Making coke a more efficient catalyst in the oxidative dehydrogenation of ethylbenzene using wide-pore transitional aluminas

The thermal activation of a silica-stabilized γ-Alumina impacts positively on the oxidative dehydrogenation of ethylbenzene (EB) to styrene (ST). A systematic thermal study reveals that the transition from γ-alumina into transitional phases at 1050C leads to an optimal enhancement of both conversion and selectivity under pseudo-steady state conditions; where active and selective coke have been deposited. The effect is observed in the reaction temperature range of 450-475C at given operation conditions resulting in the highest ST yield, while at 425C this effect is lost due to incomplete O2 conversion. The conversion increase is ascribed to the ST selectivity improvement that makes more O2 available for the main ODH reaction. The fresh aluminas and catalytically active carbon deposits on the spent catalysts were characterized by gas adsorption (N 2 and Ar), acidity evaluation by NH3-TPD and pyridine adsorption monitored by FTIR, thermal and elemental analyses, solubility in CH2Cl2 and MALDI-TOF to correlate the properties of both phases with the ST selectivity enhancement. Such an increase in selectivity was interpreted by the lower reactivity of the carbon deposits that diminished the COx formation. The site requirements of the optimal catalyst to create the more selective coke is related to the higher density of Lewis sites per surface area, no mixed Si-Al Brønsted sites are formed while the acid strength of the formed Lewis sites is relatively weaker than those of the bare alumina. © 2013 Elsevier B.V. All rights reserved.

Common priors for generalized type spaces

The notion of common prior is well-understood and widely-used in the incomplete information games literature. For ordinary type spaces the common prior is de�fined. Pint�er and Udvari (2011) introduce the notion of generalized type space. Generalized type spaces are models for various bonded rationality issues, for �nite belief hierarchies, unawareness among others. In this paper we de�ne the notion of common prior for generalized types spaces. Our results are as follows: the generalization (1) suggests a new form of common prior for ordinary type spaces, (2) shows some quantum game theoretic results (Brandenburger and La Mura, 2011) in new light.

The existence of an inverse limit of inverse system of measure spaces - a purely measurable case

The existence of an inverse limit of an inverse system of (probability) measure spaces has been investigated since the very beginning of the birth of the modern probability theory. Results from Kolmogorov [10], Bochner [2], Choksi [5], Metivier [14], Bourbaki [3] among others have paved the way of the deep understanding of the problem under consideration. All the above results, however, call for some topological concepts, or at least ones which are closely related topological ones. In this paper we investigate purely measurable inverse systems of (probability) measure spaces, and give a sucient condition for the existence of a unique inverse limit. An example for the considered purely measurable inverse systems of (probability) measure spaces is also given.

Generalized type spaces

Ordinary type spaces (Heifetz and Samet, 1998) are essential ingredients of incomplete information games. With ordinary type spaces one can grab the notions of beliefs, belief hierarchies and common prior etc. However, ordinary type spaces cannot handle the notions of finite belief hierarchy and unawareness among others. In this paper we consider a generalization of ordinary type spaces, and introduce the so called generalized type spaces which can grab all notions ordinary type spaces can and more, finite belief hierarchies and unawareness among others. We also demonstrate that the universal generalized type space exists.

Common priors for generalized type spaces

The notion of common prior is well-understood and widely-used in the incomplete information games literature. For ordinary type spaces the common prior is defined. Pinter and Udvari (2011) introduce the notion of generalized type space. Generalized type spaces are models for various bonded rationality issues, for nite belief hierarchies, unawareness among others. In this paper we dene the notion of common prior for generalized types spaces. Our results are as follows: the generalization (1) suggests a new form of common prior for ordinary type spaces, (2) shows some quantum game theoretic results (Brandenburger and La Mura, 2011) in new light.

