3,918 results
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2. Stochastic Simulation of Meteorological Non-Gaussian Joint Time-Series
- Author
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Kargapolova, Nina, Kacprzyk, Janusz, Series Editor, Pal, Nikhil R., Advisory Editor, Bello Perez, Rafael, Advisory Editor, Corchado, Emilio S., Advisory Editor, Hagras, Hani, Advisory Editor, Kóczy, László T., Advisory Editor, Kreinovich, Vladik, Advisory Editor, Lin, Chin-Teng, Advisory Editor, Lu, Jie, Advisory Editor, Melin, Patricia, Advisory Editor, Nedjah, Nadia, Advisory Editor, Nguyen, Ngoc Thanh, Advisory Editor, Wang, Jun, Advisory Editor, Obaidat, Mohammad S., editor, Ören, Tuncer, editor, and Rango, Floriano De, editor
- Published
- 2019
- Full Text
- View/download PDF
3. Industrial verification of energy saving for the single-tier cylinder based paper drying process
- Author
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Xiaobin Chen, Mengna Hong, Qifu Zheng, Yusha Hu, Jigeng Li, and Yi Man
- Subjects
Computer science ,020209 energy ,Industrial production ,02 engineering and technology ,engineering.material ,Industrial and Manufacturing Engineering ,Modeling and simulation ,020401 chemical engineering ,0202 electrical engineering, electronic engineering, information engineering ,0204 chemical engineering ,Electrical and Electronic Engineering ,Process engineering ,Civil and Structural Engineering ,business.industry ,Mechanical Engineering ,Pulp (paper) ,Papermaking ,Paper mill ,Building and Construction ,Energy consumption ,Pollution ,General Energy ,Air temperature ,engineering ,business ,Efficient energy use - Abstract
The paper drying process has the highest level of energy consumption in the pulp and paper production process. Analysis and optimization of the energy system during the paper drying process is critical for improving the energy efficiency of the entire paper mill. In the existing model for the paper drying process, the solution requires accurate boundary conditions such as the air temperature and humidity of the pocket area and the cylinder surface temperature, which are very difficult to obtain in the papermaking process. This can result in significant deviations between the model solution and the actual production process. This paper focuses on the single-tier dryer cylinder-based paper drying process that has been widely used with high-speed papermaking machines in recent years. A mathematical model is proposed based on real-time data. The verification via industrial production demonstrates that the proposed model is reliable for the paper drying process. Based on the simulation results, two optimization operations have been proposed. The energy consumption decreases from 1.51 t steam/t paper to 1.44 t steam/t paper, 4.6% of the steam and 1.26 × 106 RMB can be saved for a medium-scale paper mill with the annual production capacity of 105 t paper.
- Published
- 2019
4. Quality of grapes grown inside paper bags in Mediterranean area
- Author
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Rosario Di Lorenzo, Antonino Pisciotta, Maria Alessandra Paissoni, Diego Planeta, Simone Giacosa, Luca Giorgio Carlo Rolle, Antonino Pisciotta, Diego Planeta, Simone Giacosa, Maria Alessandra Paissoni, Rosario Di Lorenzo, and Luca Rolle
- Subjects
0106 biological sciences ,Titratable acid ,Berry ,01 natural sciences ,lcsh:Agriculture ,texture profile analysi ,0404 agricultural biotechnology ,Soluble solids ,paper bag ,Cultivar ,qualitative characteristics ,Mathematics ,Table grape ,fungi ,lcsh:S ,04 agricultural and veterinary sciences ,040401 food science ,table grape, paper bag, texture profile analysis, qualitative characteristics ,Horticulture ,Texture profile analysis ,Air temperature ,Mediterranean area ,Agronomy and Crop Science ,table grape ,010606 plant biology & botany ,texture profile analysis - Abstract
The aim of this study was to evaluate the influence of paper bagging of grape bunches on the morphological, mechanical, and chemical characteristics of berries of three table grapes varieties as an environmentally-friendly technique for protecting clusters from biotic and abiotic agents. Clusters of Italia, Autumn Royal, and Regal Seedless grape cultivars were bagged and compared to a not-bagged control. Air temperature inside and outside the bags was monitored. Bunch weight and length, number of berries per bunch, berry longitudinal and transversal diameter, berry mass, number of seeds per berry (normal in size and aborted), soluble solid content, titratable acidity, and skin color by CIEL*a*b* parameters were determined on four points of each berry. Berries were evaluated using texture analysis, and the main texture profile analysis parameters were compared. The air temperatures around not-bagged clusters were slightly higher than inside the bags. In all the cultivars under evaluation, bagged bunches were heavier compared with not-bagged ones. In Autumn Royal and Regal Seedless, these differences were mainly owing to the higher number of berries and higher berry weight of the bagged bunches. Regarding mechanical properties, in seedless varieties, the bagging treatment increased berry hardness (related to the berry firmness) and decreased berry cohesiveness and resilience, whereas an opposite behavior was found in cv. Italia. Berry skin break force was lower in the bagging treatment in all the analyzed varieties, indicating a softer and easier-to-chew berry skin. The findings demonstrate that the bagging technique affected the three variety parameters to different extents. The main differences were found in the seedless varieties in terms of berry size and bunch characteristics. For all varieties, bagged bunches achieved the quality level required by the market, confirming the suitability of this technique. However, the bag industry is proposing many different bag types (differing in material, shape, color, and closing system), therefore, further studies are needed to obtain more complete and exhaustive technical information.
- Published
- 2020
5. Mathematical Study of the Effects of Temperature and Humidity on the Morphological Development of Pleurotus Eryngii Fruit Body
- Author
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Yang, Juan, Zhao, Jingyin, Yu, Hailong, Wang, Yunsheng, Wang, Ruijuan, Tang, Lihua, Li, Daoliang, editor, and Chen, Yingyi, editor
- Published
- 2013
- Full Text
- View/download PDF
6. Effect of operating parameters on the drying performance of multicylinder paper machine dryer section
- Author
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Zhengyi Tao, Dinghua Zhang, Huanbin Liu, and Lingbo Kong
- Subjects
Engineering ,geography ,business.product_category ,geography.geographical_feature_category ,Static model ,business.industry ,020209 energy ,General Chemical Engineering ,Air humidity ,Mechanical engineering ,02 engineering and technology ,Inlet ,Sequential modeling ,Paper machine ,Air temperature ,Range (aeronautics) ,0202 electrical engineering, electronic engineering, information engineering ,Physical and Theoretical Chemistry ,business ,Solid content ,Process engineering - Abstract
The drying performance of multicylinder dryer section in a paper machine was investigated under various operating parameters: Inlet paper solid content (48–50%), inlet paper temperature (45–50°C), supply air temperature (100–90°C), and exhaust air humidity (75–85 g H2O/kg dry air). The variation in environmental conditions was also considered. In this study, an improved static model was utilized to study the influence of these operating parameters on paper drying. The model was constructed using sequential modeling approach based on the drying techniques of multicylinder dryer section of a paper machine. The calculated paper solid content leaving each paper drying module and energy use is in agreement with the measured results. The simulation results showed that higher paper solid content and temperature entering the dryer section, lower supply air temperature, and higher exhaust air humidity were favorable for drying performance within the studied range of these parameters.
- Published
- 2016
7. Genetic Algorithm-Based Optimization of Steam Consumption of Dryer Section in Paper Machine
- Author
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Yang Zhou, Wen Tao Gan, and Wei Tang
- Subjects
Consumption (economics) ,Engineering ,business.product_category ,Waste management ,business.industry ,Papermaking ,Process (computing) ,food and beverages ,General Medicine ,complex mixtures ,humanities ,Paper machine ,Section (archaeology) ,Air temperature ,Genetic algorithm ,business ,Process engineering - Abstract
In paper dryer section of the paper machine, paper dehydration is small, but the steam consumption for the process of dehydration is very large, this steam consumption has a great influence to the total steam consumption of the whole papermaking process. A method optimization of the dryer section based on genetic algorithm is proposed to reduce the dryer section steam consumption, which can reduce the total steam consumption of the papermaking process. After analyzing steam consumption of the whole drying process, the result is that the temperature of dryer section air is the key factor that influences the steam consumption. The model of paper machine dryer section is build with supply air temperature as a variable and steam consumption as the objective function, then using the genetic algorithm to optimize the supply air temperature. Simulation results show that after optimizing air temperature by genetic algorithm steam consumption of papermaking process is further reduced.
