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AbstractTimber densification is a process that has been around since the early 1900s and is predominantly used to enhance the structural properties of timber. The process of densification provides the timber with a greater mechanical strength, hardness, abrasion resistance, and dimensional stability in comparison to its virgin counterparts. It alters the cellular structure of the timber through compression, chemical impregnation, or the combination of the two. This in turn closes the voids of the timber or fills the porosity of the cell wall structure, increasing the density of the timber and, therefore, changing its properties. Several processes are reported in literature which produce densified timber, considering the effect of various parameters, such as the compression ratio, and the temperature on the mechanical properties of the densified timber. This paper presents an overview of the current processes of timber densification and its corresponding effects. The material properties of densified timber, applications, and possible future directions are also explored, as the potential of this innovative material is still not fully realised.

Although nitrogen (N) is the most limiting nutrient for agricultural production, its overuse is associated with environmental pollution, increased concentration of greenhouse gases, and several human and animal health implications. These implications are greatly affected by biochemical transformations and losses of N such as volatilization, leaching, runoff, and denitrification. Half of the globally produced N fertilizers are used to grow three major cereals—rice, wheat, and maize—and their current level of N recovery is approximately 30–50%. The continuously increasing application of N fertilizers, despite lower recovery of cereals, can further intensify the environmental and health implications of leftover N. To address these implications, the improvement in N use efficiency (NUE) by adopting efficient agronomic practices and modern breeding and biotechnological tools for developing N efficient cultivars requires immediate attention. Conventional and marker-assisted selection methods can be used to map quantitative trait loci, and their introgression in elite germplasm leads to the creation of cultivars with better NUE. Moreover, gene-editing technology gives the opportunity to develop high-yielding cultivars with improved N utilization capacity. The most reliable and cheap methods include agronomic practices such as site-specific N management, enhanced use efficiency fertilizers, resource conservation practices, precision farming, and nano-fertilizers that can help farmers to reduce the environmental losses of N from the soil–plant system, thus improving NUE. Our review illuminates insights into recent advances in local and scientific soil and crop management technologies, along with conventional and modern breeding technologies on how to increase NUE that can help reduce linked N pollution and health implications.

Water use efficiency (WUE) plays important role in understanding the interaction between carbon and water cycles in the plant-soil-atmosphere system. However, little is known regarding the impact of altered precipitation on plant WUE in arid and semi-arid regions. The study examined the effects of altered precipitation [i.e., ambient precipitation (100% of natural precipitation), decreased precipitation (DP, −50%) and increased precipitation (IP, +50%)] on the WUE of grass species (Stipa grandis and Stipa bungeana) and forb species (Artemisia gmelinii) in a temperate grassland. The results found that WUE was significantly affected by growth stages, precipitation and plant species. DP increased the WUE of S. grandis and S. bungeana generally, but IP decreased WUE especially in A. gmelinii. And the grasses had the higher WUE than forbs. For different growth stages, the WUE in the initial growth stage was lower than that in the middle and late growth stages. Soil temperature, available nutrients (i.e., NO3–, NH4+, and AP) and microorganisms under the altered precipitations were the main factors affecting plant WUE. These findings highlighted that the grasses have higher WUE than forbs, which can be given priority to vegetation restoration in arid and semi-arid areas.

Abstract The vacuum cooling of cooked meats is described in this paper. Based on the energy and mass balance, a modified mathematical model based on a previous model is developed to analyze the performance of the vacuum cooler and the evaporation-boiling phenomena during vacuum cooling of cooked meat. Validation experimentation is performed in the designed vacuum cooler. Boiling occurs inside the cooked meat. There is a boiling front, and the boiling front moves toward the center of the cooked meat as the vacuum cooling proceeds. The experimental data are compared with the simulation results. It is found that the differences of the temperature between the simulation and the experimentation are within 5 °C, and the deviation of weight loss between the simulation and the experimentation is within 4%. The simulation results agree with the experimental data well. The modified model can be used to predict the variation of the vacuum pressure in the chamber, the temperature and pressure distributions and the weight loss profiles of cylindrical cooked meats.

