Future changes of heating degree days （HDD） and cooling degree days （CDD） in the 21st century with and without considering populationfactor are investigated based on four sets of climate change simulations over Ea...Future changes of heating degree days （HDD） and cooling degree days （CDD） in the 21st century with and without considering populationfactor are investigated based on four sets of climate change simulations over East Asia using the regional climate model version 4.4 （RegCM4.4）driven by the global models of CSIRO-Mk3-6-0, EC-EARTH, HadGEM2-ES, and MPI-ESM-MR. Under global warming of 1.5℃, 2℃, 3℃,and 4℃, significant decrease of HDD can be found over China without considering population factor, with greater decrease over high elevationand high latitude regions, including the Tibetan Plateau, the northern part of Northeast China, and Northwest China; while population-weightedHDD increased in areas where population will increase in the future, such as Beijing, Tianjin, parts of southern Hebei, northern Shandong andHenan provinces. Similarly, the CDD projections with and without considering population factor are largely different. Specifically, withoutconsidering population, increase of CDD were observed over most parts of China except the Tibetan Plateau where the CDD remained zerobecause of the cold climate even under global warming; while considering population factor, the future CDD decreases in South China andincreases in North China, the Sichuan Basin, and the southeastern coastal areas, which is directly related to the population changes. The differentfuture changes of HDD and CDD when considering and disregarding the effects of population show that population distribution plays animportant role in energy consumption, which should be considered in future research.展开更多
Serving as gas diffusion layers(GDLs),the thermal conductivity of carbon paper(CP)plays a significant role in the heat transfer management in fuel cells.In the present study,the effect of graphitization degree of CP o...Serving as gas diffusion layers(GDLs),the thermal conductivity of carbon paper(CP)plays a significant role in the heat transfer management in fuel cells.In the present study,the effect of graphitization degree of CP on its through plane thermal conductivity and in-plane thermal conductivity is investigated.The relationship between heat treatment temperatures(1800,2000,2200,2400 and 2500℃)and graphitization degree is also investigated by SEM,XRD and Raman measurements.A model for CP under different graphitization degree is suggested considering the thermal conductivity difference of carbon fiber and matrix carbon.The experimental and simulation results are compared.The results show that the graphitization degree has a significant impact on the through-plane thermal conductivity and in plane thermal conductivity.展开更多
The pink bollworm （Pectinophora gossypiella）, is one of the most damaging pests_of cotton growing in the region of Thessaly in Greece. The time of exit of the adults in spring is an important factor that affects the...The pink bollworm （Pectinophora gossypiella）, is one of the most damaging pests_of cotton growing in the region of Thessaly in Greece. The time of exit of the adults in spring is an important factor that affects the infestation index in the crop during the summer. Mathematical models by Sevacherian ＆ El-Zik, and Huber, which were implemented in California, were used in this study to determine the beginning, the peak of the adults output and the end of them during the summer. A data comparison between California and region of Thessaly were applied since California and Thessaly are on the same latitude with similar meteorological conditions. The results showed that the emergence occurs when the insect completes 259 DD according to the method described by Sevacherian ＆ EI-Zik, while according to the method described by Huber 430-454 DD are needed. It was observed that either according to the method described by Sevacherian and El-Zik or according to the method described by Huber, the values （DD） showed that the appearance of adults varies between -262 DD to 59 DD and -872 DD to 115 DD respectively.展开更多
The present paper investigates the pupal development times ofLucilia sericata which were studied in the laboratory at six different constant temperatures （20, 22, 24, 26, 28 ℃ each ± ℃）. Lower thresholds （tL...The present paper investigates the pupal development times ofLucilia sericata which were studied in the laboratory at six different constant temperatures （20, 22, 24, 26, 28 ℃ each ± ℃）. Lower thresholds （tL） for development were estimated from the linear regression of the developmental rates on each temperature. These data have made it possible to calculate the ADD （Accumulated Degree-Days） necessary for L. sericata to complete the larval stage and to achieve adult emergence. The minimal duration of development from oviposition to adult emergence was found to be inversely related to temperature. Additionally, six landmarks in pupal development are showed and for each of the landmarks the ADD value was calculated for every rearing temperature involved. These data assist in calculating the duration of the pupal stage based on morphological characteristics and would be of great value for future forensic entomological casework.展开更多
