Temperature Change and Heat Capacity

CLIMATE CHANGE AND VARIABILITYIN VIETNAM AND STRATEGIESTO BE ADDAPTED ON AGRICULTUREFOR SUSTAINABLE DEVELOPMENTBy Ass.Prof.Dr. Nguyen Van VietAgrometeorologycal research centre INTRODUCTIONAs seen in Figure climate change, desertification and loss of biological diersity are intimately conected to one another- they overlap and affect, and are affectedby, eachother Studies of climate change and variability in Vietnam and strategies of sustainable development on Agriculture we have analyzed the following fluctuations:1.Analyzed some mains of climate elements related with agriculture production:9 Air temperature;9 Precipitation;9 Sunshine duration;9 Typhoon.2.Impact of climate change and variability on rice crop yield;3.Strategies of sustainable development on Agriculture. METHODOLOGY AND DATAUsed methods of statistical analyze in climate and Agrometeorology.Data have been collected in some main stations in 7 Ago-economic region:+ North mountain and midland + Red river delta + North central + South central + Central plateau + North eat south + Mekong river delta ASSESSMENT CLIMATE CHANGE AND VARIABILITY IN VIETNAM1. Air average temperature.Long term variation and trend of temperature in January, July and annual over last 35 years are increased about 0.2-1oC. 2. The dates of beginning and ending temperatures through 20oC, 25oC.The dates of beginning and ending temperatures through 20oC, 25oC are very important for defining the crop calendar and crop rotation , especially for defining the growing period for Agriculture in the North and in the Mountain regions. 3. Absolute minimum temperatureAbsolute minimum temperature is very important for distribution of perennial plant such as industrial crop coffee , rubber , tea and fruit trees such as lemon , orange, banana, longan, litchi . . 4. Sunshine durationSunshine duration are decrease excepts the south central region and high mountain in central region (see table 5) 5. Rainfall The situation of rainfall is some what complex depending on locations and seasons. In annual and summer season (May - October) small decreasing trend is found at station Hai duong, Ha noi (Red river delta region), Vinh (North central region), Can tho and Bac Lieu (Mekong river delta). On the other hand, in winter-spring season rainfall is increasing trend which observed at Bac Giang, Ha noi, Nam dinh, Vinh, Playku, Saigon [...]... increasing sunshine duration is decreasing typhoon is moving in the South, the change of rainfall is not clear for every regions. 9The effect of climate change and variability on agriculture are not similar in difference agro-ecological region of Vietnam. 9For sustainable development on agriculture to cope with climate change will have to change the cropping calendar , cropping pattern, cropping... of climate change and variability in Vietnam and strategies of sustainable development on Agriculture we have analyzed the following fluctuations: 1.Analyzed some mains of climate elements related with agriculture production: 9 Air temperature; 9 Precipitation; 9 Sunshine duration; 9 Typhoon. 2.Impact of climate change and variability on rice crop yield; 3.Strategies of sustainable Temperature Change and Heat Capacity Temperature Change and Heat Capacity Bởi: OpenStaxCollege One of the major effects of heat transfer is temperature change: heating increases the temperature while cooling decreases it We assume that there is no phase change and that no work is done on or by the system Experiments show that the transferred heat depends on three factors—the change in temperature, the mass of the system, and the substance and phase of the substance The heat Q transferred to cause a temperature change depends on the magnitude of the temperature change, the mass of the system, and the substance and phase involved (a) The amount of heat transferred is directly proportional to the temperature change To double the temperature change of a mass m, you need to add twice the heat (b) The amount of heat transferred is also directly proportional to the mass To cause an equivalent temperature change in a doubled mass, you need to add twice the heat (c) The amount of heat transferred depends on the substance and its phase If it takes an amount Q of heat to cause a temperature change ΔT in a given mass of copper, it will take 10.8 times that amount of heat to cause the equivalent temperature change in the same mass of water assuming no phase change in either substance 1/11 Temperature Change and Heat Capacity The dependence on temperature change and mass are easily