Cultivating the Assimilative Perspective in Contextual Engineering – Knowing What You Don’t Know

Contextual Engineering methodology affords engineering practitioners a more robust process for identifying socioeconomic and cultural conditions within a client community that could affect adoption and sustainability of a technical infrastructure. This methodology seeks to build an assimilative view of the client through direct interactions, which enable the practitioner to assess critical local conditions without filtering her understanding through the lens of her own experience. Many practitioners assert that direct interaction with a client community is unnecessary to achieve an assimilative view, particularly in an era when information is widely available via the internet, and communication with remote partners is possible using a variety of technologies. But assessments of the perceptions of engineering practitioners engaged in two separate projects in Latin America before and after travel to the client communities demonstrate that their understanding of community conditions were altered dramatically once they interacted with residents and experienced site conditions firsthand.

PERFORMANCE EVALUATION OF THE QUALITY OF CINA CEMENT AND BASF ADMIXTURE COMMONLY USED IN CONCRETE PRODUCTION IN THE REPUBLIC OF HAITI

A Haitian general contractor/civil engineer was having difficulties achieving the target concrete strength even when the mix was designed in compliance with the regulations and client criteria. An experiment was carried out to assess the quality and performance of the cement and admixture commonly used in construction practice in Haiti. The results of this experiment proved that the Haiti cement is an inferior product. On average, the compressive strength was 56% weaker in the Haiti mixes as compared to the US cement. Curing had significant effect of the mixes. When the mixes were not cured, the Haiti concrete never reached the target strength even when the cement content from the original design was increased to 50% and/or tested at 56 days. The admixture had no negative effect in the mixes. Significant increases in compressive strength was observed on both the Haiti and US mixes. In addition, the admixture should not be treated as a retarder. No significant increase in compressive strength was noted from 28 days to 56 days. Furthermore, the results of this research demonstrate that the most adequate solution for the Haitian contractors is to increase the cement content by at least 30% by weight from the original design. It is recommended that the Haitian Government, concrete producers, cement manufacturers, and researchers combine their expertise, effort, and resources to come up with solutions to improve the current deplorable conditions of construction practices in Haiti. This is so valuable to save lives, especially in a country like Haiti where powerful hurricanes and earthquakes are projected in the future.

Spaceborne radar imagery – An under-utilized source of information for humanitarian relief

This practical paper gives an overview about the widely unused potential of radar satellite imagery to assist humanitarian action. It briefly introduces the basic differences between optical and radar images and demonstrates the practical use of the latter in different settings based on their information content and their potential for multi-temporal analyses. It gives recommendations on further reading and closes with suggestions on the practical integration of radar data into humanitarian work.

Community-Level Resource Development and Management, Part 2: A Transferable Approach to Feasibility Analysis for Biogas as an Alternative Cooking Fuel

Energy access for all is the seventh Sustainable Development Goal (SDG) put forth by the United Nations in 2015. This initiative has been taken on by many non-governmental organizations (NGOs), national governments and communities alike. Traditional approaches to cooking often rely on three-stone fires (or other open wood fires). The smoke from these open cooking fires is known to cause significant negative health impacts, thus access to cleaner energy sources is especially important for to improve cooking conditions. One alternative cooking fuel is biogas, which has the advantages of smoke reduction, and decreased reliance on and impact of firewood collection. In this article, we develop a method of analyzing the feasibility of biogas projects for rural communities. The method enables both evaluation of an ideal digester design for specific environments and determination of the scale, cost, and yields of a biogas plant. For example, in a cooking application 1-m3 of biogas can be compared to 1.3 kg of firewood or approximately 10 minutes not spent collecting firewood. Such evaluation is critical to help communities and organizations determine whether or not this type of project is ideal for their environments. All too often, development project concepts are funded prematurely, before the realization that the implemented technology does not function properly or is unsustainable for specific applications. The feasibility analysis we describe is a contribution to the literature because it provides a condensed, simplified resource that enables development practitioners and communities to readily evaluate whether or not a biogas energy solution is appropriate and sustainable for their setting prior to investing valuable resources and time into implementation.

Community-Level Resource Development and Management, Part 1: A Transferable Approach to the Analysis of Community Water Distribution System Expansion

Access to water is extremely important in schools around the world, where students spend most of their day. As schools expand, particularly in areas with limited water resources, it is necessary to develop and manage water resources to ensure their sustainability. In this article we describe a method of analyzing water piping distribution networks using an open-source software package that allows practitioners to model the increased demands on water distribution systems associated with school growth. The methodology was then applied to the case study of a community-level water distribution system in rural Tanzania. This method is valuable because it is both condensed and easy to follow for those in the field with or without technical backgrounds. Minimal tools are needed for practitioners to develop their own system models (only a GPS, tape measurer, bucket, stopwatch and access to a computer with the software downloaded). Overall, this condensed written resource is more accessible than others available to many practitioners and thus improves the ease of modeling for pre-planning and analysis of expansion or other water distribution system modifications.

