التمثيل الغذائي للمواد الحاملة للطاقة د.اسامه محمد الحسيني

٩٢٣ ﺣﯾــث ﻟﻬــﺎ ﻣﻛــﺎﻓﺊ ﻣــﺎﺋﻰ ﺣــرارى ﻋــﺎﻟﻰ high hydrothermal equivalent وﻛــذﻟك ﻓﻬــﻰ ﻣﻛﻠﻔــﺔ ﻋﻧــد اﻟﺗــﺷﻐﯾل ، وﻗــ د ﺗــم ﺗﺻﻣﯾم اﺟﻬزة اﺣدث ﺗﺧﺗﻔﻰ ﺑﻬﺎ ﺗﻠك اﻟﻌﯾوب ٠ Gradient Layer Calorimetry : ﺑــدﻻ ﻣــن اﺳــﺗﺧدام اﻻﺟﻬــزة ﻣــن ﻧــوع ً adiabatic ﻟﻣﻧــﻊ اﻟﻔﻘــد اﻟﺣــرارى اﻟﻣﺣــﺳوس ﻣــن اﻟﻛﻼرﯾﻣﺗــر ﺣﯾــث اﻟﺣــرارة ﺗﻧﺗﻘــل ﻟﻠــﺳواﺋل اﻟــــداﺋرة وﻣﻣﻛــــن اﻟﺣــــرارة ان ﺗﺗــــدﻓق ﺧــــﻼل اﻟﺣــــواﺋط اﻟﺣﺎﻣﻠــــﺔ واذا ﻛﺎﻧــــت اﻟﺣــــواﺋط ﻟﻬــــ ﺎ ﺗوﺻــــﯾل ﺣــــرارة ﻣﻌــــروف thermal conductivity ﻟﻠﺗدﻓق اﻟﺣرارى ﻓﻣن اﻟﻣﻣﻛن ﻣﻌرﻓﺗﻪ ﺑواﺳطﺔ Fourier ` s Law اﻟذى ﯾﻧص ﻋﻠﻰ : dh -------- = λ S ( T 1 – T 0 ) t dt dh -------- = the rate of heat flow ﻣﻌدل اﻟﺗدﻓق اﻟﺣرارى dt λ = The thermal conductivity of the wall which has a surface area S and the thickness t اﻟﺗوﺻﯾل اﻟﺣرارى ﻟﻠﺣواﺋط اﻟﺗﻰ ﻟﻬﺎ ﻣﺳطﺢ S وﺳﻣك t ( T 1 – T 0 ) = The gradient of temperature between the inner and outer surface of the wall. واﻻﺳﺎس اﻟﻌﺎم ﻣوﺿﺢ ﻓﻰ اﻟﺷﻛل اﻟﺗﺎﻟﻰ : ﺷـﻛل رﻗـم ) ٤٣ ( : Principle of the modern gradient layer calorimeter devised by Benzinger . The lower diagram shows a gradient layer , consisting of copper - const antan junctions woven through an insulating layer . If this gradient layer lines the entire surface of a cavity completely and uniformly , as shown in the upper diagram , it records the total heat emitted from a source within the cavity regardless of its loca tion ant the size or shape of the cavity

٠٣٣ اذا ﻛﺎن اﻟﺳطﺢ ﻣرﺗب ﻓﻰ طﺑﻘﺔ ﻣن اﻟﻣﺎدة ﻣطﺎﺑﻘﺔ ﻟﻠﺳﻣك واﻟﺗوﺻﯾل اﻟﺣرارى ﻓﺎن ﻣﺗوﺳط اﻟﺗدرج ﻓﻰ درﺟﺔ اﻟﺣرارة ﺑﯾن اﻻﺳطﺢ اﻟداﺧﻠﯾﺔ واﻟﺧﺎرﺟﯾﺔ ﻟﻬذﻩ اﻟطﺑﻘﻪ ﺗﺗﻧﺎﺳب ﻣﻊ اﻟﻔﻘد اﻟﻛﻠﻰ اﻟﺣرارى او اﻟﺣرارة اﻟﻣﻛﺗﺳﺑﺔ ﻣن اﻟﻣﺻدر ﺧﻼل اﻟﺗﺟوﯾف ﻓﻣن اﻟﻣﻣﻛن اﻟوﺻول اﻟﻰ ﺣﺎﻟﺔ ﺛﺎﺑﺗﺔ ﻣن اﻟﺗدﻓق اﻟﺣرارى ٠ اذا ﺗﻐﯾرت اﻟﺣرارة اﻟداﺧﻠﺔ ﻓﺟﺄة ﻓﺎن درﺟﺔ اﻟﺣرارة اﻟﻣﺗدرﺟﺔ ﺗرﺗﻔﻊ ﺑﺳرﻋﻪ أو ﺗﻧﺧﻔض ﻟﻣﺳﺗوى ﺟدﯾد ﺗﻣﺛل ﺣﺎﻟﺔ ﺛﺎﺑﺗﻪ ﺟدﯾدة ﻣن اﻟﺗدﻓق اﻟﺣرارى ٠ وواﺿـﺢ اﻧـﻪ ﻛﻠﻣـﺎ زاد ﺳـﻣك اﻟﺣـواﺋط ﻛﻠﻣـﺎ ﻛﺑـر the greater the thermal gradie nt وﯾﺗطـور ، وﻛـذﻟك ﻛﻠﻣـﺎ رق ﺳـﻣك اﻟﺣواﺋط ﻛﻠﻣﺎ زاد ﺳرﻋﺔ اﻻﺳﺗﺟﺎﺑﺔ اﻟﻰ اﻟﺗﻐﯾر اﻟﻔﺟﺎﺋﻰ ﻓﻰ اﻟﺣرارة اﻟﺧﺎرﺟﯾﻪ ﺧﻼل اﻟﺟﻬﺎز ٠ وﻓﻰ ﺣﺎﻟﺔ اﻻﺟﻬزة اﻟﺑﺳﯾطﺔ اﻟﻣﻘﻔﻠﺔ ﻏﯾر اﻟﻬواﻩ ﻓﺎن اﻻﺳﺗﺟﺎﺑﺔ ﺗﻛون ﻣﺳﺗﻘﻠﺔ ﻋن اﻟطرﯾﻘـﻪ اﻟﺗـﻰ ﺗﻧﺗﻘـل اﻟﺣـرارة اﻟـﻰ اﻟطﺑﻘـﺔ ﺳـواء ﺑواﺳــطﺔ اﻻ ﺷــﻌﺎع أو اﻟﺗوﺻــﯾ ل أو اﻟﺣﻣــل اﻟﺣــرارى أو ﺗﻛﺛﯾــف ﺑﺧــﺎر اﻟﻣــﺎء اﻟﻣﺗوﻟــد ﻣــن اﻟﻣــﺻدر اﻟﺣــرارى ﺧــﻼل اﻟﺟﻬــﺎز ﻋﻠــﻰ اﻟطﺑﻘﺔ ٠ وﯾـﺳﻣﻰ اﻻﺳـﺎس اﻟـﺳﺎﺑق the gradient layer principle وﻛـﺎن أول ﻣـن اﺳـﺗﻌﻣﻠﻪ Richet and Rubbner ( 1888 ) ، ﺣﯾــث ﯾــﺳﻛن اﻟﺣﯾــوان ﻓــﻰ اﻟﺟﻬــﺎز وﺗﺣــﯾط اﻟﻘــﺷرة اﻟداﺧﻠﯾــﺔ ﺑــﺎﻟﺣﯾوان ﺗﻛــون ﻣﺣﺎظــﺔ ﺑ ﻣﻛــﺎن ﻫــواﺋﻰ ﺿــﯾق وﻫــذﻩ ﻣﺣﺎطــﺔ ﺑطﺑﻘــﺔ ﻋﺎزﻟﺔ ، وﺧﺎرج ﻫذﻩ اﻟطﺑﻘﺔ ﻣﻛﺎن ﻫواﺋﻰ أﺻﻐر ، وﻛﻼ اﻟﻣﻛﺎن اﻟﻬواﺋﻰ اﻟداﺧﻠﻰ واﻟﺧﺎرﺟﻰ ﯾﻛون ﻣﺣﻛم اﻟﺳداد ، وأى ﻓرق ﻓﻰ اﻟﺿﻐط ﺑﯾن اﻟﻣﻛﺎن اﻟﻬواﺋﻰ اﻟداﺧﻠﻰ واﻟﺧﺎرﺟﻰ ﯾﺗﻧﺎﺳب ﻣﻊ درﺟﺔ اﻟﺣرارة اﻟﻣﺗدرﺟﺔ اﻋﻠﻰ ﻣـن اﻟطﺑﻘـﺔ اﻟﻌﺎزﻟـﺔ ، واﺳـﺗﻌﻣﺎل ﻫـذﻩ اﻻ ﻣﻛﻧﺔ اﻟﻬواﺋﯾﺔ اﻟﻣﺣﻛﻣﺔ ﻛﺎﻟﺗرﻣوﻣﺗرات ﯾؤدى اﻟﻰ ﺑطﺊ ﻓﻰ اﻻﺳﺗﺟﺎﺑﺔ ٠ ﺑﻌــد ذﻟــك ﺑــدأ ﺗطــوﯾر اﻻﺟﻬــزة اﻟــﺳﺎﺑﻘﺔ ﻓﺑــدأ Benzinger اﺳــﺗﻌﻣﺎل طــرق ﺣدﯾﺛــﺔ ﻟﻘﯾــﺎس درﺟــﺔ اﻟﺣــرارة وﺻــﻣم ﺟﻬــﺎز ﻟﻺﻧــﺳﺎن ﺣﺳﺎﺳﯾﺗﻪ ﻋﺎﻟﯾﻪ وﺳرﯾﻌﻪ اﻻﺳﺗﺟﺎﺑﻪ ٠ وﺑــﺎﻟرﻏم ﻣــن ان اﺳــﺎس ﺗﻘــدﯾر اﻟﺗــدﻓق اﻟﺣــرارى ﺑــﺳﯾط ﻓــﺎن اﻟﻣــﺷﺎﻛ ل اﻟﻌﻣﻠﯾــﺔ ﻛﺛﯾــرة ﻓــﻰ ﺗﻘــدﯾر اﻟﻔﻘــد اﻟﺣــرارى ﻟﻠﺣﯾــوان واﻻﻧــﺳﺎن واﻫﻣﻬﺎ ﺗﻬوﯾﺔ اﻟﻛﻼرﯾﺗﻣر ﻻزاﻟﺔ ﺑﺧﺎر اﻟﻣﺎء ، وﺛـﺎﻧﻰ اﻛـﺳﯾد اﻟﻛرﺑـون اﻟﻧـﺎﺗﺞ ﺑواﺳـطﺔ اﻟﺣﯾـوان ، واذا ﻟـم ﯾـدﺧل اﻟﻬـواء وﻟـم ﯾﺧـرج ﻣــن اﻟﻛﻼرﯾﺗﻣــر ﺑــﻧﻔس درﺟــﺔ اﻟﺣــرارة وﺿــﻐط اﻟﺑﺧــﺎر ﻓــﺎن اﻛﺗــﺳﺎب اﻟطﺎﻗــﺔ او ﻓﻘــدﻫﺎ ﺗﺣــدث وﻻ ﺗــﺳﺟ ل ﺑواﺳــطﺔ The gradient layers of the calorimeter anclosure ٠ وﻗـد ﺻـﻣﻣت ﺑﻌـد ذﻟـك اﺟﻬـزة ﺗﺣـل ﻣـﺷﻛﻠﺔ اﻟﺗﻬوﯾـﺔ ﻛﻣـﺎ ﻓـﻰ اﻟﺷﻛل اﻟﺗﺎﻟﻰ : ﺷـﻛل رﻗـم ) ٥٣ ( : control of heat input and output in the air circulating through a gradient layer calorimeter . Air is cooled a nd saturated with water vapour to temperature T 1 in the cooler . It passes through a gradient layer heat exchanger ( 1 ) where it is brought to temperature T 2 , flows through the calorimeter and then through a second heat exchanger ( 2 ). Where its temperature i s again brought to T 2 and where any water vapour condenses . Any heat added to the air by an animal in the chamber induces a net excess potential in heat exchanger 2 , which is recorded with the thermopiles of the gradient layer of the two exchangers in seri es . Gradient layers are shown by broken lines .