Energy analysis plays an important role in developing an optimum and cost effective design of HVAC （heating, ventilating and air conditioning） system for an architecture. Although there are different energy analysis...Energy analysis plays an important role in developing an optimum and cost effective design of HVAC （heating, ventilating and air conditioning） system for an architecture. Although there are different energy analysis methods, which vary in complexity, the degree-day methods are the simplest methods and well-established tools. Energy consumption increases as the number of heating and cooling degree days increases and falls as the number of heating and cooling degree days falls. The value of degree days is a measure which can be used to indicate the demand for energy to heat or cool buildings and spaces. The monthly or annual cooling and heating requirements of specific buildings in different locations can be estimated by means of the degree-day concept. The base temperature is the outdoor temperature below or above which heating or cooling is needed. In this study, the degree days for the period of 2008-2012 were calculated for Turkey （10 cities） and also to develop new software for easy analysis about cooling degree days. This paper can be helpful for designing facade and also contribute to degree-day analyses.展开更多
Tripsacum dactyloides (L.) L., commonly known as eastern gamagrass, is useful for grazing, stored forage, soil amelioration and conservation, and as a biofuel feedstock. Our goal was to calculate accumulated growing d...Tripsacum dactyloides (L.) L., commonly known as eastern gamagrass, is useful for grazing, stored forage, soil amelioration and conservation, and as a biofuel feedstock. Our goal was to calculate accumulated growing degree days (GDD) from existing datasets collected for eastern gamagrass forage production experiments in northwestern Oklahoma, and discuss the use of GDD, instead of calendar harvest dates, in the production of eastern gamagrass forage. Growing degree days were calculated from 1 January each year using the “optimum day method”. For 10 harvest years, the first eastern gamagrass harvest required 690 ± 26 cumulative GDD. Based on long-term weather data from Woodward, Oklahoma, this would place the first harvest on or near 1 June. The second harvest required 635 ± 27 cumulative GDD which would place the second harvest on or near 15 July and the third harvest required 690 ± 23 cumulative GDD placing it on or near 30 August. Each of the 30 harvest required an average of 670 ± 15 cumulative GDD. Using GDD to predict harvest events is a useful tool that forage producer can use in the production of eastern gamagrass forage in the USA and possibly elsewhere.展开更多
According to the practicable model of the plasma arc surface quench, the influence law of the heat process, cooling course, temperature field about surface quench treatment by plasma arc due to the concentrate degree ...According to the practicable model of the plasma arc surface quench, the influence law of the heat process, cooling course, temperature field about surface quench treatment by plasma arc due to the concentrate degree of plasma arc heat source are discussed in this paper. It shows that the concentrate degree of plasma arc heat source can change the width of the hardening zone and can not change the maximum harden depth. With the increase of the concentrate degree, the area of the heat influence zone is decreased and its shape is narrowed after the heat source. Relative to cooling rate, the influence of the heat source concentrate degree for heat absorption is bigger. The correctness of the practical model are proved with experimental results for quench hardening of steel by plasma arc.展开更多
