scholarly journals Impact of fertilization on production capacity and reaction to fertilization in maize hybrids

2001 ◽  
pp. 42-46
Author(s):  
Péter Jakab
Keyword(s):  
Global Warming ◽  
Production Capacity ◽  
Weather Conditions ◽  
Extreme Weather ◽  
Available P ◽  
Maize Hybrids ◽  
New Varieties ◽  
Main Factors ◽  
The Right

New varieties and fertilization have significantly increased yields of maize in recent decades. It has to be taken into account however that the interactions and the balanced combination of cropping factors (ecological, biological and agrotechnical) are the main factors which determine yields. Weather conditions were rather unfavourable during the last decade. Extreme weather conditions occurred due to global warming; 6 of 10 years were plagued by drought. Consequently yields increased from 10-20% to 30-50%. In view of varieties the situation is advantageous, maybe the supply of hybrids is too high, nevertheless those hybrids need to be selected which are particularly well adjusted to the ecological conditions. Many technologies can be applied which vary according to intensity, but the balanced combination of cropping factors should be secured on the basis of the hybrid’s intensity. Among agrotechnical factors the compensation of nutrients and technological conditions were inadequate. These days farmers only use nitrogenous fertilizers consequently they significantly decrease the easily available P and K content of the soil which in long term leads to the deterioration of the soil’s productivity. The technological background is therefore important, because sufficient yields can only be expected if agrotechnical operations are carried out in the right time and quality. 

Corrective Solutions for the Shaft with Flange Used for Fixing the Blade on a 5 kW Wind Turbine to Withstand Extreme Weather Conditions

2014 ◽  
Vol 1029 ◽  
pp. 118-123
Author(s):  
Rodica Bădărău ◽  
Teodor Miloş ◽  
Ilare Bordeaşu ◽  
Adrian Bej
Keyword(s):  
Mechanical Strength ◽  
Wind Turbine ◽  
Weather Conditions ◽  
Extreme Weather ◽  
Original Solution ◽  
Root Area ◽  
Materials Used ◽  
Improved Design ◽  
The Right ◽  
Technical Solutions

The paper presents a case study on the original solution of a flange shaft as part of the root area of a 5 kW wind turbine blade. There were analyzed the causes that led to the shaft breakage under wind loadings in extreme weather conditions, and consequently technical solutions have been searched in order to improve the shaft design making it more reliable as mechanical strength at extreme wind loadings. The flange shaft is a welded subassembly that keeps the blades attached to the rotor hub. The first part of the paper consists in an analysis referring the loading status, the materials used for blade manufacturing, the identification of critical areas where the breaking was initiated and also the causes for which the materials assumed and specified in the technical design and manufacturing technology failed under loading at wind gusts of about 30 m/sec. Based on this preliminary analysis, the second part of the paper presents the technical solutions which were considered in reference to the materials and the improved design concept aiming to provide the right mechanical strength necessary to withstand specific wind loadings in extreme weather conditions.

scholarly journals Systems-Thinking Framework for Renewables-Powered World

2021 ◽  
Author(s):  
Lin-Shu Wang ◽  
Peng Shi
Keyword(s):  
Carbon Dioxide ◽  
Global Warming ◽  
Systems Thinking ◽  
Energy Transition ◽  
Technical Solution ◽  
Earth System ◽  
Gaia Theory ◽  
Current Transition ◽  
The Right

Humans has experienced energy transitions throughout its history and the current transition from fossil energy to renewable energy is the latest example. But this latest example is different: rather than resulting from scarcity, this energy transition results from the threat of global warming—which is generally attributed to the short-term increasing of carbon dioxide in the atmosphere but also to the long-term heat threat posed by a warming Sun, according to the Gaia theory. Perspective appreciation of the nature of this combination necessitates for us to take a systems-thinking about the Earth system as a whole rather than the standard narrative of technical solution to our problem (of how to convert a small part of the abundant solar energy [including wind energy] into useful energy). Only by framing the energy transition as a part of dealing with the existential threat of global warming as heat threat, we are capturing the right perspective. Rather than any shortfall of energy—increasing carbon dioxide, heat threat, and collapse of Earth’s ecosystems are the real threats. Cognizant of these is the beginning for humans to seize solutions to deal with the threats before it is too late.