- Published
- 2014
8. Through air drying of paper—the effect of dryer fabric
- Author
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Albert Kong, Boris Stoeber, Sheldon I. Green, and Amir Farzad Forughi
- Subjects
Materials science ,General Chemical Engineering ,04 agricultural and veterinary sciences ,040401 food science ,01 natural sciences ,Volumetric flow rate ,010309 optics ,0404 agricultural biotechnology ,Drying time ,Air temperature ,0103 physical sciences ,Air drying ,Spatiotemporal resolution ,Physical and Theoretical Chemistry ,Composite material ,Water content - Abstract
A custom experimental apparatus is designed to perform through air drying under well-controlled drying conditions such as air temperature and mass-flowrate. Using a novel optical measurement technique, the spatial distribution of moisture content in paper during through air drying is quantified as a function of time. The technique is capable of measuring the moisture content distribution with high spatiotemporal resolution while air flows through a paper mat sitting on a permeable dryer fabric. Four commercially available fabrics with different structural design and properties are used in the investigations. The effect of the fabrics’ structural properties, which are characterized using optical coherence tomography (OCT), is studied under various drying conditions. It is shown that the geometry of the contact spots of the fabrics has a significant impact on the drying time at high drying intensities. However, at low rates of drying (i.e., low air temperature and flowrate), no correlation between d...
- Published
- 2018
9. Energy Efficiency and Drying Kinetics of Recycled Paper Pulp
- Author
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L. Estrella, Sandra Rocha, and M.G.A. Vieira
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Materials science ,Waste management ,General Chemical Engineering ,Pulp (paper) ,Kinetics ,engineering.material ,Wood drying ,Pulp and paper industry ,Drying time ,Air temperature ,engineering ,Visual observation ,Physical and Theoretical Chemistry ,Water content ,Efficient energy use - Abstract
In this work, the influences of the air temperature and velocity on the drying kinetics of recycled paper pulp were analyzed. The increase of both variables positively influences the process, concerning the final moisture content and the drying time. However, optical microscopy and visual observation showed worse quality of the paper for drying conditions of high air temperature and velocity, presenting less uniformity and overdried surfaces. The dryer energy efficiency was evaluated by performance parameters and the results were compared with the ones obtained for other types of industrial paper dryers, presenting good agreement.
- Published
- 2007
10. Mathematical modeling of handmade recycled paper drying kinetics and sorption isotherms
- Author
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M.G.A. Vieira and Sandra Rocha
- Subjects
Convective drying ,Cellulose pulp ,Mathematical model ,Paper drying ,Chemistry ,General Chemical Engineering ,Kinetics ,lcsh:TP155-156 ,Thermodynamics ,Sorption ,Water sorption ,Factorial design of experiments ,Air temperature ,Drying modeling ,lcsh:Chemical engineering ,Forced-air - Abstract
The objective of this work is to analyze and compare the natural and forced convective drying of handmade recycled paper. Drying of recycled cellulose pulp was carried out under laboratory environment conditions and in a convective dryer with forced air circulation and controlled conditions of air temperature and velocity. The tests were conducted following a two-factor central composed factorial design of experiments, with six runs at the central point. The drying results were analyzed and fitted to mathematical models of Fick, Henderson and Pabis (Ficks modified equation), Page and He (considering the nonlinear Fick effect). The model of Page represented best the experimental data and the one of Henderson and Pabis resulted in an adequate fit for the paper drying kinetics. Sorption isotherms were determined for the dried paper and the models of GAB (Guggenheim-Anderson-de Boer) and GDW (Generalised DArcy and Watt) resulted in excellent fits of the experimental data. The water sorption mechanism was suggested by the analysis of the calculated parameters of the GDW model.
- Published
- 2008
11. Comments to the paper 'Analysis of early instrumental air temperature observations before and after the Tambora volcano eruption'
- Author
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A. A. Kiselev
- Subjects
Fluid Flow and Transfer Processes ,Atmospheric Science ,geography ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Volcano ,Climatology ,Air temperature ,010502 geochemistry & geophysics ,01 natural sciences ,Geology ,0105 earth and related environmental sciences ,Water Science and Technology - Published
- 2017
12. The Effect of Supply and Outdoor Air Temperature on The Enthalpy and Temperature Exchange Efficiency of a Paper Heat Exchanger
- Author
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Abudulkareem Sh. Mahdi Al-Obaidi, Kenny James Ling Neng Hui, Chin Wai Meng, and Teoh Zhi Heng
- Subjects
020401 chemical engineering ,lcsh:TA1-2040 ,020209 energy ,Air temperature ,Enthalpy ,Heat exchanger ,0202 electrical engineering, electronic engineering, information engineering ,Environmental science ,Thermodynamics ,02 engineering and technology ,0204 chemical engineering ,lcsh:Engineering (General). Civil engineering (General) - Abstract
Heat Recovery Ventilator (VHR) is widely used nowadays as it is capable to maintain high Indoor Air Quality (IAQ) while minimizing the energy loss of indoor air through air-to-air heat exchanger principle. The main component that enables VHR to perform air-to-air heat exchange is known as Paper Heat Exchanger (PP-HEX). Hence, the objective of this research is to study and analyse the performance of a PP-HEX under different return and outdoor air temperatures as well as their effect on both enthalpy and temperature exchange efficiency. Moreover, some numerical models of VHR have been developed to optimize some complex cases and the numerical models are meant to reduce the physical experiments to analyze or improve complex cases in the future. To the best of the authors knowledge, there is no experimental data available from any sources to validate the numerical models. To address this issue, two different supplies of PP-HEX are tested with an actual VHR, and both PP-HEXs will be referred to as PP-HEX-A and PP-HEX-B due to confidentiality. Furthermore, the testing is conducted in a temperature-controlled testing laboratory and the testing conditions are set according to the ISO standard. The preliminary testing results show that the temperature exchange efficiency and enthalpy exchange efficiency of the PP-HEXs have the same trends while the outdoor air temperature is fixed and varying the temperature of indoor air. In contrary, the temperature exchange efficiency and enthalpy exchange efficiency of the PP-HEXs have the same trends while the indoor air temperature is fixed and varying the temperature of outdoor air as well. With the default voltage supplies (240V) to VHR and the setup conditions (according to the ISO Standard) of return air to be 27°C and outdoor air to be 35°C, the testing results show that PP-HEX-A has a temperature exchange efficiency and enthalpy exchange efficiency with a range of (37.97 – 40.28) % and (30.77 – 57.81) % respectively. While PP-HEX-B has a temperature exchange efficiency and enthalpy exchange efficiency with a range of (35.29 – 42.5) % and (39.6 – 55.93) % respectively.
- Published
- 2021
13. Impact of Building Function on Thermal Comfort: A Review Paper
- Author
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Mamdooh Alwetaishi
- Subjects
Engineering ,Architectural engineering ,Environmental Engineering ,Building science ,General Computer Science ,business.industry ,020209 energy ,General Chemical Engineering ,media_common.quotation_subject ,General Engineering ,Energy Engineering and Power Technology ,Thermal comfort ,02 engineering and technology ,Geotechnical Engineering and Engineering Geology ,Air temperature ,0202 electrical engineering, electronic engineering, information engineering ,Function (engineering) ,business ,media_common - Abstract
One of the most problems for achieving thermal comfort in buildings is disregarding the impact of different types of building use. They are differ depending on the activity style they perform inside. In residential buildings, for instance, variations in indoor temperature is more acceptable than the case in hotels or hospitals. This review is leading to seek a solution for this problem which usually found neglected. Consequently, the selection of the reviewed papers was based on building use. Main factors affecting thermal comfort will be discussed. In addition, focus on the effect of building's function on thermal comfort such as residential buildings, office buildings, heath care buildings and educational buildings. As far as environmental aspects affecting thermal comfort, air temperature was found to be the most effective one among the rest. Moreover, the effect of building function on adaptive thermal comfort has been discussed with reference to residential, office, healthcare and educational buildings. It has to be considered that there is a noticeable effect on the different types of building in terms of its impact on the users.