Coal spontaneous combustion is a great threat to mine safety,and gas is the key index to describe coal spontaneous combustion.Taking the coal samples of different kinds of coal as research object,the temperature progr...Coal spontaneous combustion is a great threat to mine safety,and gas is the key index to describe coal spontaneous combustion.Taking the coal samples of different kinds of coal as research object,the temperature programmed oxidation experiment was carried out,and the gases produced by coal samples at different temperatures were collected and analyzed by gas chromatography.This research studied the variation characteristics of gas species and gas concentrations in different coal samples during heating oxidation.The experimental results show that different coal samples produce different kinds of gases in the process of heating and oxidation.The order of gas production is CO,C2H6,C2H4,C3H8,and the relationship between gas production and temperature is approximately exponential.With the increase of coal metamorphic degree,the turning point temperature of sharp rise in coal sample gas production rate become higher,the oxidation ability of coal sample decreases,and the quantity of gas production decreases during the same time period.展开更多
Based on the NCEP/NCAR reanalysis data and the observed precipitation data in the south of China from 1958 to 2000,the impact of 30 to 60 day oscillation of atmospheric heat sources on the drought and flood events in ...Based on the NCEP/NCAR reanalysis data and the observed precipitation data in the south of China from 1958 to 2000,the impact of 30 to 60 day oscillation of atmospheric heat sources on the drought and flood events in June in the south of China is discussed.During the flood(drought) events,there exists an anomalous low-frequency anticyclone(cyclone) at the low level of the troposphere over the South China Sea and the northwestern Pacific,accompanied with anomalous low-frequency heat sinks(heat sources),while there exists an anomalous low-frequency cyclone(anticyclone) with anomalous heat sources(sinks) over the area from the south of China to the south of Japan.On average,the phase evolution of the low-frequency in drought events is 7 to 11 days ahead of that in flood events in May to June in the south of China.In flood events,low-frequency heat sources and cyclones are propagated northward from the southern South China Sea,northwestward from the warm pool of the western Pacific and westward from the northwestern Pacific around 140°E,which have very important impact on the abundant rainfall in June in the south of China.However,in drought events,the northward propagations of the low-frequency heat sources and cyclones from the South China Sea and its vicinity are rather late compared with those in flood events,and there is no obvious westward propagation of the heat sources from the northwestern Pacific.The timing of the low-frequency heat source propagation has remarkable impact on the June rainfall in the south of China.展开更多
The weather research and forecasting（WRF） model is a new generation mesoscale numerical model with a fine grid resolution（2 km）, making it ideal to simulate the macro-and micro-physical processes and latent heatin...The weather research and forecasting（WRF） model is a new generation mesoscale numerical model with a fine grid resolution（2 km）, making it ideal to simulate the macro-and micro-physical processes and latent heating within Typhoon Molave（2009）. Simulations based on a single-moment, six-class microphysical scheme are shown to be reasonable, following verification of results for the typhoon track, wind intensity, precipitation pattern, as well as inner-core thermodynamic and dynamic structures. After calculating latent heating rate, it is concluded that the total latent heat is mainly derived from condensation below the zero degree isotherm, and from deposition above this isotherm. It is revealed that cloud microphysical processes related to graupel are the most important contributors to the total latent heat. Other important latent heat contributors in the simulated Typhoon Molave are condensation of cloud water, deposition of cloud ice, deposition of snow, initiation of cloud ice crystals, deposition of graupel, accretion of cloud water by graupel, evaporation of cloud water and rainwater,sublimation of snow, sublimation of graupel, melting of graupel, and sublimation of cloud ice. In essence, the simulated latent heat profile is similar to ones recorded by the Tropical Rainfall Measuring Mission, although specific values differ slightly.展开更多
Various physical properties such as dipole moment, heat of formation and energy of the most stable formation of nucleotides and bases were calculated by PM3 (modified neglect of diatomic overlap, parametric method num...Various physical properties such as dipole moment, heat of formation and energy of the most stable formation of nucleotides and bases were calculated by PM3 (modified neglect of diatomic overlap, parametric method number 3) and AM1 (austin model 1) methods. As distinct from previous calculations, for nucleotides the interaction with neighbours is taken into account up to gradient of convergence equaling 1. The dependencies of these variables from the place in the codon and the de- terminative degree were obtained. The difference of these variables for codons and anticodons is shown.展开更多
