Dry Areas Research Articles

Automatic ventilation and cooling of the building using the combination of wind deflector and solar chimney (state 3D with differential perspective)

Using new sources of energy and inventing new methods for energy consumption has always been the focus of researchers. The building sector is known to contribute largely in total energy consumption and CO2. Expanding the availability of energy storage technology and materials is considered as crucial as discovering new energy sources. The International Energy Outlook by the EIA (Energy Information Administration of the outlook) examines and predicts future trends in building energy usage. It anticipates a 34% growth in energy consumption within the built environment over the next two decades, with an average annual increase of 1.5%. By 2030, it is projected that approximately 67% of this consumption will be attributed to dwellings, while the non-domestic sectors will account for about 33%. This study endeavors to combine one of these ventilation techniques from ancient Persian architecture, known as the windcatcher in the form of an innovative roof radiative cooling (Windcatcher) with a solar chimney. In order to save energy consumption and reduce environmental problems by presenting the idea of using solar energy to exhaust the air inside the building through the chimney and using the latent heat of water evaporation to create cooling that is carried out in the direction of the wind by the windcatcher. Hence, fuel consumption can be created in hot and dry areas, in a comfortable environment with suitable humidity conditions. The purpose of this research is to introduce computational areas (3D) and determine the governing values and methods calculated by Ansys Fluent software, which has enabled the use of suction and the creation of moisture balance and heat reduction without fuel consumption, which plays an important role in It implements energy efficiency in the building. This system is also able to save 60% cooling energy and 80% of the ventilation energy during peak hours in a warm and arid climate. Furthermore, the effects of a wall opening on ventilation and thermal efficiency were examined.

The Logistics Cost of Cikarang Dry Port: A General Review

High logistics costs in Indonesia are thus one of the principal economic inefficiencies that restrain the country's growth and competitiveness in the global marketplace. In this context, the paper focuses on the contribution of the Cikarang Dry Port (CDP) to the national economy. This qualitative research draws on an extended narrative review of the Cikarang Dry Port. These results reflect how the CDP is pivotal in reducing logistics costs, benefiting clients and manufacturing firms around the dry port area through bettered transportation and logistics service provision. The study also puts much emphasis on the fact that logistics efficiency is not only crucial at the level of individual enterprise performance but also, more broadly, for Indonesia's economic landscape. The CDP consolidates supply chains and reduces transportation costs, ultimately building overall cost competitiveness for Indonesian enterprises in more state and international markets. The study calls for the Indonesian government to invest in developing and upgrading the infrastructure of the Cikarang and Bekasi areas. These strategic investments would also help reduce the overall cost of logistics, thereby creating an enabling environment for business operations and playing a role in the economic development and growth of the nation.

Three-Dimensional Printing of Bioinspired Hierarchical Structures for Enhanced Fog Collection Efficiency in 3D Space via Vat Photopolymerization

Collecting fog water is crucial for dry areas since natural moisture and fog are significant sources of freshwater. Sustainable and energy-efficient water collection systems can take a page out of the cactus’s playbook by mimicking its native fog gathering process. Inspired by the unique geometric structure of the cactus spine, we fabricated a bioinspired artificial fog collector consisting of cactus spines featuring barbs of different sizes and angles on the surfaces for water collection and a series of microcavities within microchannels inspired by Nepenthes Alata on the bottom to facilitate water flowing to the reservoir. However, replicating the actual shape of the cactus spine using conventional manufacturing techniques is challenging, and research in this area has faced a limitation in enhancing water-collecting efficiency. Here, we turned to 3D printing technology (vat photopolymerization) to create bio-mimetic fog collectors with a variety of geometric shapes that would allow for the most effective conveyance and gathering of water. Various barb sizes, angles between each barb in a single array, spine and barb arrangements, and quantity of barbs were tested experimentally and numeric analysis was carried out to measure the volume of water collected and optimize the mass rate. The result shows that optimal fog collection is with a mass flow rate of 0.7433 g/min, with Li = 900 μm, θ = 45°, ϕ = 90°, Nb = 2, and Ns = 5. This study presents a sustainable and ecologically sound method for efficiently collecting humid air, which is expected to be advantageous for the advancement of future-oriented fog-collection, water-transportation, and separation technologies.

