Mars Ascent Vehicle - Payload?, Spacecraft?, Launch Vehicle? - A Systems Approach to MAV

Significant effort has been expended over the past few years in order to examine propulsion technologies for an eventual robotic Mars Ascent Vehicle (MAV). The recent emphasis on studies for an overall sample return campaign, and specifically the Sample Return Lander (SRL) includes the full slate of systems required to implement a MAV. Depending on your point of view, the MAV is a major SRL flight system payload, a Mars Surface Spacecraft, or a Launch Vehicle. We will examine the MAV from these three perspectives in order to tease out the key architectural trades required to be completed prior to the start of a project Phase A activity

The information revolution and small business lending: the missing evidence

This paper provides empirical confirmation for Petersen and Rajan's (2002) widely accepted conjecture that information technology was the primary driver of the observed increase in small business borrower-lender distances in the United States in recent years. Using a different data source for small business loans, we show that annual increases in borrower-lender distances were slow and steady prior to 1993 (the end point in Petersen and Rajan's data) but accelerated rapidly after that. Importantly, we are able to assign at least half of this acceleration to the adoption of credit scoring technologies by the lending banks. Our tests also reveal strong statistical associations between lending distances and borrower characteristics, lender characteristics, market conditions, regulatory constraints, moral hazard incentives, and principal-agent incentives.

Sustainability of Solar PV Institutions in Malawi

The sustainability challenges of off-grid community energy projects using solar photovoltaics in Malawi have been widely acknowledged. However, little formal evidence has been produced regarding the factors that affect the sustainability of these projects. Under the MREAP, a study was commissioned to generate more conclusive evidence around the sustainability challenges of the current stock of schools, health centres, and other rural public institutions. An original data set consisting of performance data from 5 sustainability ‘pillars’, consisting of economic, technical, social, organizational, and environmental has been captured for 43 systems in rural Malawi. The results confirm existing anecdotal evidence and suggest that the majority of installed projects can be considered ‘unsustainable’ and at risk of failure in the near future. Many projects are now unsupported, are partially or completely non-functional, and are without reliable and effective means to resuscitate performance. Projects are ranked (relatively) in terms of overall sustainability and factors for improved sustainability are discussed. Our analysis demonstrates the complicated interactions between sustainability pillars and highlights the need for a holistic approach to project design and implementation

Technical sustainability of solar PV institutions : results from a field survey of 43 sites in Malawi

With grid connection rates in Malawi at 9% (5% for rural population) and 87% of primary schools lacking electricity, future connection for a significant share of the remaining schools through off-grid means is a plausible scenario. However, sustainability of off-grid community energy projects at public institutions in Malawi has historically been described as poor. Existing knowledge is largely anecdotal and quantitative data of any sort for off-grid installations is lacking. Efforts to document project existence and what has been effective have mildly improved recently, but this has not included in-depth sustainability analysis . Despite these efforts, it is thought that many more systems and their performance go undocumented. Thus, in 2014 a study was funded by the Scottish Government within the MREAP programme to capture sustainability factors for 43 off-grid solar PV projects at public institutions dispersed throughout Malawi

Commercial lending distance and historically underserved areas

We study recent changes in the geographic distances between small businesses and their bank lenders, using a large random sample of loans guaranteed by the Small Business Administration. Consistent with extant research, we find that small borrower-lender distances generally increased between 1984 and 2001, with a rapid acceleration in distance beginning in the late-1990s. We also document a new phenomenon: a fundamental reordering of borrower-lender distance by the borrowers' neighborhood income and race characteristics. Historically, borrower-lender distance tended to be shorter than average for historically underserved (for example, low-income and minority) areas, but by 2000 borrowers in these areas tended to be farther away from their lenders on average. This structural change is coincident in time with the adoption of credit scoring models that rely on automated lending processes and quantitative information, and we find indirect evidence consistent with this link. Our findings suggest that there has been increased entry into local markets for small business loans and this should help allay fears that movement toward automated lending processes will reduce small businesses' access to credit in already underserved markets.

Pretransitional Optical Activity In Chiral Smectic Liquid Crystals

Pretransitional optical activity measurements in smectic liquid crystals of both law and high chirality are reported. In the low chirality sample, p-(n-(decyloxybenzylidene)-p-amino-(2-methylbutyl)cin-namate (DOBAMBC), the results indicate that the optical activity in both the isotropic phase just above the smectic A phase and in the smectic A phase just above the smectic C* phase can be explained in terms of a Landau-deGennes free energy with no coupling between the chiral modes. In the high chirality sample, 1-methylheptyl 4′-[(4″-tetradecyloxyphenyl)propioloyloxy]biphenyl-4-carboxylate (14P|M7), the data in the isotropic phase above the recently discovered smectic A* phase cannot be explained in this way, even when coupling between the chiral modes is considered. Whether this is due to some feature of the smectic A* phase or is simply the result of strong coupling between the orientational and positional order parameters is a question which remains unanswered

Sustainability of Solar PV Systems in Malawi

Solar photovoltaic (PV) systems can offer a low carbon, low cost and economically competitive method of providing electricity in such remote areas unlikely to be grid connected in the near future. As such, they are being installed in significant numbers across sub-Saharan Africa. Malawi’s off grid PV installed capacity has increased from 0.2 MW in 2007 to 5.7 MW in 2017. In 2012 there was an estimated 7,000 PV systems present in the country. Despite the increase of installed capacity, many solar PV systems fall into disrepair, usually only achieving 10% of their lifetime expectancy, due to lack of maintenance, poor initial design, end-user misuse, or insufficient ownership and business model strategies. Research into factors that affect sustainability of off grid PV systems is needed to support identification of appropriate interventions and ensure project longevity with reduced lifetime costs of systems serving rural communities in sub-Saharan Africa. The study employs a novel scoring method which is used to support a sustainability evaluation of 65 off-grid community solar PV projects in Malawi. Projects are scored against the technical, economic, social, and organisational factors. An aggregated (total) sustainability factor is proposed here as a good early measure of project sustainability; however, there is insufficient evidence currently available to validate the accuracy this method as a predictor of long-term sustainability i.e. continued data collection and analysis of these sustainability factors, over several years, is required to obtain a sufficient evidence base to enable a deep understanding of the relative influence of the different sustainability factors for community energy projects in a variety of contexts

Electricity access options appraisal in Malawi : Dedza district case study

An energy audit has been conducted for the Dedza district in Malawi, which required the development and implementation of a multidisciplinary options appraisal methodology involving a literature review; solar, wind and hydro resource assessment; household and business surveys; focus group discussions and expert interviews. A decision making tool was developed to score and rank renewable energy technologies based on defined input criteria. Due to low income levels and limited capacity, small scale, low access, technologies such as pico-solar products were found to have the highest potential for widespread uptake over the district. Other innovative uses of solar energy including solar home systems and productive uses of solar also score highly due to good solar resource in the district, modularity and ease of implementation. Wind and hydro systems are ranked lower due to limited resource and lack of local capacity to implement