Based on thermal value theory, the aim of this paper is to deduce the theoretical formulas for evaluating the energy effective utilization degree in technological pyrological processes exemplified by metallurgical hea...Based on thermal value theory, the aim of this paper is to deduce the theoretical formulas for evaluating the energy effective utilization degree in technological pyrological processes exemplified by metallurgical heating furnaces. Heat transfer models for continuous heating furnaces, batch-type heating furnaces, and regenerative heating furnaces are established, respectively. By analyzing the movement path of injected infinitesimal heat attached on steel or gas, thermal value equations of continuous, batch-type, and regenerative heating furnaces are derived. Then the influences of such factors as hot charging, gas preheating and intake time of heat on energy effective utilization degree are discussed by thermal value equations. The results show that thermal value rises with hot charging and air preheating for continuous heating furnaces, with shorter intake time when heat is attached on steel or longer intake time when heat is attached on gas for batch-type heating furnaces and that with more heat supply at early heating stage or less at late stage for regenerative heating furnaces.展开更多
Nitrogen(N),the building block of plant proteins and enzymes,is an essential macronutrient for plant functions.A field experiment was conducted to investigate the impact of different N application rates(28,57,85,114,1...Nitrogen(N),the building block of plant proteins and enzymes,is an essential macronutrient for plant functions.A field experiment was conducted to investigate the impact of different N application rates(28,57,85,114,142,171,and 200 kg ha^(−1))on the performance of spring wheat(cv.Ujala-2016)during the 2017–2018 and 2018–2019 growing seasons.A control without N application was kept for comparison.Two years mean data showed optimum seed yield(5,461.3 kg ha^(−1))for N-application at 142 kg ha^(−1) whereas application of lower and higher rates of N did not result in significant and economically higher seed yield.A higher seed yield was obtained in the 2017–2018(5,595 kg ha^(−1))than in the 2018–2019(5,328 kg ha^(−1))growing seasons under an N application of 142 kg ha^(−1).It was attributed to the greater number of growing degree days in the first(1,942.35°C days)than in the second year(1,813.75°C).Higher rates of N(171 and 200 kg ha^(−1))than 142 kg ha^(−1) produced more number of tillers(i.e.,948,300 and 666,650 ha^(−1),respectively).However,this increase did not contribute in achieving higher yields.Application of 142,171,and 200 kg ha^(−1) resulted in 14.15%,15.0%and 15.35%grain protein concentrations in comparison to 13.15%with the application of 114 kg ha^(−1).It is concluded that the application of N at 142 kg ha^(−1) could be beneficial for attaining higher grain yields and protein concentrations of wheat cultivar Ujala-2016.展开更多
文摘Future changes of heating degree days （HDD） and cooling degree days （CDD） in the 21st century with and without considering populationfactor are investigated based on four sets of climate change simulations over East Asia using the regional climate model version 4.4 （RegCM4.4）driven by the global models of CSIRO-Mk3-6-0, EC-EARTH, HadGEM2-ES, and MPI-ESM-MR. Under global warming of 1.5℃, 2℃, 3℃,and 4℃, significant decrease of HDD can be found over China without considering population factor, with greater decrease over high elevationand high latitude regions, including the Tibetan Plateau, the northern part of Northeast China, and Northwest China; while population-weightedHDD increased in areas where population will increase in the future, such as Beijing, Tianjin, parts of southern Hebei, northern Shandong andHenan provinces. Similarly, the CDD projections with and without considering population factor are largely different. Specifically, withoutconsidering population, increase of CDD were observed over most parts of China except the Tibetan Plateau where the CDD remained zerobecause of the cold climate even under global warming; while considering population factor, the future CDD decreases in South China andincreases in North China, the Sichuan Basin, and the southeastern coastal areas, which is directly related to the population changes. The differentfuture changes of HDD and CDD when considering and disregarding the effects of population show that population distribution plays animportant role in energy consumption, which should be considered in future research.
