Búsqueda avanzada


Área de conocimiento




21 resultados, página 1 de 3

Distance learning for farmers: Experience during the pandemic

Andrea Gardeazabal (2023, [Documento de trabajo])

In response to the COVID-19 pandemic's disruption of farmer training—a crucial component for enhancing the resilience and livelihoods of smallholder farmers—CIMMYT innovated educational solutions to sustain capacity building in agri-food systems. Addressing the challenges of limited mobile device access, poor internet connectivity, and digital illiteracy, CIMMYT implemented two pilot projects in Mexico. These projects facilitated distance learning for adult farmers in rural areas, employing both internet-based and non-internet methods. The non-internet approach utilized traditional media like print, while the internet-based approach leveraged WhatsApp for educational content delivery. Building on these experiences, CIMMYT expanded its offerings by creating micro -courses delivered through WhatsApp, hosted on the Co-LAB's new Learning Network platform, specifically targeting farmers. This paper delves into the various strategies, methods, and techniques adopted, documenting the learning outcomes, results, and key conclusions drawn from these innovative training initiatives.

Distance Learning Digital Inclusion Innovative Training CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA DISTANCE EDUCATION CAPACITY DEVELOPMENT METHODS COMMUNICATION TECHNOLOGY

Autotrophic denitrification of nitrate rich wastewater in fluidized bed reactors using pyrite and elemental sulfur as electron donors

Maria Federica Carboni Simon Mills SONIA LORENA ARRIAGA GARCIA Gavin Collins Umer Zeeshan Ijaz Piet Nicolaas Luc Lens (2022, [Artículo])

"This study compared denitrification performances and microbial communities in fluidized bed reactors (FBRs) carrying out autotrophic denitrification using elemental sulfur (S0) and pyrite (FeS2) as electron donors. The reactors were operated for 220 days with nitrate loading rates varying between 23 and 200 mg N-NO-3 /Lmiddotd and HRT between 48 and 4 h. The highest denitrification rates achieved were 142.2 and 184.4 mg NNO-3 /Lmiddotd in pyrite and sulfur FBRs, respectively. Pyrite-driven denitrification produced less SO2- 4 and no buffer addition was needed to regulate the pH. The sulfur FBR needed instead CaCO3 to maintain the pH neutral and consequentially more sludge was produced (CaSO4 precipitation). The active community of pyrite-based systems was investigated and Azospira sp., Ferruginibacter sp., Rhodococcus sp. and Pseudomonas sp. were the predominant genera, while Thiobacillus sp. and Sulfurovum sp. dominated the active community in the sulfur FBR. However, Thiobacillus sp. became more dominant when operating at elevated nitrogen loading rate. Patterns of diversity and microbial community assembly were assessed and revealed three distinct stages of microbial community succession which corresponded with the operation of a period of high influent nitrate concentration (135 mg N-NO-3 /L). It is proposed that a high degree of functional redundancy in the initial microbial communities may have helped both reactors to respond better to such high influent nitrate concentration."

Pyrite Elemental sulfur Fluidized bed rector Nitrogen removal 16S rRNA Community assembly CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA

Universal fixation system for pad printing of plastic parts

JOSE ALEJANDRO FERNANDEZ RAMIREZ (2023, [Artículo])

Pad printing is used in automotive, medical, electrical and other industries, employing diverse materials to transfer a 2D image onto a 3D object with different sizes and geometries. This work presents a universal fixation system for pad printing of plastic parts (UFSP4) in response to the needs of small companies that cannot afford to invest in the latest technological advances. The UFSP4 comprises two main subsystems: a mechanical support system (i.e., support structure, jig matrix and braking system) and a control system (i.e., an electronic system and an electric-hydraulic system). A relevant feature is the combination of a jig matrix and jig pins to fixate complex workpieces with different sizes. Using finite element analysis (FEA), in the mesh convergence, the total displacement converges to 0.00028781 m after 12,000 elements. The maximum equivalent stress value is 1.22 MPa for the polycarbonate plate in compliance with the safety factor. In a functionality test of the prototype performed in a production environment for one hour, the jigs fixed by the plate did not loosen, maintaining the satisfactory operation of the device. This is consistent with the displacement distribution of the creep analysis and shows the absence of the creep phenomenon. Based on FEA that underpinned the structural health computation of the braking system, the prototype was designed and built, seeking to ensure a reliable and safe device to fixate plastic parts, showing portability, low-cost maintenance and adaptability to the requirements of pad printing of automotive plastic parts.

Use of AI tools declaration: The authors declare they have not used Artificial Intelligence (AI) tools in the creation of this article.

Acknowledgments: To the company Plásticos Decorados and Centro de Tecnología Avanzada (CIATEQ A.C.) for the facilities and support to carry out this work. To the Consejo Nacional de Humanidades, Ciencias y Tecnologías (CONAHCYT) for a Ph.D. scholarship support number 500839 and CONAHCYT SNI.

Conflict of interest: The authors declare there are no conflicts of interest.