Climate Change, Global Warming, and Agricultural Droughts

2005 ◽  
Author(s):  
Gennady V. Menzhulin ◽  
Sergey P. Savvateyev
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
Human Activities ◽  
Fossil Fuels ◽  
Weather Conditions ◽  
Climatic Conditions ◽  
Spatial Variations ◽  
Geological Time ◽  
The Earth

The climate of a region is a representation of long-term weather conditions that prevail there. Over the millions of years of the existence of the atmosphere on the earth, the climate has changed all the time; ice ages have come and gone, and this has been the result of natural causes. Recently (on geological time scales) the human population has expanded—from half a billion in 1600, to 1 billion in 1800, to almost 3 billion in 1940, and it now stands at about 6 billion. The climate may well now be influenced not only as before by natural events but also by human activities. For example, we are producing vast amounts of carbon dioxide by burning fossil fuels, and this is causing the temperature of the earth to rise significantly. If we argue that we should control our activities to preserve this planet as a habitable environment for future generations, we need to have some scientific knowledge of the effects of our present activities on climate. In recent years the evidence has been accumulating that on the time scale of decades there is global warming (i.e., the global annual mean surface temperature is increasing). There is also evidence accumulating that part of this increase is a consequence of human activities. The evidence is largely statistical. Within this trend there are bound to be temporal fluctuations and spatial variations. Moreover, in addition to the increase in temperature, it is reasonable to assume that there is, overall, an increase in evaporation of water from the surface of the earth and that there will be a consequent increase in precipitation. But within this overall scenario there are bound to be local variations; some areas may experience more precipitation, but some areas may experience less precipitation. The effect of climate change on the proneness to drought is therefore not uniform but can be expected to vary from place to place. Therefore, whether one is concerned with considering the relation between climate and proneness to drought from the historical evidence or whether one is trying to use models to predict the effect of future climatic conditions, it is necessary to consider the local spatial variations.

scholarly journals Understanding Mesoscopic Chemo-Mechanical Distress and Mitigation Mechanisms of Concrete Subject to ASR

2020 ◽  
Author(s):  
Md Asif Rahman
Keyword(s):  
Global Warming ◽  
Service Life ◽  
Mechanical Damage ◽  
Extreme Weather ◽  
Extreme Weather Events ◽  
Alkali Silica Reaction ◽  
Weather Events ◽  
Temperature And Humidity ◽  
Concrete Damage

