Hasil untuk "Irrigation engineering. Reclamation of wasteland. Drainage"

Eduard Enoiu, Jean Malm, Gregory Gay

We explore the concept of folklore within software engineering, drawing from folklore studies to define and characterize narratives, myths, rituals, humor, and informal knowledge that circulate within software development communities. Using a literature review and thematic analysis, we curated exemplar folklore items (e.g., beliefs about where defects occur, the 10x developer legend, and technical debt). We analyzed their narrative form, symbolic meaning, occupational relevance, and links to knowledge areas in software engineering. To ground these concepts in practice, we conducted semi-structured interviews with 12 industrial practitioners in Sweden to explore how such narratives are recognized or transmitted within their daily work and how they affect it. Synthesizing these results, we propose a working definition of software engineering folklore as informally transmitted, traditional, and emergent narratives and heuristics enacted within occupational folk groups that shape identity, values, and collective knowledge. We argue that making the concept of software engineering folklore explicit provides a foundation for subsequent ethnography and folklore studies and for reflective practice that can preserve context-effective heuristics while challenging unhelpful folklore.

S. Mirshekari, F. Yaghoubi, S.A. Hashemi

Introduction The 21st century is witnessing the increase of climate change as an important challenge due to its destructive environmental and socio-economic effects. Extreme climatic conditions have become frequent and more intense in recent decades as a result of human activities. Iran, as one of the countries in the Middle East with a different climate in each region of the country, has suffered significant adverse effects of climate change. Considering the importance of the climate change, it is important to investigate the changes in climate variables to know the future conditions and make management decisions. In the field of climate research, global climate models are useful tools that are often used to investigate the global climate system, including historical and projected periods. Since the use of the CMIP6 dataset provides improved clarity and accuracy for predicting future climate forecasts, the main objective of the present study is to predict the temperature and precipitation changes in the near, mid, and far future in Sistan-va-Baluchestan province.   Materials and Methods The minimum temperature, maximum temperature, and precipitation data of 10 general circulation models (GCMs) of the 6th IPCC report for the baseline (1990-2014) were downloaded from the Global Climate Research Program database (https://esgf-node.llnl.gov). Then GCMs were including ACCESS-CM2, CMCC-ESM2, CNRM-CM6-1-HR, CNRM-ESM2-1, EC-Earth3-CC, EC-Earth3-Veg-LR, INM-CM4-8, INM-CM5-0, MIROC6, and NorESM2-MM. Four statistical indicators including correlation coefficient (R2), RMSE, Nash-Sutcliffe efficiency (NSE), and mean absolute error (MAE) were used to evaluate the performance of 10 GCMs. Based on the results obtained from the these indicators, the models that had higher performance in predicting the temperature and precipitation data were selected as the best models for forecasting in the future. The ensemble of these models under two SSP2-4.5 and SSP5-8.5 scenarios for the near, middle, and far future (2026-2050, 2051-2075, and 2076-2100) were extracted from the World Climate Research Program database. CMhyd (Climate Model data for hydrologic modeling) tool was used to bias correction climate data of the selected models. In order to choose the best bias correction method, the R2, RMSE, NSE, and MAE were estimated. After bias correction, the climate data of selected models were ensembled and then the changes in precipitation and maximum and minimum temperature in three future periods compared to the baseline was estimated.   Results and Discussion The results showed that out of 10 GCMs, seven models had good performance (R2 > 0.40, 4.23 < RMSE < 12.02°C, 0.12 < NSE < 0.74, and 3.36 < MAE < 9.59°C) in simulating daily minimum and maximum temperature. However, the performance of all models in simulated daily precipitation was poor (R2 > 0.19, 1.24 < RMSE < 3.70 mm, -7.41 < NSE < -0.57, and 0.23 < MAE < 0.85 mm). Among the different bias correction methods of temperature and precipitation available in CMhyd, the distribution mapping method had the best performance. In all three regions, compared to the baseline, the average annual minimum and maximum temperature under two scenarios will increase in the future periods and precipitation will decrease in most periods and scenarios. These changes will be mainly in the SSP5-8.5 scenario compared to SSP2-4.5 and also in the far future period compared to the middle and near future. Averaged across all locations, annual maximum temperature showed increases in near, middle, and far projected periods of 1.3, 2.1, and 2.8°C under SSP2-4.5 and 1.6, 3.1, and 5.1°C under SSP5-8.5, respectively (Fig. 2), while for minimum temperature, the increases will be of 1.6, 2.6, and 3.4°C for SSP2-4.5 and 1.9, 3.9, and 6.3°C for SSP5-8.5. The range of annual precipitation among all sites was from –58.22 to 49.33% under SSP5-8.5 in the near and far future periods in Zabol and Iranshahr, respectively. The annual increase in the average maximum and minimum temperature will be mainly due to the increase in air temperature in the months of January, February, August, September, October, November and December. The annual decrease in precipitation will mainly result from the decrease in precipitation in January, February, March, November, and December, and the annual increase in precipitation will result from the significant increase in precipitation in May and October compared to the baseline.   Conclusion The results showed that under different scenarios of climate change, the maximum and minimum temperatures in the near, middle, and far future periods will face an increase compared to the baseline. However, the precipitation changes in the future time periods are not the same as compared to the baseline, and in some periods the precipitation will decrease and in others it will increase. But in general, the decrease in precipitation will be more than its increase. Therefore, it is very important to formulate and implement appropriate management programs for the needs of each region, in order to properly manage water resources and adapt to extreme temperatures and their consequences.

