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1.
Prosthet Orthot Int ; 45(3): 240-245, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33993152

RESUMO

STUDY DESIGN: A mechanical testing protocol was used to compare the material properties of commercially available foams with that of a newly designed granular jamming orthosis prototypes. BACKGROUND: Foot orthoses have an inherent limitation of predetermined mechanical material properties coupled with a fixed orthotic interface shape that cannot be readily changed. OBJECTIVES: To develop and test a novel orthotic insole design concept that incorporates principles of granular jamming. METHODS: Granular media were used in combination with vacuum pressure to create a variable stiffness granular foot orthosis. Four types of granular media (rice, poppy seeds, micropolystyrene, and polystyrene beads) were tested in different prototype configurations varying in volume fill and particulate size. Stress-strain curves were obtained from uniaxial compression tests to characterize granular foot orthosis prototypes in comparison with commercial orthotic foams. RESULTS: Increasing vacuum pressure increased prototype stiffness for most configurations. A single granular jamming orthosis could exhibit energy absorption values that spanned the entire commercial foam performance range, and in some cases extended far beyond the upper values of the tested foams. CONCLUSION: The results suggest that granular jamming principles can provide clinicians the capability for rapid selection of mechanical properties over a wide range of orthosis stiffnesses. Importantly, patients could don the orthosis because the clinician makes real-time assessments and adjustments in the clinic.


Assuntos
Órtoses do Pé , Braquetes , Desenho de Equipamento , Humanos
2.
Dev Eng ; 5: 100046, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33426261

RESUMO

Smallholder farmers provide the foundation for food security in South Asia. However, increasing seasonal labor scarcity caused by rural out-migration has resulted in growing agricultural labor costs, presenting challenges to cash-constrained smallholder farmers that hire manual labor for land preparation, sowing, harvest and post-harvest operations. Technological innovations in small-scale agricultural machinery appropriate for the small field sizes and limited resource endowments of South Asia's farmers have been proposed as a potential solution to this problem. An increasing number of development initiatives also promote rural entrepreneurial approaches to mechanization, whereby smallholder farmers can access and use machinery in their own fields on an affordable fee-for-service basis offered by machinery owners. This approach reduces capital constraints for smallholder farmers while enabling entrepreneurs who can afford equipment to enter into business serving stallholder farmers as clients. This approach is now widely practiced in Bangladesh, where machinery entrepreneurs play a crucial role in providing access to productive technologies for smallholder farmers who could not otherwise afford direct purchase of labor- and cost-saving machinery. In order to maintain low machinery purchase costs for emerging yet capital constrained rural entrepreneurs, while also assuring high quality standards, cost-effective domestic production of agricultural machinery is increasingly championed as an important long-term national development objective. With no safety standards or guidelines for best production practices, the few manufacturing workshops that exist within Bangladesh operate inefficiently and without clear rationalization of manufacturing processes. Haphazard copying of prototypes or imported available machinery is common. This leads to inefficient production and poor product quality in an emerging but potentially highly beneficial industry. This paper addresses these problems and presents a case study to increase machinery manufacturers' capacity while improving manufacturing operations and workplace safety through equipment selection, workshop layout, and usability. Janata Engineering (JE) is a small-scale machinery manufacturing enterprise in Bangladesh, specializing in two-wheel tractor attachments such as bed planters, local derivations of power-tiller operated seeders, and other equipment for planting, irrigating, and processing crops. JE was expanding and setting up a second factory for which the authors provided assistance on its design. Our research question was whether participatory action research (PAR) supported by empirical data could provide improved factory design in terms of functionality, safety and human interactions, when compared with conventional approaches driven by technical efficiency concerns alone. Using PAR, we developed a number of alternative process and layout recommendations for JE to increase the efficiency of labor and machinery through improved workflow, throughput, and output. While immediately useful for JE, the process and protocols proposed in this paper are relevant for emerging agricultural machinery manufacturers in Bangladesh and more widely in South Asia.

3.
Irrig Drain ; 67(4): 559-571, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31543700

RESUMO

Much of South Asia experiences a monomodal rainfall pattern with a distinct dry season following the annual monsoon. Enabling irrigation during the dry season has therefore been crucial in assuring improved productivity and double-cropping. This is particularly the case in southern Bangladesh, where recent government initiatives have called for an expansion of surface water irrigation to reduce pressure on groundwater tables in intensively cultivated areas in the north of the country, where dry season boro rice is grown. This paper describes a method based on first principles of fluid mechanics to characterize the performance of surface water irrigation pumps used by small-scale farmers in South Asia and Bangladesh. This method is unique, as it incorporates an optimized protocol suitable for resource-limited conditions found in many developing countries and provides a comprehensive yet simple-to-use pump selection method for surface water irrigation pump customers. Using pump impellers as a case study, the method also characterizes the effect of pump geometric variations resulting from the variable production and assembly practices found in different manufacturing workshops. This method was validated with a case study in Bangladesh supported by both full-scale field testing and numerical simulation results. © 2018 The Authors. Irrigation and Drainage published by John Wiley & Sons Ltd on behalf of International Commission for Irrigation and Drainage.