- Published
- 2016
14. Comments to Paper Entitled: Development of a Data-Driven Predictive Model of Supply Air Temperature in an Air-Handling Unit for Conserving Energy. Energies 2018, 11, 407
- Author
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Wei Yang and Yaolin Lin
- Subjects
Control and Optimization ,Renewable Energy, Sustainability and the Environment ,lcsh:T ,020209 energy ,Nuclear engineering ,Energy Engineering and Power Technology ,02 engineering and technology ,lcsh:Technology ,Data-driven ,Unit (housing) ,Development (topology) ,n/a ,Air temperature ,0202 electrical engineering, electronic engineering, information engineering ,Environmental science ,Electrical and Electronic Engineering ,Engineering (miscellaneous) ,Energy (signal processing) ,Energy (miscellaneous) - Abstract
I have read, with interest, the article authorized by Hong and Kim, which was published in Energies 2018, 11, 407; doi:10.3390/en11020407: entitled “Development of a Data-Driven Predictive Model of Supply Air Temperature in an Air-Handling Unit for Conserving Energy”[...]
- Published
- 2018
15. Evaluation of the influence of ambient air temperature and air velocity on mortar cement durability using a forced convection solar dryer
- Author
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Bahammou, Younes, Kouhila, Mounir, Moussaoui, Haytem, Lamsyehe, Hamza, Tagnamas, Zakaria, Lamharrar, Abdelkader, and Idlimam, Ali
- Published
- 2022
- Full Text
- View/download PDF
16. Active Wildland Fires in Central Chile and Local Winds (Puelche).
- Author
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Hayasaka, Hiroshi
- Subjects
METEOROLOGICAL charts ,FIRE weather ,METEOROLOGICAL stations ,JET streams ,WEATHER - Abstract
Central Chile (CC, latitudes 32–40°S) experienced very active fires in 2017 and 2023. These fires burned large areas and killed many people. These unprecedented fires for CC presented a need for more defined fire weather conditions on the synoptic scale. In this paper, fire weather conditions were analyzed using various satellite-derived fire data (hotspots, HSs), wind streamlines, distribution maps of wind flow and temperature, and various synoptic-scale weather maps. Results showed that local winds, known as Puelche, blew on the peak fire days (26 January 2017 and 3 February 2023). The number of HSs on these days was 2676 and 2746, respectively, about 90 times the average (30). The occurrence of Puelche winds was confirmed by streamlines from high-pressure systems offshore of Argentina to the study area in CC. The formation of strong winds and high-temperature areas associated with Puelche winds were identified on the Earth survey satellite maps. Strong winds of about 38 km h
−1 and high temperatures above 32 °C with low relative humidity below 33% were actually observed at the weather station near the fire-prone areas. Lastly, some indications for Puelche winds outbreaks are summarized. This paper's results will be used to prevent future active fire occurrences in the CC. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
17. OS2-6 Experimental Study of Intake Air Temperature Effects on NOx and Soot Emissions in a Direct Injection Diesel Engine(OS2 EGR combustion,Organized Session Papers)
- Author
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Jae-min Lee, Kyung-wook Choi, and Kihyung Lee
- Subjects
Diesel exhaust ,Waste management ,Air temperature ,medicine ,Environmental science ,Session (computer science) ,Combustion ,medicine.disease_cause ,Diesel engine ,NOx ,Automotive engineering ,Soot - Published
- 2012
18. Position paper - tank inlet air temperatures
- Author
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G.K. Goolsby
- Subjects
geography ,Engineering ,Temperature control ,geography.geographical_feature_category ,Waste management ,business.industry ,Environmental engineering ,Radioactive waste ,Inlet ,Position (vector) ,Storage tank ,Air temperature ,Underground storage ,Position paper ,business - Abstract
Position Paper to develop and document a position on the design inlet air temperature of the heat removal system for the waste storage tanks currently being designed by project W-236A, the MWTF Project.
- Published
- 1995
19. The reply of the authors to the comments by A.A. Kiselev to the paper 'Analysis of early instrumental air temperature observations before and after the Tambora volcano eruption'
- Author
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Dmitry M. Sonechkin and N. V. Vakulenko
- Subjects
Fluid Flow and Transfer Processes ,Atmospheric Science ,geography ,geography.geographical_feature_category ,Volcano ,Meteorology ,Climatology ,Air temperature ,Geology ,Water Science and Technology - Published
- 2017
20. The Effect of Intense Air Drying on Material Distribution and Quality in Coated Papers
- Author
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Heikki Häkkänen, Carl-Gustav Berg, Pasi Rajala, and Richard Solin
- Subjects
Convection ,Materials science ,Starch ,General Chemical Engineering ,education ,engineering.material ,chemistry.chemical_compound ,chemistry ,Coating ,Air temperature ,engineering ,Material distribution ,Air drying ,Physical and Theoretical Chemistry ,Composite material ,Water content ,Air dryer - Abstract
The aim of this study was to find out what will happen to paper coating quality and material gradients if coating is dried in one air dryer at a high convection rate (150 kg/m2h). Different printing papers were coated, calendered and printed with pilot machines. The binder and pigment gradients of the coated, and also printed, samples were analyzed with LIPS (Laser Induced Plasma Spectrometry). It was found that drying affects the migration of starch, but not latex. Total air drying can be used to dry printing papers, if air temperature, velocity and moisture content can be separately controlled. The control of web temperature is more important for paper quality formation in a coater drying section than that of evaporation rate.