understood Owing to the fact that the (average) kinetic energy of an atom or molecule is proportional to the absolute temperature, the internal energy of a system is proportional to the absolute temperature and the number of atoms or molecules Owing to the fact that the transferred heat is equal to the change in the internal energy, the heat is proportional to the mass of the substance and the temperature change The transferred heat also depends on the substance so that, for example, the heat necessary to raise the temperature is less for alcohol than for water For the same substance, the transferred heat also depends on the phase (gas, liquid, or solid) Heat Transfer and Temperature Change The quantitative relationship between heat transfer and temperature change contains all three factors: Q = mcΔT, where Q is the symbol for heat transfer, m is the mass of the substance, and ΔT is the change in temperature The symbol c stands for specific heat and depends on the material and phase The specific heat is the amount of heat necessary to change the temperature of 1.00 kg of mass by 1.00ºC The specific heat c is a property of the substance; its SI unit is J/( kg⋅K ) or J/( kg⋅ºC ) Recall that the temperature change (ΔT) is the same in units of kelvin and degrees Celsius If heat transfer is measured in kilocalories, then the unit of specific heat is kcal/( kg⋅ºC ) Values of specific heat must generally be looked up in tables, because there is no simple way to calculate them In general, the specific heat also depends on the temperature [link] lists representative values of specific heat for various substances Except for gases, the temperature and volume dependence of the specific heat of most substances is weak We see from this table that the specific heat of water is five times that of glass and ten times that of iron, which means that it takes five times as much heat to raise the temperature of water the same amount as for glass and ten times as much heat to raise the temperature of water as for iron In fact, water has one of the largest specific heats of any material, which is important for sustaining life on Earth Calculating the Required Heat: Heating Water in an Aluminum Pan A 0.500 kg aluminum pan on a stove is used to heat 0.250 liters of water from 20.0ºC to 80.0ºC (a) How much heat is required? What percentage of the heat is used to raise the temperature of (b) the pan and (c) the water? Strategy 2/11 Temperature Change and Heat Capacity The pan and the water are always at the same temperature When you put the pan on the stove, the temperature of the water and the pan is increased by the same amount We use the equation for the heat transfer for the given temperature change and mass of water and aluminum The specific heat values for water and aluminum are given in [link] Solution Because water is in thermal contact with the aluminum, the pan and the water are at the same temperature Calculate the temperature difference: ΔT = Tf − Ti = 60.0ºC Calculate the mass of water Because the density of water is 1000 kg/m3, one liter of water has a mass of kg, and the mass of 0.250 liters of water is mw = 0.250 kg Calculate the heat transferred to the water Use the specific heat of water in [link]: Qw = mwcwΔT = (0.250 kg)(4186 J/kgºC)(60.0ºC) = 62.8 kJ Calculate the heat transferred to the aluminum Use the specific heat for aluminum in [link]: QAl = mAlcAlΔT = (0.500 kg)(900 J/kgºC)(60.0ºC)= 27.0 × 104J = 27.0 kJ Compare the percentage of heat going into the pan versus that going into the water First, find the total transferred heat: QTotal = QW + QAl ...Abstract of thesis entitled “A Study of Channel Estimation for OFDM Systems and System Capacity for MIMO-OFDM Systems” Submitted by Zhou Wen For the degree of Doctor of Philosophy at the university of Hong Kong in July 2010 This thesis concerns about two issues for the next generation of wireless communications, namely, the channel estimation for orthogonal frequency-division multiplexing (OFDM) systems and the multiple-input multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) system capacity. For channel estimation for OFDM systems over quasi-static fading channels having resolvable mulitipath number L, a novel fast linear minimum mean square error (LMMSE) channel estimation method is proposed and investigated. The proposed algorithm deploys Fourier transform (FFT) and the computational complexity is therefore significantly reduced to O(Nplog2(Np)), as compared to that of O(Np3) for the conventional LMMSE method, where the notation O(·) is the Bachmann–Landau function