Extreme events normally have negative effects on crop growth. Many studies have reported findings on drought and flood events, while only sparse studies have focused on new types of extreme events, such as drought-flood abrupt alternation (DFAA). We attempted to gain an insight on the effects of DFAA over two-year field experiment on biomass, grain yield and quality, then simulated the yield loss to DFAA in history and future in summer maize planting area in the Northern Anhui Plain. Results show that DFAA significantly reduced root biomass and shoot biomass by 77.1% and 60.1% compared with that in the control systems. The negative effect lasted until mature stage. The grain yield loss was 14.1%–38.4% in different DFAA treatments. The numerical simulation reveals that the average annual yield loss due to DFAA has been increasing in the Northern Anhui Plain, with 21.19%–30.98% during 1964–2017, 14.10%–33.40% during 2020–2050. The spatial distribution of yield loss changed as well. This study increases our knowledge of the effects of DFAA on crop production and highlights the need to consider the targeted countermeasures.

Arbuscular mycorrhizal fungi (AMF) can form symbiotic relationships with most terrestrial plants and regulate the uptake and distribution of antimony (Sb) in rice. The effect of AMF on the uptake and transport of Sb in rice was observed using pot experiments in the greenhouse. The results showed that AMF inoculation increased the contact area between roots and metals by forming mycelium, and changed the pH and Eh of the root soil, leading to more Sb entering various parts of the rice, especially at an Sb concentration of 1,200 mg/kg. The increase in metal toxicity further led to a decrease in the rice chlorophyll content, which directly resulted in a 22.7% decrease in aboveground biomass, 21.7% in underground biomass, and 11.3% in grain biomass. In addition, the antioxidant enzyme results showed that inoculation of AMF decreased 22.3% in superoxide dismutase, 9.9% in catalase, and 20.7% in peroxidase compared to the non-inoculation groups, further verifying the negative synergistic effect of AMF inoculation on the uptake of Sb in rice. The present study demonstrated the effect of AMF on the uptake and transport of Sb in the soil–rice system, facilitating future research on the related mechanism in the soil–rice system under Sb stress.