فاطمه رزاقی, محمد اسماعیلی, علیرضا سپاسخواه

برای برنامه‌ریزی و مدیریت بهتر منابع آب به‌خصوص در مناطق خشک و نیمه خشک، برآورد دقیق  تبخیر-تعرق محصولات مختلف کشاورزی از اهمیت زیادی برخوردار می‌باشد. یکی از این گیاهان پرمصرف در سبد غذایی خانوار پیاز است که به خاطر آبیاری مکرر، نیاز آبی بالایی داشته و چنانچه در مراحل اولیه رشد دچار کمبود آب گردد، محصول آن به‌طور چشم‌گیری کاهش می‌یابد. لذا  این تحقیق با هدف تعیین ضرایب گیاهی یگانه، دوگانه و تبخیر-تعرق استاندارد گیاه پیاز در سه لایسیمتر بیلان آبی  انجام شد. مقدار تبخیر-تعرق گیاه مرجع با استفاده از دادههای ایستگاه هواشناسی و معادله فائو پنتمن مانتیث اصلاح شده محاسبه شد. میزان تبخیر-تعرق استاندارد پیاز (ETc) با استفاده از معادله بیلان آب خاک تعیین و سپس مقادیر ضرایب گیاهی یگانه در مراحل مختلف رشد محاسبه گردید. با توجه به قرار دادن میکرو‌لایسیمتر در سه لایسیمتر، میزان ضریب تبخیر ( ) و ضرایب تعرق پایه ( ) در مراحل مختلف رشد نیز محاسبه شد. میانگین محصول غده پیاز 24 تن در هکتار بود. مقدار ETc و تعرق در کل فصل کشت به‌ترتیب برابر 2/651 میلی‌متر و 296 میلی‌متر محاسبه شد. طول مراحل اولیه، میانی و نهایی رشد گیاه به‌ترتیب برابر 56، 25 و 21 روز به‌دست آمد. مقدار میانگین ضریب گیاهی یگانه در مرحله اولیه، میانی و نهایی رشد به‌ترتیب 50/0، 04/1 و 7/0 تعیین شد. مقدار ضریب  در مرحله اولیه، میانی و نهایی رشد به ترتیب 42/0، 26/0 و 47/0 به‌دست آمد. مقدار ضریب  در مرحله اولیه، میانی و نهایی رشد به‌ترتیب 08/0، 78/0 و 22/0 تعیین شد.  در نهایت با استفاده از  ضرایب گیاهی تعیین شده  توسط لایسیمتر، می‌توان مقدار دقیق نیاز آبی گیاه پیاز را در مناطقی با اقلیم مشابه و برای مراحل مختلف رشد تعیین نمود.

