Application of Semi-Empirical Ventilation Models in A Mediterranean Greenhouse with Opposing Thermal and Wind Effects. Use of Non-Constant Cd (Pressure Drop Coefficient Through the Vents) and Cw (Wind Effect Coefficient)

The present work analyses the natural ventilation of a multi-span greenhouse with one roof vent and two side vents by means of sonic anemometry. Opening the roof vent to windward, one side vent to leeward, and the other side vents to windward (this last vent obstructed by another greenhouse), causes opposing thermal GT (m3 s−1) and wind effects Gw (m3 s−1), as outside air entering the greenhouse through the roof vent circulates downward, contrary to natural convection due to the thermal effect. In our case, the ventilation rate RM (h−1) in a naturally ventilated greenhouse fits a second order polynomial with wind velocity uo (RM = 0.37 uo2 + 0.03 uo + 0.75; R2 = 0.99). The opposing wind and thermal effects mean that ventilation models based on Bernoulli’s equation must be modified in order to add or subtract their effects accordingly—Model 1, in which the flow is driven by the sum of two independent pressure fields GM1=√(∣∣G2T±G2w∣∣) , or Model 2, in which the flow is driven by the sum of two independent fluxes GM2=|GT±Gw| . A linear relationship has been obtained, which allows us to estimate the discharge coefficient of the side vents (CdVS) and roof vent (CdWR) as a function of uo [CdVS = 0.028 uo + 0.028 (R2 = 0.92); CdWR = 0.036 uo + 0.040 (R2 = 0.96)]. The wind effect coefficient Cw was determined by applying models M1 and M2 proved not to remain constant for the different experiments, but varied according to the ratio uo/∆Tio0.5 or δ [CwM1 = exp(−2.693 + 1.160/δ) (R2 = 0.94); CwM2 = exp(−2.128 + 1.264/δ) (R2 = 0.98)]

通常学級における平仮名書字指導の諸問題

小学校の通常の学級に在籍する児童の中に，一斉指導だけでは平仮名書きを十分に習得できない児童がおり，そのような児童に対するより適切な指導方法が求められている。そこで，平仮名書字の一斉指導及び個別指導の方法とそれらの問題点を1年生の学級担任を対象にしてアンケート調査した。本研究の目的は，この調査を通して通常学級における平仮名書字指導の現状を把握し，今後検討すべき課題を明らかにすることである。その結果，検討課題として以下のことが明らかにされた。第一は指導時間の確保である。1年生という学年も考慮して，一斉指導の中で個別指導の時間をいかに確保していくかが課題である。第二は児童の学習状態にみる個人差の問題である。学級の中には書字学習が極めて困難な児童からほぼ学習が終了している児童までいる。一斉指導の中でそれらの児童が興味を失うことなく学習ができるような工夫が必要である。第三は鉛筆の持ち方，字形，筆順の改善をいかに行うかという問題である。入学時に既に平仮名書きを学習している児童の中に，誤った学習をしている者が多く，その状態の把握方法と改善の手だての工夫が必要である。第四は筆圧のコントロールの問題である。書字学習困難児の中には筆圧が弱い児童がおり，筆圧を適切にコントロールできるようにするための指導方法の工夫が必要である。First-grade teachers in Joetsu Area were surveyed with a questionnaire that asked about the teaching method of handwriting and its problems in their regular classes. The investigation revealed the following problems : 1. Teachers are teaching children who have disabilities in writing Japanese letters (hiragana) with all other children in their classes. Therefore they manage to find time to teach such poor writers during the lesson. 2. Because first-grade children enter an elementary school with big individual variations in writing abilities, it\u27s very difficult that teachers fascinate all children to learn how to write letters. 3. Some children who have already learned how to write letters have a bad grip of a pencil, write a letter with a wrong shape and a wrong writing order. Teachers are required to evaluate those problems in each child, so we need a new method to do it. 4. Some children write letters with an inadequate writing pressure. We need a new method to evaluate a writing pressure and made it better

Use of mesh windbreaks for soil erosion in olive groves in southeastern Spain

We used windbreak nets to reduce erosion and sediment transport in a semiarid area. A 13x30thread·cm-2 and 39% mesh net facing the wind increased average erosion reduction up to 72% at a height of 0.4 m in recently tilled olive groves. The use of sonic anemometry techniques for identifying wind movement patterns has rarely been exploited for improving field studies, and much less for windbreaks. Sample components collected in traps placed at different heights and distances from the windbreak were analyzed. A Principal Components Analysis was carried out analyzing the combined effect of height and windbreak distance on variables associated with the first two components. Component C1 identified the height at which data were obtained, while Component C2 identified windbreak distance from the sampling point. The effectiveness of this system is shown by the reduction in weight of material caught in traps, and is a cheap and reusable tool applicable after tilling

Interdigitated μ-electrodes for development of an impedimetric immunosensor for atrazine detection.