١٣٣ ﺣﯾث ﯾﺑرد اﻟﻬواء اﻟداﺧل أوﻻ اﻟﻰ درﺟﺔ اﻟﺣـرارة اﻟﻣـﺿﺑوطﺔ ً T 1 ﺛـم ﯾـﺷﺑﻊ ﺑﺑﺧـﺎر اﻟﻣـﺎء وﺑﻌـدﻫﺎ ﯾﻣـر ﺧـﻼل اﻟﻣﺑـﺎدل اﻟﺣـرارى او Plate meter ﺣﯾـــث ﺗـــﺳﺧن اﻟـــﻰ درﺟـــﺔ اﻟﺣـــرارة اﻟﻣﻔروﺿـــﺔ T 2 ٠ ﺗﻘـــﺎس اﻟﺣـــرارة اﻟداﺧﻠـــﺔ ﺑــــ gradient layers ا ﻟﻣﺗـــﺻﻠﺔ ﺑﺎﻟﻣﺑــﺎدل اﻟﺣــرارى وﯾــدﺧل اﻟﻬــواء ﻓــﻰ اﻟﻛﻼرﯾﺗﻣــر واذا ﻛــﺎن اﻟﺣﯾــوان ﻣوﺟــود ﻓــﺎن ﻣــن اﻟﻣؤﻛــد ان ﺗرﺗﻔــﻊ اﻟرطوﺑــﺔ وﺳــوف ﺗزﯾــد ﺑﺎﻟﺗــﺎﻟﻰ درﺟــﺔ اﻟﺣــرارة ، ﺛــم ﯾﺧــرج اﻟﻬــواء ﻣــن اﻟﻛﻼرﯾﺗﻣــر ﺧــﻼل اﻟﻣﺑــﺎدل اﻟﺣــرارى اﻟﺛــﺎﻧﻰ ﺣﯾــث ﯾﻌــود ﺑدرﺟــﺔ اﻟﺣــرارة اﻟــﻰ T 2 واﻟﺿﻐط اﻟﺑﺧﺎرى اﻟﻰ اﻟﺗﺷﺑﻊ ﻋﻧد T 2 ، ﻓﻰ ﻫذا Platemeter ﯾﻘﺎس اﻟﻔﻘد اﻟﺣرارى ﻣرة اﺧرى ﻣن اﻟﻬواء ﺑواﺳطﺔ gradient layer واﻟﻔرق ﺑﯾن اﻟﺣـرارة اﻟداﺧﻠﯾـﻪ ﻓـﻰ the ingoing platemeter واﻟﺣـرارة اﻟﺧﺎرﺟﯾـﻪ ﻓـﻰ the outging platemeter ﯾﻌﺗﺑـــر ﻣﻘﯾـــﺎس دﻗﯾـــق ﻟﻠﺣـــرارة اﻟﻣـــﺿﺎﻓﺔ ﻟﻠﻬـــواء اﻟـــداﺋرى ﺑزﯾـــﺎدة درﺟـــﺔ ﺣرارﺗـــﻪ او اﻟـــﺿﻐ ط اﻟﺑﺧـــﺎرى وﺗﻘـــﺎس temperature gradients ﻓﻰ ﻛل اﻷﺟﻬزة اﻟﺣدﯾﺛﺔ ﺑواﺳطﺔ thermo couples ﺣﯾث ﺗﺗﺻل ﻛـل اﻟوﺻـﻼت ) ﻣـن ﻣﻌـدن ﻧـﺷط ﺣـرارى ﻛﻬرﺑﻰ A ﻵﺧر B ﻟﺳطﺢ واﺣد ﻣن gradient layer وﺟﻣﯾﻊ اﻟوﺻﻼت B اﻟﻰ A ﺳطﺢ آﺧر ٠ All junctions of the thermoelectrically active metal A to thermoelecricallt active metal B are attached to one surface of the gradient layer, and all junctions B to A to the other surface. One surface ----------------- B to A Other surface --------------- A to B ﺑﺎﻟﻧﺳﺑﺔ ﻟﻌﻠﻣﺎء اﻟﻔﺳﯾوﻟوﺟﻰ ﻓﺗوﺟد اﺟﻬزة ﻛﺛﯾرة وﻣﻌظﻬﺎ ﻏﺎﻟﻰ ، واﻟﻣﺗوﻓر ﺗﺟﺎرﯾﺎ ﻧوع ﻋﺑﺎرة ﻋن ﺷرﯾط ﻣﻔرد ﻣﻛون ً ﻣن ﻧﺣﺎس ﻣﻠﺣوم ﻣن ﻛل ﺣﺎﻓﺔ ﻣﻧﻪ ﻓﻰ اﻟﺣﺎﻓﺔ اﻻﺧرى وﯾﻌﻣل ﺷق او ﻗطﻊ ﻓﻰ ﻫذا اﻟﺷرﯾط ﯾﺗﻛون وﺻﻼت ﺣرارﯾﺔ ﻛﺛﯾرة thermo junctions وﻫذﻩ ﻣﻣﻛن ﺗﺷﺎﺑﻛﻬﺎ ﻓﻰ ﻟوح ﻣن اﻟﺑﻼ ﺳﺗﯾك ﻟﺗﻌطﻰ a gradient layer وﺑﻬذﻩ اﻟوﺻﻼت اﻟﻛﺛﯾرة اﻟﻌدد ﻓﺎن ﯾﺟب ﺿرورى ﺿﺑط درﺟﺔ اﻟﺣرارة ﻟـ calorimeter jacket ﺑدﻗﻪ ﻻﻧﻪ اذا ﺗﻐﯾرت درﺟﺔ اﻟﺣرارة ﻟﻪ ﺧﻼل اﻟﺗﺟرﺑﺔ ﻓﺎﻧﻪ ﺳﯾﺣدث ﺗدﻓق ﻟﻠﺣرارة ﺧﺎرج او اﻟﻰ داﺧل gradient layer وﯾﺗم ذﻟك ﺑواﺳطﺔ دوران اﻟﻣﺎء ﺑدرﺣﺔ ﺣرراة ﻣﺿﺑوطﺔ ﺑﺣرص ﻓﻰ اﻟﻘﺷرة اﻟﺧﺎرﺟﯾﺔ ، وﯾﺟب ﻣراﻋﺎة ان ﺗﻛون اﻻرﺿﯾﺔ ﻗوﯾﺔ ﺟدا ً ٠

٢٣٣ BOMB CALORIMETRY 1. Purpose of Bomb Calorimetry Experiments Bomb calorimetry is used to determine the enthalpy of combustion,  comb H , for hydrocarbons: C x H Y O z (s) + (2X+Y/2 - Z)/2 O 2 (g)  X CO 2 (g) + Y H 2 O (l) Since combustion reactions are usually exothermic (give off heat),  comb H is typically negative. (However, be aware that older literature defines the "heat of combustion" as  comb H , so as to avoid compiling tables of neg ative numbers!) 2. Construction of a Bomb Calorimeter therm om eter O 2 sam ple water stirrer ignition unit bom b dewar ﺷﻛل رﻗم ) ٦٣ ( : The bomb calorimeter consist primarily of the sample , oxygen , the stainless steel bomb , and water . The dewar prevents heat flow from the calorimeter to the rest of the universe, i.e. , q calorimeter = 0 Since the bomb is made from stainless steel, the combustion reaction occurs at constant volume and there is no work, i.e. , w calorimeter =  p d V = 0 Thus, the change in internal energy,  U , for the calorimeter is zero  U calorimeter = q ca lorimeter + w calorimeter = 0 The thermodynamic interpretation of this equation is that the calorimeter is isolated from the rest of the universe.