Vállalati magatartás és túlélési esélyek a posztszocialista átmenetgazdaságban (Corporate behaviour and chances of survival in a post-socialist transitional economy)

A tanulmányban paneladatokra támaszkodva vizsgáljuk a hazai feldolgozóipari vállalkozások középtávú túlélési esélyeit befolyásoló tényezőket. A kutatás során az 1993-ban mintába került cégekhez tértünk vissza 2000-ben. Az adatok szerint az ágazat, a létszám és a kapacitáskihasználtság mellett a vezetői magatartás és a vállalati stratégia is érdemben befolyásolta a vállalatok fennmaradási esélyeit. Azok a szervezetek, amelyekben a vezetők 1993-ban úgy vélekedtek, hogy a gazdaságban a normaszegő magatartás sikerre számíthat, az átlagosnál kisebb valószínűséggel maradtak életben az évtized végére. Azok a vállalatok, amelyeknek vezetői a vizsgálat elején sikeresnek tartották cégüket, illetve amelyek már 1993-ban is inkább megoldó jellegű válságmenedzselési eszközöket alkalmaztak, nagyobb arányban maradtak fenn, mint azok, amelyek halasztó jellegű eszközökkel próbáltak úrrá lenni a transzformációs visszaesés okozta krízisen. ________ The study uses panel data to examine the factor affected medium-term changes in the chances of survival among Hungarian manufacturing firms. The researchers revisited in 2000 firms surveyed in a 1993 sample. The figures show firms survival chances vary essentially not only by industry, size of labour force and utilization of capacity, but according to managerial behaviour and corporate strategy. Those whose managers be-lieved in 1993 that behaviour breaching accepted norms would succeed in the economy had a lower than average likelihood of surviving until the end of the decade. The survival rate was higher among those whose managers thought they would be successful or were already applying crisis-management techniques of a remedial nature in 1993, than among those using delaying tactics to tackle a crisis caused by the transformational recession.

Profile of Florida: Services in transitional housing programs for homeless women with children

Family homelessness is a disturbing social problem in the United States. This study was conducted to determine the scope of components that included services and programs available for homeless women with children in transitional housing programs in Florida and the effectiveness of these components in helping these women move towards independence. Primary data for this study were obtained through questionnaires sent to directors of homeless centers in Florida. Supportive services offered by these centers were evaluated to determine if they enabled homeless women with children to become self-sufficient. The findings of this research indicated that regardless of the size, length of participation, and scope of services provided by the centers, these women showed gains in their ability to move toward self-sufficiency. The results support the hypothesis that transitional housing programs have a positive effect on homeless women with children. ^

Law Enforcement Actions in Urban Spaces Governed by Violent Non-State Entities: Lessons from Latin America

In response to a crime epidemic afflicting Latin America since the early 1990s, several countries in the region have resorted to using heavy-force police or military units to physically retake territories de facto controlled by non-State criminal or insurgent groups. After a period of territory control, the heavy forces hand law enforcement functions in the retaken territories to regular police officers, with the hope that the territories and their populations will remain under the control of the state. To a varying degree, intensity, and consistency, Brazil, Colombia, Mexico, and Jamaica have adopted such policies since the mid-1990s. During such operations, governments need to pursue two interrelated objectives: to better establish the state’s physical presence and to realign the allegiance of the population in those areas toward the state and away from the non-State criminal entities. From the perspective of law enforcement, such operations entail several critical decisions and junctions, such as: Whether or not to announce the force insertion in advance. The decision trades off the element of surprise and the ability to capture key leaders of the criminal organizations against the ability to minimize civilian casualties and force levels. The latter, however, may allow criminals to go to ground and escape capture. Governments thus must decide whether they merely seek to displace criminal groups to other areas or maximize their decapitation capacity. Intelligence flows rarely come from the population. Often, rival criminal groups are the best source of intelligence. However, cooperation between the State and such groups that goes beyond using vetted intelligence provided by the groups, such as a State tolerance for militias, compromises the rule-of-law integrity of the State and ultimately can eviscerate even public safety gains. Sustaining security after initial clearing operations is at times even more challenging than conducting the initial operations. Although unlike the heavy forces, traditional police forces, especially if designed as community police, have the capacity to develop trust of the community and ultimately focus on crime prevention, developing such trust often takes a long time. To develop the community’s trust, regular police forces need to conduct frequent on-foot patrols with intensive nonthreatening interactions with the population and minimize the use of force. Moreover, sufficiently robust patrol units need to be placed in designated beats for substantial amount of time, often at least over a year. Establishing oversight mechanisms, including joint police-citizens’ boards, further facilities building trust in the police among the community. After disruption of the established criminal order, street crime often significantly rises and both the heavy-force and community-police units often struggle to contain it. The increase in street crime alienates the population of the retaken territory from the State. Thus developing a capacity to address street crime is critical. Moreover, the community police units tend to be vulnerable (especially initially) to efforts by displaced criminals to reoccupy the cleared territories. Losing a cleared territory back to criminal groups is extremely costly in terms of losing any established trust and being able to recover it. Rather than operating on a priori determined handover schedule, a careful assessment of the relative strength of regular police and criminal groups post-clearing operations is likely to be a better guide for timing the handover from heavy forces to regular police units. Cleared territories often experience not only a peace dividend, but also a peace deficit – in the rise new serious crime (in addition to street crime). Newly – valuable land and other previously-inaccessible resources can lead to land speculation and forced displacement; various other forms of new crime can also significantly rise. Community police forces often struggle to cope with such crime, especially as it is frequently linked to legal business. Such new crime often receives little to no attention in the design of the operations to retake territories from criminal groups. But without developing an effective response to such new crime, the public safety gains of the clearing operations can be altogether lost.