- Published
- 2003
21. Composition and carbon dynamics of forests in northeastern North America in a future, warmer worldThis article is one of a selection of papers from NE Forests 2100: A Synthesis of Climate Change Impacts on Forests of the Northeastern US and Eastern Canada
- Author
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Jacqueline E. Mohan, R. M. Cox, and Louis R. Iverson
- Subjects
Global and Planetary Change ,Geography ,Ecology ,Air temperature ,Biological Stress ,Acid deposition ,Forestry ,Energy source - Abstract
Increasing temperatures, precipitation extremes, and other anthropogenic influences (pollutant deposition, in creasing carbon dioxide) will influence future forest composition and productivity in the northeastern United States and eastern Canada. This synthesis of empirical and modeling studies includes tree DNA evidence suggesting tree migrations since the last glaciation were much slower, at least under postglacial conditions, than is needed to keep up with current and future climate warming. Exceedances of US and Canadian ozone air quality standards are apparent and offset C02-induced gains in biomass and predispose trees to other stresses. The deposition of nitrogen and sulfate in the northeastern United States changes forest nutrient availability and retention, reduces reproductive success and frost hardiness, causes physical damage to leaf surfaces, and alters performance of forest pests and diseases. These interacting stresses may increase future tree declines and ecosystem disturbances during transition to a warmer climate. Recent modeling work predicts warmer cli mates will increase suitable habitat (not necessarily actual distribution) for most tree species in the northeastern United States. Species whose habitat is declining in the northeastern United States currently occur in Canadian forests and may ex pand northward with warming. Paleoecological studies suggest local factors may interact with, even overwhelm, climatic effects, causing lags and thresholds leading to sudden large shifts in vegetation. Resume: L'augmentation des temperatures, les extremes de precipitation et d'autres facteurs anthropogeniques (les depots d'agents polluants, l'augmentation du dioxyde de carbone) influenceront la composition et la productivite future des forets du nord-est des Etats-Unis et de l'est du Canada. Cette synthese d'etudes empiriques et de modelisation inclut des preuves basees sur I' ADN des arbres qui indiquent que les migrations d'arbres depuis la derniere glaciation ont ete beaucoup plus lentes, du moins dans les conditions qui ont suivi la glaciation, qu'elles devraient l'etre pour suivre le rythme du re chauffement actuel et futur du climat. Les depassements des normes de qualite de l'air des Etats-Unis et du Canada pour l'ozone sont apparents; ils annulent les gains de biomasse dus au C02- et predisposent les arbres a d'autres stress. Les de pots d'azote et de sulfates dans le nord-est modifient la disponibilite et la retention des nutriments dans les forets, redui sent le succes de reproduction et la resistance au gel, causent des dommages physiques a la surface des feuilles et modifient la performance des organismes nuisibles et des maladies des arbres. Ces stress qui interagissent les uns avec les autres pourraient accentuer le deperissement des arbres et la perturbation des ecosystemes durant la periode de transition vers un climat plus chaud. Des travaux recents de modelisation predisent que des conditions climatiques plus chaudes aug menteront les habitats (pas necessairernent l'aire de repartition actuelle) qui conviennent ala plupart des especes d'arbres dans le nord-est des Etats-Unis. Des especes dont l'habitat est en declin aux Etats-Unis sont presentes dans les forets cana diennes aujourd'hui et pourraient s'etendre vers le nord avec le rechauffement. Des etudes paleoecologiques indiquent que des facteurs locaux pourraient interagir avec les effets du climat, voir meme les eclipser, causant des decalages et des seuils entrainant des changements soudains et importants dans la vegetation. (Traduit par la Redaction)
- Published
- 2009
22. Thermal comfort prediction of air-conditioned and passively cooled engineering testing centres in a higher educational institution using CFD
- Author
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Kwong, Qi Jie, Yang, Jim Yexin, Ling, Oliver Hoon Leh, Edwards, Rodger, and Abdullah, Jamalunlaili
- Published
- 2021
- Full Text
- View/download PDF
23. ATECHNIQUE FOR STABILIZING DROPLET SPOTS ON OIL-SENSITIVE PAPER
- Author
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M. Salyani
- Subjects
Spots ,business.industry ,Chemistry ,food and beverages ,Mineralogy ,Radiation ,Agricultural and Biological Sciences (miscellaneous) ,Petroleum product ,Optics ,Distribution pattern ,Air temperature ,medicine ,Relative humidity ,business ,Mineral oil ,medicine.drug - Abstract
The article describes a technique that was effective in stabilizing oil spots, deposited on oil-sensitive paper. The technique involves the use of acetone vapor and could be used indoors or in the field. Treated targets were very stable and the size, shape, and color of the spots did not change in more than a year. Air temperature, relative humidity, and solar radiation did not affect either dimension or color of the oil spots.
- Published
- 1999
24. Climate stress as a precursor to forest decline: paper birch in northern Michigan, 1985–1990
- Author
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David D. Reed, Hal O. Liechty, Elizabeth A. Jones, Glenn D. Mroz, and Peter J. Cattelino
- Subjects
Betulaceae ,Global and Planetary Change ,geography ,Marsh ,geography.geographical_feature_category ,Ecology ,biology ,Environmental factor ,Growing season ,Forestry ,biology.organism_classification ,medicine.disease_cause ,Air temperature ,medicine ,PEST analysis ,Buprestidae ,Bronze birch borer - Abstract
Widespread paper birch (Betulapapyrifera Marsh.) mortality associated with the activity of the bronze birch borer (Agrilusanxius Gory) was observed across northern Michigan in 1991. This mortality occurred at two study sites on which paper birch growth has been intensively monitored since 1985. Recent warmer than normal growing seasons and lower than normal moisture availability are statistically associated with a reduction in annual diameter growth. On one study site 62% of the paper birch study trees were dead and 13% were visibly declining; on the other study site, although no trees were dead, 25% of the paper birch study trees were visibly declining. Growth reductions since 1985 suggest that the species was under climatic stress, making it more vulnerable to pest–pathogen activity. The evidence of the role of climatic conditions acting as a precursor to decline and mortality on these sites is of serious concern given recent projections of warmer temperatures and lower precipitation for this region by several global-climate models.
- Published
- 1993
25. Performance evaluation of the semicylindrical solar tunnel dryer for drying handmade paper
- Author
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M. S. Sevda and N. S. Rathore
- Subjects
Engineering ,Waste management ,Renewable Energy, Sustainability and the Environment ,business.industry ,Dry basis ,Environmental engineering ,Humidity ,computer.software_genre ,Load testing ,Air temperature ,Air flow rate ,Relative humidity ,Waste recycling ,business ,computer ,Water content - Abstract
A walk in type semicylindrical solar tunnel dryer for drying 1500 handmade papers per batch has been commissioned at M/s Cellulosic Waste Recycling Education Project, Vidhya Bhawan Society, Udaipur, Rajasthan, India. A solar tunnel dryer with 122.95 m 2 solar collector area was sufficient for drying handmade paper from 53.85% to 9.96% moisture content (dry basis) in 4–5 h. In this paper the results are shown in terms of the variation of air temperature, solar flux density, relative humidity, air flow rate, moisture content, etc., which indicate that the performance of solar tunnel dryer was quite satisfactory. The performance of the dryer for drying handmade papers has been analyzed through no load and full load test. Technoeconomic analysis of solar tunnel dryers was also carried out by using different economic indicators.
- Published
- 2010
26. Thermal comfort analyses of naturally ventilated university classrooms
- Author
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Hamzah, Baharuddin, Ishak, Muhammad Taufik, Beddu, Syarif, and Osman, Mohammad Yoenus
- Published
- 2016
- Full Text
- View/download PDF
27. Performance of Calcium Chloride and Silica Gel as Solid Desiccant Dehumidifiers for Indoor Air Quality
- Author
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Nur Kamila Ramli, Yusri Yusup, Christabel Lam Pei Lin, Mardiana Idayu Ahmad, and Baharin Azahari
- Subjects
Desiccant ,chemistry.chemical_compound ,Indoor air quality ,chemistry ,Silica gel ,Air temperature ,Carbon dioxide ,Environmental chamber ,Environmental science ,Relative humidity ,Particulates ,Pulp and paper industry - Abstract
Desiccant materials are recently discovered as a viable alternative in dehumidification technology due to their naturally hygroscopic qualities and minimal energy requirement. This paper discusses the performance of four brand samples of selected desiccants used for dehumidification. In this study, dehumidification ability and indoor air quality (IAQ) tests were carried out. The dehumidification ability test was conducted in a controlled environmental chamber at a temperature of 25°C, relative humidity of 70%, and air velocity of 2 m/s for 45-minute session. Meanwhile, the IAQ test was carried out in a naturally ventilated test room, and six IAQ parameters (relative humidity, air velocity, air temperature, particulate matter (PM10), airborne bacteria and carbon dioxide (CO2) were studied. The IAQ test was performed for five different conditions: control, application of brand samples A, B, C and D in the test room. From this study, it was found, brand A (0.6823 g/kg) and brand B (0.6849 g/kg) had a relatively good dehumidification ability during the 45-minute dehumidification ability test compared to brand C (0.3108 g/kg) and brand D (0.3982 g/kg). The IAQ test revealed that brand A had the biggest variation in indoor-outdoor relative humidity of 13.12%, while brand D had the smallest difference of 11.83%. Brand B had the highest average PM10 concentration of 0.037 μg/m3. The airborne bacterial count for all conditions had no statistical significance, indicating the application of desiccants were not effective in reducing airborne bacteria. From this study, it can be concluded that calcium chloride (brand A and B) samples performed better than silica gel (brand C and D) samples in terms of dehumidification ability and IAQ profile.