٣٣٣ ﺷﻜﻞ رﻗﻢ ) ٧٣ ( ﺷﻜﻞ رﻗﻢ ) ٣ ٨ (

٤٣٣ 3. U a n d H i n a B o m b C a l o r i m e t e r 3. A. Internal energy change  U S ince the calorimeter is isolated from the rest of the universe, we can define the reactants (sample and oxygen) to be the system and the rest of the calorimeter (bomb and water) to be the surroundings. The change in internal energy of the reactants upon co mbustion can be calculated from                               dV V U dT T U dU dU dU dU dU T V s urr sys surr sys tot 0 Since the process if constant volume, dV =0. Thus, recognizing the definition of heat capacity C v yields dT C dU v sys   Assuming C v to be independent of T over small temperature ranges, this expression can be integrated to give T C U     v wher e C v is the heat capacity of the surroundings, i.e. , the water and the bomb. 3. B. Enthalphy change  H By definition of enthalpy ) ( pV U H      Since there is very little expansion work done by condensed phases,  ( pV )  0 for solids and liquids. Assuming the gas to be ideal yields gas n RT U H      3. C. Intuitive difference between  U and  H Recall that  U = q v is the heat flow under constant volume conditions, whereas  H = q p is the heat flow under constant pressure conditions. The difference between these two situations is that pV work can be done under constant pressure conditions, whereas no pV work is done under constant volume conditions. Consider the case where  n gas > 0. i.e. , the system expands during the reaction. The same amount of energy is released by the reaction under both sets of conditions. However, some of the energy is released in the form of work at constant pressure; thus, the heat released will be less than at constant volume. Mathematically, U H U H          released energy released heat In the case where  n gas < 0. i.e. , the system contracts during the reaction, the surroundings does work on the system. Thus, this work is available for energy release from the system back to the surroundings in the form of heat. Mathematically, U H U H          released energy released heat

٥٣٣ These cases can be depicted pictorially as follows:   n gas > 0 work done by system  H <  U or  H >  U  q v =  U  q p =    w const V const p    n gas < 0 work done on system  H >  U or  H <  U  q v =  U  q p =   w const V const p 4. Calibration of the Calorimeter 4. A. Estimating C v The heat capacity of the bomb calorimeter can be estimated by considering the calorimeter to be compo sed of 450 g water and 750 g stainless steel. Knowing the specific heat capacity of water to be 1 cal/g·K and estimating the specific heat capacity of steel to be 0.1 cal/g·K yields K cal 525 K cal 75 K cal 450 K g cal 1 . 0 g 750 K g cal 1 g 450 ) steel ( ) steel ( ) water ( ) water ( ) r calorimete ( v v v                          C m C m C 4. B. Measuring C v For accurate work, the heat capacity of the calori meter must be measured. This is done by depositing a known amount of energy into the calorimeter and observing the temperature increase. The two most common methods for measuring C v are 1. Burning a standard with known  U , e.g. , benzoic acid. m benzoic acid  U benzoic acid = m benzoic acid  6318 cal/g·K =  C v  T 2. Doing electrical work by passing current though a resistor.  U = w + q = V · I · t + 0 = C v  T 5. Corrections in Bomb Calorimetry 5. A. Combustion of fuse Nickel and iron fuses can burn acc ording to Ni + 2 1 O 2  NiO or

٦٣٣ 2Fe + 2 3 O 2  Fe 2 O 3 The heat released by combustion of the fuse is accounted for by recognizing that  U =  U sample · m sample +  U burned fuse · m burned fuse =  C v  T where the mass of the burned fuse is determined by weighing the fu se before and after firing the bomb. 5. B. Nonadiabaticity of calorimeter A bomb calorimeter is only approximately adiabatic. In reality, there is a small heat leak through the dewar ( q calorimeter  0) and the stirrer does work on the calorimeter ( w calo rimeter  0). Nonadiabaticity is corrected for with an empirical radiative correction , RC . RC attempts to make areas equal  T 0 3 6 9 12 15 18 time (min) T ﺷـﻛل رﻗـم ) ٩٣ ( : The time at which the bomb is considered to be fired is the time that makes the areas indicated in the above figure equal . For the Parr calorimeter , this is estimated to be at t = 7 minutes . Thus , the temperature at t = 6 minutes must be extrapolated forward 1 minute by the pre - firing slope , and the temperature at t = 12 minutes must be extrapolated backward 5 minutes by the post - firing slope . Mathe matically , this is done as follows RC T T T T T T T T T T T T T T T T T T T T T                                     6 12 0 6 12 18 6 12 0 6 12 18 6 12 0 6 6 12 18 12 6 ) ( ) ( 5 min 6 min) 1 ( min 6 min) 5 ( min 6 min) 1 ( min 6 min) 5 ( 5. C. Nitric acid formation At high temperatures, nitrogen can form nitric acid in the presence of oxygen and water. (This reaction also occurs in automobile engines and is partially responsible for smog production.) N 2 + 2 5 O 2 + H 2 O  2HNO 3 Flushing the bomb with oxygen prior to firing, thereby displacing all nitrogen, eliminates nitric acid formation.

٧٣٣ 6. Application of c o m b H In addition to measuring the energy release of one particular reaction, calorimetry is an im portant tool for determining the enthalpy of formation for the compound under study. This information can then be applied to any reaction involving the compound. The enthalpy of combustion for the reaction can be written as  comb H (C x H y O z ) = v (C x H y O z )  f H °(C x H y O z ) + v (O 2 )  f H °(O 2 ) + v (CO 2 )  f H °(CO 2 ) + v (H 2 O)  f H °(H 2 O)  comb H (C x H y O z ) = v (C x H y O z )  f H °(C x H y O z ) + v (O 2 )  f H °(O 2 ) + v (CO 2 )  f H °(CO 2 ) + v (H 2 O)  f H °(H 2 O) where v ( i ) is the stoichiometric coefficient of i . Since  f H °(C x H y O z ) and  f H °(H 2 O) are known (and  f H °(O 2 ) equals zero), measurement of  comb H (C x H y O z ) allows calcualtion of  f H °(C x H y O z ). 7. Other Types of Calorimeters There are many kinds of calorimeters, each designed for measuring the heat released by a particular chemical process. Some examples in clude: ﺷﻛل رﻗم ) ٠٤ (: Flame Calorimeter The combustible gas is metered into the calorimeter. Temperatures of all reactants must be controlled. Since the reaction occurs at constant pressure,  comb H is measured directly. ﺷﻛل رﻗم ) ١٤ (: Solution Ca lorimeter Reactants are initially separated. The temperature change is measured when they are allowed to mix. Quantities that can be determined include  mix H ,  dilution H , and  solvation H . Calorimeter design is very tricky, especially for processes invol ving very small energy changes, e.g. , protein folding, or energy changes on top of a large background, e.g. , excess heat from "cold fusion". Heat leaks must be minimized, and all other heat generating processes must be accounted for.