This contribution describes the development of an impedimetric immunosensor for atrazine detection. This immunosensor is based on the use of interdigitated metallic μ-electrodes (IDμEs) The method described in this work does not use any redox mediator and relies on the direct detection of immunochemical competitive reaction between the pesticide and a haptenized-protein immobilized on interdigitated μ-electrodes for the specific antibody. The immunoreagents used were specifically developed to detect atrazine. The immunochemical detection of this pesticide is achieved without using any label. The immunosensor shows a limit of detection of 8.34±1.37 μg L-1, witch is lower than the Maximun Residue Level (MRL) (50μg L-1)established by EU (European Union)for residues of atrazine as herbicide in the wine grapes and other foodstuff products.Peer ReviewedPostprint (published version

Scheduling vegetable sales to supermarkets in Europe: The tomato case

This article analyzes the temporal programming of sales for a horticultural marketing company, e.g. a cooperative. The empirical study references the European tomato market, where most of the production is sold through the retail channel dominated by large distribution chains. We study the marketing schedule for an individual company, or even a prominent farmer, using a modified Markowitz model, assuming that his decisions do not affect the balance of market prices. As a result, this model can manage risk and improve decision-making. The data also provide information on the risk borne by marketers depending on their sales calendar, which often depends on their geographic locatio

Caracterización genética y de caracteres reproductivos en variedades de vid sin semilla de Armenia

Trabajo presentado en las IV Jornadas del Grupo de Viticultura de la SECH (Sociedad Española de Ciencias Hortícolas), celebrada en Pamplona (España), los días 26 y 28 de octubre de 2022La apirenia de la mayoría de las variedades comerciales de la vid (Vitis vinifera L.) procede de 'Sultanina', una variedad con origen en Asia Menor. El principal objetivo de este trabajo ha sido la caracterización de posibles fuentes alternativas de apirenia en el germoplasma armenio. Se han estudiado 40 accesiones apirenas de las colecciones armenias de vid en Echmiadzin (ARM006) y en Nalbandyan (ARM011), así como de explotaciones privadas de la región de Armavir (Armenia). El análisis fenotípico de bayas se realizó de acuerdo con los descriptores de la OIV, y el análisis genético mediante el estudio de la mutación causal de apirenia en Sultanina en el gen VviAGL11 y del marcador VviAPT3 ligado al locus del sexo. El análisis de viabilidad y morfología de los granos de polen se visualizó por microscopía óptica y electrónica de barrido. El análisis fenotípico de bayas reveló una amplia variación en el peso de las mismas, así como en la formación de rudimentos seminales. Las flores de nueve cultivares son hermafroditas con un alto nivel de viabilidad del polen. La accesión 'Karmir kishmish' se caracterizó por tener flores funcionalmente femeninas con baja viabilidad de polen y se confirmó genéticamente con VviAPT3. El análisis de microscopía mostró que los granos de polen de las flores hermafroditas tienen forma esferoidal con 3 colporaciones y numerosas perforaciones, mientras que el de la variedad 'Karmir kishmish' es también esferoidal, pero acolporado y con menos perforaciones. El análisis genético reveló que todas las accesiones portan la mutación puntual dominante en VviAGL11 que causa la estenospermocarpia en 'Sultanina'. De hecho, el análisis de 7 marcadores SSR y 48 SNPs demostró que todas son descendientes de la misma. Este estudio confirma que las variedades apirenas armenias descienden de 'Sultanina', y motiva la búsqueda de otros determinantes genéticos que causen variación en el contenido de semillas de las uvas para utilizar como fuentes alternativas en programas de mejora de uva de mesa

Insights into Medieval Grape Cultivation in Al-Andalus: Morphometric, Domestication, and Multivariate Analysis of Vitis vinifera Seed Types

Understanding the origins and evolution of modern grapevine varieties in the Iberian Peninsula and western Europe necessitates an examination of the proportions of Vitis vinifera cultivars, their relationships with wild grapevine populations, and the utilization of seedless cultivars in al-Andalus. Employing morphometric studies, domestication indices, multivariate analysis, and Bayesian hypothesis testing, this study investigates several distinct seed types identified in materials from Roman and medieval deposits. These seeds exhibit a spectrum from highly domesticated to purely wild. Our findings reveal the predominance of Proles Occidentalis Negrul, and the presence of feral-like grapevines associated with Proles Euphratica. Additionally, we observe the continuous presence of wild grapevines related to Vitis sylvestris CC Gmelin throughout the studied period. Seeds exhibiting intermediate characteristics are documented, alongside the identification of “stenosperms”, suggesting anomalies in seed formation. Notably, the presence of Vitis vinifera raisins “stenospermocarpics” of the sultana type is suggested, potentially elucidating the absence of table grapes and raisins of the Proles Orientalis Negrul in the archaeological record, despite frequent mentions by medieval agronomy writers from al-Andalus