and Np is the number of pilots for an OFDM symbol. The normalized mean square errors (NMSE) are derived in closed-form expressions. Numerical results show that the NMSE is marginally the same with that of the conventional LMMSE for signal to noise ratio (SNR) ranges from 0 dB to 25 dB. For channel estimation for OFDM systems over fast fading and dispersive channels, a novel channel estimation and data detection method is proposed to reduce the inter-carrier interference (ICI). A new pilot pattern composed of the comb-type and the grouped pilot pattern is proposed. A closed-form expression for channel estimation mean square error (MSE) has been derived. For SNR = 15 dB, normalized Doppler shift of 0.06, and L = 6, both computer simulation and numerical results have consistently shown that the ICI is reduced by 70.6% and 43.2%, respectively for channel estimation MSE and bit error rate (BER). The pilot number per OFDM symbol is also reduced significantly by 92.3%, as compared to the comb-type pilot pattern. A closed-form mathematic expression has been proposed for the capacity of the closed-loop MIMO-OFDM systems with imperfect feedback channel. The lower threshold of feedback SNR is derived. For L = 6, numerical results show that the lower threshold of feedback SNR is proportional to antenna numbers N′ and system SNR. The increasing rate of the feedback SNR threshold increases from 0.82 to 1.01 when N′ increases from 2 to 16. The variance and mean of OFDM system capacity over Rayleigh channels and Ricean channels have been respectively investigated that the closed-form expression for the capacity variance has been proposed. The resultant system capacity variances over the two channels are respectively evaluated by numerical method and also verified by computer simulation. The joint probability density function (PDF) of two arbitrary correlated Ricean random variables has also been derived in an integral form. Numerical results reveal that the variance of OFDM system is proportional to SNR and inversely proportional to L for the two channels respectively. For the same two respective channels, the variance marginally increases with a linear rate of 0.166 bit2/dB and 0.125 bit2/dB, when L = 2 and SNR ranges 1 Master Thesis No 52 Master Thesis in Rural Development with Specialization in Livelihood and Natural Resource Management Climate change and farmers’ adaptation A case study of mixed - farming systems in the coastal area in Trieu Van commune, Trieu Phong district, Quang Tri province, Vietnam Le Thi Hong Phuong, Hue University of Agriculture and Forestry, Viet Nam master thesis in rural Department of Urban and Rural Development Faculty of Natural Resources and Agriculture Sciences Swedish University of Agricultural Sciences i Climate change and farmers’ adaptation A case study of mixed - farming systems in the coastal area in Trieu Van commune, Trieu Phong district, Quang Tri province, Vietnam Le Thi Hong Phuong, Hue University of Agriculture and Forestry, Hue City, Vietnam Supervisor: Dr. Hoang Minh Ha, SLU , Assistant Supervisor: Dr. Le Dinh Phung , Hue University of Agriculture and Forestry , Examiner: Prof. Adam Pain and Dr Malin Beckman, , Credits: 45 hec Level: E Course code: EX0521 Programme/education: MSc program in Rural Development, Livelihoods and Natural Resource Management Place of publication: Uppsala, Sweden Year of publication: 2011 Picture Cover: Le Thi Hong Phuong Online publication: http://stud.epsilon.slu.se Key Words: climate change, drought, agriculture, impact, adaptation, capacity Swedish University of Agricultural Sciences Faculty of Natural Resources and Agriculture Sciences Department of Urban and Rural Development Division of Rural Development ii ABSTRACT The objectives of this research are (1) to describe and analyze science and local perceptions on long-term changes in temperature, precipitation and drought, (2) to assess impact of drought on mixed farming system, various farm-level adaptation measures and capacity of community to drought adaptation. The study was conducted in a coastal commune, named Trieu Van commune in Trieu Phong district, Quang Tri province. Data and information were collected using in depth interview, group discussion and questionnaire with 59 households. The findings showed that drought heavily influenced daily livelihood of local people in the study area. The statistical analysis of the climate data showed that temperature and drought has been increased over the years. Precipitation was characterized by large inter-annual variability and a decreased amount during