٨٣٣ اﻟﺘﻘﺪﯾﺮ ﻏﯿﺮ اﻟﻤﺒﺎﺷﺮ ﻟﻄﺎﻗﺔ اﻟﻤﻮاد وﺗﺤﻮﯾﻼﺗﮭﺎ The indirect estimation of heat from material transformations ﯾــﺷﻣل اﻟﺗﻘــدﯾر اﻟﻣﺑﺎﺷــر ﻟﻠﺣــرارة اﻟﻧﺎﺗﺟــﺔ ﻣــن اﻛــﺳدة اﻟﻐــذاء ﺑواﺳــطﺔ اﻟﺣﯾــوان اﺳــﺗﺧدام اﻻﺟﻬــزة اﻟﻣﺗﺧﺻــﺻﺔ اﻣــﺎ اﻟطــرق ﻏﯾــر اﻟﻣﺑﺎﺷــرة ﻓــﻼ ﺗﻘــدﯾر ﻟﻠﺣــرارة ﻣﺑﺎﺷــرة ، وﻫــذﻩ اﻟطــرق ﺗــﺷﻣل ﺗﻘــدﯾر ﻣﻘــدار اﻻﻛــﺳﺟﯾن اﻟﻣــﺳﺗﻬﻠك ﺑواﺳــطﺔ اﻟﺣﯾــوان وﺑﻣﻘــدار ﺛــﺎﻧﻰ اﻛـــﺳﯾد اﻟﻛرﺑـــون اﻟﻧـــﺎﺗﺞ واﻟﻧﯾﺗـــروﺟﯾن اﻟﻣﻔـــرز ﻓـــﻰ اﻟﺑـــول وﻣـــن ذﻟـــك ﯾﻣﻛـــن ﺣـــﺳﺎب اﻟطﺎﻗـــﺔ اﻟﻧﺎﺗﺟـــﺔ ، وﻫـــذﻩ اﻟطـــرق ﻣﻧﺎﺳـــﺑﺔ ﻟﻠــــ short - term observation of metabolism ٠ طﺎﻗﺔ اﻟرواﺑط Bond energies : ﻣن اﻟواﺿﺢ ان ﺣر ارة اﻧﻘﺳﺎم ﺟزﺋﻰ ﻣﻌﻘد ﻟﻣﻛوﻧﺎﺗﻪ اﻟذرﯾـﺔ وﻻﺑـد ان ﺗـﺳﺎوى طﺎﻗـﺔ اﻟـرواﺑط اﻟﺗـﻰ ﺗـرﺑط اﻟـذرات ﻓـﻰ اﻟﺟـزئ ﻣﻌـﺎ ، وﯾﻣﻛن ﺣﺳﺎب ﺣرارة اﻟﺣرق ﻣن ﺗرﻛﯾب اﻟﻣﺎدة وﺣـرارة ﺗﻛوﯾﻧﻬـﺎ ﻣـن ﻣﻛوﻧﺎﺗﻬـﺎ اﻟﻌﻧـﺻرﯾﺔ او اﻟذرﯾـﺔ ، واﻟطـرق اﻟﻣـﺳﺗﺧدﻣﺔ اﻣﺗـداد ﻟﻘﺎﻧون Hess ﻓﺎذا ﻋرف اﻟﺗرﻛﯾـب اﻟﻛﯾﻣـﺎوى ﻟﻠﻣـﺎدة ﻓﺣـر ارة ﺗﻛوﯾﻧﻬـﺎ وﺣـرارة ﺣرﻗﻬـﺎ ﻣﻣﻛـن ﺗﻘـدﯾرﻫﺎ ﻣـن اﻟطﺎﻗـﺔ اﻟﻣﻌروﻓـﺔ ﻟﻠـرواﺑط اﻟﻛﯾﻣﺎوﯾﺔ اﻟﻣﺣﺗوﯾﺔ ﻋﻠﯾﻬﺎ ، وﻫذﻩ اﻟطرﯾﻘﻪ اﻛﺗﺷﻔﻬﺎ linus pauling ٠ وﻗد وﺟد أن طﺎﻗﺔ اﻟـرواﺑط اﻟﻛﯾﻣﺎوﯾـﺔ ﻟﻠـرواﺑط اﻟﺑـﺳﯾطﻪ ﻣﺛـل C = C او c – H ﻗـﯾم ﻣﺗوﺳـطﺔ وﺑﺎﻟﻧـﺳﺑﺔ اﻟـﻰ اﻟﺗراﻛﯾـب اﻟﻣﺗـرددة ﻣﺛل ﺣﻠﻘـﺔ اﻟﺑﻧـزﯾن ، ﻣﺟﻣوﻋـﺔ اﻟﻛرﺑوﻛـﺳﯾل او ﻣﺟﻣوﻋـﺔ اﻻﻣﯾـد ﻓـﺎن اﻟﻣرﻛﺑـﺎت اﻟﻣﺣﺗوﯾـﺔ ﻫـذﻩ اﻟﻣﺟـﺎﻣﯾﻊ ﻟﻬـﺎ طﺎﻗـﺔ ﻋﺎﻟﯾـﺔ ﻣﻘﺎرﻧـﺔ ﺑﺎﻟطﺎﻗﺔ اﻟﻣﺗوﻗﻌﺔ ﻣن طﺎﻗـﺔ اﻟـرواﺑط ﺑﻣﻔردﻫـﺎ ٠ وﯾﺟـب ﻋﻣـل ﺗـﺻﺣﯾﺢ ﻟﻠﺗـردد ﺣﯾـث اﻟﺗﺑـﺎﯾن ﺑـﯾن اﻟﻘـﯾم اﻟﻣﺣـﺳوﺑﺔ واﻟﻣﻼﺣظـﺔ ﻻ ﯾﺗﻌـــدى ١٠.٠ % ﻣـــن اﻟﻘﯾﻣـــﺔ اﻟﺣﻘﯾﻘﯾـــﺔ ٠ واﻻﻓـــﺿل ﺣﺎﻟﯾـــﺎ ان ً ﻧـــﺳﺗﻧﺗﺞ ﺣـــرارة ﺗﻛـــوﯾن اﻟﺟزﯾﺋـــﺎت ﻣـــن اﻋﺗﺑـــﺎرات اﻟطـــول وزواﯾـــﺎ اﻟـرواﺑط اﻟﻛﯾﻣﺎوﯾـﺔ ﻣــن ﻫﻧدﺳـﺔ اﻟﺟزﯾﺋـﺎت ٠ وﻣــن اﻟﻣﻌـروف اﻧـﻪ ﯾوﺟــد ﻋﻼﻗـﺔ ﻗوﯾـﺔ ﺑــﯾن اﻟﺗرﻛﯾـب اﻟﺟزﺋـﻰ وﺣــرارة ﺗﻛوﯾﻧـﺔ وﺣــرارة ﺣرﻗـﺔ وﻻ ﯾﻣﻛـن ﺣــﺳﺎب ﺣـرارة اﻟﺗﻛـوﯾن واﻟﺣــرق ﺑدﻗـﺔ ﺑواﺳــطﺔ ﻣﻌرﻓـﺔ ﻋـدد ﻣﺧﺗﻠــف اﻧـواع اﻟــزرات اﻟﻣﻛوﻧـﺔ ﻟﻠﺟز ﺋـﻰ ﻓﻘــط ﺑـل ﻣــن اﻟﺿرورى ﻣﻌرﻓﺔ اﻟﺗرﻛﯾب ﺑدﻗﺔ ٠ اﻟطرق اﻟﻔﺳﯾوﻟوﺟﯾﺔ ﻟﻠﺗﻘدﯾر The physiological approach : ﻻ ﺗﺗــﺿﻣن اﻟطــرق اﻟﻔــﺳﯾوﻟوﺟﯾﺔ اﻟﺗﻘﻠﯾدﯾــﺔ ﻟﺗﻘــدﯾر اﻟﺣــرارة ﻣــن اﻟﺗرﻛﯾــب اﻟﻛﯾﻣــﺎوى اﻻﻋﺗﺑــﺎرات اﻟﻣﻔــﺻﻠﻪ ﻟﻠﺗرﻛﯾــب اﻟﺟزﺋــﻰ ، ﻋﻠــﻰ ﻋﻛس ذﻟك ﻓﺎن ﺣرارة اﻟﺣرق ﻣﻣﻛن ﺣﺳﺎﺑﻬﺎ ﻓﻘط ﻣن اﻟﺗر ﻛﯾب اﻟﻌﻧﺻرى اﻷوﻟﻰ ﻟﻠﻣﺎدة ٠ وﯾﻌﺗﻣد اﻟطرق اﻟﻔﺳﯾوﻟوﺟﯾﺔ ﻋﻠﻰ ان اﻟﺟﺳم ﯾﺗﻛـون ﻣـن ٣ ﻣرﻛﺑـﺎت ﻛﯾﻣﺎوﯾـﺔ اﺳﺎﺳـﯾﺔ ﯾـﺗم اﻛـﺳدﺗﻬﺎ وﻫـﻰ ﻛرﺑوﻫﯾـدرات – دﻫـن – ﺑروﺗﯾن ، وﺗﺑﻧﻰ اﻟﺣﺳﺎﺑﺎت ﻋﻠـﻰ اﺳـﺎس اﻻﻛـﺳﺟﯾن اﻟﻣـﺳﺗﻬﻠك وﻛﻣﯾـﺔ ك أ ٢ ، اﻟﻧﯾﺗـروﺟﯾن اﻟﻣﻔـرز ﺑواﺳـطﺔ اﻟﺣﯾـوان ﻋﻧـد اﻛـﺳدة ﻫــذﻩ اﻟﻣرﻛﺑــﺎت اﻟــ ﺛﻼث ، وﯾطﻠــق ﻋﻠــﻰ اﻟﻧــﺳﺑﺔ ﺑــﯾن ﺣﺟﻣــﻰ ك أ ٢ اﻟﻧــﺎﻟﺗﺞ اﻟــﻰ أ ٢ اﻟﻣــﺳﺗﻬﻠك اﻟﻧــﺳﺑﺔ اﻟﺗﻧﻔــﺳﯾﺔ respiratory quotient ( R . Q ) وﻫـــﻰ ﺗﺧﺗﻠــف ﻋﻧـــد أﻛـــﺳدة اﻟﻣرﻛﺑــﺎت اﻟﻛﯾﻣﺎوﯾـــﺔ اﻟـــﺛﻼث ، وﺗﻌﺗﻣــد ﺗﻘـــدﯾر اﻟطﺎﻗـــﺔ ﻋﻠــﻰ اﻻﻗـــﺳﺎم اﻟرﺋﯾـــﺳﯾﺔ ﻟﻠﻣرﻛﺑﺎت اﻟﻛﯾﻣﯾﺎﺋﯾﺔ اﻟﻣؤﻛﺳدة ﻓﻰ اﻟﺟﺳم واﻟﺗﻰ ﻻ ﺗﺣﺗوى ﻧﺗروﺟﯾن ) ﻛرﺑواﯾدرات ودﻫـون ( اﻟﻣﺛـﺎل اﻟﺗـﺎﻟﻰ اﻛـﺳدة اﻟﻛرﺑوﻫﯾـدرات ) ﺟﻠوﻛوز ( ، اﻟدﻫون ) ﺣﻣض ﺑﺎﻟﻣﺗﯾك ( ﻓﻰ اﻟﺟﺳم ٠ G – Glucose C 6 H 12 O 6 + 6 O 2 -------- 6 CO 2 + 6 H 2 O - H c = 673.0 Kcal. P - Palmitic acid CH 3 (CH 2 )14 C OO H + 2 3 O 2 ------ 16 C O 2 + 16 H 2 O - H c = 2398.4 Kcal. ﺟدول رﻗم ) ٣٥ (: ﻛﻣﯾﺔ أ ٢ اﻟﻣﺳﺗﻬﻠك ، ك أ ٢

= 673.0 Kcal. P - Palmitic acid CH 3 (CH 2 )14 C OO H + 2 3 O 2 ------ 16 C O 2 + 16 H 2 O - H c = 2398.4 Kcal. ﺟدول رﻗم ) ٣٥ (: ﻛﻣﯾﺔ أ ٢ اﻟﻣﺳﺗﻬﻠك ، ك أ ٢ واﻟﺣرارة اﻟﻧﺎﺗﺟﺔ ﻣﻣﻛن ﻛﺗﺎﺑﺗﻬﺎ ﻓﻰ اﻟﻣﻌﺎدﻻت اﻟﺗﺎﻟﯾﺔ : Molar ratio of CO2 to O2 = Respiratory Quotient Heat Envolved ( - Hc) Moles Co2 Produced ( Y ) Moles O 2 Consumed ( X ) Compound 1.0 0.7 673.0 2398.4 6 Y 16 Y 6 X 23 X Glucose Palmitic acid وﻟﺣﺳﺎب اﻟﻣﻌﺎدﻟﺔ اﻟﻌﺎﻣﺔ ﻟﺗﻘدﯾر Hc ﯾﻛون ﺣﺎﺻل ﺿرب اﻟﻣﻌﺎدﻟﺔ اﻷوﻟﻲ × ٦١ ا و ﺣﺎﺻل ﺿرب اﻟﻣﻌﺎدﻟﺔ اﻟﻠﺛﺎﻧﯾﺔ × ٦ : - Hc = 25.91 CO 2 Produced + 86.25 O 2 consumed ( moles) ( moles )