- Published
- 2021
28. Simulation of the future warming over the Egyptian Mediterranean coast
- Author
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Shaltout, Mohamed, Elkhouly, Nada, Privitera, Riccardo, and Elbessa, Mohamed
- Published
- 2024
- Full Text
- View/download PDF
29. Flammability of Paper Towels in a Domestic Microwave Oven
- Author
-
M. R. Wolski, M.M. Ishii, and T. K. Ishii
- Subjects
Smoke ,Test food ,Waste management ,Microwave oven ,Metals and Alloys ,Condensed Matter Physics ,Combustion ,Electronic, Optical and Magnetic Materials ,Air temperature ,Ceramics and Composites ,Environmental science ,Electrical and Electronic Engineering ,Microwave ,Flammability - Abstract
Principles of microwave combustion of paper towels in a domestic microwave oven are studied. Various passive methods for the determination of the smoke starting time of paper towels with food samples heated in a microwave oven are reviewed. Statistically reliable, repeatable and consistent results were obtained by an exhaust air temperature method. The paper towels were used in 2×2 (2 complete sheets of towels below and 2 towels above the test food) and 4×4 applications. The food samples used were bacon, hotdogs and potatoes.
- Published
- 1987
30. Increased productivity of liquid smoke through fast thawing with refrigeration systems at low air temperatures
- Author
-
Muhammad Faizal, Irwin Bizzy, Riman Sipahutar, and Baiti Hidayati
- Subjects
food.ingredient ,Renewable Energy, Sustainability and the Environment ,Mechanical Engineering ,General Engineering ,Refrigeration ,Transportation ,Pulp and paper industry ,Liquid smoke ,food ,Air temperature ,Environmental science ,Safety, Risk, Reliability and Quality ,Productivity ,Civil and Structural Engineering - Abstract
Liquid smoke increased in demand by the community because it is made from environmentally friendly waste can directly reduce environmental pollution. The smoke condensing process that is carried out conventionally using water can be continuously replaced using a refrigeration system, the smoke condensation process can be carried out using controlled low-temperature air, this can minimize machine space and energy. In this study, an analysis of variations in air temperature will be carried out to maximize the productivity of liquid smoke. The raw material for palm kernel shell is -4 + 5 mesh with cabin temperature variations of 10-15°C, 5-10°C, and 0-5°C and pyrolysis temperature of 300-400°C. Based on the research results obtained maximum results at a temperature of 0-5°C with 23.6% liquid smoke, 3.7% tar, 63.8% charcoal, and 8.9% gas. The test results of chemical compounds, liquid smoke has an average phenol value of 56.59%. The lower the air temperature used to condense the smoke, the maximum liquid smoke will be and the less gas escapes to the air. It can directly reduce air pollution in the process of making liquid smoke.
- Published
- 2022
31. Different environmental factors drive tree species diversity along elevation gradients in three climatic zones in Yunnan, southern China
- Author
-
Yong Tang, Zhenhua Sun, Akihiro Nakamura, Jie Yang, Melinda J. Laidlaw, Min Cao, Xiaoyang Song, Jieqiong Li, Roger L. Kitching, and Wenfu Zhang
- Subjects
0106 biological sciences ,QH301-705.5 ,Seedling ,Plant Science ,Subtropics ,010603 evolutionary biology ,01 natural sciences ,Air temperature ,Tree species distribution ,Tree diversity ,Biology (General) ,Transect ,Climate zones ,Ecology, Evolution, Behavior and Systematics ,Ecology ,Elevation ,Botany ,Species diversity ,Understory ,Montane forest ,Southern china ,QK1-989 ,Soil moisture ,Tree species ,Research Paper ,010606 plant biology & botany - Abstract
Elevational patterns of tree diversity are well studied worldwide. However, few studies have examined how seedlings respond to elevational gradients and whether their responses vary across climatic zones. In this study, we established three elevational transects in tropical, subtropical and subalpine mountain forests in Yunnan Province, southern China, to examine the responses of tree species and their seedlings to elevational gradients. Within each transect, we calculated species diversity indices and composition of both adult trees and seedlings at different elevations. For both adult trees and seedlings, we found that species diversity decreased with increasing elevation in both tropical and subalpine transects. Species composition showed significant elevational separation within all three transects. Many species had specific elevational preferences, but abundant tree species that occurred at specific elevations tended to have very limited recruitment in the understory. Our results highlight that the major factors that determine elevational distributions of tree species vary across climatic zones. Specifically, we found that the contribution of air temperature to tree species composition increased from tropical to subalpine transects, whereas the contribution of soil moisture decreased across these transects., Highlights • Species richness and diversity decreased with increasing elevation in tropical and subalpine transects. • Species similarity between adult trees and seedlings decreased with increasing elevation in the tropical transect. • Species similarity between adult trees and seedlings increased with increasing elevation in the subalpine transect. • Effect of temperature on species distribution increased from tropical to subalpine zones. • The effect of soil moisture on species distribution decreased from tropical to subalpine zones. • Abundant tree species at each elevation often had very limited seedlings.
- Published
- 2021
32. Influence of Blanching and Drying Air Temperature on Drying Kinetics of Banana Slices
- Author
-
Prashant kumar, Om Prakash Pandey, Sushil Kumar Dhiman, and Ravi Kumar
- Subjects
Materials science ,Blanching ,Mechanical Engineering ,Air temperature ,Kinetics ,Pulp and paper industry ,Engineering (miscellaneous) ,Agricultural and Biological Sciences (miscellaneous) ,Computer Science Applications - Published
- 2021
33. Exploring Recent (1991–2020) Trends of Essential Climate Variables in Greece.
- Author
-
Lagouvardos, Konstantinos, Dafis, Stavros, Kotroni, Vassiliki, Kyros, George, and Giannaros, Christos
- Subjects
ATMOSPHERIC temperature ,LONG-range weather forecasting ,OCEAN temperature ,CLIMATE change ,TREND analysis - Abstract
Europe and the Mediterranean are considered climate change hot spots. This is the reason why this paper focuses on the analysis of the trends of essential climate variables in a Mediterranean country, Greece. The analyzed period is 1991–2020, and the dataset used is ERA5-Land (produced by the European Center for Medium-Range Weather Forecasts), which has global coverage and an improved resolution of ~9 × 9 km compared to other datasets. Significant climatic changes across Greece have been put in evidence during the analyzed period. More specifically, the country averaged a 30-year trend of temperature of +1.5 °C, locally exceeding +2 °C, and this increasing trend is positively correlated with the distance of the areas from the coasts. Accordingly, the number of frost days has decreased throughout the country. In terms of rainfall, a major part of Greece has experienced increasing annual rainfall amounts, while 86% of the Greek area has experienced a positive trend of days with heavy rainfall (>20 mm). Finally, a multiple signal of the trend of consecutive dry days was found (statistically non-significant in the major part of Greece). [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