Journal of Humanitarian Engineering Guest Editorial

Journal of Humanitarian Engineering Guest Editorial

Development and external validation of a logistic regression derived algorithm to estimate a 12-month post open defecation free slippage risk

Appropriate open defecation free (ODF) sustainability interventions are key to further mobilise communities to consume sanitation and hygiene products and services that enhance household’s quality of life and embed household behavioural change for heathier communities. This study aims to develop a logistic regression derived risk algorithm to estimate a 12-month ODF slippage risk and externally validate the model in an independent data set. ODF slippage occurs when one or more toilet adequacy parameters are no longer present for one or more toilets in a community. Data in the Zambia district health information software for water sanitation and hygiene management information system for Chungu and Chabula chiefdoms was used for the study. The data was retrieved from the date of chief Chungu and Chabula chiefdoms' attainment of ODF status in October 2016 for 12 months until September 2017 for the development and validation data sets respectively. Data was assumed to be missing completely at random and the complete case analysis approach was used. The events per variables were satisfactory for both the development and validation data sets. Multivariable regression with a backwards selection procedure was used to decide candidate predictor variables with p < 0.05 meriting inclusion. To correct for optimism, the study compared amount of heuristic shrinkage by comparing the model’s apparent C-statistic to the C- statistic computed by nonparametric bootstrap resampling. In the resulting model, an increase in the covariates ‘months after ODF attainment’, ‘village population’ and ‘latrine built after CLTS’, were all associated with a higher probability of ODF slippage. Conversely, an increase in the covariate ‘presence of a handwashing station with soap’, was associated with reduced probability of ODF slippage. The predictive performance of the model was improved by the heuristic shrinkage factor of 0.988. The external validation confirmed good prediction performance with an area under the receiver operating characteristic curve of 0.85 and no significant lack of fit (Hosmer-Lemeshow test: p = 0.246). The results must be interpreted with caution in regions where the ODF definitions, culture and other factors are different from those asserted in the study.

The design and usage of a portable incubator for inexpensive in-field water analysis

Humanitarian engineers need an inexpensive, fast, visually compelling way to assess bacterial water quality in remote locations. One way to do this is with 3M Petrifilm E. coli/Coliform (EC) Count Plates to detect E. coli in water samples. These require incubation at close to body temperature. To meet this need, we provide a free, open-source design of a battery-powered incubator capable of maintaining 35°C ± 1°C for up to 65 hours in ambient temperature of 25°C. Our incubator, called the Armadillo, can be replicated by an ordinarily skilled person in five hours for under USD $200.00 in materials cost. This paper summarises the reference documentation for construction, sample handling, inoculation, and incubation using Petrifilms and the Armadillo. Colony-forming unit (CFU) counts generated by the Armadillo are compared side-by-side with a laboratory-grade incubator. Incubation performance at ambient temperatures of 25°C and 4°C shows that a single battery charge reliably powers a full incubation period of 48 hours under normal ambient temperatures.

Species, grading, and mechanical properties of locally sourced timber in the Joyabaj region of Guatemala

The purpose of this project was to research the timber used by Engineers without Borders (EWB) groups in the Joyabaj region of Guatemala. This project aimed to investigate the species of wood, evaluate the quality by assessing the distribution of timber grades, and determine mechanical properties. The results will aid EWB groups in the design of wood structures in the Joyabaj region of Guatemala.Samples were collected for species investigation and mechanical testing. Species investigation was triangulated from interviews with the sawmill owner, construction foreman, testing by the USDA Forest Products Laboratory, and comparisons to literature. The results were inconclusive and indicated multiple species were intermixed at the sawmill with no distinction made when purchased. Timber quality was evaluated by using a visual grading guide developed by the authors to assess the distribution of grades within a large order of lumber. Static bending and compression parallel to grain tests were conducted to obtain modulus of rupture, compression parallel to grain, and modulus of elasticity. Specific gravity was also obtained.The results indicate that three different species were collected. Ninety per cent (90%) of the timber was No. 3 or better and 50% to 80% was No. 2 or better depending on the size. Clear wood testing values were similar to those of Eastern White Pine. Structural design should be performed based on National Design Specification (NDS) design values for a No. 3 or No. 2 Eastern White Pine, depending on the degree of wood selection in the construction process.

Journal of Humanitarian Engineering Volume 6, No. 2 (2018) Guest Editorial

Journal of Humanitarian Engineering Volume 6, No. 2 (2018) Guest Editorial