Maria Janicka, Aneta Kutkowska, Jakub Paderewski

In recent years, there has been increasing interest in the floristic diversity of agroecosystems, particularly for plant conservation. While old plantations claim to be more floristically diverse, little is known about this for Salix viminalis L. plantations. The aim of study was to analyse the vegetation accompanying S. viminalis and its dynamics as plantations age. The vegetation was identified in 20 plantations, based on 244 phytosociological relevés. For each species, the following were defined: botanical family, geographical and historical groups, origin of apophytes, biological stability, life-form, botanical class and phytosociological class. The relative coverage of major plant groups was statistically processed using the analysis of variance with a linear mixed model. The flora of S. viminalis plantations is rich and diverse; in central Poland, it consisted of 193 plant species. These species belonged to many phytosociological classes, of which two dominated: Molinio-Arrhenatheretea (46 species) and Artemisietea vulgaris (32 species). Perennial species, meadow, woodland, and shrub apophytes, as well as hemicryptophytes, were prevalent. As the plantations aged, the proportion of perennial species, meadow, woodland, and shrub apophytes increased, while therophytes and anthropophytes declined. Photophilous species dominated mainly in young crops (4–5 years old), but their coverage and frequency decreased over time. With plantations age, vascular flora diversity (total number of species) and coverage of ecologically important groups (Poaceae family, Molinio-Arrhenatheretea class) decreased. These were gradually replaced by mega- and nanophanerophytes and species from the A. vulgaris class. The stabilisation of flora occurred after eight years of willow cultivation.

Vidya Venkatesan, Aomawa L. Shields, Russell Deitrick et al.

Eccentric planets may spend a significant portion of their orbits at large distances from their host stars, where low temperatures can cause atmospheric CO2 to condense out onto the surface, similar to the polar ice caps on Mars. The radiative effects on the climates of these planets throughout their orbits would depend on the wavelength-dependent albedo of surface CO2 ice that may accumulate at or near apoastron and vary according to the spectral energy distribution of the host star. To explore these possible effects, we incorporated a CO2 ice-albedo parameterization into a one-dimensional energy balance climate model. With the inclusion of this parameterization, our simulations demonstrated that F-dwarf planets require 29% more orbit-averaged flux to thaw out of global water ice cover compared with simulations that solely use a traditional pure water ice-albedo parameterization. When no eccentricity is assumed, and host stars are varied, F-dwarf planets with higher bond albedos relative to their M-dwarf planet counterparts require 30% more orbit-averaged flux to exit a water snowball state. Additionally, the intense heat experienced at periastron aids eccentric planets in exiting a snowball state with a smaller increase in instellation compared with planets on circular orbits; this enables eccentric planets to exhibit warmer conditions along a broad range of instellation. This study emphasizes the significance of incorporating an albedo parameterization for the formation of CO2 ice into climate models to accurately assess the habitability of eccentric planets, as we show that, even at moderate eccentricities, planets with Earth-like atmospheres can reach surface temperatures cold enough for the condensation of CO2 onto their surfaces, as can planets receiving low amounts of instellation on circular orbits.

Roberto Verdecchia, Justus Bogner

While mastered by some, good scientific writing practices within Empirical Software Engineering (ESE) research appear to be seldom discussed and documented. Despite this, these practices are implicit or even explicit evaluation criteria of typical software engineering conferences and journals. In this pragmatic, educational-first document, we want to provide guidance to those who may feel overwhelmed or confused by writing ESE papers, but also those more experienced who still might find an opinionated collection of writing advice useful. The primary audience we had in mind for this paper were our own BSc, MSc, and PhD students, but also students of others. Our documented advice therefore reflects a subjective and personal vision of writing ESE papers. By no means do we claim to be fully objective, generalizable, or representative of the whole discipline. With that being said, writing papers in this way has worked pretty well for us so far. We hope that this guide can at least partially do the same for others.

Mesut Koçyiğit, Bahman Javadi, Russell Thomson et al.