基金Projects(2020 JJ 5142,2019 RS 2067)supported by the Science and Technology Planning Project of Hunan Province,ChinaProject(19 C 0581)supported by the Research Foundation of Education Bureau of Hunan Province,China。
文摘Serving as gas diffusion layers(GDLs),the thermal conductivity of carbon paper(CP)plays a significant role in the heat transfer management in fuel cells.In the present study,the effect of graphitization degree of CP on its through plane thermal conductivity and in-plane thermal conductivity is investigated.The relationship between heat treatment temperatures(1800,2000,2200,2400 and 2500℃)and graphitization degree is also investigated by SEM,XRD and Raman measurements.A model for CP under different graphitization degree is suggested considering the thermal conductivity difference of carbon fiber and matrix carbon.The experimental and simulation results are compared.The results show that the graphitization degree has a significant impact on the through-plane thermal conductivity and in plane thermal conductivity.
文摘The pink bollworm （Pectinophora gossypiella）, is one of the most damaging pests_of cotton growing in the region of Thessaly in Greece. The time of exit of the adults in spring is an important factor that affects the infestation index in the crop during the summer. Mathematical models by Sevacherian ＆ El-Zik, and Huber, which were implemented in California, were used in this study to determine the beginning, the peak of the adults output and the end of them during the summer. A data comparison between California and region of Thessaly were applied since California and Thessaly are on the same latitude with similar meteorological conditions. The results showed that the emergence occurs when the insect completes 259 DD according to the method described by Sevacherian ＆ EI-Zik, while according to the method described by Huber 430-454 DD are needed. It was observed that either according to the method described by Sevacherian and El-Zik or according to the method described by Huber, the values （DD） showed that the appearance of adults varies between -262 DD to 59 DD and -872 DD to 115 DD respectively.
文摘The present paper investigates the pupal development times ofLucilia sericata which were studied in the laboratory at six different constant temperatures （20, 22, 24, 26, 28 ℃ each ± ℃）. Lower thresholds （tL） for development were estimated from the linear regression of the developmental rates on each temperature. These data have made it possible to calculate the ADD （Accumulated Degree-Days） necessary for L. sericata to complete the larval stage and to achieve adult emergence. The minimal duration of development from oviposition to adult emergence was found to be inversely related to temperature. Additionally, six landmarks in pupal development are showed and for each of the landmarks the ADD value was calculated for every rearing temperature involved. These data assist in calculating the duration of the pupal stage based on morphological characteristics and would be of great value for future forensic entomological casework.
文摘Energy analysis plays an important role in developing an optimum and cost effective design of HVAC （heating, ventilating and air conditioning） system for an architecture. Although there are different energy analysis methods, which vary in complexity, the degree-day methods are the simplest methods and well-established tools. Energy consumption increases as the number of heating and cooling degree days increases and falls as the number of heating and cooling degree days falls. The value of degree days is a measure which can be used to indicate the demand for energy to heat or cool buildings and spaces. The monthly or annual cooling and heating requirements of specific buildings in different locations can be estimated by means of the degree-day concept. The base temperature is the outdoor temperature below or above which heating or cooling is needed. In this study, the degree days for the period of 2008-2012 were calculated for Turkey （10 cities） and also to develop new software for easy analysis about cooling degree days. This paper can be helpful for designing facade and also contribute to degree-day analyses.