34. Evaluating warming trend over the tibetan plateau based on remotely sensed air temperature from 2001 to 2020.
- Author
-
Xin, Yan, Xu, Yongming, Tong, Xudong, Mo, Yaping, Liu, Yonghong, and Zhu, Shanyou
- Abstract
The Tibetan Plateau (TP), the Third Pole of the world, has experienced significant warming over the past several decades. Previous studies have mostly relied on station-observed air temperature (T
a ), reanalysis data, and remotely sensed land surface temperature (LST) to analyze the warming trend over the TP. However, the uneven distribution of stations, the poor spatial resolution of reanalysis data, and the differences between LST and Ta may lead to biased warming rates. This paper first maps Ta over the TP from 2001 to 2020 based on multi-source remote sensing data, and then quantifies the spatio-temporal variations of remotely sensed Ta and elevation dependent warming (EDW) of this region. The monthly mean Ta is estimated using machine learning (ML) method year by year, and its accuracy is validated based on station-observed Ta . The coefficient of determination (R2 ranges from 0.97 to 0.98 and the mean absolute error (MAE) ranges from 1.01 to1.04 °C. The remotely sensed Ta is used to analysis warming trend and EDW over the TP. The overall warming trend of the TP during 2001–2020 is 0.17 ℃/10a, and warming mainly distributed in the eastern TP, central TP and western Kunlun Mountains. Among the four seasons, autumn shows the most significant warming, tripling the annual warming rate. Winter shows a significant cooling trend, with the warming rate of -0.18 ℃/10a. The study also reveales the existence of EDW at both the annual and seasonal scales. This paper suggests the potential of remotely sensed Ta in global warming study, and also provides an improved understanding of climate warming over the TP. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
35. Heat strain and mortality effects of prolonged Central European heat wave : an example of June 2019 in Poland
- Author
-
Anna Błażejczyk, Kaja Czarnecka, Krzysztof Błażejczyk, Piotr Wałach, and Robert Twardosz
- Subjects
Atmospheric Science ,Hot Temperature ,extreme heat wave ,Atmospheric circulation ,Health, Toxicology and Mutagenesis ,Climate ,Overheating (economics) ,Heat strain ,Thermal energy storage ,Heat Stress Disorders ,heat-related mortality ,Meteorology ,Heat-related mortality ,heat strain ,Humans ,Weather ,Original Paper ,Ecology ,Human organism ,Advection ,Heat wave ,Total mortality ,Air temperature ,Climatology ,UTCI ,Environmental science ,Poland ,Extreme heat wave - Abstract
The occurrence of long-lasting severe heat stress, such as in July–August 2003, July 2010, or in April–May 2018 has been one of the biggest meteorological threats in Europe in recent years. The paper focuses on the biometeorological and mortality effects of the hot June that was observed in Central Europe in 2019. The basis of the study was hourly and daily Universal Thermal Climate Index (UTCI) values at meteorological stations in Poland for June 2019. The average monthly air temperature and UTCI values from 1951 to 2018 were analysed as background. Grosswetterlagen calendar of atmospheric circulation was used to assess synoptic conditions of heat wave. Several heat strain measures were applied : net heat storage (S), modelled heart rate (HR), sultriness (HSI), and UTCI index. Actual total mortality (TM) and modelled strong heat-related mortality (SHRM) were taken as indicators of biometeorological consequences of the hot June in 2019. The results indicate that prolonged persistence of unusually warm weather in June 2019 was determined by the synoptic conditions occurring over the European region and causing advection of tropical air. They led to the emergence of heat waves causing 10% increase in TM and 5 times bigger SHRM then in preceding 10 years. Such increase in SHRM was an effect of overheating and overload of circulatory system of human organism. Supplementary Information The online version contains supplementary material available at 10.1007/s00484-021-02202-0.
- Published
- 2022
36. Performance Analysis of Red Chilli in a Hybrid Collector with Solar Dryer
- Author
-
E Murali
- Subjects
Solar dryer ,Thermal efficiency ,Moisture ,business.industry ,General Mathematics ,Pulp and paper industry ,Education ,Forced convection ,Computational Mathematics ,Computational Theory and Mathematics ,Air temperature ,Environmental science ,business ,Electrical efficiency ,Water content ,Thermal energy - Abstract
This article performed various analysis on Red chilli by hybrid collector with solar dryer (HCSD). This study was carried out forced convection solar dryer which performed better in all aspects such as drying time, moisture removal rate, electrical efficiency, electrical thermal efficiency, thermal efficiency and overall thermal efficiency. In general, solar radiation was provided a sources of generating energy to drive a solar dryer. Hybrid collector has been provided the electrical and thermal energy to run a solar dryer. The solar dryer was tested by drying 12 kg of red chilli in the drying air temperature in the range of 32 0C – 56 0C. The initial moisture content of the red chilli was 71.5 % (weight basis) and was reduced to the final moisture content of 16.2 % (weight basis) in 6 consistent days with clear sunny days. The HCSD was operated between 9 hrs to 16 hrs. Finally, comparative study was also handled for better understanding in HCSD, in which solar dryer drying made better outcome than open sun drying.
- Published
- 2021
37. Performance evaluation of hybrid photovoltaic thermal (PVT) solar dryer for drying of cassava
- Author
-
E. Veeramanipriya and Ar. Umayal Sundari
- Subjects
Evacuated tube ,Solar dryer ,Materials science ,Renewable Energy, Sustainability and the Environment ,020209 energy ,Photovoltaic system ,Thin layer ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Pulp and paper industry ,Air temperature ,Thermal ,0202 electrical engineering, electronic engineering, information engineering ,General Materials Science ,0210 nano-technology ,High standard ,Water content - Abstract
A prototype hybrid Photovoltaic Thermal (PV – T) solar dryer aided with Evacuated Tube Collector (ETC) is presented for drying of cassava slices under the meteorological conditions of Thanjavur, Tamilnadu, India. Further the morphological, structural and physical properties of thin layer drying kinetics are studied and compared with natural sun drying. The designed dryer reduces the moisture content of cassava from 91.5% (wb) to 10.67% (wb) which is considered to be a safe level for storage in 8 h. There is a wide scope to save the conventional fuel by adopting the designed solar dryer as the air temperature inside the chamber rise is 30–40 °C than the ambient temperature. Non – linear regression analysis is performed to find out the drying kinetics of cassava using IBM SPSS 23 statistical package. Two - term model is proved to be the most suitable model for predicting thin-layer drying behaviour of cassava slices with R2 = 0.982, χ2 = 0.017553 for hybrid dryer and R2 = 0.998, χ2 = 0.001247 for open sun drying. XRD results exhibit ‘A’ type crystalline pattern that indicates semi–crystalline nature of cassava for both hybrid and sun dried cassava. Structural, morphological and proximate composition analysis reveals that the quality of hybrid dried cassava is better in terms of physical and chemical compositions than sun dried cassava. The proposed hybrid dryer is capable of producing high standard dried products for exporting and can make a good profit.
- Published
- 2021
38. Synoptic-Scale Wildland Fire Weather Conditions in Mexico.
- Author
-
Hayasaka, Hiroshi
- Subjects
WILDFIRES ,FIRE weather ,WEATHER ,PRECIPITABLE water ,SEA breeze ,SYNOPTIC meteorology ,FIRE management - Abstract
Future climate change is expected to increase the risk and severity of wildland fires in tropical regions. Synoptic-scale fire weather conditions in Mexico were carefully analyzed using 20 years of satellite hotspot and rainfall data, hourly weather data, and various climate data. Fire analysis results showed that eighty-four percent of all fires in Mexico occurred south of 22° N. Southwest Mexico (SWM, N < 22°, 94–106° W) and Southeast Mexico (SEM, N < 22°, 86–94° W), account for 50% and 34% of all fires in Mexico. Synoptic-scale analysis results using hourly data showed that westerly wind sea breezes from the Pacific Ocean blow toward the coastal land areas of the SWM while easterly wind sea breezes from the Caribbean blow into the SEM. The most sensitive weather parameters were "relative humidity" for the SWM and "temperature" for the SEM. The fire-related indices selected were "precipitable water vapor anomaly" for the SWM and "temperature anomaly" for the SEM. The SWM fire index suggests that future fires will depend on dryness, while the SEM fire index suggests that future fires will depend on temperature trends. I do hope that this paper will improve local fire forecasts and help analyze future fire trends under global warming in Mexico. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
39. Assessing the Quality of Non-Professional Meteorological Data for Operational Purposes.
- Author
-
Sládek, D. and Kolář, P.