Urban parks can mitigate local heat, yet irrigation control is usually tuned for water savings rather than cooling. We report on SIMPaCT (Smart Irrigation Management for Parks and Cool Towns), a park-scale deployment that links per-zone soil-moisture forecasts to overnight irrigation set-points in support of urban cooling. SIMPaCT ingests data from 202 soil-moisture sensors, 50 temperature-relative humidity (TRH) nodes, and 13 weather stations, and trains a per-sensor k-nearest neighbours (kNN) predictor on short rolling windows (200-900h). A rule-first anomaly pipeline screens missing and stuck-at signals, with model-based checks (Isolation Forest and ARIMA). When a device fails, a mutual-information neighbourhood selects the most informative neighbour and a small multilayer perceptron supplies a "virtual sensor" until restoration. Across sensors the mean absolute error was 0.78%, comparable to more complex baselines; the upper-quartile error (P75) was lower for kNN than SARIMA (0.71% vs 0.93%). SIMPaCT runs daily and writes proposed set-points to the existing controller for operator review. This short communication reports an operational recipe for robust, cooling-oriented irrigation at city-park scale.

Nahid Sultana, M. M. Rizvi, G. M. Wali Ullah

Sustainable irrigation and food security increasingly depend on efficient water resource management in the face of growing climatic and economic constraints. In this study, we develop two single objective optimization models for irrigation planning, one that maximizes net benefit and the other that minimizes environmental flow deficiency, and compare their performance with established models reported in previous studies. We then extend the analysis to a multiobjective programming formulation solved through scalarization and genetic approaches to evaluate trade-offs. Numerical experiments on the Muhuri Irrigation Project reveal three outcomes: (i) a complete scenario view with profits ranging from $ \$ 0.2 \times 10^9$ to $ \$ 1.497\times 10^9$ and environmental flow deficits between 0 and 1200 GL, where the 1200 GL represents the theoretical annual maximum under a 100 GL uniform monthly target; (ii) explicit trade-offs showing higher profits correspond to greater ecological shortfalls; and (iii) an integration based approach producing nearly 1000 Pareto optimal solutions within seconds, greatly outperforming earlier studies.

Mirco Tincani, Khaled Kerouch, Umberto Garlando et al.

Sensory processing at the edge requires ultra-low power stand-alone computing technologies. This is particularly true for modern agriculture and precision irrigation systems which aim to optimize water usage by monitoring key environmental observables continuously using distributed efficient embedded processing elements. Neuromorphic processing systems are emerging as a promising technology for extreme edge-computing applications that need to run on resource-constrained hardware. As such, they are a very good candidate for implementing efficient water management systems based on data measured from soil and plants, across large fields. In this work, we present a fully energy-efficient neuromorphic irrigation control system that operates autonomously without any need for data transmission or remote processing. Leveraging the properties of a biologically realistic spiking neural network, our system performs computation, and decision-making locally. We validate this approach using real-world soil moisture data from apple and kiwi orchards applied to a mixed-signal neuromorphic processor, and show that the generated irrigation commands closely match those derived from conventional methods across different soil depths. Our results show that local neuromorphic inference can maintain decision accuracy, paving the way for autonomous, sustainable irrigation solutions at scale.

Jerzy Księżak, Jolanta Bojarszczuk

Soybean is an important legume crop globally due to its rich protein, oil content, and functional components. The purpose of this study was to evaluate the yield of selected soybean cultivars depending on cultivation methods. The three-year field experiment, conducted from 2018 to 2020 at the Agricultural Experimental Station in Kępa-Puławy, Osiny farm (Institute of Soil Science and Plant Cultivation – State Research Institute in Puławy), investigated these variations. The first experimental factor was the soil cultivation method: A – conventional tillage, B – reduced tillage, and C – strip tillage. The second variable was soybean cultivar: ‘Aldana’ and ‘Merlin’. The soybean cultivars were selected for their differing maturity rates: ‘Aldana’ (000) is an early cultivar, while ‘Merlin’ (000++) semi-late cultivar. The field experiment utilised a split-plot design on Luvisol soil with sandy loam texture, belonging to a good rye complex, class IIIb–IVa, and was replicated four times. The study showed that the productivity (seed and protein yield) of the ‘Merlin’ cultivar grown in the central-eastern part of Poland was approximately 8% higher than that of the ‘Aldana’ cultivar. The cultivation method had a relatively minor influence on soybean yield, the content of selected nutrients, morphological features, and elements of the yield structure. The soil in strip-tillage method was more compact than the soil cultivated with a plough. After harvesting soybeans at a depth of 30, and 40 cm, the compactness of soil in strip-tillage or with reduced tillage was much lower than in spring, highlighting a positive effect of soybean cultivation on loosening the arable layer.