٩٣٣ ﻫذﻩ اﻟﻣﻌﺎدﻟﺔ ﺗﺄﺧذ اﻟﻛرﺑوﻫﯾدرات اﻻﺧرى او اﻻﺣﻣﺎض اﻟدﻫﻧﯾﺔ اﻻ ﺧرى او اﻟدﻫون ﻛﻧﻘطﺔ ﺑداﯾﺔ وﯾﻣﻛن ﺑـذﻟك ﺣـﺳﺎب H c ﻻى ﻣﺧﻠـوط ﻣـن اﺛﻧـﯾن ﻣـن اﻟﻣرﻛﺑﺎت اﻟﻣﺧﺗﺎرة وذﻟك ﺑواﺳطﺔ ﻣﻌرﻓﺔ اﻻوﻛﺳﺟﯾن ) O 2 ( اﻟﻣﺳﺗﻬﻠك ، ﺛﺎﻧﻰ اﻛﺳﯾد اﻟﻛرﺑـون CO 2 اﻟﻧـﺎﺗﺞ ﻣـن ﺧـﻼل ﻋﻣﻠﯾـﺎت اﻻﻛـﺳدة ﻟﻠﻣرﻛﺑـﺎت ، وﺗوﺟـد ﺟــداول ﺗﺑــﯾن ﻗــﯾم ﺣــرارة اﺣﺗــراق اﻟﻣرﻛﺑــﺎت اﻟﻣوﺟــودة ﻓــﻰ اﻟﻐــذاء ﺑو اﺳــطﺔ Bomb calometery ﺑﺣــﺳﺎب ﻛﻣﯾــﺔ اﻟﺣــرارة اﻟﻧﺎﺗﺟــﺔ ﻣــن اﻻﺣﺗــراق ﻟﻠﻣرﻛــب ﻣﺣــﺳوﺑﺔ ﻣــن ﻛﻣﯾــﺔ أ ٢ اﻟﻣــﺳﺗﻬﻠك ، ﻛﻣﯾــﺔ ك أ ٢ اﻟﻧﺎﺗﺟــﺔ ﻣــن اﺣﺗراﻗﻬــﺎ وذﻟــك ﺑﺎﺳــﺗﻌﻣﺎل اﻟﻣﻌﺎدﻟــﺔ وﺑﺎﺗﺧــﺎذ اﻟﺟﻠوﻛــوز وﺣﻣــض اﻟﺑﺎﻟﻣﺗﯾــك reference وﻗــد وﺟد ﻓﻰ ﺣﺎﻟﺔ ﺳﻌرات اﻟﺑﻧﺗوزات واﻟﻬﻛﺳوزات اﻟﺑﺳﯾطﺔ واﻟﺳﻛرات اﻟﺛﻧﺎ ﺋﯾﺔ واﻟﺛﻼﺛﯾﺔ ان ﺧطﺄ ﺗﻘدﯾر ﺣرارة اﻻﺣﺗـراق ﺑـﺳﯾطﺔ اﻗـل ﻣـن ٥.٠ % ﺑﯾﻧﻣـﺎ اﻟـﺳﻛرات اﻟﻌدﯾدة ﻣﺛل اﻟﻧﺷﺎ واﻟﺳﻠﯾﻠوز ﻓﯾﻛون ﺣرارة اﺣﺗراﻗﻬﺎ Underestimated by 60% وﻫذا ﻓرق ﻣﺣﺳوس ﺟدا ً ٠ ﺑﺎﻟﻧـﺳﺑﺔ ﻟﻼﺣﻣـﺎض اﻟدﻫﻧﯾـﺔ ذات طـول ﺳﻠـﺳﻠﺔ اﻗــل ﻣـن اﻟﺑﺎﻟﻣﺗﯾـك ﻓـﺎن ﺣـرارة اﻻﺣﺗـراق ﺗﻛــون Overestima ted وﻫـذا اﻟﺗﻧـﺎﻗض اﻛﺑـر ﻣـن ٢ % ﻓﻘـط ﻓــﻰ ﺣﺎﻟﺔ اﻻﺣﻣﺎض اﻻﻗل ﻣن ٤ ذرات ﻛرﺑون ، وﻋـدم اﻟﺗـﺷﺑﻊ ﻟﻼﺣﻣـﺎض ﺗـؤدى اﻟـﻰ overestimation of its calorific value اﻻﺧطـﺎء اﻟﺑـﺳﯾطﺔ ﻓـﻰ اﻻﺗﺟﺎﻩ اﻟﻌﻛﺳﻰ ﺗﺣدث ﻣﻊ اﻻﺣﻣﺎض اﻟدﻫﻧﯾـﺔ ذات ﺳﻠـﺳﻠﺔ اﻛﺑـر ﻣـن اﻟﺑﺎﻟﻣﺗﯾـك وﻓـﻰ ﺣﺎﻟـﺔ اﻟﻛﻣﯾـﺎت اﻟﺑـﺳﯾطﺔ ﻟﻠﻐـذاء ﻓـﺎن ﺣـرارة اﻟﺣـرق ﻟﻠﺟﻠﯾـﺳرول ﺗﻛـون underestimated وﺑﺎﻟﻧـــﺳﺑﺔ ﻟﻼﺣﻣـــﺎض اﻟﺛﻧﺎﺋﯾـــﺔ اﻟﻛرﺑوﻛـــﺳﯾل اﻟﻣـــﺷﺑﻌﺔ overestimated saturated dicarlioxulic acids وﻣـــدى the overestimation ﯾﻘــل ﺑزﯾــﺎدة ﺣﺟــم اﻟﺟزﺋــﻰ ٠ ﻛﻣــﺎ ان ﻋــدم اﻟﺗــﺷﺑﻊ ﯾــؤدى اﻟــﻰ اﺧطــﺎء ﻛﺛﯾــرة ، واى ﻣﺣﺎوﻟــﺔ ﻟﻠﺗﻧﺑــﺄ ﺑﺣــرارة اﺣﺗــراق اﻟﻣرﻛﺑــﺎت ﺑواﺳــطﺔ ﻣﻌرﻓﺔ ﻓﻘط ك أ ٢ اﻟﻣﺳﺗﻬﻠك ﻓﻰ ﻋﻣﻠﯾﺔ اﻻﻛﺳدة ﺳواء ﺑواﺳطﺔ اﻟﺣﯾواﻧﺎت او invitro ﻻ ﺗﺗم وذﻟك ﻟﺳﺑب ﺑﺳﯾط ﻻن ﻫذا ﯾـؤدى اﻟـﻰ ﺗﺟﺎﻫـل ﻓـﻰ اﻟﺗرﻛﯾـب اﻟﻬﻧدﺳﻰ ﻟﻠﻣرﻛﺑﺎت ، وﺣﺗﻰ اﻵن ﻓﺎن اﻟﺧطﺄ ﻓﻰ ﺗﻘدﯾر اﻟﺣرارة ﻣن ﺣﺟم ك أ ٢ اﻟﻧﺎﺗﺞ وﺣﺟم أ ٢ اﻟﻣﺳﺗﻬﻠك ﺑواﺳطﺔ اﻟﺣﯾوان اﻟـذى ﯾﺗﻐـذى ﻏـذاء طﺑﯾﻌـﻰ ﻟﯾس ﻛﺑﯾر ﻛﻣﺎ ﻫو ﻣﺗوﻗﻊ ، ﺣﯾث molecular species وﺗﻛون اﻻﺧطﺎء اﻛﺑر ﻣن ﻣﻛوﻧﺎت اﻟﻐذاء اﻟﺻﻐرى ٠ وﯾﻣﻛن ﺗﻘﻠﯾل اﻻﺧطﺎء ﺑﺎﺧﺗﯾﺎر ﺳﻠﯾم ﻟﻠﻣواد اﻟﻘﯾﺎﺳـﯾﺔ reference substances وﺑﺎﻟﻧـﺳﺑﺔ ﻟﻠﻛرﺑوﻫﯾـدرات واﻟـدﻫون ﻓﻣـن اﻟﻣﻣﻛـن اﺧﺗﯾـﺎر ٢ ﻣﻣﺛﻠـﯾن ﻋﻧﻬﻣـﺎ ﻟﺗﻣﺛﻼ اﻟ ﻣواد ﻋﻧد ﻫدﻣﻬﺎ : ١ - ﻋﻧد ﺗﻘدﯾر اﻟﺣرارة اﻟﻧﺎﺗﺟﺔ ﻣن ﻋﺟل رﺿﯾﻊ ﯾﺗﻐـذى ﻋﻠـﻰ اﻟﻠـﺑن ﻓـﺎن the reference carbohydrate ﺗﻛـون ﺳـﻛر اﻟﻼﻛﺗـوز ، ﻛـذﻟك the reference fatty acid ﯾﻛـون واﺣـد ﻣـن اﻻﺣﻣـﺎض ذات طـول ﺳﻠـﺳﻠﺔ اﻗـﺻر ﻣـن ٨١ ذرة ﻛرﺑـون وذﻟـك ﺑـﺳﺑب اﻟﻌـدد اﻟﻛﺑﯾـر ﻟﻼﺣﻣـﺎض اﻟدﻫﻧﯾﺔ ذات اﻟﺳ ﻠﺳﻠﺔ اﻟﻘﺻﯾرة ﻓﻰ دﻫن اﻟﻠﺑن ٠ ٢ - ﺑﺎﻟﻧــﺳﺑﺔ ﻟﻠﻣﺟﺗــرات اﻟﻛﺑﯾــرة اﻟــﺳن ، ﻓــﺎن the reference carbohydrate ﯾﻛــون اﻟﻧــﺷﺎ او اﻟــﺳﯾﻠﯾوز وﻣﻣﻛــن ﻓــﻰ ﺣﺎﻟــﺔ اﻻﺣﻣــﺎض اﻟدﻫﻧﯾــﺔ اﺳﺗﺧدام ﺣﻣض ﺳﯾﺗﺎرﯾك او ﺑﺎﻟﻣﺗﯾك ﺑدون ﺧطﺄ ﻛﺑﯾر ٠ ٣ - ﻓﻰ ﺑﻌـض اﻟﺣـﺎﻻت ﻣﺛـل اﻟﺗﺟـﺎرب اﻟﺗـﻰ ﺑﻬـﺎ ﺣﻣـض اﻟﺧﻠﯾـك ﻫـو اﻟﻣـﺻدر اﻟوﺣﯾـد ﻟ ﻠطﺎﻗـﺔ ﻓـﻼ ﯾوﺟـد ﺧطـﺄ اذا اﻫﻣـل ﺣـﺳﺎب ك أ ٢ اﻟﻧـﺎﺗﺞ ﻣـن اﻻﻛﺳدة وﯾﻛون اﻟﺣﺳﺎب ﻋﻠﻰ اﺳﺎس ان ﻛل ﻣول اوﻛﺳﺟﯾن ﻣﺳﺗﻬﻠك ﯾرﺗﺑط ﻣـﻊ اﻧﺗـﺎج 105 Kcal ﺣـرارة ٠ وﺗﻌﺗﺑـر ﻛـل ﺣﺎﻟـﺔ ﻣﻧﻔـﺻﻠﺔ ﻋـن اﻻﺧــرى وﯾﻔــﺿل اﺳــﺗﺧدام اﻻﺣﻣــﺎض اﻟدﻫﻧﯾــﺔ ﻋــن ﻣﺧﻠــوط اﻟﺟﻠــﺳرﯾدات اﻟﺛﻼﺛﯾــﺔ ﻟــدﻫن اﻟﺟــﺳم ﻛﻣــﺻدر ﻟﻠطﺎﻗــﺔ ﺣﯾــث ﺣــر ارة اﻻﺣﺗــراق ﻟﻬــﺎ ﺻﻐﯾرة ﺑدرﺟﺔ ﻋﯾر ﻛﺎﻓﯾﺔ ﻻﺳﺗﺧداﻣﻬﺎ ﻓﻰ اﻟﺗﻘدﯾر ٠ ﺟدول رﻗم ) ٤٥ (: The heat of combustion of compounds of C , H and O likely to be present in food