- Subjects
METEOROLOGICAL stations ,ATMOSPHERIC temperature ,METEOROLOGY - Abstract
Non-professional weather stations are often omitted from the networks of standard/professional stations at various spatial scales. Nevertheless, there are many tasks when such non-professional datasets can serve as the only or the most relevant available source respectively. Its acquisition costs, sufficient quality and capacity together with its moveability represent properties that should be taken into consideration when planning operational usage of various meteorological data. In this paper, we focus on the datasets of air temperatures and relative humidities measured both with professional and nonprofessional devices at nearly the same location. Four years of almost continual measurements (2016-2019) ensure robust sample of mutual comparison, which we analyze in the paper more in detail in order to assess the potential of non-professional datasets for utilization in aviation meteorology. Particular issues such as value difference patterns, large errors occurrence, temporal signal stability and seasonality are elaborated as well [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
40. LOW PRESSURE CENTRIFUGAL FANS OPERATING WITH DIFFERENT AIR TEMPERATURES.
- Author
-
BOGDANOVIĆ-JOVANOVIĆ, Jasmina B., STAMENKOVIĆ, Živojin M., and PETROVIĆ, Jelena D.
- Subjects
ATMOSPHERIC temperature ,STATIC pressure ,AIR conditioning ,HIGH temperatures ,ENERGY consumption - Abstract
For normal operating conditions of the centrifugal fan, the manufacturers provide operating curves (total pressure of the fan, static pressure of the fan, power, and efficiency) for standard air conditions. However, when a fan operates with air at different, usually elevated temperatures, their operating curves can significantly differ. As a result, the fan efficiency decreases, and the energy efficiency of the fan may be reduced. Fan operation in such air conditions also affects its acoustic characteristics. This paper investigates two types of centrifugal fans: with forward curved and backward inclined blades. The main goal was to determine how their operating and acoustic characteristics change with the change in air temperature. For this analysis, low pressure centrifugal fans are used, for which we already had measured operating and acoustic characteristics. The influence of the type of impeller and the curvature of the blades play an important role in the operation of the fan. For numerical investigation, ANSYS CFX software was used, and obtained results show excellent agreement with experimental measurements. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
41. In-season weather data provide reliable yield estimates of maize and soybean in the US central Corn Belt
- Author
-
Axel Garcia y Garcia, Seth L. Naeve, Maciej J. Kazula, Jeffrey A. Coulter, and Vijaya R. Joshi
- Subjects
Atmospheric Science ,Indiana ,010504 meteorology & atmospheric sciences ,Health, Toxicology and Mutagenesis ,01 natural sciences ,Zea mays ,03 medical and health sciences ,Yield (wine) ,Linear regression ,Weather index ,Yield forecasting ,Weather ,030304 developmental biology ,0105 earth and related environmental sciences ,0303 health sciences ,Original Paper ,Ecology ,Statistical modeling ,Agronomy ,Air temperature ,Weather data ,Environmental science ,Crop modeling ,Illinois ,Seasons ,Soybeans - Abstract
Weather conditions regulate the growth and yield of crops, especially in rain-fed agricultural systems. This study evaluated the use and relative importance of readily available weather data to develop yield estimation models for maize and soybean in the US central Corn Belt. Total rainfall (Rain), average air temperature (Tavg), and the difference between maximum and minimum air temperature (Tdiff) at weekly, biweekly, and monthly timescales from May to August were used to estimate county-level maize and soybean grain yields for Iowa, Illinois, Indiana, and Minnesota. Step-wise multiple linear regression (MLR), general additive (GAM), and support vector machine (SVM) models were trained with Rain, Tavg, and with/without Tdiff. For the total study area and at individual state level, SVM outperformed other models at all temporal levels for both maize and soybean. For maize, Tavg and Tdiff during July and August, and Rain during June and July, were relatively more important whereas for soybean, Tavg in June and Tdiff and Rain during August were more important. The SVM model with weekly Rain and Tavg estimated the overall maize yield with a root mean square error (RMSE) of 591 kg ha−1(4.9%nRMSE) and soybean yield with a RMSE of 205 kg ha−1(5.5%nRMSE). Inclusion of Tdiff in the model considerably improved yield estimation for both crops; however, the magnitude of improvement varied with the model and temporal level of weather data. This study shows the relative importance of weather variables and reliable yield estimation of maize and soybean from readily available weather data to develop a decision support tool in the US central Corn Belt.
- Published
- 2020
42. Cyclical variation of drying air temperature on Mytilus galloprovincialis convective drying
- Author
-
Abdelkader Lamharrar, Hind Mouhanni, Younes Bahammou, Mounir Kouhila, Ali Idlimam, Hamza Lamsyehe, Haytem Moussaoui, and Zakaria Tagnamas
- Subjects
Convection ,Solar dryer ,Yield (engineering) ,Materials science ,Moisture ,biology ,Renewable Energy, Sustainability and the Environment ,020209 energy ,Total Viable Count ,02 engineering and technology ,021001 nanoscience & nanotechnology ,biology.organism_classification ,Pulp and paper industry ,Thermal diffusivity ,Mytilus ,Air temperature ,0202 electrical engineering, electronic engineering, information engineering ,General Materials Science ,0210 nano-technology - Abstract
Cyclic drying has been reported as an innovative drying technique for the drying of food materials in terms of drying time, energy cost and product quality. In this study, drying characteristics and product quality of continuous and cyclic drying of Mytilus galloprovincialis in a convective solar dryer were investigated. A two-stage increasing–decreasing drying air temperature (sinusoidal pattern) of the solar dryer was used to obtain the desired cyclical variation of the drying temperature while keeping other drying air parameters constants. The advantages of employing cyclic heating on the drying kinetics, energy consumption are demonstrated. Analytical results illustrated an effective drying time of mussels by a reduction of 1.5% and optimum energy consumption does not exceed 23 kWh of drying process by applying cyclic drying technique compared to continuous drying of air temperature. Furthermore, According to the proximate composition of AOAC method and following Total viable count (TPC) of the dried mussels, it was observed that cyclic air temperature allows to yield higher retention of protein, glycogen, reduce significantly the effect of stresses compared to the constant conditions of drying, and it is possible the reduce the overall color change as well as an accepted texture. Several empirical and semi-empirical models were used to fitting drying curves of experimental data. It was found that the Page model seems to be most suitable to describe the drying curves of Mytilus galloprovincialis. The second law of Fick’s was used to determine the effective moisture diffusivity at different conditions of drying. As results, the values of effective diffusivity obtained by applying cyclic drying were in the margin with the drying at constant conditions that was reached 2.84 × 10−9 m2/s.
- Published
- 2020
43. Glacier energy balance and air temperature: comments on a paper by Dr M. Kuhn
- Author
-
Roger J. Braithwaite
- Subjects
010506 paleontology ,geography ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Meteorology ,Air temperature ,Energy balance ,Glacier ,01 natural sciences ,Geology ,0105 earth and related environmental sciences ,Earth-Surface Processes - Published
- 1980
44. Enviro-Economic Analysis of Ginger Drying in Hybrid Active Greenhouse Solar Dryer
- Author
-
M.K. Gaur and Pushpendra Singh
- Subjects
Solar dryer ,Moisture ,Payback time ,Air temperature ,Heat exchanger ,Economic analysis ,Environmental science ,Greenhouse ,Pulp and paper industry ,Water content - Abstract
The storage of high moisture crop for longer duration is not possible because of its faster degradation due to the presence of excess moisture. The drying of crops makes them suitable for storage without getting spoiled. The hybrid active greenhouse dryers are suitable for drying such high moisture products. In this greenhouse dryer, the hot water from evacuated tube solar collector is supplied to the heat exchanger kept in the drying chamber which also acts as the drying bed for the products to be dried. In our experimentation, ginger has been dried from 92.8% (wb) to 10% (wb) moisture content in 21 h. The maximum air temperature inside the greenhouse is 55.33 °C. The economic and environmental feasibility of the dryer is tested in the paper. The dryer is capable of producing 232 kg of dried ginger annually with payback time of 1.15 years only. In its entire lifetime, the dryer will mitigate 16.41 tonnes of CO2 that prove it as a sustainable solution for drying purpose.
- Published
- 2021
45. Aircraft Cruise Altitude and Speed Profile Optimization in a Real Atmosphere.
- Author
-
Alexandrov, V. A., Zybin, E. Yu., Kosyanchuk, V. V., Selvesyuk, N. I., Stefanyuk, E. A., Tremba, A. A., and Khlebnikov, M. V.