Yvonne Dittrich, Helen Sharp, Cleidson de Souza

Ethnography has become one of the established methods for empirical research on software engineering. Although there is a wide variety of introductory books available, there has been no material targeting software engineering students particularly, until now. In this chapter we provide an introduction to teaching and learning ethnography for faculty teaching ethnography to software engineering graduate students and for the students themselves of such courses. The contents of the chapter focuses on what we think is the core basic knowledge for newbies to ethnography as a research method. We complement the text with proposals for exercises, tips for teaching, and pitfalls that we and our students have experienced. The chapter is designed to support part of a course on empirical software engineering and provides pointers and literature for further reading.

Jennifer Chien, Kevin R. McKee, Jackie Kay et al.

Researchers and developers increasingly rely on toxicity scoring to moderate generative language model outputs, in settings such as customer service, information retrieval, and content generation. However, toxicity scoring may render pertinent information inaccessible, rigidify or "value-lock" cultural norms, and prevent language reclamation processes, particularly for marginalized people. In this work, we extend the concept of algorithmic recourse to generative language models: we provide users a novel mechanism to achieve their desired prediction by dynamically setting thresholds for toxicity filtering. Users thereby exercise increased agency relative to interactions with the baseline system. A pilot study ($n = 30$) supports the potential of our proposed recourse mechanism, indicating improvements in usability compared to fixed-threshold toxicity-filtering of model outputs. Future work should explore the intersection of toxicity scoring, model controllability, user agency, and language reclamation processes -- particularly with regard to the bias that many communities encounter when interacting with generative language models.

Juan M. Murillo, Jose Garcia-Alonso, Enrique Moguel et al.

As quantum computers advance, the complexity of the software they can execute increases as well. To ensure this software is efficient, maintainable, reusable, and cost-effective -key qualities of any industry-grade software-mature software engineering practices must be applied throughout its design, development, and operation. However, the significant differences between classical and quantum software make it challenging to directly apply classical software engineering methods to quantum systems. This challenge has led to the emergence of Quantum Software Engineering as a distinct field within the broader software engineering landscape. In this work, a group of active researchers analyse in depth the current state of quantum software engineering research. From this analysis, the key areas of quantum software engineering are identified and explored in order to determine the most relevant open challenges that should be addressed in the next years. These challenges help identify necessary breakthroughs and future research directions for advancing Quantum Software Engineering.

Ranim Khojah, Mazen Mohamad, Philipp Leitner et al.

Large Language Models (LLMs) are frequently discussed in academia and the general public as support tools for virtually any use case that relies on the production of text, including software engineering. Currently there is much debate, but little empirical evidence, regarding the practical usefulness of LLM-based tools such as ChatGPT for engineers in industry. We conduct an observational study of 24 professional software engineers who have been using ChatGPT over a period of one week in their jobs, and qualitatively analyse their dialogues with the chatbot as well as their overall experience (as captured by an exit survey). We find that, rather than expecting ChatGPT to generate ready-to-use software artifacts (e.g., code), practitioners more often use ChatGPT to receive guidance on how to solve their tasks or learn about a topic in more abstract terms. We also propose a theoretical framework for how (i) purpose of the interaction, (ii) internal factors (e.g., the user's personality), and (iii) external factors (e.g., company policy) together shape the experience (in terms of perceived usefulness and trust). We envision that our framework can be used by future research to further the academic discussion on LLM usage by software engineering practitioners, and to serve as a reference point for the design of future empirical LLM research in this domain.