Une grande partie de l'Asie du Sud connaît un régime pluviométrique monomodal avec une saison sèche distincte après la mousson annuelle. Permettre l'irrigation pendant la saison sèche a donc été crucial pour assurer une meilleure productivité et une double culture. C'est particulièrement le cas dans le sud du Bangladesh, où des initiatives gouvernementales récentes ont demandé une expansion de l'irrigation avec des eaux de surface pour réduire la pression sur les nappes phréatiques dans les zones intensément cultivées du nord du pays où pousse le riz boro de saison sèche. Cet article décrit une méthode basée sur les premiers principes de la mécanique des fluides pour caractériser les performances des pompes d'irrigation avec des eaux de surface utilisées par les petits agriculteurs en Asie du Sud et au Bangladesh. Cette méthode est unique car elle incorpore un protocole optimisé adapté aux conditions de ressources limitées dans de nombreux pays en développement et fournit une méthode de sélection de pompe complète mais simple à utiliser pour les clients de pompes d'irrigation d'eau de surface. En utilisant des turbines de pompage comme étude de cas, la méthode caractérise également l'effet des variations géométriques de la pompe résultant des pratiques variables de production et d'assemblage trouvées dans différents ateliers de fabrication. Cette méthode a été validée à l'aide d'une étude de cas au Bangladesh appuyée à la fois par des essais sur le terrain à grande échelle et des résultats de simulation numérique. © 2018 The Authors. Irrigation and Drainage published by John Wiley & Sons Ltd on behalf of International Commission for Irrigation and Drainage.

4.
Public Health Nutr ; 19(10): 1823-33, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26631171

RESUMO

OBJECTIVE: Dietary practices in Kenya often fail to provide adequate nutrition during the first 1000 days of life, from conception to 2 years of age. We developed and qualitatively assessed the acceptability of easy-to-use dietary tools consisting of a marked bowl, slotted spoon and illustrated counselling card to support appropriate dietary practices during pregnancy, exclusive breast-feeding and complementary feeding of children aged 6-24 months. DESIGN: We conducted qualitative research to assess community acceptability and obtain feedback on the design of the dietary tools. SETTING: This research took place in urban and rural communities in Western Kenya. SUBJECTS: We conducted twelve focus group discussions with community members (mothers, husbands, mothers-in-law, community leaders) and five interviews with government nutritionists to assess acceptability and obtain recommendations on design and delivery of the tools. We conducted 24-28 d of user testing with fourteen pregnant women, fourteen breast-feeding women and thirty-two mothers with infants aged 6-18 months. RESULTS: Tools were positively received by communities. Mothers perceived improvements in their own and their children's food intakes including quantity, frequency, consistency and diversity. Many attributed perceived own and child's weight gain and/or increased energy to tool use. A minority reported using the bowl for other activities (n 9) or not using the bowl due to food insecurity (n 5). CONCLUSIONS: Results suggest that such tools have the potential to positively impact maternal and child dietary practices. Future work should quantitatively assess the impact on diet and nutrition outcomes and the underlying behavioural domains associated with changes.


Assuntos
Dieta , Promoção da Saúde/métodos , Fenômenos Fisiológicos da Nutrição do Lactente , Fenômenos Fisiológicos da Nutrição Materna , Aleitamento Materno , Feminino , Grupos Focais , Humanos , Lactente , Quênia , Gravidez , Pesquisa Qualitativa
5.
Food Nutr Bull ; 36(1): 24-32, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25898713

RESUMO

BACKGROUND: Dietary practices in India often fail to provide adequate nutrition during the first 1,000 days of life. OBJECTIVE: To explore the acceptability and utility of a low-cost and simple-to-use feeding toolkit consisting of a bowl with marks to indicate meal volume and frequency, a slotted spoon, and an illustrated counseling card to cue optimal dietary practices during the first 1,000 days. METHODS: In Samastipur District, Bihar, India, we conducted 16 focus group discussions and 8 key informant interviews to determine community acceptability and obtain feedback on design and delivery of the feeding toolkit. We conducted 14 days of user testing with 20 pregnant women, 20 breastfeeding women 0 to 6 months postpartum, and 20 mothers with infants 6 to 18 months of age. RESULTS: The toolkit, which is made of plastic, was well accepted by the community, although the communities recommended manufacturing the bowl and spoon in steel. The proportion of pregnant and breast-feeding women taking an extra portion of food per day increased from 0% to 100%, and the number of meals taken per day increased from two or three to three or four. For children 6 to 18 months of age, meal frequency, quantity of food consumed during meals, and thickness of the foods increased for all age groups. Children 6 to 8 months of age who had not yet initiated complementary feeding all initiated complementary feeding during the testing period. CONCLUSIONS: Simple feeding tools are culturally acceptable and can be appropriately used by families in Bihar, India, to improve dietary practices during the first 1,000 days of life. Research is needed to assess whether the tools promote dietary and nutritional improvements over and above counseling alone.


Assuntos
Aleitamento Materno , Dieta , Métodos de Alimentação/instrumentação , Fenômenos Fisiológicos da Nutrição do Lactente , Pré-Escolar , Comportamento do Consumidor , Comportamento Alimentar , Feminino , Grupos Focais , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Índia , Lactente , Alimentos Infantis , Recém-Nascido , Estado Nutricional , Gravidez
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