Alkali-silica reaction (ASR) is one of the common sources of concrete damage worldwide. The surrounding environment, namely, temperature and humidity greatly influence the alkali-silica reaction induced expansion. Global warming (GW) has caused frequent change in the climate and initiated extreme weather events in recent years. These extreme events anticipate random change in temperature and humidity, and convey potential threats to the concrete infrastructure. Moreover, external loading conditions also affect the service life of concrete. Thus, complex mechanisms of ASR under the impact of seasonal change and global warming require a precise quantitative assessment to guide the durable infrastructure materials design practices. Despite decades of phenological observation study, the expansion behavior of ASR under these situations remains to be understood for capturing the ASR damage properly. Within this context this research focuses on the mathematical model development to quantify and mitigate ASR-induced damage. Mesoscale characteristics of ASR concrete was captured in the virtual cement-concrete lab where the ASR gel-induced expansion zone was added as a uniform thickness shell. Finite element method (FEM) was used to solve the ASR formation and expansion evolution. The results of this study are presented in the form of one conference and their journal manuscripts. The first manuscript focuses on the development of the governing equations based on the chemical formulas of alkali-silica reaction to account for the ASR kinetics and swelling pressure exerted by the ASR expansion. There is a fluid flow and mass transfer in the concrete domain due to ASR gel associated from ASR kinetics. This paper involves derivation of the mass and momentum balance equation in terms of the thermo-hygro-mechanical (THM) model. THM model accounts for thermal expansion and hygroscopic swelling in addition to traffic loads to represent volumetric change in the concrete domain. The second manuscript is a case study based on different cement-aggregate proportions and alkali hydroxide concentrations. It is important to know how ASR evolves under variable concentration of the chemical species. The simulated results show that high concentration of hydroxide ion in concrete initiates more reaction and damage in concrete. Also chemical reaction moves to the right direction with low cement to aggregate ratio which means ASR expansion depends on the availability of the reactive aggregates in the concrete domain. The third manuscript attempts to develop a simplified ASR model that integrates chemo-physio-mechanical damage under stochastic weather impact. Stochasicity incorporates the random behavior of surrounding nature in the model. The simulated results elucidate that ASR expansion is more severe under the influence of global warming and climate change. This will support long-term damage forecasts of concrete subjected to extreme weather events. The fourth manuscript focuses on the quantification of mechanical damage under ASR expansion and a dedicated mitigation scheme to minimize it. Added creep loads and physics identify the role of creep damage on ASR expansion. The results from this paper confirms that the ASR-induced damage significantly minimize the load carrying capacity of concrete. It directly affects the compressive strength, tensile strength, and modulus of elasticity of concrete. Damage in aggregates domain is more than the mortar phase under the creep loadings. Among many supplementary materials, fly ash is the most effective in minimizing ASR expansion and damage. This work also includes a petrographic comparison between different mineral types collected from different locations to identify the reactivity of certain aggregates. Thus, the final outcome of this research is a complete model which is a conclusive solution to the long-term ASR damage prediction. The validated model provides better understanding of ASR kinetics from mesoscale perspective. The developed model can potentially accelerate the precise prediction of concrete service life and mitigation schemes as well as can be used as an alternative scope to the costly laboratory tests methods.

Short- and Long-Term Health Challenges of Transportation Workforce due to Extreme Weather Conditions

2021 ◽  
Author(s):  
Sanjgna Karthick ◽  
Sharareh Kermanshachi ◽  
Behzad Rouhanizadeh ◽  
Mostafa Namian
Keyword(s):  
Weather Conditions ◽  
Extreme Weather ◽  
Short And Long Term

BLUE MASTER: USE OF COREXIT®9500 TO DISPERSE IFO 180 SPILL1

2001 ◽  
Vol 2001 (2) ◽  
pp. 815-819 ◽  
Author(s):  
Richard M. Kaser ◽  
Julie Gahn ◽  
Charlie Henry
Keyword(s):  
Weather Conditions ◽  
Fuel Oil ◽  
Heavy Fuel Oil ◽  
Tier Ii ◽  
Response Team ◽  
Calm Weather ◽  
Unified Command ◽  
The Right ◽  
Time Limitations

ABSTRACT COREXIT®9500 was used to disperse 100 barrels (bbls) of Intermediate Fuel Oil (IFO) 180 30 nautical miles south of Galveston, Texas. The dispersant was highly effective in dispersing this heavy fuel oil. Efficacy was based on the fact that only 1.5 barrels of oil washed up on the beach in the form of tarballs a week later. No reports of oiled birds or wildlife related to the incident were received. The pre-authorization limits of the Regional Response Team (RRT) Region VI On-Scene Coordinator (OSC) Pre-Approved Dispersant Use Manual were outdated; COREXIT®9500 was placed on the National Contingency Plan (NCP) Product Schedule list of approved dispersants after the manual was written. COREXIT®9500 enables dispersal of heavier products than those originally considered by the RRT. The specific gravity of IFO 180 is 0.988 while the OSC Pre-Approved Dispersant Use Manual considered 0.953 an upper limit. The dispersant was applied outside the 6-hour time limit because an overflight showed little to no emulsification of the oil because of calm weather conditions. Although current conditions were calm, thunderstorms were expected to develop in the area that would provide the mixing action needed to enhance dispersal. The Unified Command considered this dispersant application a “cautious success.” The small amount of oil that reached the beach and the absence of oiled birds support a statement of success but, because of time limitations, Tier II SMART (Specialized Monitoring of Applied Response Technologies) data were not obtained to substantiate this conclusion. Following this case, RRT Region VI convened a committee to review the Pre-Approved Dispersant Use Manual, to evaluate whether the pre-approved protocols were still relevant, and to develop changes to the Pre-Approved Dispersant Use Manual if needed for consideration and approval by the RRT. At its January 2000 meeting, RRT Region VI approved several short-term changes to the manual and authorized continued work on several mid- and long-term revisions. These changes not only give the OSC more flexibility in choosing the right dispersant tools, but also give greater requirements to document dispersant operations.

