Extraction based thermodynamic balancing for a humidification dehumidification desalination plant

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2012.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student submitted PDF version of thesis.Includes bibliographical references (p. 54).Humidification dehumidification (HDH) desalination is a thermal driven desalination technology. One of the main issues with HDH desalination is the high energy consumption involved. The energy efficiency of thermal desalination systems is given by a non-dimensional number known as the gained output ratio (GOR) which is a ratio of the latent heat of evaporation of the water produced to the net heat input. In Lienhard Research Group at MIT, a particular method of increasing GOR has been invented. This method involves matching the heat capacity ratio (HCR) of the flows exchanging heat and mass to approach unity. Specifically, based on theoretical studies done previously in the group, it had been proposed that mass extraction of air from the humidification device to the dehumidification device changes the HCR favorably. This thesis looks to show the same experimentally. By making adjustments of the HCR in different parts of the process it is possible to increase the GOR substantially. In the current study it has been shown that the GOR is increased from 2.4 to 3.1 for a specific set of boundary conditions. All mass extraction cases found an improved GOR value, confirming that this process reduces the total system irreversibility.by Victor Nevarez.S.B

TREATMENT OF MENTAL ILLNESS CO-OCCURRING WITH INTELLECTUAL DISABILITIES

Past literature has showed that there have been several misdiagnosis of mental illness due to client’s delays in speech or introspection caused by an intellectual disability. It is believed that the intellectual disability is either interfering with the proper mental health diagnosis or a mental health diagnosis is unnecessarily being added to an intellectual disability. The study used a qualitative design that asked four psychiatrists on how they are treating their clients with an intellectual disability in addition to their mental illness. The interview guide asks about the difficulty in diagnosing individuals with a mental illness and a co-occurring intellectual disability. The proportion of clients also having an intellectual disability and co-occurring mental illness ranged from 5 to 20%. The problems that psychiatrists are running into are the fact that patients are not being correctly diagnosed before the age of 18 and are not able to get the resources that are needed, such as Inland Regional services

Meeting the Need for K-8 Teachers for Classrooms with Culturally and Linguistically Diverse Students: The Promise and Challenge of Early Field Experiences

The writers present the findings of their study focused on teacher learning through early fieldwork experiences to address the problem of teachers working with a culturally and linguistically diverse student population. Data were analyzed from an archive collected from approximately 500 students enrolled in six undergraduate child development courses at three state university campuses located in urban areas of California. Findings suggest that early field experiences provide participants with opportunities for career goal clarification, and the context of field experience is significant and may lead to outcomes beyond the initial goal of the experience

Context dependent substitution biases vary within the human genome

Background: Models of sequence evolution typically assume that different nucleotide positions evolve independently. This assumption is widely appreciated to be an over-simplification. The best known violations involve biases due to adjacent nucleotides. There have also been suggestions that biases exist at larger scales, however this possibility has not been systematically explored. Results: To address this we have developed a method which identifies over- and under-represented substitution patterns and assesses their overall impact on the evolution of genome composition. Our method is designed to account for biases at smaller pattern sizes, removing their effects. We used this method to investigate context bias in the human lineage after the divergence from chimpanzee. We examined bias effects in substitution patterns between 2 and 5 bp long and found significant effects at all sizes. This included some individual three and four base pair patterns with relatively large biases. We also found that bias effects vary across the genome, differing between transposons and non-transposons, between different classes of transposons, and also near and far from genes. Conclusions: We found that nucleotides beyond the immediately adjacent one are responsible for substantial context effects, and that these biases vary across the genome

Minority Workforce Issues in Athletic Training

Certified Athletic Trainers belonging to ethnic minority groups have many issues in the profession. This paper addresses workforce issues including distribution of minorities, recruitment and retention of minority Certified Athletic Trainers, and support systems for minority Certified Athletic Trainers

Use of response surface methodology to optimise environmental stress conditions on Penicillium glabrum, a food spoilage mould

International audienceFungi are ubiquitous micro-organisms often associated with spoilage and biodeterioration of a large variety of foods and feedstuffs. Their growth may be influenced by temporary changes in intrinsic or environmental factors such as temperature, water activity, pH, preservatives, atmosphere composition, all of which may represent potential sources of stress. Molecular-based analyses of their physiological responses to environmental conditions would help to better manage the risk of alteration and potential toxicity of food products. However, before investigating molecular stress responses, appropriate experimental stress conditions must be precisely defined. Penicillium glabrum is a filamentous fungus widely present in the environment and frequently isolated in the food processing industry as a contaminant of numerous products. Using response surface methodology, the present study evaluated the influence of two environmental factors (temperature and pH) on P. glabrum growth to determine ‘optimised' environmental stress conditions. For thermal and pH shocks, a large range of conditions was applied by varying factor intensity and exposure time according to a two-factorial central composite design. Temperature and exposure duration varied from 30 to 50°C and from 10 min to 230 min, respectively. The effects of interaction between both variables were observed on fungal growth. For pH, the duration of exposure, from 10 to 230 min, had no significant effect on fungal growth. Experiments were thus carried out on a range of pH from 0.15 to 12.50 for a single exposure time of 240 min. Based on fungal growth results, a thermal shock of 120 min at 40°C or a pH shock of 240 min at 1.50 or 9.00 may therefore be useful to investigate stress responses to non-optimal conditions