4,065 research outputs found
Bioremediation of biodiesel and diesel contaminated soil by pseudomonas putida
As occurs to the diesel fuel, the commercialization of biodiesel and their diesel blends can cause environmental damages due to accidental spillage. Presence of these contaminants containing polyaromatic hydrocarbons (PAHs) in soil is toxic to humans, plants and soil microorganisms due to their recalcitrant and mutagenic or carcinogenic properties. Therefore, this study was conducted to suggest a new technique of treatment to clean up the biodiesel and diesel contaminated soil by Pseudomonas putida. Spill simulations with biodiesel, diesel and their blends in sandy gravel soil were performed according to previous study with some modification. Briefly, 200 mL of Pseudomonas putida was inoculated into soil samples: B5 (5% biodiesel + 95% diesel), B20 (20% biodiesel + 80% diesel), B50 (50% biodiesel + 50% diesel), B100 (100% biodiesel) and D100 (100% diesel). As a control sample, there is no addition of biodiesel and diesel into the sample. All samples were stored in the incubator at 35 ÂşC throughout the 24 days of treatment. Samples were analyzed for: soil particle size, moisture content, pH, total nitrogen (TN), orthophosphate, sulfate, total organic carbon (TOC), soxhlet extraction of PAHs and enumeration of Pseudomonas putida. The measurement of all testing parameters was carried out at interval of three days starting from Day 0 to Day 24 of bioremediation period. Results showed that the highest removal of total nitrogen (TN), orthophosphate, sulfate, total organic carbon (TOC) and PAHs were observed in the sample B100 with up to 70.43%, 69.47%, 68.08%, 97.66% and 96.28% removal, respectively. The degradation rates of PAHs and survival of Pseudomonas putida were also observed highest in the sample B100 with up to 0.149 mg/kg/day and 60 Ă— 106 cfu/g, respectively. Based on these overall findings, it can be verified that the sample B100 has the higher biodegradability than other samples. According to results, it can conclude that, the capability and effectiveness of Pseudomonas putida as oil-biodegradable agent in soil bioremediation were proved and bioremediation of contaminated samples may be considered as a successful and feasible practice
Saturn S-IB Stage assembly and test report, S-IB-1
Manufacture, assembly, and static tests of Saturn S-IB-1 stag
Silencios deliberados, silencios falsos: La Condamine y la cacerĂa de fábulas en el siglo XVIII (Estudios)
A high-input impedance differential millivolt meter for use with solid ceramic oxygen electrolyte cells
Design factors are given for a high-input impedance differential millivolt meter designed, built, and tested as an inexpensive solid-state electronic system for use in measuring the electromotive force from solid ceramic oxygen electrolyte cells. A schematic diagram is included
Student Engagement: The Role of Teaching Within an Ecological Model of Adolescent Development
Due to the short- and long-term benefits associated with better student engagement teachers, parents, and the broader community have sought to understand how best to improve students’ engagement. Teachers and modifications to teaching, as a proximal factor to students’ engagement, have been a focus of efforts to enhance engagement. Furthermore, ecological models of adolescent development assert that factors from the individual student, family, peer group, and community are likely to be influential in the development of adolescent outcomes, including student engagement. To date the empirical engagement literature has failed to consider the potential for factors from multiple contexts to concurrently influence student engagement. Further, studies of student engagement have been limited in that they have prioritised either traditional school-based indicators of engagement (i.e., academic grades, suspension, attendance, dropout) or students’ subjective perspectives of engagement (i.e., psychological). These student perspectives are in response to the demands of school and encompass: i) a student’s overt and less readily observable behaviours; ii) liking and enthusiasm for school; and iii) efforts to understand the prescribed curriculum.
The aims of the research were to: i) understand the extent to which teachers can improve students’ engagement; ii) elaborate upon non-teaching factors that influence engagement and; iii) recommend teaching modifications that can be employed to improve students’ engagement.
Three studies were undertaken to address the overall research aims. The first study was a systematic review of existing research. Thirty-three cross-sectional and 13 longitudinal studies that investigated associations between teacher-student relationships and multiple indicators of engagement were synthesised. The second study, a self-report survey of 88 Year 7 students in Victoria, Australia, conceptualised teaching via self-determination theory. The students reported their perceptions of their teachers, family support, and individual factors including academic grades and mental health. Finally, a pre-existing dataset, from the International Youth Development Study was analysed. Adolescents (n = 719) were surveyed in Grade 10 and again in Grade 11 on a range of factors from the individual, school, family, peer, and community contexts.