Personal Experience, Extreme Weather Events, and Perceptions of Climate Change

2017 ◽  
Author(s):  
Christopher P. Borick ◽  
Barry G. Rabe
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
Social Science Research ◽  
Weather Conditions ◽  
Extreme Weather ◽  
Extreme Weather Events ◽  
Severe Drought ◽  
Seasonal Temperature ◽  
Individual Level ◽  
Weather Events

The factors that determine individual perceptions of climate change have been a focus of social science research for many years. An array of studies have found that individual-level characteristics, such as partisan affiliation, ideological beliefs, educational attainment, and race, affect one’s views on the existence of global warming, as well as the levels of concern regarding this matter. But in addition to the individual-level attributes that have been shown to affect perceptions of climate change, a growing body of literature has found that individual experiences with weather can shape a variety of views and beliefs that individuals maintain regarding climate change. These studies indicate that direct experiences with extreme weather events and abnormal seasonal temperature and precipitation levels can affect the likelihood that an individual will perceive global warming to be occurring, and in some cases their policy preferences for addressing the problem. The emerging literature on this relationship indicates that individuals are more likely to express skepticism regarding the existence of global warming when experiencing below average temperatures or above average snowfall in the period preceding an interview on their views. Conversely, higher temperatures and various extreme weather events can elevate acceptance of global warming’s existence. A number of studies also find that individuals are more likely to report weather conditions such as drought and extreme heat affected their acceptance of global warming when such conditions were occurring in their region. For example, the severe drought that has encompassed much of the western United States between 2005 and 2016 has increasingly been cited by residents of the region as the primary reason for their belief that climate change is occurring. What remains unclear at this point is whether the weather conditions are actually changing opinions regarding climate change or if the preexisting opinions are causing individuals to see the weather events in a manner consistent with those opinions. Notably, the relationship between weather experiences and beliefs regarding climate change appear to be multidirectional in nature. Numerous studies have found that not only do weather experiences shape the views of individuals regarding global warming, but also individuals’ views on the existence of global warming can affect their perceptions of the weather that they have experienced. In particular, recent research has shown that individuals who are skeptical about the existence of global warming are less likely to report the weather recorded in their area accurately than individuals who believe global warming is happening.

scholarly journals Dynamics of the availability of available moisture in soil by optimization of sowing time and density of statement of sunflower plants in the Right-Bank Steppe of Ukraine

2020 ◽  
Vol 2 (3) ◽  
pp. 68-77
Author(s):  
Hennadii Pinkovskyi ◽  
Semen Tanchyk
Keyword(s):  
Crop Yields ◽  
Soil Layer ◽  
Weather Conditions ◽  
Sowing Time ◽  
Flowering Phase ◽  
The Right ◽  
Sowing Period ◽  
Favorable Conditions ◽  
To Receive