A hybrid approach: remote sensing, analytic hierarchy process and geographic information system for groundwater potential mapping in Dediapada, India.

In recent years, the overexploitation of groundwater accompanied by a significant climatic shift has placed a burden on the world's groundwater supply. This has generated a rising need for potential groundwater zones. In recent year the ever-increasing demand for potable water across the world for various groundwater exploration investigation. The present study explores the utility of remote sensing (RS) and geographic information system (GIS) to identify potential water zones in the dry deciduous forest area of Dediapada Taluka, Narmada District, Gujarat, India. Twelve thematic layers of different environmental variables including geology, geomorphology, land use/land cover (LULC), drainage density, lineament density, rainfall, soil, slope, roughness, topographic wetness index (TWI), topographic position index (TPI), and curvature were integrated. GIS mode was subjected to weight analysis using Saaty's 9-point scale. The result was normalized using analytic hierarchy process (AHP), and five distinct groundwater potential zones (GWPZs) were identified namely very high, high, moderate, low, and very low. The area occupied by each category was 6.52%, 3.1%, 60.1%, 14.32%, and 15.99%. The output aids in validation assessment with the existing well data. The groundwater potential zones maps generated using AHP technique can prove beneficial for designing strategies for water management for the present taluka and can be extended to the different talukas also.

Improving plant growth, anthocyanin production and oxidative status of red lettuce (Lactuca sativa cv. Lolla Rossa) by optimizing red to blue light ratio with a constant green light fraction in a plant factory

Previous studies have reported contrasting effects of light quality on plant growth and anthocyanin content in lettuce leaves. This study aimed to optimize the red-to-blue light ratio with a constant green light fraction to improve biomass and anthocyanin production in red lettuce (Lactuca sativa cv. ‘Lolla Rossa’) in a plant Factory. Six treatments with varying proportions of red (R, 660 nm) and blue (B, 450 nm), along with a constant fraction of green (G, 540 nm) light, recorded as R125:B25:G50, R120:B30:G50, R112:B37:G50, R100:B50:G50, R75:B75:G50, and R50:B100:G50 were set up in this study. The total photosynthetic photon flux density for all treatments was 200 μmol m−2s−1 with a green light intensity of 50 μmol m−2s−1. The results showed that, compared with treatment R50:B100:G50, the fresh and dry weights, leaf length, leaf area and stem width of lettuce plants under treatment R125:B25:G50 showed an increase of 73.4 %, 47.8 %, 35.5 %, 54.9 %, and 58.3 %, respectively. Additionally, red light was found to promote increased weight of lettuce plant roots. Further, the anthocyanin content, nitrate content, and stomata density under treatment R50:B100:G50 were 6.75, 1.5, and 1.42 times higher than those under treatment R125:B25:G50. Enzymatic activities such as hydrogen peroxide (H2O2), superoxide dismutase (SOD), ascorbic acid (AsA), and anthocyanin concentration per fresh weight of plant were higher under treatment R100:B50:G50, comparing with those under treatment R125:B25:G50. The above results indicate that a higher red-to-blue light ratio enhances plant biomass, photosynthesis, and certain nutrients, while increasing the blue ratio promotes anthocyanin accumulation and antioxidants, protecting cells from oxidative stress. Based on this analysis, treatment R100:B50:G50 can be considered as the suitable light spectrum for optimal growth, anthocyanin accumulation and antioxidant activity of lettuce plants. Further researches are needed to explain these effects and refine lighting methods for optimal lettuce production and nutritional quality.