文摘Tripsacum dactyloides (L.) L., commonly known as eastern gamagrass, is useful for grazing, stored forage, soil amelioration and conservation, and as a biofuel feedstock. Our goal was to calculate accumulated growing degree days (GDD) from existing datasets collected for eastern gamagrass forage production experiments in northwestern Oklahoma, and discuss the use of GDD, instead of calendar harvest dates, in the production of eastern gamagrass forage. Growing degree days were calculated from 1 January each year using the “optimum day method”. For 10 harvest years, the first eastern gamagrass harvest required 690 ± 26 cumulative GDD. Based on long-term weather data from Woodward, Oklahoma, this would place the first harvest on or near 1 June. The second harvest required 635 ± 27 cumulative GDD which would place the second harvest on or near 15 July and the third harvest required 690 ± 23 cumulative GDD placing it on or near 30 August. Each of the 30 harvest required an average of 670 ± 15 cumulative GDD. Using GDD to predict harvest events is a useful tool that forage producer can use in the production of eastern gamagrass forage in the USA and possibly elsewhere.
文摘According to the practicable model of the plasma arc surface quench, the influence law of the heat process, cooling course, temperature field about surface quench treatment by plasma arc due to the concentrate degree of plasma arc heat source are discussed in this paper. It shows that the concentrate degree of plasma arc heat source can change the width of the hardening zone and can not change the maximum harden depth. With the increase of the concentrate degree, the area of the heat influence zone is decreased and its shape is narrowed after the heat source. Relative to cooling rate, the influence of the heat source concentrate degree for heat absorption is bigger. The correctness of the practical model are proved with experimental results for quench hardening of steel by plasma arc.
基金National Natural Science Foundation of China(No.51474086)Hebei Province Natural Science Foundation(No.E2014209138)the North China University of Science and Technology Fostering Fund Project(No.GP201511)for the financial supports
文摘Coal spontaneous combustion is a great threat to mine safety,and gas is the key index to describe coal spontaneous combustion.Taking the coal samples of different kinds of coal as research object,the temperature programmed oxidation experiment was carried out,and the gases produced by coal samples at different temperatures were collected and analyzed by gas chromatography.This research studied the variation characteristics of gas species and gas concentrations in different coal samples during heating oxidation.The experimental results show that different coal samples produce different kinds of gases in the process of heating and oxidation.The order of gas production is CO,C2H6,C2H4,C3H8,and the relationship between gas production and temperature is approximately exponential.With the increase of coal metamorphic degree,the turning point temperature of sharp rise in coal sample gas production rate become higher,the oxidation ability of coal sample decreases,and the quantity of gas production decreases during the same time period.
基金National Key Program for Developing Basic Research (2009CB421404)Key Program of National Science Foundation of China (40730951)Program of National Science Foundation of China(40605028)
文摘Based on the NCEP/NCAR reanalysis data and the observed precipitation data in the south of China from 1958 to 2000,the impact of 30 to 60 day oscillation of atmospheric heat sources on the drought and flood events in June in the south of China is discussed.During the flood(drought) events,there exists an anomalous low-frequency anticyclone(cyclone) at the low level of the troposphere over the South China Sea and the northwestern Pacific,accompanied with anomalous low-frequency heat sinks(heat sources),while there exists an anomalous low-frequency cyclone(anticyclone) with anomalous heat sources(sinks) over the area from the south of China to the south of Japan.On average,the phase evolution of the low-frequency in drought events is 7 to 11 days ahead of that in flood events in May to June in the south of China.In flood events,low-frequency heat sources and cyclones are propagated northward from the southern South China Sea,northwestward from the warm pool of the western Pacific and westward from the northwestern Pacific around 140°E,which have very important impact on the abundant rainfall in June in the south of China.However,in drought events,the northward propagations of the low-frequency heat sources and cyclones from the South China Sea and its vicinity are rather late compared with those in flood events,and there is no obvious westward propagation of the heat sources from the northwestern Pacific.The timing of the low-frequency heat source propagation has remarkable impact on the June rainfall in the south of China.