Abstract. The article presents the results of scientific researches on the influence of sowing time and density of standing of sunflower plants on the dynamics of the content of available moisture in soil in the conditions of the Right-bank Steppe of Ukraine. One of the decisive factors for the achievement of high and sustainable crop yields in the conditions of unstable moistening of the Right-Bank Steppe of Ukraine is the accumulation and rational use of moisture, which is one of the most important unregulated factors limiting the yield. On average, during the years of research, the most available moisture in the 0-10 cm soil layer was in the first sowing period - when it was heated to a depth of seed 5 - 60C and was 25.0 mm. It was found that the moisture available to plants in the meter layer of soil at the time of sowing remained high and significantly influenced the dynamics of emergence of seedlings. On average, during the years of research, the most available moisture in the 0-100 cm soil layer was during the first sowing period - for warming it to a depth of seed 5 - 60C - 178.6 mm. In such conditions, quite favorable conditions of moistening of the sowing layer of soil are created in order to receive friendly and complete seedlings when sowing in the first - second decade of April. However, at the end of the third decade of April, there is a significant decrease in gross moisture reserves in the sowing and deeper layers of soil, which limits the productivity of crops. Of particular importance for sunflower plants is the content of available moisture in the 0 - 100 cm layer of soil after the formation of baskets. During this period, the sunflower intensively consumes the available moisture from the deeper layers of soil. Analyzing the results of the research, it should be noted that in most cases, a higher seed yield in sunflower hybrids was formed in those variants where the period from the formation of the basket to flowering occurred in June or the first decade of July, regardless of the year of fall medium long-term indicators. It was also found that the moisture available to plants in the meter layer of soil in the flowering phase was different during the years of research and varied in terms of sowing and depended on the density of plants. The highest moisture reserves available to the plants in the soil layer were 0-100 cm, in the crops of Forward hybrids, LG 56.32, LG 54.85, LG 55.82 were at planting densities of 60 thousand hectares, at the first sowing period - in the flowering phase - 127 mm.  The optimal sunflower sowing period for LG 55.82 and LG 54.85 hybrids in the Right Bank steppe is soil warming up to a depth of seed 5-60C, for Forward and LG 56.32 hybrids is warming up to, a depth of seed 9-100C, optimal density - 60 thousand on ha. Under these conditions, the LG 55.82 hybrid produced a yield of 3.85 t / ha, the LG hybrid 54.85 - 3.64 t / ha, the Forward - 3.09 t / ha, the LG hybrid 56.32 - 3.62 t / ha. Taking into account the annual variation of weather conditions of spring sowing, it should be differentiated with regard to water and heat regimes.

scholarly journals Prediction of Climate Change Effect on Outdoor Thermal Comfort in Arid Region

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4730
Author(s):  
Mohamed Elhadi Matallah ◽  
Waqas Ahmed Mahar ◽  
Mushk Bughio ◽  
Djamel Alkama ◽  
Atef Ahriz ◽  
...  
Keyword(s):  
Climate Change ◽  
Heat Stress ◽  
Thermal Comfort ◽  
Weather Conditions ◽  
Extreme Weather ◽  
Simulation Software ◽  
Summer Season ◽  
Outdoor Thermal Comfort ◽  
The Impact

Climate change and expected weather patterns in the long-term threaten the livelihood inside oases settlements in arid lands, particularly under the recurring heat waves during the harsh months. This paper investigates the impact of climate change on the outdoor thermal comfort within a multifamily housing neighborhood that is considered the most common residential archetype in Algerian Sahara, under extreme weather conditions in the summer season, in the long-term. It focuses on assessing the outdoor thermal comfort in the long-term, based on the Perceived Temperature index (PT), using simulation software ENVI-met and calculation model RayMan. Three different stations in situ were conducted and combined with TMY weather datasets for 2020 and the IPCC future projections: A1B, A2, B1 for 2050, and 2080. The results are performed from two different perspectives: to investigate how heat stress evolution undergoes climate change from 2020 till 2080; and for the development of a mathematical algorithm to predict the outdoor thermal comfort values in short-term, medium-term and long-term durations. The results indicate a gradual increase in PT index values, starting from 2020 and progressively elevated to 2080 during the summer season, which refers to an extreme thermal heat-stress level with differences in PT index averages between 2020 and 2050 (+5.9 °C), and 2080 (+7.7 °C), meaning no comfortable thermal stress zone expected during 2080. This study gives urban climate researchers, architects, designers and urban planners several insights into predicted climate circumstances and their impacts on outdoor thermal comfort for the long-term under extreme weather conditions, in order to take preventive measures for the cities’ planning in the arid regions.

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