysymystä kokonaisvaltaisesti. Laadullisen tutkimuksen tarkoituksena on myös löytää tai tuoda esille tosiasioita sen sijaan, että todennettaisiin jo olemassa olevia väittämiä (Hirsijärvi, Remes & Sajavaara 2000, 152). Tutkimusmetodina aineiston keräämisessä käytettiin tutkimushaastattelua, joka toteutettiin tapaustutkimuksena. Tapaustutkimukselle tyypillisesti haastattelu oli puolistrukturoitu, joten haastateltavat vastasivat tutkijan esittämiin kysymyksiin, jotka olivat samat molemmille haastateltaville, mutta keskustelua ei rajoitettu. Huoneistokeskuksen edustajan mukaan brändejä pitää tarpeen tullen uudistaa, mutta se ei saa olla itsetarkoituksena. Mikäli brändi on brändijohtaja alallaan, ei suuria muutoksia kannata lähteä tekemään vain tekemisen vuoksi, vaan niille pitää olla jokin selvä tarkoitus. Brändin viestin vahvistaminen onkin brändijohtajana toimivalle yritykselle usein parempi ratkaisu, kuin toimivan konseptin uudistaminen. Huoneistokeskus pyrkiikin varmistamaan sen, että brändin viesti ei pääse unohtumaan asiakkailta. Huom!:in liiketoimintajohtajan mukaan brändiä uudistettaessa on tärkeää, että brändiä konkreettisesti muutetaan. Huom! onkin tästä syystä positioinut itsensä aikaisemmasta poiketen edelläkävijäksi pitkäikäisyyden painottamisen sijaan. Huom! on myös painottanut entistä enemmän laadukkuuttaan ja avoimuuttaan ja nämä pyritään osoittamaan verkkosivujen asiakasarvosteluilla. Johtopäätöksenä voidaan todeta, että molemmat yritykset pitävät kaikkia brändipääomatekijöitä tärkeinä kiinteistönvälitysalalla. Tästä huolimatta brändiä vahvistettaessa Huoneistokeskuksen edustaja oli sitä mieltä, että tärkeintä on keskittyä brändin tunnettuuteen. Huom!:in edustaja sen sijaan oli sitä mieltä, että brändiä uudistettaessa tärkeintä on keskittyä laadun tuottamiseen ja yhdistämään tämä myös mielleyhtymäksi. Haastateltavia oli kuitenkin vain kaksi, joten tutkimuksen johtopäätöksiä ei voida yleistää koskemaan koko toimialaa.

Bullying as a social process : factors influencing bystander behaviour

Bullying was approached as a social phenomenon in the present study. The central aim of this thesis was to uncover some of the factors that contribute to the attitudes and behavioural choices of bystanders during bullying situations. With this type of information, interventions can be tailored to change the behaviour of bystanders during bullying situations, and thus the ethos of the larger group. Thus, acting to alter the available sources of reinforcement for bullying behaviour and peer intervention attempts. Six hundred and twenty-six students participated. Students were sampled from grades 4 (n=140), 5 (n=l 13), 7 (n=205), and 8 (n=168). Students were measured for their involvement in bullying and victimization, as well as for involvement in the following bystander behaviours: encouraging, onlooking, defending, and seeking adult support. In addition, students were measured for tolerance of deviance, pro-victim attitudes, social anxiety and fear, and self-efficacy for peer intervention. Last, students were asked to complete a series of qualitative measures, including a series of hypothetical vignettes and open-ended questions. Analyses centered on the following areas: 1) rates of bullying, victimization, and bystander behaviour; 2) the influence of age and gender on bystander behaviour; 3) the characteristics associated with students who predominantly report involvement with defending, seeking adult assistance, encouraging, and onlooking behaviour; and 4) the influence of past involvement with bullying and victimization on bystander behaviour. b .--' -i . k Rates of bullying, victimization, and bystander behaviour were comparable to findings in the existing literature, where male students were more likely than female students to report involvement in both bullying and victimization. Boys were more likely than girls to report participation in encouraging and onlooking behaviours, while being less likely to report involvement in defending and seeking adult assistance. Partly consistent with existing findings, older students were more likely to report involvement in bullying, encouraging, and onlooking behaviour than younger students, who were more likely to report victimization, defending, and seeking adult assistance. Self-identified encouragers and onlookers reported a similar array of characteristics, in that they tended express high levels of tolerance of deviance, while expressing low levels of pro-victim attitudes and self-efficacy for peer intervention. Likewise, self-identified defenders and seekers of adult assistance tended to report a similar array of characteristics to each other, in that they tended to report low levels of tolerance of deviance, while expressing high levels of pro-victim attitudes and self efficacy for peer intervention. Additionally, self-identified bullies and self-identified bully-victims tended to report increased involvement in encouraging and onlooking, whereas self-identified victims tended to report increased involvement in defending behaviour and seeking adult assistance. Results are discussed in terms of implications for bullying prevention and intervention. Specifically, evidence from the present study suggests that as bystanders, students predominantly act to either support bullying acts or to support the victims of these acts, or alternatively, to actively remain outside bullying situations. Thus, encouraging students to make small changes in the way they express these sentiments during bullying situations would act to alter the culture of the larger peer group and the sources of reinforcement available for bullying acts as well as peer intervention attempts.