Assessment of Genetic Variability in Sorghum Genotypes under Dry Low Land Areas of Ethiopia

Assessment of Genetic Variability in Sorghum Genotypes under Dry Low Land Areas of Ethiopia

Unraveling the genetic architecture of stripe rust resistance in ICARDA spring wheat

Stripe rust, also known as yellow rust, caused by Puccinia striiformis f. sp. tritici (Pst), is among the most destructive fungal diseases affecting global wheat productivity. Identifying genetic loci associated with Pst resistance is crucial for developing durable Pst-resistant wheat varieties. This study aimed to discover genetic markers linked to Pst-resistance in wheat using a 15 K single-nucleotide polymorphism (SNP) array. Field screenings were conducted over two years (2018 and 2019) on a panel of 245 wheat breeding lines developed by the International Center for Agricultural Research in the Dry Areas (ICARDA) at the Kulumsa Agricultural Research Center in Ethiopia. Importantly, 36 breeding lines exhibited consistent immunity or resistance across both growing seasons. Genome-wide association studies (GWAS) identified 34 marker-trait associations (MTAs) across 10 loci that surpassed the significance threshold. Half of these SNP markers were located on chromosome 7B, while the remaining were distributed across chromosomes 1B, 2B, 4B, 5 A, and 6B. Many identified quantitative trait loci (QTLs) were in close proximity to known Pst resistance genes/QTLs, suggesting they correspond to the same genetic regions. Additionally, three QTLs—EWYY5A.2, EWYY6B.1, and EWYY7B.3—were notably distant from any of previously identified Pst resistance genes, emerging as potential novel loci from this study. These QTLs represent promising candidates for marker-assisted selection, facilitating the development of wheat cultivars with enhanced resistance to Pst. Additionally, this study recommends incorporating the 36 consistently resistant lines into national and international wheat breeding programs to enhance Pst disease management efforts.

The Use of Nanotechnology in Improving Irrigation Efficiency

Nanotechnology is becoming a major force in agriculture, especially when it comes to making watering more efficient. This essay looks into how nanomaterials and nanotechnology can be used to improve the way water is used in irrigation systems. This could help solve the serious problems of water shortage and low crop yields. With 9.7 billion people expected to live on Earth by 2050, there has never been a bigger need for efficient farming methods. A lot of water is lost through evaporation, deep percolation, and flow when people use traditional ways to water their plants. Nanotechnology can help with these problems in new and creative ways. One interesting use is making nanoparticles that can be mixed into soil or irrigation systems to help water stay in the soil longer and evaporate less quickly. Nanoparticles can improve the structure and ventilation of soil, which lets more water soak in and less water run off. Nanosensors can also be used to measure the amount of water in the soil in real time. This lets farmers use precise watering to get the best food growth with the least amount of water. These monitors can collect information that can be used to plan watering and automate systems so that water is only used when it's needed. Nanotechnology can also be used to make hydrogels and materials that take a lot of water. This could change the way water is managed in dry areas. These materials can hold a lot of water and slowly give it to plants, so they don't need to be watered as often.

X-BASE: the first terrestrial carbon and water flux products from an extended data-driven scaling framework, FLUXCOM-X

Abstract. Mapping in situ eddy covariance measurements of terrestrial land–atmosphere fluxes to the globe is a key method for diagnosing the Earth system from a data-driven perspective. We describe the first global products (called X-BASE) from a newly implemented upscaling framework, FLUXCOM-X, representing an advancement from the previous generation of FLUXCOM products in terms of flexibility and technical capabilities. The X-BASE products are comprised of estimates of CO2 net ecosystem exchange (NEE), gross primary productivity (GPP), evapotranspiration (ET), and for the first time a novel, fully data-driven global transpiration product (ETT), at high spatial (0.05°) and temporal (hourly) resolution. X-BASE estimates the global NEE at −5.75 ± 0.33 Pg C yr−1 for the period 2001–2020, showing a much higher consistency with independent atmospheric carbon cycle constraints compared to the previous versions of FLUXCOM. The improvement of global NEE was likely only possible thanks to the international effort to increase the precision and consistency of eddy covariance collection and processing pipelines, as well as to the extension of the measurements to more site years resulting in a wider coverage of bioclimatic conditions. However, X-BASE global net ecosystem exchange shows a very low interannual variability, which is common to state-of-the-art data-driven flux products and remains a scientific challenge. With 125 ± 2.1 Pg C yr−1 for the same period, X-BASE GPP is slightly higher than previous FLUXCOM estimates, mostly in temperate and boreal areas. X-BASE evapotranspiration amounts to 74.7×103 ± 0.9×103 km3 globally for the years 2001–2020 but exceeds precipitation in many dry areas, likely indicating overestimation in these regions. On average 57 % of evapotranspiration is estimated to be transpiration, in good agreement with isotope-based approaches, but higher than estimates from many land surface models. Despite considerable improvements to the previous upscaling products, many further opportunities for development exist. Pathways of exploration include methodological choices in the selection and processing of eddy covariance and satellite observations, their ingestion into the framework, and the configuration of machine learning methods. For this, the new FLUXCOM-X framework was specifically designed to have the necessary flexibility to experiment, diagnose, and converge to more accurate global flux estimates.