- Subjects
ENERGY consumption ,WIND speed ,ALTITUDES ,ATMOSPHERIC temperature ,AIRCRAFT fuels - Abstract
This paper considers subsonic turbojet aircraft fuel consumption minimization problem during cruise phase, assuming fixed time of arrival. The problem takes into account real atmosphere data. We utilize tailwind/headwind component values at various flight levels, as well as air temperatures and atmospheric pressures at various altitudes. The solution to the altitude and speed flight profile optimization problem is through constrained coordinate descent method. The paper considers optimizing the fuel consumption of a medium-haul aircraft during the cruise phase using sample data set on temperature, pressure, and wind speed. The proposed approach achieves a decrease in fuel consumption of 1.2% when optimizing with regard to real atmosphere. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
46. Temperature and relative humidity effect on equilibrium moisture content of cassava pulp
- Author
-
Ratinun Luampon and Suparerk Charmongkolpradit
- Subjects
Adsorption ,Chemistry ,Pulp (paper) ,Air temperature ,engineering ,Animal Science and Zoology ,Relative humidity ,engineering.material ,Pulp and paper industry ,Agronomy and Crop Science ,Water content ,Equilibrium moisture content - Published
- 2019
47. Combined conventional thermal and microwave drying process for typical Chinese lignite
- Author
-
Yong He, Yanqun Zhu, Jin Ge, Kefa Cen, Zhihua Wang, Kang Zhang, and Huang Zhenyu
- Subjects
Materials science ,Moisture ,General Chemical Engineering ,04 agricultural and veterinary sciences ,02 engineering and technology ,Pulp and paper industry ,040401 food science ,0404 agricultural biotechnology ,020401 chemical engineering ,Scientific method ,Air temperature ,Thermal ,0204 chemical engineering ,Physical and Theoretical Chemistry ,Water content ,Microwave - Abstract
A combined conventional and microwave drying process for Ximeng lignite was investigated in this paper. Samples were firstly dehydrated by hot air to achieve a conversion moisture content, and then were managed to final moisture content by microwave drying. Results showed that the drying rate was significantly improved in the decreasing rate period by microwave drying, approximately 3–5 times faster than that of conventional drying. Finally, the orthogonal test was used to clarify the effects of each factor on the energy consumption, and the magnitude ranking order was conversion moisture content > microwave power > hot air temperature.
- Published
- 2018
48. Predicted sweat rates for group water planning in sport: accuracy and application
- Author
-
Samuel N. Cheuvront, Lindsay B. Baker, and Kurt J. Sollanek
- Subjects
Original Paper ,Dehydration ,QH301-705.5 ,Mean squared prediction error ,Physical Therapy, Sports Therapy and Rehabilitation ,Exercise fluid replacement ,Confidence interval ,Fluid balance ,SWEAT ,Water planning ,Concordance correlation coefficient ,Physiology (medical) ,Match play ,Air temperature ,Sports medicine ,Statistics ,Orthopedics and Sports Medicine ,Fluid intake ,Biology (General) ,High group ,RC1200-1245 ,human activities ,Mathematics - Abstract
This study tested the accuracy of a novel, limited-availability web application (H2QTM) for predicting sweat rates in a variety of sports using estimates of energy expenditure and air temperature only. The application of predictions for group water planning was investigated for soccer match play. Fourteen open literature studies were identified where group sweat rates were reported (n = 20 group means comprising 230 individual observations from 179 athletes) with fidelity. Sports represented included: walking, cycling, swimming, and soccer match play. The accuracy of H2QTM sweat rates was tested by comparing to measured group sweat rates using the concordance correlation coefficient (CCC) with 95% confidence interval [CI]. The relative absolute error (RAE) with 95% [CI] was also assessed, whereby the mean absolute error was expressed relative to an acceptance limit of 0.250 L/h. The CCC was 0.98 [0.95, 0.99] and the RAE was 0.449 [0.279, 0.620], indicating that the prediction error was on average 0.112 L/h. The RAE was < 1.0 for 19/20 observations (95%). Drink volumes modeled as a proxy for sweat losses during soccer match play prevented dehydration (< 1% loss of body mass). The H2QTM web application demonstrated high group sweat prediction accuracy for the variety of sports activities tested. Water planning for soccer match play suggests the feasibility of easily and accurately predicting sweat rates to plan group water needs and promote optimal hydration in training and/or competition.
- Published
- 2020
49. Experimental studies on mass transfer during convective drying of spent coffee grounds generated in the soluble coffee industry
- Author
-
Fernando Cruz-Peragón, José M. Palomar-Carnicero, Francisco J. Gómez-de la Cruz, and Quetzalcoatl Hernandez-Escobedo
- Subjects
Convection ,Air velocity ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Moisture ratio ,Thermal diffusivity ,Pulp and paper industry ,01 natural sciences ,Isothermal process ,010406 physical chemistry ,0104 chemical sciences ,Coffee grounds ,Mass transfer ,Air temperature ,Environmental science ,Physical and Theoretical Chemistry ,0210 nano-technology - Abstract
Drying is a very important stage in the treatment of spent coffee grounds destined to biofuels production. The mass transfer during the convective drying of spent coffee grounds generated in the soluble coffee industry is analyzed. An experimental design from sixteen isothermal drying experiments for different sample thicknesses (5 mm, 10 mm, 15 mm and 20 mm) and drying air temperatures (100 °C, 150 °C, 200 °C and 250 °C) using a drying air velocity of 1 m s−1 was proposed. Drying times, drying rates and effective diffusivity coefficients were obtained. Drying curves were fitted with the main mathematical model proposed in the literature, and the drying rates were studied from the moisture ratio and the drying air temperature. Constant and time-dependence effective diffusivity was evaluated using polynomial surface models. Drying times range between 18 min (test at 5 mm and 250 °C) and 3 h (test at 20 mm and 100 °C). Drying rate and effective diffusivity values were found between 0.0000226 and 0.001722 s−1 and 1.79 × 10−9 and 29.1 × 10−9 m2 s−1, respectively. The main differences between these experiments and those carried out by the same authors about the drying of spent coffee grounds obtained in the services sector were studied and analyzed.
- Published
- 2020
50. UTILIZATION OF DRYING AIR TEMPERATURE AND RELATIVE HUMIDITY FOR SAVING THE REQUIRED TIME AND ENERGY FOR DRYING ROSEMARY PLANTS
- Author
-
G. K. Arafa
- Subjects
Drying time ,Air temperature ,Dry basis ,Environmental science ,Relative humidity ,Rosemary Plants ,Pulp and paper industry ,Water content - Abstract
The purpose of this study is to test and evaluate the effect of drying temperature on the behavior of moisture content and relative humidity of the drying air and drying time of orchid plants at four different levels of temperature. An experimental dryer was designed and installed with local components, which can control the temperature under study to the levels of (35, 40 , 45 and 50 oC) with a corresponding relative humidity of to the levels of (32.2, 28.3, 24.5 and21.2) respectively. The air speed was adjusted at (1.5 m / s) to achieve maximum utilization of energy used in drying. The average primary moisture content of the rosemary was 80% on a wet basis. There is an inverse relationship between the temperature and relative humidity of the air inside the dryer where the relative humidity of the air decreases from 32.2% to 21.2% when the temperature increased from 35 to 50 oC . There is an inverse relationship between temperature and final moisture content values where the final moisture content is reduced from 80 to 32.65% on a dry basis with temperatures increasing from 35 to 50 ° C. There is a difference between the temperature in and out of the drying air and the difference is greater at the beginning of the drying process has decreased to reach the lowest value at the end of the drying process. The highest value of the relative humidity outside of the air was at the beginning of the drying process and it was reduced during the drying process until it reaches its lowest value at the end of the drying process. There is an inverse relation between temperature and drying time, the higher the temperature the lower the drying time.
- Published
- 2020
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