ث ﺣــر ارة اﻻﺣﺗــراق ﻟﻬــﺎ ﺻﻐﯾرة ﺑدرﺟﺔ ﻋﯾر ﻛﺎﻓﯾﺔ ﻻﺳﺗﺧداﻣﻬﺎ ﻓﻰ اﻟﺗﻘدﯾر ٠ ﺟدول رﻗم ) ٤٥ (: The heat of combustion of compounds of C , H and O likely to be present in food , and the prediction of their heats of consumed from the amounts of CO 2 produced and consumed in th eir combustion Compound Determined heat of combustion (Kcal/mole) Calculated heat of combustion (Kcal/mole*) Calculated ــــــــ x 100 Determined Carbohydrates Xylose 561.5 560.8 99.9 Glucose 673.0 673.0 100.0 Galactose 670.7 673.0 100.3 Fructose 675.6 673.0 99.6 Sucrose 1349.6 1345.9 99.7 Lactose 1350.8 1345.9 99.6 Maltose 1350.2 1345.9 99.7 Raffinose 2025.5 2018.9 99.7 Glycogen ( / g) 4.116 3.913 95.0 Starch ( / g) 4.179 3.913 93.6 Cellulose ( / g) 4 .181 3.913 93.6 Fatty acids C 1 formic 65.1 69.1 106.1 C 2 acetic 209.4 224.3 107.1 C 3 propionic 367.2 379.6 103.2 C 4 n - butric 524.3 534.9 102.0 C 5 n - valeric 681.6 690.2 101.3 C 6 caprioc 831.0 845.5 101.7 C 12 lauric 1771.7 1777.2 100.3 C 14 myristic 2085.8 2087.7 100.1 C 16 palmitic 2398.4 2398.4 100.0 C 18 stearic 2711.8 2708.9 99.9 C 22 arachidic 3025.9 3019.6 99.8 C 22 behenic 3338.4 3330.1 99.8 C 18 oleic 2657.0 2665.8 100.3 Poly alcohols Glycerol 397.0 379.6 95.6 Dicarboxylic ac ids ( saturated ) Oxalic acid 60.2 94.9 157.6 Succinic acid 357.1 405.5 113.6 Glutaric acid 514.9 560.8 108.9 * Using as reference substances glucose and palmitic acid. (See equation page 16). The oxidation of protein :

٠٤٣ ﯾﺧــﺗص اﻟﺟــزء اﻟﺛــﺎﻧﻰ ﻣــن اﻟﻣﻧﺎﻗــ ﺷﺔ اﻟﻔــﺳﯾوﻟوﺟﯾﺔ ﺑﺗﻘــدﯾر ﺣــرارة اﺣﺗــراق اﻟﻐــذاء ﻣــن ﻧــواﺗﺞ اﻟﺣــرق واﺳــﺗﻬﻼك اﻻوﻛــﺳﺟﯾن اﻟﻣﺧـــﺗص ﺑﺗﻘـــدﯾر اﻟﺣـــرارة اﻟﻣرﺗﺑطـــﺔ ﺑﻬـــدم اﻟﺑـــروﺗﯾن واﻟﻣرﻛﺑـــﺎت اﻻﺧـــرى اﻟﻣﺣﺗوﯾـــﺔ ﻋﻠـــﻰ ﻧﯾﺗـــروﺟﯾن وﻛﻣﺛـــﺎل ﻟـــذﻟك اﻛـــﺳدة ﺣﺎﻣض اﻣﯾﻧﻰ اﻻﻧﯾن ، وﺣرارة اﺣﺗراق اﻻﺣﻣﺎض اﻻﻣﯾﻧﯾﺔ ﺗﻣﺛل اﻛـﺳدﺗﻬﺎ ﻛـﺎﻣﻼ اﻟـﻰ ك أ ً ٢ + ﻣـﺎء + ﻏـﺎز ﻧﯾﺗـروﺟﯾن ﻓـﻰ اﻟﺟﺳم وﻻ ﯾﺗﺄﻛﺳد اﻟﻧﯾﺗروﺟﯾن ﻛﺎﻣﻼ وﯾﻔرز ﻏﺎﻟﺑﺎ ﻋﻠﻰ ﺻورة ﯾورﯾﺎ ، وﺣرارة اﻟﺗﻔﺎﻋل ﻣﻣﻛن ﺗﻘدﯾرﻫﺎ ﺑواﺳطﺔ ﻗـﺎﻧون ًً Hess ﺣﯾث اﻻﺣﻣﺎض اﻻﻣﯾﻧﯾﺔ ﻻ ﺗﺗﺄﻛﺳد ﻛﻠﯾﺔ ٠ ﻣﺛﺎل : اﻻﻵﻧﯾن ﻛﻣﺛﺎل ﻟﻸﺣﻣﺎض اﻻﻣﯾﻧﯾﺔ ﻣن اﻛﺳدﺗﻬﺎ اﻛﺳدة ﻛﺎﻣﻠﺔ ٠ 4 CH 3 – CH – C ooH + 15 O 2 ------ 12 CO 2 + 14 H 2 O + 2 N 2 NH 2 - Hc/mole alanine = 387.7 Kcal (1550.8 / 4 = 387.7) . اﻟﯾورﯾﺎ ﻋﻧد اﻻﻛﺳدة اﻟﻛﺎﻣﻠﺔ ٠ 2 Co (NH 2 ) 2 + 3 O 2 ------ 2 CO 2 + 4 H 2 O + 2 N 2 - Hc/mole Urea = 151.6 Kcal (303 .2 / 2mole = 151.6) . ﺑﺎﻟطرح ﯾﻧﺗﺞ ﺣرارة اﻛﺳدة اﻻﻵﻧﯾن اﻟﻰ ك أ ٢ + ﯾد ٢ أ + ﯾورﯾﺎ ٠ NH 2 4 CH 3 CH (NH 2 ) CooH + 12 O 2 -------- 10 CO 2 + 10 H 2 O + 2 CO NH 2 - Hc/mole alanine = 311.9 (1550.8 - 303.2 = 1247.6 / 4=311.9 ) Then 1247.6 + 303.2 = 1550.8 Kcal. Constant heat summation = hess low . Incomplete oxidation of carbohydrate : ١ - اﺳـــﺗﻧﺗﺎج اﻟــــ Factors ﻟﺣـــﺳﺎب اﻟﺣـــرارة ﻣـــن اﻟﺗﺑـــﺎدل اﻟﻐـــﺎزى واﻓـــراز اﻟﻧﺗـــروﺟﯾن ﻓـــﻰ اﻟﺑـــول ﻛﺟـــزء ﻣـــن اﻓـــراز اﻟﯾورﯾـــﺎ واﻻﻛﺳدة اذا ﻛﺎﻧت ﻛﺎﻣﻠﺔ ﺗﻧﺗﻬﻰ ﺑﺗﻛوﯾن ك أ ٢ + ﯾد ٢ أ ٠ ٢ - ﻓـﻰ ﺣﺎﻟـﺔ اﻟﻣﺟﺗــرات ﺗـﺗم اﻟﻌﻣﻠﯾـﺎت اﻟﻣﻌﻘــدة ﻟﻬـدم اﻟﻛرﺑوﻫﯾـدرات ﺣﯾــث اﻟﻣراﺣـل اﻷوﻟﯾـﺔ ﺑﻛﺗﯾرﯾــﺔ وﯾﻧـﺗﺞ اﻟﻣﯾﺛـﺎن ﺑﻛﻣﯾــﺎت ﻛﺑﯾرة ﺗﻌﺎدل 40 litre / Kg dry foo d eaten ﻓﻰ اﻟﻣﺗوﺳط ٠ ٣ - ﺗوﺟد طرق ﻣﺷﺎﺑﻬﺔ ﺗﺧﺗص ﺑـ the incomplete oxidation ﻟﻧﯾﺗروﺟﯾن اﻟﺑروﺗﯾﻧﺎت ﻟﻌﻣل ﺗﺻﺣﯾﺢ ﻟ ﻸﻛﺳدة ﻏﯾـر اﻟﻛﺎﻣﻠﺔ the incomplete oxidation وﻫذا اﻟﺗﺻﺣﯾﺢ ﺻﻐﯾر وﯾﺷﻣل ﺧﺻم 0.5 Kcal / litre methane . ٤ - ﻓـﻰ ﺣﺎﻟــﺔ اﻟﺣـرق ﻏﯾــر اﻟﻛﺎﻣــل Incomplete oxidation ﯾظﻬـر ﺣﺎﻟــﺔ Ketosis ﻓــﻰ اﻟﺣﯾواﻧـﺎت وﺑﻣﻌرﻓــﺔ ﻛﻣﯾــﺎت aceto - acetic acid , B - hydroxy - butyric acid and acetone اﻟﻣﻔــرزة ﺗــﺿ ﺎف ﻋﺎﻣــل ﺗــﺻﺣﯾﺢ آﺧــر ﻟﻠﻣﻌﺎدﻟﺔ اﻵﺗﯾﺔ : Heat produced (Kcal) = O2 consumed + CO2 produced - Nexoreted – CH4 produced (Littres) (Littres) In unine (g) ٥ - ﻓـﻰ ﺣﺎﻟـﺔ اﻻﻏـراض اﻟﻌﻠﻣﯾـﺔ ﻓـﺎن اﻟﻔﻘـد اﻟﺣـ رارى ﯾﻘـدر ﺑـﺿرب أ ٢ اﻟﻣـﺳﺗﻬﻠك ) ﻟﺗـر ( × ٨.٤ = اﻟﺣـرارة اﻟﻣﻧﺗﺟـﺔ Kca l ﺑﺎﻫﻣﺎل ﻛﻼ ﻣن ك أ ٢ اﻟﻣﻔﻘود واﻟﻧﺗروﺟﯾن اﻟﻣﻔرز ٠ Synthesis : ﻣـن اﻟﻣﻣﻛــن ان ﯾـؤﺛر اﻻﻧــﺳﺎن واﻟﺣﯾـوان ﻋﻠــﻰ اﻟﺗﻛـوﯾن اﻟــﺻﺎﻓﻰ ﻟﻠﻣــواد اﻟﺟدﯾـدة ﻓــﺎﻟﺣﯾوان ﯾﻛـون دﻫــن اﻟﺟـﺳم ﻣــن اﻟﻛرﺑوﻫﯾــدرات اﻟﻣوﺟــودة ﻓــﻰ اﻟﻐــذاء وأﯾــﺿﺎ ً ﺗﻛــوﯾن اﻟﺑﺎﻟﻣﺗﯾــك ﻣــن اﻟﺟﻠﻛــوز ﺣﯾــث ﺗﺗﻛــون اﻻﺣﻣــﺎض اﻟدﻫﻧﯾــﺔ ﺗــدرﯾﺟﯾﺎ ﻣــن ً 2 carbon fragments ( acetyl COA ) وﻣن اﻟﻣﻌروف ان ﺟزئ واﺣد ﻣن اﻟﺟﻠوﻛوز ﯾﻧﺗﺞ 2 – carbon fragments 8 C 6 H 12 O 6 + 25 O 2 ------ CH 3 (CH 2 ) 14 CooH 32 CO 2 + 32 H 2 O وﺣـرارة ﻫـذا اﻟﺗﻔﺎﻋـل - H = 2986 Kcal واذا اﺳـﺗﺧدﻣت اﻟﻌﺎدﻟـﺔ 25.91 Kcal / mole CO 2 + 86.25 Kcal / mole O 2 ﻓﺎن اﻟﺣرارة اﻟﻣﺣﺳوﺑﺔ ﺑﻬذﯾن اﻟﻌﺎﻣﻠﯾن ﺗﻛون 2986 Kcal وﻫﻰ ﻧﻔس اﻟﻘﯾﻣﺔ اﻟﺳﺎﺑﻘﺔ ﺑﺎﻟﺿﺑط ٠ 25.91 x 32 + 86.25 x 25 = 2982.37 .