Effects of Foliar Application of Magnesium Fertilizer on Photosynthesis and Growth in Grapes

Efforts to increase grape yields have focused on using nitrogen, phosphorus, and potassium fertilizers, often causing unintended magnesium (Mg) deficiencies. To overcome Mg deficiency, different concentrations of MgSO4·7H2O (0, 1, 2, 3, 4 mM) and GABA (2.5 mM), as foliar sprays, were applied during the fruit enlargement and color transition stages. Key physiological parameters such as leaf growth, photosynthesis, and chlorophyll fluorescence were assessed. Interestingly, foliar Mg application increased the key physiological parameters, with the 3 mM treatment (M3) delivering the best improvement. Compared to the control, the M3 treatment increased dry weight and leaf area by 35.9% and 37.2%, respectively. Specifically, the foliar Mg application (M3) improved the photosynthesis (Pn), transpiration (Tr), and stomatal conductance (gs) of leaves when compared to the control. Additionally, the foliar Mg application improved the PSII photosynthetic efficiency, electron yield, and electron transport rates, following the order M2 > M3 > M1 > M0 > M4. This study demonstrated the essential role of foliar-applied Mg, with GABA, in improving grape physiology. Interestingly, the curve-fitting analysis of foliar Mg concentration and grape yield identified 2.14 mM of Mg as the optimal concentration for promoting grape growth.

Societal uses of the main water bodies inhabited by malaria vectors and implications for larval source management

BackgroundLarval source management (LSM) effectively reduces mosquito populations at their breeding sites, addressing issues like insecticide resistance that limit the effectiveness of primary interventions such as insecticide-treated nets (ITNs). Although traditionally used in urban and dry areas, recent research suggests it might also be effective in rural settings in eastern and southern Africa, where Anopheles funestus thrives in permanent water bodies that sustain year-round transmission. Targeting these habitats could enhance LSM, but it requires understanding local community practices, as mosquito breeding sites often overlap with community water resources. This study examined how communities use aquatic habitats and how these practices may impact LSM strategies, with a focus on habitats used by An. funestus.MethodsThis study was conducted in three villages in the Ulanga and Malinyi districts of southeastern Tanzania using a mixed-methods approach. Quantitative data were collected through cross-sectional surveillance, and qualitative data through unstructured interviews, focus group discussions, and field observations. Data analysis integrated both quantitative and qualitative findings to develop a comprehensive understanding of community perspectives.ResultsA survey of 931 aquatic habitats found mosquito larvae in 73% of them, with late instar An. funestus present in 23%. River streams made up 41% of the habitats, while ground pools accounted for 4%. Most habitats (90%) were used by communities, including 95% of those with An. funestus larvae, for activities such as domestic chores, agriculture, livestock rearing, brickmaking, and fishing. Focus group discussions revealed a willingness to adopt LSM, with a preference for larviciding and habitat modification over habitat removal, as the water sources were vital for daily use. Community concerns centered on the safety of larvicides for humans and animals, the environmental impact, and the need for better awareness of how LSM affects health and livelihoods.ConclusionThis study highlights community perspectives on LSM, focusing on the dual function of aquatic habitats as mosquito breeding sites and essential community water sources. This dual role presents both challenges and opportunities, suggesting that LSM strategies must balance public health needs with socio-economic realities. There was a clear preference for larviciding and habitat modification over removal, with a strong emphasis on health and environmental safety. The study emphasizes the importance of educating communities on the safety and effectiveness of LSM, and tailoring LSM strategies to fit the needs and preferences of local communities.