In Study 1 (Chapter 6), results indicated that when students and teachers formed a high quality caring relationship students were more likely to have better academic grades, attendance, and psychological engagement. Students were also more likely to have reduced levels of disruptive behaviours, suspensions, and dropout. Study 2 (Chapter 8) presented results of hierarchical regression analyses. After controlling for individual and family factors, better quality teaching was uniquely associated with behavioural and emotional engagement. The discussion explored the need for an integrated model of teaching to improve students’ engagement. The third and final study identified limits to teaching modifications within an ecological model of adolescent engagement. Specifically, Grade 10 teacher support was not a statistically significant predictor of Grade 11 engagement when factors from the individual, family, peer, and community were introduced to the analyses. It was proposed that prior individual educational experiences (i.e., academic grades and engagement) exerted a greater influence on high school engagement than short-term teaching modifications. Overall, teaching remains a proximal factor to students’ engagement. Students who experience high-quality caring relationships with their teachers and better classroom instruction and management were more likely to have better engagement. This was the case across both school-based and students’ subjective indicators of engagement. However, limits to teaching exist. Prior educational experiences and factors from the family, peer, and community were statistically significant predictors of engagement in the ecological models presented.
Future research into engagement would benefit from longitudinal study designs that collect student-reported and school-based indicators of engagement at multiple time-points across the duration of a student’s academic career. Moreover, theoretical models of engagement should seek to elaborate upon the likely bi-directional relationships between the current predictors and student engagement outcomes. Practical recommendations included a need to recognise the limits to teaching and a need to identify how precisely a student’s engagement can be supported
A current state analysis of preventive control requirements and traceability infrastructure in small U.S. food facilities
In 2011, the U.S. government enacted the Food Safety Modernization Act (FSMA). The goal of the new legislation was to reduce the 48 million people per year in the U.S. who are affected by food borne illnesses through the requirement of preventive controls in food supply chains. Compliance dates for small food businesses started in 2017, when the new preventive control measures were required to be implemented. This research focuses on understanding the current state of FSMA preventive control requirements in relationship to small food facilities. Also, an assessment of the traceability infrastructure within small food facilities was performed. A questionnaire based survey was developed from using the FDA’s FSMA Final Rule for Preventive Controls for Human Food and Animal Food along with the Institute of Food Technologist pilot study for FSMA traceability. The questionnaire was distributed to small food facilities in the state of Iowa. Fourteen different factors were analyzed from the questionnaire data: (i) food allergen controls, (ii) verification activities, (iii) current good manufacturing practices, (iv) food safety plan, (v) training records (vi) standard operating procedures, (vii) hazard analysis, (viii) recall plan, (ix) preventive controlled qualified individual, (x) operational control, (xi) accounting programs, (xii) inventory records, (xiii) lot coding, (xiv) business management software. Results were compared against the type of manufacturing, the size of the company, and how many years the company has been in business. A significant factor affecting the adoption of FSMA within the small business category proved to be company size. Chi-square analysis revealed significant results in preventive control practices and traceability infrastructure at divisions of 0-24 employees, and 25-499 employees. Companies that had 25-499 employees showed better preparation in implementing preventive controls for distinct FSMA compliance requirements. Also, companies that had 25-499 employees showed a leading advancement in technology adoption for establishment of traceability infrastructure versus companies that had 0-24 employees. The small business category spans a large range of employee sizes (499 or less). The results indicate that a special focus may be needed on businesses with less than 25 employees for FSMA preventive control requirements to be successful in small businesses
Report drawn up on behalf of the Committee on Agriculture on the proposal from the Commission of the European Communities to the Council (Doc. 1-449/79) for a regulation on the charging by the Community of a fee for permits authorizing a vessel flying the flag of a Member State of the Community to fish for salmon in the Swedish fishing zone. EP Working Documents 1979-80, Document 1-717/79, 11 February 1980
As Big As A...
An article exploring the phenomenon of online sizegivers and the process of collecting and engaging with communities that make these images.
Featuring an image essay with images from Corinne Quin's ongoing archive. This started with Sizegiver (book) and continues as Sizegiver Daily Archive (instagram)
Editorial
Welcome to the first publication of the Journal of Teaching and Learning for Graduate Employability. This peer-reviewed web-based journal is a continuous publication, ensuring that papers have currency and authors are not faced with the long lead time between acceptance and publication that characterises print-based journals. As an e-journal it is available to anyone with access to the internet at no cost
- …