Modular fixtures Jig matrix Prototype design Pad printing Fixture methods INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS OTRAS ESPECIALIDADES TECNOLÓGICAS OTRAS OTRAS

On-farm storage loss estimates of maize in Kenya using community survey methods

Hugo De Groote Anani Bruce (2023, [Artículo])

Maize is the most important staple in sub-Saharan Africa (SSA), with highly seasonal production. High storage losses affect food security, but good estimations are lacking. A new method using focus group discussions (FGDs) was tested with 121 communities (1439 farmers, 52% women) in Kenya's six maize-growing zones, to estimate the maize losses to storage pests and analyze farmer practices. As control strategies, half of the farmers used chemical pesticides (49%), while hermetic bags (16%) and botanicals (15%) were also popular. Relative loss from weevils in the long rains was estimated at 23%, in the short rains 18%, and annually 21%. Fewer farmers were affected by the larger grain borer (LGB) than by maize weevils: 42% in the long rainy season and 32% in the short rainy season; losses from LGB were also smaller: 19% in the long season, 17% in the short season, and 18% over the year. Total storage loss, from both species combined, was estimated at 36%, or 671,000 tonnes per year. The greatest losses occur in the humid areas, especially the moist mid-altitudes (56%), and with smaller loss in the drylands (20–23%). Extrapolating the point data and overlaying with the maize production map shows the geographic distribution of the losses, with the most important area found around Lake Victoria. FGDs provide convenient and cheap tools to estimate storage losses in representative communities, but a total loss estimate of 36% is higher than is found in other studies, so its accuracy and framing effects need to be assessed. We conclude that storage pests remain a major problem, especially in western Kenya, and that the use of environmentally friendly technologies such as hermetic storage and botanicals needs more attention, both by the public extension service and private agrodealers.

Larger Grain Borer Maize Weevil CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA MAIZE STORAGE LOSSES PESTS SURVEY METHODS

Strategies steering intensification pathways of farmers in central Malawi

Carl Timler Jeroen Groot Sieglinde Snapp Pablo Tittonell (2023, [Artículo])

Smallholder farmers face many challenges to improve their livelihoods and food security. Intensification of agricultural production can help to achieve these goals. Yet farmers are highly heterogenous in their strategies towards intensification, potentially following unsustainable intensification pathways. Using Q Methodology, we ascertain different strategies regarding farm improvement and intensification of smallholder farmers in the Dedza and Ntcheu Extension Planning Areas in Central Malawi. These strategies were associated to coherent sequential choices as expressed in “managerial intensification pathways” (MIPs). Three main strategies emerged: Seed Saving Peasants, Aspirant Modern Farmers and Entrepreneurial Business(wo)men. These were subsequently linked to four MIPs. Seed Saving Peasants focus strongly on local seed systems and post-harvest protection of grains, but also allocate more labour to improving crop residue use and manure quality, thus pointing to a labour-oriented MIP. Aspirant Modern Farmers willingly adopt hybrid seeds and inorganic fertilizers but require more extension support; these farmers follow a technology-oriented MIP. Entrepreneurial Business(wo)men are early adopters of new technologies and benefit from improved access to market information and suppliers of new technologies and follow a sustainable technology-based or techno-ecological intensification pathway. This study shows that strongly contrasting perspectives on intensification exist among smallholders and it is expected that their preferred intensification choices will have diverging impacts on the sustainability of their farms. A diversity of extension, advice and incentive instruments will be needed to support farmer decision making towards sustainably intensified farms.

Smallholder Farmers Q Methodology CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA SMALLHOLDERS STRATEGIES SUSTAINABLE INTENSIFICATION

Influence of novel coconut oil and beeswax edible coating and MAP on postharvest shelf life and quality attributes of lemon at low temperature

Mohammad Mainuddin Molla Ashfak Ahmed Sabuz Md Abdul Matin (2023, [Artículo])

Weight loss, turning of peel colour from green to yellow and microbial infections are the major postharvest problems of lemon. Lipid-based edible coatings and modified atmospheric packaging (MAP) are effective techniques in maintaining postharvest quality of fruits for long-term storage. With this view, an investigation was conducted for the preservation of green lemon using coconut oil and beeswax edible coating and MAP during storage at low temperature. Physiologically matured lemons were collected and washed with potable water; fruit surface water was removed and then coated with coconut oil-beeswax (90:10) or only coconut oil. After coating, lemons were packaged in MAP or kept in open crates and stored at 12±1 °C and 85±5% relative humidity (RH) for 8 weeks and a week interval, the sampling was conducted. The results revealed that coconut oil-beeswax coating had immense effect on retaining shiny green colour, reducing respiration, weight loss, shrivelling and preserving firmness and ascorbic acid of lemon throughout the storage. On the other hand, MAP mainly helped to retain moisture & firmness and reduce shrivelling. Uncoated lemons kept open lost the highest amount of ascorbic acid and retained only 13.7 mg/100 g that is significantly (p < 0.05) less than the lemons of all other treatments at 8th week of storage period. While lemons coated with coconut oil-beeswax and packaged in MAP was preserved the highest amount (24.2 mg/100 g) of ascorbic acid and there was no significant difference (p < 0.05) with the amount of ascorbic acid content of lemons coated with only coconut oil and packaged in MAP at the last week (8th week) of storage. Hue angle value was 93.4 in uncoated lemons packaged in MAP while it was 113.67 in coconut oil-beeswax coated lemon kept open and 112.64 in lemon coated with coconut oil-beeswax and packaged in MAP at 8th week of storage. Based on all sensory, physical and chemical parameters uncoated lemons kept open was acceptable up to 1 week, coconut oil-beeswax coated lemon kept open was 6 weeks and coconut oil-beeswax coated lemon packaged in MAP was 8 weeks with good quality and shiny green colour.

Edible Coating Sensory Quality Hue Angle Yellowing CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA EDIBLE FILMS RESPIRATION RATE LEMONS MODIFIED ATMOSPHERE PACKAGING COLD