Probing ozone effects on European hornbeam (Carpinus betulus L. and Ostrya carpinifolia Scop.) leaf water content through THz imaging and dynamic stomatal response

We investigated the impact of ozone exposure on Hornbeam using a novel dual approach based on Terahertz (THz) imaging in a free-air ozone exposure experiment (three ozone levels: ambient; 1.5 times ambient; twice ambient). The research aims at unraveling the physiological responses induced by elevated ozone levels on water dynamics. THz imaging unveiled dynamic changes in leaf water content, providing a non-invasive approach to leaf water monitoring. Leaf gas exchange measurements assessed stomatal responses to light variation. Our findings showcase a compelling correlation between elevated ozone levels and reduction in photosynthetic rate and impairment of stomatal function, i.e. “stomatal sluggishness”, indicative of nuanced regulatory mechanism. Stomatal sluggishness was particularly evident in Carpinus betulus (CB) compared to Ostrya carpinifolia (OC) and was linked to reduction in photosynthetic capacity. THz-based imaging techniques confirmed this result indicating a negative effect of O3 on leaf-level total water content. In addition, spatial analysis of leaf water status using these techniques also highlighted that the negative effect of O3 on water status was progressing even in less sensitive OC plants though visible foliar injury was not detected. In fact, OC showed a relative dry area of 1.6 ± 1.6 % in the control group and 3.8 ± 1.3 % under high ozone levels. THz-based imaging techniques provided a deep understanding of O3 behavior in plants and may be recommended for precision biosensing in the early detection of O3-induced damage. The integration of THz imaging and physiological analysis resulted in comprehensive understanding of Hornbeam acclimation response to ozone exposure.

Role of Vermicompost and algae Extract in Improving Growth and Fruit Quality of Mango (Keitt)

This research, spanning the 2021 and 2022 seasons, aimed to explore the impact of vermicomposting on the growth and productivity of Mango trees (cv. Keitt) cultivated in sandy soil at Ahmed Orabi Agricultural region, El-Obour City, Cairo Governorate, Egypt. The selected trees underwent various treatments, including water (control), vermicomposting at 1 or 2 Kg/tree, Spirulina platensis algae extract at (5 or 10ml/l), and their combinations. Optimal results in terms of leaf fresh and dry weight, leaf area, and chlorophyll content were observed with the treatment of 2kg vermicompost + 10ml/l algae extract. Furthermore, the addition of vermicompost along with algae extract improved the leaf status of N, P, K, and Ca. Application of both vermicompost and algae extract, whether individually or in combination, demonstrated positive effects on the physicochemical quality of the fruit. The findings suggest that the simultaneous use of vermicompost and algae extract holds promise as a supplementary material for enhancing the growth, productivity, and fruit quality of Mango trees.

Basti as Ardha Chikitsa in the management of Vata-Pitta Samsrushta Grudrasi - A Case Report of Lumbar Spondylosis

Lumbar Spondylosis is the commonly observed chronic degenerative disorder especially in the geriatric age group. This signifies that disorder is majorly due to Dhatu Kshaya (~depletion of body building and sustaining factors). In the present case report of Lumbar Spondylosis, was diagnosed as Vata Pitta Samsrushta Grudrasi (~sciatica formed by Vata and Pitta Dosha in their equal dominance) with the application of Trividha Bodhya Samgraha (~cause, situation and nature of disease). A 53 year housewife hailing from rural sector of Jangala Desha (dry area) reported with severe burning sensation in right foot, low backache, referred pain in right calf associated with numbness. Vata and Pitta were elicited as Sthanika (~functional unit of its own place) and Agantu Dosha (~functional unit entered from other part) respectively through Samsarga Dosha Laxana. Yapana Basti (~Enema Therapy) schedule was designed to pacify Pakvashayagata Vata-Pitta (~Vata and Pitta situated in lower gut). Qualitative assessment done before and after treatment revealed successful outcomes where score reduced from 12 to 2 indicating improved quality of life. Basti acts as Ardha Chikitsa (~half treatment) when proper Yukti (planning) is applied in designing protocol, selecting appropriate formulations by incorporating multiple Chikitsa Siddhanta (~treatment principle) such as Sthanivat Chikitsa.