١٤٣ وﻗـــد اﺳـــ ﺗﺧدﻣت ﻋـــدة ﺗﺟـــﺎرب ﻻﯾﺟـــﺎد ﻗﯾـــﺎس ﻣﺑﺎﺷـــر ﻟﻠﺣـــرارة ﻣﺛـــل اﻟﺗﺑـــﺎدل اﻟﻐـــﺎزى ﻓـــﻰ اﻟﻣﺣﺗوﯾـــﺎت اﻟﺗـــﻰ ﺗﻛـــون دﻫـــن واﻟﻌﺎﻣـــل اﻟﻣﺳﺗﺧدم ﻟـ ك أ ٢ ٠ 1.1 and 1.3 Kcal/Litre Co2 produced in different experiments) وواﺿــﺢ اﻧــﻪ ﺑﺎﺳـــﺗﺧدم اﻟﺛواﺑــت ﻓـــﻰ ﺗﻛــوﯾن اﻟــدﻫن ﻓـــﺳوف ﺗﺧﺗﻠــف ﺣـــﺳب ﺗرﻛﯾــب اﻻﺣﻣــﺎض اﻻﻣﻧﯾـــﺔ واﻻﻫــم ﻣـــن ذﻟــك ﺗﻛـــوﯾن اﻟﻣرﻛﺑﺎت اﻟﻣﻌﻘدة ﻣﺛل اﻟﺳﺗﯾروﻻت واﻟﺑورﻓوﯾرﯾن . ٠ ك أ ٢ اﻟﻧﺎﺗﺞ وﯾﺟب ﻣﻌرﻓﺔ ان ﻧﺳﺑﺔ : ــــــــــــ = اﻟﻧﺳﺑﺔ اﻟﺗﻧﻔﺳﯾﺔ ) R . Q ( وﺗﺳﺗﺧدم ﻟﻠﻌﻣﻠﯾﺎت اﻟﺗﻣﺛﯾﻠﯾﺔ ﻓﻰ اﻟﺟﺳم ٠ أ ٢ اﻟﻣﺳﺗﻬﻠك وﺑﺎﻟﻧﺳﺑﺔ اﻟﻰ اﻟﻬدم واﻻﻛﺳدة اﻟﻛﺎﻣﻠﺔ ﻓﻰ ﺣﺎﻟﺔ اﻟﻣرﻛﺑﺎت اﻟﻣﺣﺗوﯾﺔ ﻛرﺑون واﯾدروﺟﯾن واﻛﺳﺟﯾن ﻓﯾﺳﺗﺧدم اﻻوﻛﺳﺟﯾن اﻟﻣـﺳﺗﻬﻠك و ك أ ٢ اﻟﻧــﺎﺗﺞ ﻓـــﻰ اﻻﻛــﺳدة اﻟﺟزﺋﯾـــﺔ ﻟﻼﺣﻣــﺎض اﻻﻣﯾﻧﯾـــﺔ وﺗﻛــون ﺣـــرارة اﻟﺗﻔﺎﻋــل Overstimated ﺑﻣﻘـــدار ٤ % ﺑﺎﻟﻧـــﺳﺑﺔ ﻟﺣﻣــض اﻻﻻﻧــﯾن ، ٦ % ﻟﺣﻣــض اﻟﺟﻠوﺗﺎﻣﯾــك واﻟﻘــﯾ م اﻻﺧــرى ٦ % ﻟﻠﺟﻠﯾــﺳﯾن ، ٧ % ﺣﻣــض اﻟﻠﯾوﺳــﯾن واﻻﯾزوﻟﯾوﺳــﯾن ، وﻫــذﻩ اﻟﻧﺳب ﺗﻌﺗﺑر اﺧطﺎء واﻟﺗﺻﺣﯾﺢ ﻣﻣﻛن ﻋﻠﻰ اﺳﺎس اﻟﻣﺣﺗوى اﻟﻧﺗروﺟﯾﻧﻰ وﻓـﻰ ﺣﺎﻟـﺔ اﻛـﺳدة اﻟﺣﻣـض اﻻﻣﯾﻧـﻰ ﻓـﺎن اﻟﻔـروق ﺑـﯾن اﻟﺣرارة اﻟﻣﺣﺳوﺑﺔ واﻟﺣرارة اﻟﻣﻘدرة 0.828 Kcal / gm nitrogen ٠ وﺑﺎﻟﺗﺎﻟﻰ ﻓﺎن ﺣرارة أﻛﺳدة اﻟﺣﻣض ا ﻻﻣﯾﻧﻰ ﻓﻰ اﻟﺟﺳم اﻟﻰ ك أ ٢ + ﯾد ٢ أ + ﯾورﯾﺎ ﻣﻣﻛن ﺣﺳﺎﺑﻬﺎ ﻣن اﻟﻣﻌﺎدﻟﺔ اﻵﺗﯾﺔ : Heat = 25.91 X moles + 86.25 X moles - 0.828 gm N Produced CO 2 prod. O 2 Consumed exerted as urea. وﺑذﻟك ﺗﺻﺑﺢ اﻟﻣﻌﺎدﻟﺔ اﻟﻌﺎﻣﺔ : Heat produced = a O 2 consumed + b CO 2 produced - c N excreted in - d CH4 product (litres) (litres) Urine (g) (litres) واﻟﻧﺳﺑ ﺔ اﻟﺗﻧﻔﺳﯾﺔ R . Q اذا ﻛﺎﻧت 0.7 ﻓﻬﻰ ﺗﻌﻧﻰ اﻛﺳدة اﻟدﻫن ﺑﻣﻔردة ، اذا ﻛﺎﻧـت ٥٠١ ﻓﻬـﻰ اﻛـﺳدة ﻟﻠﻛرﺑوﻫﯾـدرات واذا ﻛﺎﻧـت اﻛﺑر ﻣن ٥٠١ ﻓﻬﻰ ﺗﻌﻧﻰ ﺗﻛوﯾن اﻟدﻫن ﻣن اﻟﻛرﺑوﻫﯾدرات ، واذا اﺳﺗﺧدم اﻟﺟﻠوﻛوز ﻛﺑداﯾﺔ ﻟﺗﻛـوﯾن اﻟـدﻫن ﻓـﺎن R . Q ﻻ ﯾﻣﻛـن ان ﺗزﯾد اﻛﺛر ﻣن ٣.١ ٠ وﻗــد وﺟـــد ان اﻟﻘﯾﻣــﺔ اذا ﻛﺎﻧـــت زﯾــﺎدة ﻋـــن ٤.١ ﻓﻬـــﻰ وﺟــدت ﻓـــﻰ ﺣﺎﻟــﺔ ﺗﻐذﯾـــﺔ marmots ﻋﻠـــﻰ ﻏــذاء ﺑـــﻪ ﻛﻣﯾــﺎت ﻛﺑﯾـــرة ﻣـــن اﻟﻛرﺑوﻫﯾدرات ﻗﺑل اﻟﺑﯾﺎت اﻟﺷﺗوى winter hibernation ، وﻓﻰ ﺣﺎﻟﺔ اﻻوز ﻋﻧد ﺗزﻏﯾطﺔ ﺑﺎﻟﻛرﺑوﻫﯾدرات ﻻﻧﺗﺎج اﻟﻛﺑد اﻟدﻫﻧﻰ Fatty livers ﺣﯾـث Culinary base of pate de foie gras . واﻟﻣﻌﻠوﻣـﺎت ﺑـﺳﯾ طﺔ ﻓـﻰ ﺣﺎﻟـﺔ اﻟﻣﯾﺗـﺎﺑوﻟﯾزم ﻋﻧـد ﻫـذﻩ اﻟدرﺟــﺔ اﻟﻌﺎﻟﯾــﺔ ﻣــن R . Q ٠ واﻟﻘــﯾم اﻟﻌﺎﻟﯾــﺔ ﻻ ﯾﻣﻛــن ﺗﻔــﺳﯾرﻫﺎ ﻓــﻰ ﺣﺎﻟــﺔ اﻻﺣﻣــﺎض اﻟدﻫﻧﯾــﺔ ﻏﯾــر اﻟﻣــﺷﺑﻌﺔ اﻟﻣﺗﻛوﻧــﺔ او اﻟطوﯾﻠــﺔ اﻟﺳﻠﺳﻠﺔ ، وﻟﻛن ﻣن اﻟﻣﻣﻛن ﺗﻔﺳﯾرﻫﺎ اذا ﻛﺎن ﺗﻛوﯾن اﻟدﻫن ﻣن اﻟﻛرﺑوﻫﯾدرات ﻓﻰ ادﻧﻰ درﺟﺔ ﻓﻰ اﻟﺟﺳم ﻛﻠﻪ ٠ Computation of h eat from body retentions : اذا ﻛﺎﻧــت ﺣـــرارة اﺣﺗـــراق اﻟﻌﻧﺎﺻـــر اﻟﻐذاﺋﯾـــﺔ اﻟﻣﻣﺗـــﺻﻪ ﺑواﺳـــطﺔ اﻟﺣﯾـــوان ﻣﻌروﻓـــﺔ وﺣـــرارة اﺣﺗـــراق ﻣﻛوﻧـــﺎت اﻟﺟـــﺳم اﻟﻣﺧزﻧـــﻪ او اﻟﻣﻔﻘــودة ﻣﻣﻛــن ﺗﻘــدﯾرﻫﺎ ﻓﺗﻛــون اﻟﻔــروق ﻓــﻰ ﺗﻘــدﯾر ﺣــرارة اﻟﺗﻔﺎﻋــل اﻟﻛﻠﯾــﺔ ﺑﻬــﺎ اﺧــﺗﻼف ﺑــﺳﯾط ، ﻓﻬــذﻩ اﻟﺗﻘــدﯾرات ﻏﯾــر اﻟﻣﺑﺎﺷــرة ﻟﻠطﺎﻗﺔ اﻟﻧﺎ ﺗﺟﺔ ﺗﺳﻣﻰ ﻣﯾزان اﻻزوت واﻟﻛرﺑون ، وﻣﻣﻛن اﺳﺗﺧداﻣﻬﺎ ﻟﺗﻘدﯾر ﻗﯾم اﻟطﺎﻗﺔ اﻟﺣرارﯾﺔ ﻟﻠﻣواد اﻟﻣﺧزﻧﻪ او اﻟﻣﻔﻘـودة ﻣـن اﻟﺟﺳم ٠ ﺗﻌﺗﺑـر طرﯾﻘـﺔ ﻣﯾـزان اﻟﻛرﺑـون واﻻزوت واﺣـدة ﻣـن اﻗـدم اﻟطـرق ﻏﯾـر اﻟﻣﺑﺎﺷـرة وﻗـد اﺳـﺗطﺎع Maximilion II of Bavaria and Pettenkfer and Voit ﺗﺻﻣﯾم أول ﺟﻬﺎز ﺳﻧﺔ ٦٦٨١ ﻟﺗﻘدﯾر ﻣﯾزان اﻻزوت واﻟﻛرﺑون ﻋﻠـﻰ اﻻﻧـﺳﺎن ، وﻓـﻰ ﻧﻔـس اﻟوﻗـت ﻗـدم Grouven ﺟﻬـﺎز