summer. Farmers’ perceptions on temperature and precipitation as well as drought were consistent with trends found in climatic data records. Agricultural land and water resources were affected increasingly and negatively by drought. The indicators of these negative impacts are: the reduction of yields and quality of products of crops, livestock, and aquaculture due to increasing pests and diseases. As a result, production costs are increased. The study has also shown how local farmers have made significant efforts to implement adaptation measures to drought and to its impacts. Several farming adaptation options were found, such as using drought-tolerant varieties and local breeds; 42.3% of surveyed households applied VAC(R) model; adjusting seasonal calendar and scale of crops, livestock and fish production (100% interviewed farmers applied this); intercropping, rotational cultivation and diversifying crops and animals in the farm; changing land preparation and mulch techniques in crop production as well as techniques in livestock and fish management. Finding alternative livelihood options and migration were found as important adaptation options. Access to natural resource, supports from policies and non-government organizations, farming experiences, forest OCTOBER 2009 PREVENTING EPIDEMICS. PROTECTING PEOPLE. ISSUE REPORT Health Problems Heat Up: CLIMATE CHANGE AND THE PUBLIC’S HEALTH TFAH BOARD OF DIRECTORS Lowell Weicker, Jr. President Former 3-term U.S. Senator and Governor of Connecticut Cynthia M. Harris, PhD, DABT Vice President Director and Associate Professor Institute of Public Health, Florida A&M University Patricia Baumann, MS, JD Treasurer President and CEO Bauman Foundation Gail Christopher, DN Vice President for Health WK Kellogg Foundation John W. Everets David Fleming, MD Director of Public Health Seattle King County, Washington Arthur Garson, Jr., MD, MPH Executive Vice President and Provost and the Robert C. Taylor Professor of Health Science and Public Policy University of Virginia Robert T. Harris, MD Former Chief Medical Officer and Senior Vice President for Healthcare BlueCross BlueShield of North Carolina Alonzo Plough, MA, MPH, PhD Director, Emergency Preparedness and Response Program Los Angeles County Department of Public Health Theodore Spencer Project Manager Natural Resources Defense Council REPORT AUTHORS Jeffrey Levi, PhD Executive Director Trust for America’s Health and Associate Professor in the Department of Health Policy The George Washington University School of Public Health and Health Services Serena Vinter, MHS Senior Research Associate Trust for America’s Health Daniella Gratale, MA Government Relations Manager Trust for America’s Health Chrissie Juliano, MPP Policy Development Manager Trust for America’s Health Laura M. Segal, MA Director of Public Affairs Trust for America’s Health PEER REVIEWERS TFAH thanks the reviewers for their time, expertise, and insights. The opinions expressed in the report do not necessarily represent the views of the individuals or the organization with which they are associated. Georges Benjamin, MD Executive Director American Public Health Association Cynthia M. Harris, PhD, DABT Vice President Director and Associate Professor Institute of Public Health, Florida A&M University Kim Knowlton, DrPH Senior Scientist, Health & Environment Program Natural Resources Defense Council Jennifer Li, MHS Director, Environmental Health National Association of County and City Health Officials Gino Marinucci, MPH Senior Director, Environmental Health Policy Association of State and Territorial Health Officials This report is supported by the Pew Environment Group, the conservation arm of the Pew Charitable Trusts. The opinions expressed in this report are those of the authors and do not necessary reflect the views of the foundation. ACKNOWLEDGEMENTS T RUST FOR AMERICA’S HEALTH IS A NON-PROFIT, NON-PARTISAN ORGANIZATION DEDICATED TO SAVING LIVES BY PROTECTING THE HEALTH OF EVERY COMMUNITY AND WORKING TO MAKE DISEASE PREVENTION A NATIONAL PRIORITY . The Pew Environment Group is the conservation arm of the Pew Charitable Trusts, a nongovernmental organization headquartered in the United States that applies a rigorous, analytical approach to improving public policy, informing the public and stimulating civic life. TABLE OF CONTENTS Executive Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 SECTION 1: Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 SECTION 2: Why Climate Change Requires a Public Health Response . . . . . . . . . . . . . . . . . . . .11 