Effect of different packaging methods and storage conditions on postharvest quality and shelf-life of Manila Tamarind (Pithecellobium dulce (Roxb.) Benth.) var. PKM2

Manila tamarind (Pithecellobium dulce (Roxb.) Benth.), is a dry land fruit crop that belongs to the Fabaceae family commonly known Camacchile or Jungle jilebi. Pithecellobium dulce (Roxb.) has the potential to become productive under harsh climatic and edaphic conditions of dry land areas but its pods have a shorter shelf life. The most important objective was to use proper packaging methods to reduce moisture loss, slow down physiological and biochemical changes and prevent spoilage. The study evaluated 8 packaging methods, including different combinations of CFB (Corrugated Fiberboard) lined with 100-gauge polythene film with 0 %, 5 % and 10 % vents, CFB with 0 %, 5 % and 10 % vents, vacuum packing and a control, under cold storage (13-15 °C) and ambient conditions (26 ± 2 °C). On the 15th day of cold storage conditions, vacuum packing showed minimum physiological loss of weight (19.82 %), titratable acidity (0.68 %), ascorbic acid (77.20) and total sugar (8.36 %). Maximum total soluble solids (15.32 ?Brix), Anthocyanin (22.72 mg 100 g-1 m), shelf life (15 days) followed by CFB with 10 % vent. On the 12th day of ambient storage condition, vacuum packing recorded minimum physiological loss of weight (16.42 %), titratable acidity (0.42 %), ascorbic acid (76.13) and total sugar (8.53 %). Maximum total soluble solids (14.93 ?Brix), Anthocyanin (21.83 mg 100 g-1 m) and shelf life (11.5 days) followed by CFB with 10 % vent. In this study, the overall results indicated that both vacuum packaging and CFB with 10 % vent at cold storage had synergistic effect in manila tamarind fruit pods, not only in extending the shelf life but also maintained the physiological and biochemical attributes of manila tamarind.

Assessment of Soil Moisture through Climatic Variables Using Remote Sensing Data in Semi-Arid Sokoto State, Nigeria

Soil moisture availability is an indispensable requirement for not only the growth of crops but also other living organisms in any ecological settings This study determined soil moisture condition in Sokoto State using climate-based water index. Satellite-based estimations of mean monthly rainfall data was obtained from the USGS/FEWS database for each of the local government areas. Also, approximations of monthly values of minimum and maximum air temperatures (AIRS) were downloaded from the NASA website. The latter variables were utilised in the computation of potential evapotranspiration using Hargreaves equation. It was very clear from the results that water surplus occurred in the months of July, August and September across almost all the locations. In addition, places lying in the southern part of the State such as Kebbe, Yabo, Tambuwal and Shagari recorded higher positive values of moisture availability in contrast to their counter parts in the extreme north bordering Niger republic. Thus, this study revealed slight spatio-temporal variation in soil moisture condition across the entire study area decreasing from the southern locations towards the north. Hence, the research could help improve agricultural planning and suggest irrigation during dry periods. Consequently, the findings could offer useful insights for managing water resources and improving farming in dry areas.

Increasing shallot production with chitosan application to support food resilience in dry climate areas

Abstract Shallots are an important ingredient in many dishes around the world, but their production can be challenging, especially in dry climates. Efforts to increase shallot production are carried out by applying chitosan which can increase plant resistance in drought conditions. This research aims to analysed the effect of concentration and time interval of chitosan administration on the growth and production of shallots in dry climate areas. The research design used was a randomized block design with two factors, namely chitosan concentration (0; 1; 2 and 3 g/L) and application time interval (10; 15 and 20 days). The study was conducted in 2023 between April and August at the research area of the Meteorology, Climatology and Geophysics Agency in Sampali Village, Deli Serdang Regency. The research results showed that the chitosan concentration had a noteworthy impact on the growth of leaves., while the interaction of concentration and application time interval significantly impacted the growth of the tuber’s diameter and dry weight. To increase shallot production in dry climates, it is recommended to use a 2 g/L concentration of chitosan an application interval of every 20 days.