ZHANG Xuanshuo, LI Hongbo, LI Sheng et al.

【Objective】 Soil salinization in the Ningxia Yellow River diversion irrigation area has been found to damage the microstructure and reduce the strength of concrete linings of the channels. The objective of this paper is to study the efficacy of using high-activity silica fume to enhance the concrete linings. 【Method】 Fifteen types of composite cementing materials were prepared using ordinary Portland cement (PO), sulphoaluminate cement (SAC), and aluminate cement (AC) with silica fume as a substitute. The mechanical behavior of the composite adhesives was studied using compressive strength and impermeability tests, combined with SEM, EDS, and XRD characterization. The micro hydration mechanism was also investigated. 【Result】 With the increase in silica fume content, the impermeability of PO, SAC and AC increased gradually. Adding 6% of silica fume significantly increased the strength of PO at the early stage. The C-S-H gel and AFt crystals cemented and interlocked with each other to form a three-dimensional network structure, effectively reducing early deterioration of the strength of the matrix caused by stacking of Ca(OH)2. The Ca/Si of C-S-H gel decreased, and the degree of polymerization increased, ensuring the stability of the system strength. The strength of SAC pastes measured 3 and 28 days after the test increased first and then decreased with the increase in silica fume replacement rate. The nucleation effect and pozzolanic effect of silica fume promoted the increase in SAC hydration products. The coarse rod like AFt crystals played a skeleton role in hardening pastes and were covered by AH3 gel, forming a stronger combination. With the increase in the replacement rate of silica fume, the strength of AC paste measured 3 and 28 days after the test showed a negative increase, and the strength measured 90 days after the test increased first and then decreased with the silica fume replacement rate. The addition of 4% silica fume restricted the crystallization reaction of CAH10 and C2AH8, and reduced the porosity significantly, which improved the strength reversion phenomenon at the later stage of AC. 【Conclusion】 Adding an appropriate amount of silica fume can significantly enhance the strength of the concrete lining and optimize its microscopic morphology, thereby improving its impermeability. Further studies could explore the effect of varying amounts of silica fume on other types of cementing materials and in different environmental conditions.

LIU Xiaoyi, LIU Chao, NIE Ruihua et al.

【Objective】 Water use efficiency (WUE) and the factors affecting its spatiotemporal variation are important in water management at catchment scale. The objective of this paper is to analyze the variations of WUE and its determinants in the source region of Yellow River (SRYR). 【Method】 The analysis was based on MODIS remote sensing data, from which we estimated the ecosystem WUE from 2000 to 2014 and its spatiotemporal variation, as well as the underlying drivers using trend analysis and correlation analysis. 【Result】 Spatially, the mean annual WUE increased from the west to the east, with an average of (0.59±0.35) gC/(m2·mm) from 2000 to 2014. Temporally, WUE did not show any decreasing or increasing trend (p>0.05). The areas that have seen a significant increase in WUE account for 30.29% of the studied region, distributing mainly in the west and north of SRYR. Areas with low and medium vegetation coverage are dominated by grassland and farmland. Spatial variation of WUE was mainly affected by hydrothermal factors and leaf area index. 【Conclusion】 In the context of mediating the detrimental effects of climate warming and flooding, improving vegetation in areas with low and medium vegetation coverage is expected to enhance WUE significantly.