A. Needs Assessments Proc Natl Conf Theor Phys 37 (2012), pp 180-186 MOLAR HEAT CAPACITY UNDER CONSTANT VOLUME OF MOLECULAR CRYOCRYSTALS OF NITROGEN TYPE WITH HCP STRUCTURE: CONTRIBUTION FROM LATTICE VIBRATIONS AND MOLECULAR ROTATIONAL MOTION NGUYEN QUANG HOC Hanoi National University of Education, 136 Xuan Thuy Street, Cau Giay District, Hanoi NGUYEN NGOC ANH, NGUYEN THE HUNG, NGUYEN DUC HIEN Tay Nguyen University, 456 Le Duan Street, Buon Me Thuot City NGUYEN DUC QUYEN University of Technical Education, Vo Van Ngan Street, Thu Duc District, Ho Chi Minh City Abstract The analytic expression of molar heat capacity under constant volume of molecular cryocrystals of nitrogen type with hcp structure is obtained by the statistical moment method and the self-consistent field method taking account of the anharmonicity in lattice vibrations and molecular rotational motion Numerical results for molecular cryocrystals of N2 type (β-N2 ,β-CO) are compared with experiments I INTRODUCTION The study of heat capacity for molecular cryocrystals of nitrogen type is carried out experimentally and theoretically by many researchers For example, the heat capacity of solid nitrogen is measured by Giauque and Clayton [1], Bagatskii, Kucheryavy, Manzhelii and Popov [2] The heat capacity of solid carbon monoxide is determined by Clayton and Giauque [3], Gill and Morrison [4] Theoretically, the heat capacity of solid nitrogen and carbon monoxide is investigated by the Debye heat capacity theory, the Einstein heat capacity theory, the self-consistent phonon method (SCPM), the self-consistent field method (SCFM), the pseudo-harmonic theory and the statistical moment method (SMM) [5, 6, 7] In [5, 6] the heat capacities at constant volume and at constant pressure of β−N2 and β−CO crystals are calculated by SMM only taking account of lattice vibration and the obtained results only agreed qualitatively with experiments The heat capacity at constant volume of crystals of N2 type in pseudo-harmonic approximation is considered by SCFM only taking account of molecular rotations [8] In this report we study the heat capacity at constant volume of α−N2 and α−CO crystals in pseudo-harmonic approximation by combining SMM and SCFM taking account of both lattice vibrations and molecular rotations In section 2, we derive the heat capacity at constant volume for crystals with hcp structure taking into account lattice vibrations by SMM and for crystals of N2 type taking into account molecular rotations by SCFM Our calculated vibrational and rotational heat capacities for β−N2 and β−CO crystals are summarized and discussed in section 181 II THEORY 2.1 The heat capacity at constant volume of crystals with hcp structure by SMM The displacement of a particle from equilibrium position on direction x (or direction y) is given approximately [6] by: ux0 ≈ i=1 γθ (kx + kxy )2 where: 2kx − kxy kxy 3γ a1 = (1 − X) − X, a2 = a1 X + kx kx kx + kxy a4 = − i , , a3 = 3kx + 2kxy 18γ a21 2X − kx (kx + kxy ) kx + kxy 108γ ∂ ϕi0 a (X − 1) , X ≡ x coth x, θ = k T, k ≡ x B ∂u2ix kx (kx + kxy )2 i  ∂ ϕi0 ∂ ϕi0  ∂ ϕi0 kxy ≡ + ,γ ≡ ∂uix ∂uiy eq ∂u3ix eq ∂uix ∂u2iy i i ≡ mωx2 , x = eq ωx , 2θ  , (1) eq Here kB is the Boltzmann constant, T is the absolute temperature, m is the mass of particle at lattice node, ωx is the frequency of lattice vibration on direction x (or y), kx , kxy and γ are the parameters of crystal depending on the structure of crystal lattice and the interaction potential between particles at nodes, ϕi0 is the interaction potential between the ith particle and the 0th particle and uiα is the displacement of ith particle from equilibrium position on direction α(α = x, y, z) The lattice constant on direction x (or y) is determined by a = a0 + ux0 ,where a0 is the distance a at temperature 0K and is determined from experiments The displacement of a particle from equilibrium position on direction z approximately is as follows [6]: uz0 ≈ i=1 θ kz 1/2 i bi , where : τ1 τ1 τ2 +τ3 2 kz ux0 , b2 = kz ... the transferred heat also depends on the phase (gas, liquid, or solid) Heat Transfer and Temperature Change The quantitative relationship between heat transfer and temperature change contains... symbol for heat transfer, m is the mass of the substance, and ΔT is the change in temperature The symbol c stands for specific heat and depends on the material and phase The specific heat is the... heat is used to raise the temperature of (b) the pan and (c) the water? Strategy 2/11 Temperature Change and Heat Capacity The pan and the water are always at the same temperature When you put