Shifts in Plant Phenology Significantly Affect the Carbon Allocation in Different Plant Organs.

Earlier start of the growing season (SGS) and delayed end of the growing season (EGS) affect plant carbon uptake. However, the effects of phenological changes on carbon allocation to different plant organs remain unclear. Here, we examined the effects and potential mechanisms of phenological changes on carbon allocation to different organs over the northern hemisphere (> 30° N). We found the earlier SGS facilitated allocating carbon to roots in warm areas, and delayed EGS benefited allocating carbon to roots in dry areas. Moreover, the effects of SGS and EGS on carbon accumulation in different organs significantly enhanced over time. Path analyses indicated that phenological changes contributed to root-stem ratio mainly by regulating the growing season length. Our findings further highlight that phenological changes alter plants' investment strategies in carbon allocation for above- and below-ground parts, and considering this role is critical for accurately estimating the carbon budget in terrestrial ecosystems.

Application and simulation of IEC water chillers for summer free cooling in data centers

Free cooling is regarded as the most effective way to reduce the energy consumption of the cooling system in data centers. This study proposes a novel water-medium indirect evaporative cooling (IEC) chiller used in a data center to achieve free cooling throughout the year as an alternative to electrical chillers. Field tests and numerical modeling of the IEC water chillers are both reported to evaluate the performance and efficiency. This paper first-time reports on the application of IEC water chillers to deliver year-round free cooling for a data center in Changji, China. The wet-bulb efficiency of the tested chiller is measured as 120% to 152.8% and the dew-point efficiency is 27% to 62.7%. A numerical model is established to verify the operating conditions, and some common operational optimizations are pointed out in this test for energy savings. PUE can be reduced to 1.212 after the optimization. More future performance predictions of the IEC water chillers are studied when the data center load rate increases and when the local weather changes in a year to discuss the year-round availability. For further study, the performance of IEC water chillers in different climate regions is also forecasted. The results indicate that it’s an effective way for IEC to achieve free cooling in regions where natural cold resources are abundant. In this study, the field test performance and prediction of IEC water chillers are provided as a typical and practical application as the natural cooling source in data centers in hot and dry areas.

ANÁLISE ESPACIAL E TEMPORAL DE EVENTOS DE SECAS NA REGIÃO HIDROGRÁFICA ALTO RIO PARANÁ DE 1990 A 2020

The Paraná River Hydrographic Region is of great socioeconomic relevance for Brazil. Therefore, due to the history of droughts in the region, the aims of the current study were to assess rainfall spatial and temporal variability, as well as to analyze drought features based on using the Normalized Percentage Index (NPI) to contribute to water management processes in Upper Paraná River (UPR). The study area encompasses 14 Planning and Management Units, distributed in Goiás, Mato Grosso do Sul, Minas Gerais and São Paulo states. Climate data were obtained from the National Hydrometeorological Network database. A geostatistical analysis of rainfall was carried out, based on the annual series of 408 stations, and subsequently the calculation of NPI for classifying the droughts severity. All periods analyzed (1990-2020) showed spatial dependence (moderate to high), allowing the elaboration of droughts maps. The dry and rainy periods and areas did not indicate direct influence of El Niño-Southern Oscillation (ENSO). Mato Grosso do Sul and São Paulo units were the main contributors to the identified droughts. The data showed that 2010-2020 was the driest decade of the period, with a greater contribution from the 2019/2020 period, where droughts exceeded 60% of the area for two consecutive years, an event never identified in the last 3 decades. The NPI curves referring to “initial drought” and “mild” allowed verifying years of water crisis when their summed percentages reached at least 50% of the region. The methodology used is versatile, allowing its use in any watershed. Keywords: Rains. Water management. NPI. Kriging.