ﻣﺑﺎﺷـرة وﻗـد اﺳـﺗطﺎع Maximilion II of Bavaria and Pettenkfer and Voit ﺗﺻﻣﯾم أول ﺟﻬﺎز ﺳﻧﺔ ٦٦٨١ ﻟﺗﻘدﯾر ﻣﯾزان اﻻزوت واﻟﻛرﺑون ﻋﻠـﻰ اﻻﻧـﺳﺎن ، وﻓـﻰ ﻧﻔـس اﻟوﻗـت ﻗـدم Grouven ﺟﻬـﺎز ﻣﻣﺎﺛــل ﻟﻠﺣﯾواﻧــﺎت اﻟﻣزرﻋﯾــﺔ ﺣﯾــث ﻗــدر اﻟﻣــوازﯾن اﻟﻛﻠﯾــﺔ ﻟﻠﻛرﺑــون واﻟﻧﺗــروﺟﯾن واﻟﻬﯾــدروﺟﯾن واﻻوﻛــﺳﺟﯾن ، واﺳــﺎس اﻟطرﯾﻘــﺔ ﻫــو اﻓﺗراض ان اﻟﻣواد اﻟﻣوﺟـودة ﻓـﻰ اﻟﺟـﺳم ﺗﺗرﻛـب اﻣـﺎ ﻣـن دﻫـن او ﺑـروﺗﯾن ، وان اﻟﺑـروﺗﯾن اﻟﻣﺧـزن ﻣﻣﻛـن ﺗﻘـدﯾرﻩ ﻣـن اﻟﻧﺗـروﺟﯾن اﻟﻣﺣﺗﺟز واذا ﻛﺎن ﺟزء ﻣن اﻟﻛرﺑون اﻟﻛﻠﻰ اﻟﻣﺧزن ﯾﺧزن ﻋﻠﻰ ﺻورة ﺑروﺗﯾن ﻓﯾﺗم طرﺣﻪ واﻟﺑﺎﻗﻰ ﯾﻣﺛـل اﻟﻛرﺑـون اﻟﻣﺧـزن ﻋﻠـﻰ ﺻورة دﻫن ٠ وﻫذا اﻻﻓﺗراض ﻟﯾس ﺣﻘﯾﻘﻰ وﻟﻛﻧﺔ ﺗﻘرﯾﺑـﻰ ، اﻟﻣـواد اﻟﻣﺣﺗﺟـزة ﻓـﻰ اﻟﺟـﺳم ﻻ ﺗﺗرﻛـب ﻣـن ﺟﻠـﺳرﯾدات ﺛﻼﺛﯾـﺔ وﺑـروﺗﯾن ﻓـﻰ ﺗرﻛﯾﺑـﺔ ﺛﺎﺑﺗﺔ وﻟﻛن ﺗﺗﻛون ﻣرﻛﺑﺎت ﻛﺛﯾرة ﻣﻌﻘدﻩ ﻣﻧﻬﺎ اﻟﺟﻠﯾﻛوﺟﯾن واﻻﺳﺗﯾروﻻت واﻻﺣﻣﺎض اﻟﻧووﯾﺔ ، phospholipins ﻣﻌﺎ ﻣﻊ ﻋدﯾد ﻣــن اﻟﺟﻠــﺳرﯾدات اﻟﺛﻼﺛﯾــﻪ وﺑروﺗﯾﻧــﺎت وﻫــذا اﻟﻧظــﺎم اﻟﻣﻌﻘــد ﻟﻣــود ﺗﺣﺗــوى ﻧﯾــروﺟﯾن او ﺧﺎﻟﯾــﻪ ﻣــن اﻟﻧﯾﺗــروﺟﯾن ، وﻗــد ﺗوﺟــد ﻋواﻣــل ﻣــﺷﺎﺑﻬﺔ ﺗــﺳﺗﺧدم ﻟﺗ ﻘــدﯾر اﻟﺣــرارة أواﻟطﺎﻗــﺔ ﻣــن اﻟﺗﺑــﺎدل اﻟﻐــﺎزى وﻟﻛــن ﻣــﻊ ﻣﻼﺣظــﺔ اﻧــﻪ ﻻ ﯾﻣﻛــن اﻟوﺻــول اﻟــﻰ اﻟدﻗــﺔ اﻟﻣطﻠﻘــﺔ ،