On the estimation of three-dimensional porosity of insect-proof screens

The two-dimensional estimation is the approach to porosity par excellence in the literature of insect-proof screens for their geometric characterisation and estimation of their aerodynamic parameters. However, this is not an accurate estimation, since the geometry of insect-proof screens consists of interlaced threads that create a three-dimensional woven structure, leading to different thicknesses and overlapping of threads. This paper suggests a mathematical approach to reconstruct computationally the 3D structure of the screens and to estimate the volumetric porosity, relying solely on easily measurable quantities such as diameter of threads, spacing of threads and thickness. The results on the application to 20 + 6 insect-proof screens in this work evidence that the suggested approach outperforms the standard two-dimensional modelling. These results also support experimental observations in the relationship between porosity and pressure drop not explainable by the two-dimensional approach. To increase the reliability on the analysis of porosity, the propagation of experimental uncertainty has been also included in the comparison between brand new and old&washed insect-proof screens. A software (Poro3D v1.0) using the methodology developed in this work can be downloaded as supplementary material to this manuscript to instantly obtain both 3D and 2D porosities, as well as the reconstruction of 3D geometries

Immunosensor impedimetrico para la detección de pesticidas

En este trabajo describimos un immunosensor impedimétrico para la detección de pesticidas. Para demostrar dicho sensor hemos utilizado atrazina, como pesticida de test. Este sensor está basado en el uso de μ-electrodos interdigitados así como en reactivos específicamente desarrollados para la detección de este pesticida. Los anticuerpos utilizados no incluyen ningún tipo de etiqueta. Así mismo, el sensor no incluye ningún tipo de par redox que amplifique la señal. La detección immunoquímica de atrazina se alcanza mediante una reacción competitiva entre el antígeno tapizado y el pesticida por una pequeña cantidad de anticuerpo. Los cambios en la impedancia producidos por la inclusión de los bioreactivos son interpretados utilizando un circuito equivalente, el cual representa el sistema de manera fiable. La detección se monitoriza a partir de medidas impedimétricas diferenciales en un amplio espectro de frecuencia. El immunosensor muestra límites de detección en el rango de pocos ppb's, lo cual está muy por debajo del Maximum Residue Level (MRL) (50 μg L-1) establecido por la Unión Europea para los residuos de atrazina en uvas de vino así como en otros productos alimenticios. Aunque en este trabajo el immunosensor se ha demostrado para la atrazina, otros pesticidas podrían detectarse mediante este método siempre que se utilicen los reactivos adecuados.Peer ReviewedPostprint (author’s final draft

Six Collective Challenges for Sustainability of Almería Greenhouse Horticulture

Globally, current food consumption and trade are placing unprecedented demand on agricultural systems and increasing pressure on natural resources, requiring tradeoffs between food security and environmental impacts especially given the tension between market-driven agriculture and agro-ecological goals. In order to illustrate the wicked social, economic and environmental challenges and processes to find transformative solutions, we focus on the largest concentration of greenhouses in the world located in the semi-arid coastal plain of South-east Spain. Almería family farming, predominantly cooperative, greenhouse intensive production, commenced after the 1960s and has resulted in very significant social and economic benefits for the region, while also having important negative environmental and biodiversity impacts, as well as creating new social challenges. The system currently finds itself in a crisis of diminishing economic benefits and increasing environmental and social dilemmas. Here, we present the outcomes of multi-actor, transdisciplinary research to review and provide collective insights for solutions-oriented research on the sustainability of Almeria’s agricultural sector. The multi-actor, transdisciplinary process implemented collectively, and supported by scientific literature, identified six fundamental challenges to transitioning to an agricultural model that aims to ameliorate risks and avoid a systemic collapse, whilst balancing a concern for profitability with sustainability: (1) Governance based on a culture of shared responsibility for sustainability, (2) Sustainable and efficient use of water, (3) Biodiversity conservation, (4) Implementing a circular economy plan, (5) Technology and knowledge transfer, and (6) Image and identity. We conclude that the multi-actor transdisciplinary approach successfully facilitated the creation of a culture of shared responsibility among public, private, academic, and civil society actors. Notwithstanding plural values, challenges and solutions identified by consensus point to a nascent acknowledgement of the strategic necessity to locate agricultural economic activity within social and environmental spheres.This paper demonstrates the need to establish transdisciplinary multi-actor work-schemes to continue collaboration and research for the transition to an agro-ecological model as a means to remain competitive and to create value