基金The National Key Basic Research Program of China under contract No.2014CB953904the Natural Science Foundation of Guangdong Province under contract No.2015A030311026the National Natural Science Foundation of China under contract Nos 41275145 and 41275060
文摘The weather research and forecasting（WRF） model is a new generation mesoscale numerical model with a fine grid resolution（2 km）, making it ideal to simulate the macro-and micro-physical processes and latent heating within Typhoon Molave（2009）. Simulations based on a single-moment, six-class microphysical scheme are shown to be reasonable, following verification of results for the typhoon track, wind intensity, precipitation pattern, as well as inner-core thermodynamic and dynamic structures. After calculating latent heating rate, it is concluded that the total latent heat is mainly derived from condensation below the zero degree isotherm, and from deposition above this isotherm. It is revealed that cloud microphysical processes related to graupel are the most important contributors to the total latent heat. Other important latent heat contributors in the simulated Typhoon Molave are condensation of cloud water, deposition of cloud ice, deposition of snow, initiation of cloud ice crystals, deposition of graupel, accretion of cloud water by graupel, evaporation of cloud water and rainwater,sublimation of snow, sublimation of graupel, melting of graupel, and sublimation of cloud ice. In essence, the simulated latent heat profile is similar to ones recorded by the Tropical Rainfall Measuring Mission, although specific values differ slightly.
文摘Various physical properties such as dipole moment, heat of formation and energy of the most stable formation of nucleotides and bases were calculated by PM3 (modified neglect of diatomic overlap, parametric method number 3) and AM1 (austin model 1) methods. As distinct from previous calculations, for nucleotides the interaction with neighbours is taken into account up to gradient of convergence equaling 1. The dependencies of these variables from the place in the codon and the de- terminative degree were obtained. The difference of these variables for codons and anticodons is shown.
文摘Based on thermal value theory, the aim of this paper is to deduce the theoretical formulas for evaluating the energy effective utilization degree in technological pyrological processes exemplified by metallurgical heating furnaces. Heat transfer models for continuous heating furnaces, batch-type heating furnaces, and regenerative heating furnaces are established, respectively. By analyzing the movement path of injected infinitesimal heat attached on steel or gas, thermal value equations of continuous, batch-type, and regenerative heating furnaces are derived. Then the influences of such factors as hot charging, gas preheating and intake time of heat on energy effective utilization degree are discussed by thermal value equations. The results show that thermal value rises with hot charging and air preheating for continuous heating furnaces, with shorter intake time when heat is attached on steel or longer intake time when heat is attached on gas for batch-type heating furnaces and that with more heat supply at early heating stage or less at late stage for regenerative heating furnaces.
基金the Researchers Supporting Project No.(RSP2023R410),King Saud University,Riyadh,Saudi Arabia.
文摘Nitrogen(N),the building block of plant proteins and enzymes,is an essential macronutrient for plant functions.A field experiment was conducted to investigate the impact of different N application rates(28,57,85,114,142,171,and 200 kg ha^(−1))on the performance of spring wheat(cv.Ujala-2016)during the 2017–2018 and 2018–2019 growing seasons.A control without N application was kept for comparison.Two years mean data showed optimum seed yield(5,461.3 kg ha^(−1))for N-application at 142 kg ha^(−1) whereas application of lower and higher rates of N did not result in significant and economically higher seed yield.A higher seed yield was obtained in the 2017–2018(5,595 kg ha^(−1))than in the 2018–2019(5,328 kg ha^(−1))growing seasons under an N application of 142 kg ha^(−1).It was attributed to the greater number of growing degree days in the first(1,942.35°C days)than in the second year(1,813.75°C).Higher rates of N(171 and 200 kg ha^(−1))than 142 kg ha^(−1) produced more number of tillers(i.e.,948,300 and 666,650 ha^(−1),respectively).However,this increase did not contribute in achieving higher yields.Application of 142,171,and 200 kg ha^(−1) resulted in 14.15%,15.0%and 15.35%grain protein concentrations in comparison to 13.15%with the application of 114 kg ha^(−1).It is concluded that the application of N at 142 kg ha^(−1) could be beneficial for attaining higher grain yields and protein concentrations of wheat cultivar Ujala-2016.