هوشنگ قمرنیا, میثم پالاش, مریم بشی پور

محاسبات تبخیر و تعرق به روش فائو پنمن مانتیث نیازمند پارامترهای زیادی است و کمبود برخی از آن‌ها، محاسبات را با مشکل مواجه می‌سازد. از‌طرفی استفاده از روش‌هایی که محاسبات آن‌ها راحت‌تر بوده و به‌راحتی برای کشاورزان قابل فهم باشد، الزامی است. یکی از روش‌های غیرمستقیم برآورد تبخیر- تعرق مرجع، روش تبخیراز تشت است که می‌تواند به عنوان شاخصی مناسب، برای برآورد تبخیر– تعرق گیاه مرجع و در نهایت گیاه اصلی قلمداد شود. در این روش جهت محاسبه تبخیر- تعرق پتانسیل باید نتایج حاصل از تبخیر تشت را در ضریبی بنام ضریب تشت ضرب نمود. محاسبات دقیق مربوط به برآورد ضریب تشت بسیار حائز اهمیت است زیرا در مواقع فقدان تجهیزات لایسیمتری جهت برنامه‌ریزی‌های آبیاری می‌تواند مورد استفاده قرار گیرد. لذا در این تحقیق با استفاده از داده‌های هواشناسی روزانه، ساعتی و داده‌های تشت تبخیر کلاس A ایستگاه هواشناسی کل استان کرمانشاه در یک دوره دراز‌مدت، مقادیر تبخیر و تعرق پتانسیل از روش فائو پنمن- مانتیث و سپس مقدار ضریب تشت برآورد گردید. ضرایب به‌دست آمده به‌عنوان معیاری جهت بررسی تخمین روش‌های کونیکا، آلن پروت، اشنایدر، اشنایدر اصلاح شده، اورنگ در نظر گرفته شد. بر اساس نتایج روش اورنگ و اشنایدر اصلاح شده نسبت‌به سایر روش‌ها از دقت بالاتری برخوردار بودند. مقدار R2با روش اورنگ برای شهرستان‌های اسلام‌آبادغرب، قصرشیرین، کرمانشاه، سرارود، سنقر، گیلان‌غرب، سرپل‌ذهاب، کنگاور به‌ترتیب 84/0، 77/0، 72/0، 76/0، 85/0، 79/0، 77/0، 73/0 محاسبه شد. در نهایت مقادیر ضرایب تشت با روش‌های مذکور در ایستگاه‌های مطالعاتی محاسبه و ارائه گردید.

سمانه نوری, جواد بهمنش, وحید رضاوردی نژاد et al.

یکی از روش‌های نوین صرفه‌جویی در مصرف آب و کاهش هزینه‌های آبیاری استفاده از سوپر‌جاذ‌ب‌ها می‌باشد. ازآنجاکه نانو‌ذره زئولیت سطح ویژه بزرگ‌تری دارد، لذا می‌تواند آب و عناصر غذایی را جذب کرده و در زمان نیاز گیاه آزاد نماید. آزمایشی گلخانه‌ای دو ساله برای بررسی تأثیر سطوح مختلف آبیاری و نانوزئولیت بر شاخص‌های رشدی، محتوای نسبی آب و نشت یونی در گیاه ریحان اجرا شد. آزمایش به‌صورت کرت‌های ‌خردشده در قالب بلوک‌های کامل تصادفی با سه تکرار انجام شد. تیمارهای آزمایش شامل سطوح آبیاری در سه سطح ( FC75/0I1= یا کم‌آبیاری، FC I2= یا آبیاری نرمال و FC 25/1 I3= یا بیش‌آبیاری) و سطوح سوپرجاذب نانوزئولیت در چهار سطح (Z0 بدون سوپرجاذب، Z5 پنج گرم سوپرجاذب در هر کیلوگرم خاک، Z10 10 گرم سوپرجاذب در هر کیلوگرم خاک و Z15 15 گرم سوپرجاذب در هر کیلوگرم خاک) بود. نتایج نشان داد با افزایش شدت خشکی، رشد قطری و ارتفاعی و سایر صفات مانند تعداد برگ، سطح برگ، وزن ماده خشک (زیست‌توده) ریحان به‌صورت معنی‌داری کاهش یافت سطح آبیاری 75 درصد منجر به کاهش صفات رویشی، کاهش محتوای نسبی آب برگ و افزایش نشت یونی گردید، هم‌چنین نتایج نشان داد استفاده از نانوزئولیت اثر معنی‌داری در سطح یک درصد بر پارامترهای موردبررسی دارد، به‌طوری‌که کاربرد این سوپرجاذب به مقدار پنج و 10 گرم در هر کیلوگرم خاک در تمام تیمار‌های آبیاری (I1، I2 و I3) به‌ترتیب موجب افزایش 22 و 30 درصدی ارتفاع ساقه گیاه در دو سال متوالی، هم‌چنین افزایش قطر ساقه ریحان به‌ترتیب به میزان 33 و 29 درصد، بالارفتن تعداد شاخه‌های جانبی ریحان نیز در دو سال به‌ترتیب به مقدار 90 و 89 درصد، ازدیاد تعداد برگ‌های ریحان نیز  به‌ترتیب برابر با 49 و 76 درصد، رشد سطح برگ نیز به‌ترتیب با افزایش 25 و 19 درصدی مواجه شد. وزن خشک گیاه نیز افزایش 40 و 30 درصدی را به‌ترتیب داشتند، محتوای نسبی آب برگ نیز با افزایش 14 و  هفت درصدی در دو سال متوالی روبه‌رو شد. در نشت الکترولیت برعکس پارامترهای قبلی، کاربرد سوپرجاذب باعث کاهش نشت یونی ریحان شد، اما با اعمال کم‌آبیاری شاهد افزایش این پارامتر بودیم. این مطالعه نشان داد که از نظر آماری تفاوت معنی‌داری (05/P>) در عملکرد محصول در بین تیمارهای  Z5 و Z10 وجود ندارد.