An examination of the effects of locus of control on perceptions of core job dimensions and job satisfaction

This study examined the moderating effects of locus of control on core job dimensions (skill variety, task identity, task significance, autonomy, feedback) and job satisfaction. Survey data were collected from 1995 educators in Southern Ontario. When core job dimensions were perceived to be high, job satisfaction scores were high. The converse relationship was also true; when core job dimensions were perceived to be low, job satisfaction scores were also low. As well, the investigation explored the effect of educators' locus of control of reinforcement on the relationship between core job dimensions and job satisfaction. Internals (N = 483-486) perceived more skill variety, more task identity, more task significance, more autonomy, more feedback and greater job satisfaction than externals (N = 626-629). However, contrary to expectation, the correlations between specific core job dimensions namely autonomy and feedback, were not systematically greater for internals compared to externals. In addition the findings reported here suggest some appropriate directions and strategies for measuring and increasing job satisfaction among teachers.

Independent Chronicle Vol. XLIV No. 3,273- August 24, 1812

A semi-weekly paper that was published from 1801 to 1817. It was previously called the Independent chronicle and the universal advertiser, and was later the Independent chronicle and Boston patriot (Semiweekly). Publishers were Abijah Adams and Ebenezer Rhoades. Topics of interest in this issue include: Page 1: notice from the U.S. War Department seeking proposals for the supply of rations to troops; essay in support of the war; U.S. Secretary of War requests that the Governor of Maryland order 350 militia into active service; statement from the Convention of Republican Delegates in New Jersey in support of the war; statement from U.S. President James Madison in support of the war; statement from Maj. Gen. Isaac Brock to residents of Upper Canada urging their support in the war; U.S. Secretary of war sends 1,500 reinforcement troops to Detroit; Page 2: account from U.S. Gen. Hull of a battle near Fort Malden and news of troops in other areas; editorial against the British alliance with the Indians; letter from a U.S. Officer describing military gains near Detroit; news of U.S. infantry marching from Forts Independence and Warren to Albany, N.Y.; Page 3: news of British cargo ships captured by U.S. ships; 2 reward notices for the return of deserters from the military; report of possible 60 day armistice ratified by James Madison; Page 4: notice to British subjects living in Massachusetts that they must report themselves to the marshall; 2 reward notices for return of deserters from the military;

Functional analysis and treatment of OCD-related behaviour in a child with Autism Spectrum Disorder

Research indicates that Obsessive-Compulsive Disorder (OCD; DSM-IV-TR, American Psychiatric Association, 2000) is the second most frequent disorder to coincide with Autism Spectrum Disorder (ASD; Leyfer et aI., 2006). Excessive collecting and hoarding are also frequently reported in children with ASD (Berjerot, 2007). Although functional analysis (Iwata, Dorsey, Slifer, Bauman, & Richman, 1982/1994) has successfully identified maintaining variables for repetitive behaviours such as of bizarre vocalizations (e.g., Wilder, Masuda, O'Connor, & Baham, 2001), tics (e.g., Scotti, Schulman, & Hojnacki, 1994), and habit disorders (e.g., Woods & Miltenberger, 1996), extant literature ofOCD and functional analysis methodology is scarce (May et aI., 2008). The current studies utilized functional analysis methodology to identify the types of operant functions associated with the OCD-related hoarding behaviour of a child with ASD and examined the efficacy of function-based intervention. Results supported hypotheses of automatic and socially mediated positive reinforcement. A corresponding function-based treatment plan incorporated antecedent strategies and differential reinforcement (Deitz, 1977; Lindberg, Iwata, Kahng, and DeLeon, 1999; Reynolds, 1961). Reductions in problem behaviour were evidenced through use of a multiple baseline across behaviours design and maintained during two-month follow-up. Decreases in symptom severity were also discerned through subjective measures of treatment effectiveness.

Top-down and Bottom-up influences on ACC activation: Evaluation of a proposed model of the feedback-related negativity

The Feedback-Related Negativity (FRN) is thought to reflect the dopaminergic prediction error signal from the subcortical areas to the ACC (i.e., a bottom-up signal). Two studies were conducted in order to test a new model of FRN generation, which includes direct modulating influences of medial PFC (i.e., top-down signals) on the ACC at the time of the FRN. Study 1 examined the effects of one’s sense of control (top-down) and of informative cues (bottom-up) on the FRN measures. In Study 2, sense of control and instruction-based (top-down) and probability-based expectations (bottom-up) were manipulated to test the proposed model. The results suggest that any influences of medial PFC on the activity of the ACC that occur in the context of incentive tasks are not direct. The FRN was shown to be sensitive to salient stimulus characteristics. The results of this dissertation partially support the reinforcement learning theory, in that the FRN is a marker for prediction error signal from subcortical areas. However, the pattern of results outlined here suggests that prediction errors are based on salient stimulus characteristics and are not reward specific. A second goal of this dissertation was to examine whether ACC activity, measured through the FRN, is altered in individuals at-risk for problem-gambling behaviour (PG). Individuals in this group were more sensitive to the valence of the outcome in a gambling task compared to not at-risk individuals, suggesting that gambling contexts increase the sensitivity of the reward system to valence of the outcome in individuals at risk for PG. Furthermore, at-risk participants showed an increased sensitivity to reward characteristics and a decreased response to loss outcomes. This contrasts with those not at risk whose FRNs were sensitive to losses. As the results did not replicate previous research showing attenuated FRNs in pathological gamblers, it is likely that the size and time of the FRN does not change gradually with increasing risk of maladaptive behaviour. Instead, changes in ACC activity reflected by the FRN in general can be observed only after behaviour becomes clinically maladaptive or through comparison between different types of gain/loss outcomes.