Design and Development of Scalable Solar Powered Water Purification Systems for Developing Nations

This thesis presents the design and development of solar powered water purification systems. The systems were designed to meet specific customer requirements that were established from the experiences gained after the installation of five water purification systems in various Haitian communities. The systems are scalable and are able to supply 10,000-20,000 gallons of clean drinking water per day. The design consists of a three-stage filtration system with a disc-type sediment filter, a 0.1 micron ultrafiltration membrane, and an ultraviolet light for disinfection. The backwash cycle extends the life of the ultrafiltration membrane to 4-7 years before a new filter is required. Simplicity in operation was an important design consideration because it facilitates local operator training, and understanding. To ensure complete understanding of operation, a pictorial quick-start manual was developed so that operators only need to follow the diagrams laid out on the manual. The design folder with CAD drawings, schematics, datasheets, and troubleshooting guide are left with the local operators. Testing before shipping and after installation to ensure proper operation upon installation. On-site water quality testing ensures the system will promote improved community health

Guiding gene-specific methylation of histones in C. elegans

A cell’s function depends on its gene expression, which is controlled by two stores of information: the DNA sequence and the regulatory molecules that interact with DNA. While the information stored within DNA is well-studied, the function of regulatory molecules that influence gene expression is less understood. A key class of regulatory molecules is histone modifiers, which facilitate the methylation, acetylation, and other chemical modifications of histones. These modifications can affect the accessibility of DNA to enzymes that regulate gene expression. Histone modifications are conserved in multiple organisms, from fission yeast to mammals. However, there is contradictory evidence suggesting alternative roles for supposed inhibitory marks. Previous research has used mutations of histone-modifying enzymes to deduce the impact of the histone modifications on gene regulation. However, inferences from such experiments are complicated because the mutation can have an impact on a chromosomal scale, making it difficult to infer about single loci. Therefore, we are developing a dCas9-based platform to target histone modifiers, and their modifications, to a specific locus. Thus far we have found that dCas9 binding alone does not significantly disrupt gene expression within C. elegans, although we detected increased variation within somatic tissues of a ubiquitously expressed gene. Having completed this essential control, we will next introduce a histone modifier that adds H3K36me3 modifications to the same locus through a dCas9 fusion protein and determine its impacts on gene expression.Maryland Center for Undergraduate Researc

CEO Extraversion and the Cost of Equity Capital

We examine whether CEO extraversion, an important personality trait associated with leadership, is associated with firms\u27 expected cost of equity capital. We measure CEO extraversion using CEOs\u27 speech patterns during the unscripted portion of conference calls. After controlling for multiple CEO and firm-specific variables, we find a strong positive incremental association between CEO extraversion and firms\u27 expected cost of capital. Moreover, cost of equity increases when a more extraverted CEO replaces a less extraverted CEO. In addition, we find that firms with relatively extraverted CEOs take more risk and exhibit lower credit ratings, which is associated with higher cost of equity capital. These results are statistically and economically meaningful and do not appear to be driven by reverse causality, endogenous matching, look-ahead bias, or bias in analysts\u27 earnings forecast

Portable Water Purification System

An ultra-portable water purification system (1). The system (1) can include a pump (22) for pumping water under pressure through the water purification system (1). The system (1) can also include a battery (14) for supplying power to operate the pump (22), a power source (10) for providing power to the battery (14) and the pump (22), and a charge controller (18), electrically connected to the power source (10), battery (14), and pump (22), for regulating power received from the power source (10) and limiting the power provided to the battery (14) to power the pump (22). The water purification system (1) can also include a mesh strainer (20) upstream of the pump (22), a sediment filter (26), and an electropositive filter (30). The mesh strainer (20), sediment filter (26) and electropositive filter (30) are arranged in series such that the source water is pumped sequentially therethrough

Performance and value creation in international acquisitions: an empirical analysis of foreign acquisitions by Indian firms

This study examines the announcement effect and the post-acquisition long-term performance of 96 Indian international acquisitions of U.S. firms made in the period 1999-2005. We find that while the international acquisition announcements by Indian firms create significant short-term shareholders’ wealth, in the long-run international acquisitions have a negative impact on the shareholders’ wealth

Analysis of categorical multiple response variables in marketing research

Multiple Response Data (MRD) can be defined as the set of answers to a question that allows the respondent to pick more than one response, also known as a pick any/J format. Such questions have become very popular for marketing research, and are frequently encountered in the analysis of survey data . Although widely used, the analysis of these types of responses is becoming increasingly complex. The purpose of this paper is to examine the underlying issues and subsequent solutions for dealing with aggregated MRD. The paper also presents a summary of benefits and drawbacks associated with different analytical methods

Project Haiti 2012: Providing an Experiential Learning Experience Through the Design and Delivery of a Water Purifier in Haiti

In this paper, we share our experiences and lessons learned from Project Haiti 2012, a project to design and install a water purification system serving 20,000 people per day in the largest tent city in Haiti. Project Haiti 2012 was the third and largest system we have built for Haitians and represents a huge success for all participants and stakeholders. This paper discusses the unique experiential learning opportunity involved in the design and delivery of the water purifier in a foreign developing country. Multiple positive educational, social, and economic outcomes were achieved including students applying knowledge gained from coursework towards a greater cause, faculty gaining experience in leading an overseas student trip, engaging Haitians to be less dependent on foreign aid, and relieving water crisis in Haiti. We hope that this paper inspires others to pursue similar experiential learning experiences and develop a repeatable engineering education model for international community improvement projects

Design and Commissioning of a Community Scale Solar Powered Membrane-Based Water Purification System in Haiti

This paper presents the design and commissioning of a solar powered water purification system at the Ryan Epps Home for Children (REHC) in Michaud, Haiti. This system supplies clean drinking water to the 200 children who live and go to school at REHC and also to the community in the form of a micro-business. This micro-business is the mechanism for income generation for sustainable system operation. The purifier uses a three stage filtration system with a disc-type sediment filter, a 0.1 micron ultrafiltration membrane, and an ultraviolet light for disinfection. The backwash cycle extends the life of the ultrafiltration membrane to 4 – 7 years before a new filter is required. Simplicity in operation was an important design consideration because it facilitates local operator training, and understanding. To further ensure complete understanding of operation, a pictorial quick-start manual was developed so that operators only need to follow the diagrams laid out on the manual. The design folder with CAD drawings, schematics, datasheets, and troubleshooting guide are left with the local operators. Testing before shipping and after installation to ensure proper operation upon installation and on-site water quality testing ensures it will promote improved community health