Comparison of two mentoring programs for at -risk Black adolescents: A traditional one -to -one mentoring program and a school -to -work transitional program

The purposes of this study were: (a) to compare the impact of One-to-One (OTO) mentoring interventions administered in the high school setting, and the workplace of the students who participated in the School-to-Work (STW) transitional program, and (b) to identify how the participants perceived their experience in the OTO mentoring program and the STW transitional program. A qualitative approach was used to identify how participants perceived their mentoring experiences with the STW and OTO mentoring programs by utilizing focus groups and content analysis. A quantitative approach was used to compare the statistical differences of outcomes between the STW and OTO mentoring programs, by utilizing descriptive statistics, independent samples t-tests, chi-square analyses, and logistic regression. The sample was limited to participants in the STW and OTO mentoring programs resulting in 21 participants for the qualitative approach and 114 participants for the quantitative approach. ^ Results from the qualitative approach indicated that focus group participants in the STW program were satisfied with the program and the relationship with their mentors. They also suggested that the STW program be lengthened to include the entire academic year. Participants from the OTO focus group were dissatisfied with their program due to inadequate mentor involvement. Results from the quantitative approach showed that the increase in school attendance for the STW program's at-risk Black male youth was statistically significant compared to the OTO program participants; the STW program participants displayed a better outlook for attending college that was statistically significant compared to those in the OTO program; and the OTO program participants displayed a better outlook for permanent employment compared to those in the STW program. ^ Therefore, this study finds that mentoring can contribute to reducing school absences and high school completion in order for at-risk Black adolescents to attend college. It is recommended that the OTO program be restructured to eliminate the disparity that exists regarding the administration of the STW program and the OTO program. ^

Differential outcomes of two -way and transitional programs on English language learners at different entry levels

This study investigated the effects of two types of bilingual education programs (two-way and transitional) on the academic performance, attitudes, and metacognitive awareness of 5th grade students who entered kindergarten or first grade with different levels of English proficiency. The multi-stage sample consisted of students who had participated in each program for a period of at least five years. A mixed model design allowed for the collection of quantitative and qualitative data that were analyzed accordingly and integrated. ^ The findings indicated no significant differences between the two groups on measures of academic achievement in English. Significant differences were found in the number of semesters required for the students to become proficient English speakers. An important conclusion, based on these findings, was that the students enrolled in the two-way bilingual education (TWBE) programs learned English faster. Moreover, they maintained a high level of proficiency in Spanish, scoring significantly higher than the transitional bilingual education group on measures of Spanish reading ability.^ Questionnaire and interview data indicated that the students in the two-way bilingual education programs tended to use more Spanish for recreational purposes and tended to rate themselves as more proficient Spanish speakers than their peers. Conversely, the students enrolled in the transitional bilingual education programs tended to rate themselves as more proficient in English than their peers. ^ The level of English language proficiency upon entering school (five years later) was found to make a difference in academic achievement, as measured by standardized tests. Five years of schooling did not fully eliminate the gap in academic performance between students with different ESOL entry levels at kindergarten. However, entry level did not have an effect on attitudes towards bilingualism. ^ It is concluded that, although there was no significant difference between the two groups on measures of academic achievement in English, TWBE and transitional programs have differential effects. Students in the TWBE programs acquired oral language at a faster rate, developed literacy skills in their native language, and acquired more positive attitudes towards bilingualism. Theoretical, methodological, and policy implications of the findings are discussed. ^