La production animale est une source essentielle de revenus et d'émissions de gaz à effet de serre (GES) agricoles en Colombie, au Brésil, en Argentine, au Costa Rica, en Uruguay, au Mexique et au Pérou. Plusieurs options de gestion et technologiques, avec un potentiel d'atténuation du méthane entérique, ont été évaluées et leur mise à l'échelle devrait contribuer à la réalisation des objectifs de réduction des émissions de GES. Pourtant, l'adoption généralisée d'options d'atténuation prometteuses reste limitée, ce qui soulève des questions quant à savoir si les objectifs de réduction des émissions envisagés sont réalisables. À l'aide de données générées localement, nous explorons les potentiels d'atténuation des technologies et des pratiques de gestion actuellement proposées pour atténuer les émissions de méthane entérique, pour les systèmes de production bovine dans les pays d'Amérique latine les plus émetteurs. Nous discutons ensuite des obstacles à l'adoption d'innovations qui réduisent considérablement les émissions de méthane entérique d'origine bovine et des changements majeurs dans les politiques et les pratiques qui sont nécessaires pour relever les ambitions nationales dans les pays à forte émission. En utilisant la science la plus récente et la pensée actuelle, nous fournissons notre point de vue sur une approche inclusive et ré-imaginons comment les secteurs universitaire, de la recherche, des affaires et des politiques publiques peuvent soutenir et encourager les changements nécessaires pour élever le niveau d'ambition et atteindre les objectifs de développement durable en envisageant des actions allant de la ferme à l'échelle nationale. La producción ganadera es una fuente fundamental de ingresos y emisiones de gases de efecto invernadero (GEI) agrícolas en Colombia, Brasil, Argentina, Costa Rica, Uruguay, México y Perú. Se han evaluado varias opciones de gestión y tecnológicas, con potencial de mitigación de metano entérico, y se prevé que su escalado contribuya al logro de los objetivos de reducción de emisiones de GEI. Sin embargo, la adopción generalizada de opciones de mitigación prometedoras sigue siendo limitada, lo que plantea dudas sobre si los objetivos de reducción de emisiones previstos son alcanzables. Utilizando datos generados localmente, exploramos los potenciales de mitigación de las tecnologías y prácticas de manejo actualmente propuestas para mitigar las emisiones de metano entérico, para los sistemas de producción ganadera en los países de mayor emisión de América Latina. Luego discutimos las barreras para adoptar innovaciones que reduzcan significativamente las emisiones de metano entérico en el ganado y los cambios importantes en las políticas y prácticas que se necesitan para aumentar las ambiciones nacionales en los países con altas emisiones. Utilizando la ciencia más reciente y el pensamiento actual, brindamos nuestra perspectiva sobre un enfoque inclusivo y reimaginamos cómo los sectores académico, de investigación, empresarial y de políticas públicas pueden apoyar e incentivar los cambios necesarios para elevar el nivel de ambición y alcanzar los objetivos de desarrollo sostenible considerando acciones desde la granja hasta la escala nacional. Livestock production is a pivotal source of income and agricultural greenhouse gas (GHG) emissions in Colombia, Brazil, Argentina, Costa Rica, Uruguay, Mexico and Peru. Several management and technological options, with enteric methane mitigation potential, have been evaluated and their scaling is anticipated to contribute towards achieving GHG emission reduction targets. Yet, widespread adoption of promising mitigation options remains limited, raising questions as to whether envisaged emission reduction targets are achievable. Using locally generated data, we explore the mitigation potentials of technologies and management practices currently proposed to mitigate enteric methane emissions, for cattle production systems in the higher emitting countries of Latin America. We then discuss barriers for adopting innovations that significantly reduce cattle-based enteric methane emissions and the major shifts in policy and practice that are needed to raise national ambitions in the high emitting countries. Using the latest science and current thinking, we provide our perspective on an inclusive approach and re-imagine how the academic, research, business and public policy sectors can support and incentivize the changes needed to raise the level of ambition and achieve sustainable development goals considering actions all the way from the farm to the national scale. الإنتاج الحيواني هو مصدر محوري للدخل وانبعاثات غازات الدفيئة الزراعية في كولومبيا والبرازيل والأرجنتين وكوستاريكا وأوروغواي والمكسيك وبيرو. تم تقييم العديد من خيارات الإدارة والخيارات التكنولوجية، مع إمكانية تخفيف الميثان المعوي، ومن المتوقع أن يساهم قياسها في تحقيق أهداف خفض انبعاثات غازات الدفيئة. ومع ذلك، لا يزال الاعتماد الواسع النطاق لخيارات التخفيف الواعدة محدودًا، مما يثير تساؤلات حول ما إذا كانت أهداف خفض الانبعاثات المتوخاة قابلة للتحقيق. باستخدام البيانات التي تم إنشاؤها محليًا، نستكشف إمكانات التخفيف من التقنيات وممارسات الإدارة المقترحة حاليًا للتخفيف من انبعاثات الميثان المعوية، لأنظمة إنتاج الماشية في البلدان ذات الانبعاثات الأعلى في أمريكا اللاتينية. ثم نناقش العوائق التي تحول دون اعتماد الابتكارات التي تقلل بشكل كبير من انبعاثات الميثان المعوي القائم على الماشية والتحولات الرئيسية في السياسات والممارسات اللازمة لرفع الطموحات الوطنية في البلدان ذات الانبعاثات العالية. باستخدام أحدث العلوم والتفكير الحالي، نقدم وجهة نظرنا حول نهج شامل ونعيد تصور كيف يمكن للقطاعات الأكاديمية والبحثية وقطاع الأعمال والسياسة العامة دعم وتحفيز التغييرات اللازمة لرفع مستوى الطموح وتحقيق أهداف التنمية المستدامة مع الأخذ في الاعتبار الإجراءات على طول الطريق من المزرعة إلى النطاق الوطني.