شهرام قبادی, علی مریدی

ارزش­گذاری اقتصادی آب در تخصیص کارآمد منابع آب، اتخاذ سیاست­های مناسب و تصمیمات مؤثر، دارای نقش مهم و تعیین‌کننده­ای است. ادبیات کشور حاوی تعداد زیادی از مقالات و تلاش­های قابل‌توجه در زمینه ارزش­گذاری اقتصادی آب می­باشد. گستردگی و تنوع مطالعات موجود، ایجاب می‌نماید که با مروری بر کارهای پژوهشی انجام‌شده، چشم‌اندازی کلی از ارزش­گذاری­ اقتصادی آب در کشور، ارائه شود. در این مقاله سعی بر آن است تا با استخراج، دسته‌بندی و تحلیل مطالعات موجود در مورد ارزش‌گذاری آب در بخش‌های مختلف اقتصاد، به یک جمع­بندی در مورد روش­های رایج و سیاست‌های پیشنهادی در این مطالعات، نائل آید. به‌علاوه، در این کار تلاش شده است تا با نقد و بررسی شیوه­های به­کار گرفته‌شده، خلأهای مطالعاتی را شناسایی نموده و پیشنهادهایی برای پژوهش‌های آتی در زمینه ارزش­گذاری اقتصادی آب، ارائه شود. براساس جمع­بندی، افزایش قیمت آب در کلیه مصارف (صنعتی، شهری و کشاورزی) توصیه شده ­است. شرایط قیمت­گذاری مبتنی بر ارزش آب در مصارف صنعتی و شهری مهیاست و در بخش کشاورزی مستلزم حمایت دولت و توسعه فناوری است. ارزش اقتصادی خدمات اکوسیستمی وابسته به آب، در زمره بالاترین سطوح ارزش اقتصادی در استفاده‌های آب است. لذا توصیه شده است که حفظ جریان طبیعی در اکوسیستم­های آبی در اولویت تخصیص منابع قرار گیرد.

Pedro Moreno, Ricardo Rocha

Lock-free data structures are an important tool for the development of concurrent programs as they provide scalability, low latency and avoid deadlocks, livelocks and priority inversion. However, they require some sort of additional support to guarantee memory reclamation. The Optimistic Access (OA) method has most of the desired properties for memory reclamation, but since it allows memory to be accessed after being reclaimed, it is incompatible with the traditional memory management model. This renders it unable to release memory to the memory allocator/operating system, and, as such, it requires a complex memory recycling mechanism. In this paper, we extend the lock-free general purpose memory allocator LRMalloc to support the OA method. By doing so, we are able to simplify the memory reclamation method implementation and also allow memory to be reused by other parts of the same process. We further exploit the virtual memory system provided by the operating system and hardware in order to make it possible to release reclaimed memory to the operating system.