Calories conversion

For chemical reactions and phase transformations, the energy absorbed or liberated is measured as heat. The principal unit for reporting heat is the calorie, which is defined as the energy needed to raise the temperature of 1 gram of water at l4.5° C by a single degree. The term kilocalorie refers to 1,000 calories. Another unit of energy is the joule (rhymes with school), which is equal to 0.239 calories. Conversely, a calorie is 4.184 joules. The translation of calories to joules, or kilocalories to kilojoules, is so common in chemical calculations that you should memorize the conversion factors. 

One might expect the frequency factor A for desorption to be around 10 sec (note Eq. XVII-2). Much smaller values are sometimes found, as in the case of the desorption of Cs from Ni surfaces [133], for which the adsorption lifetime obeyed the equation r = 1.7x 10 exp(3300// r) sec R in calories per mole per degree Kelvin). A suggested explanation was that surface diffusion must occur to desorption sites for desorption to occur. Conversely, A factors in the range of lO sec have been observed and can be accounted for in terms of strong surface orientational forces [134]. 

Early applications of crystalline fructose focused on foods for special dietary applications, primarily calorie reduction and diabetes control. The latter application sought to capitalize on a signiftcandy lower serum glucose level and insulin response in subjects with noninsulin-dependent diabetes melUtus (21,22) and insulin-dependent diabetes (23). However, because fmctose is a nutritive sweetener and because dietary fmctose conversion to glucose in the hver requires insulin in the same way as dietary glucose or sucrose, recommendations for its use are the same as for other nutritive sugars (24). Review of the health effects of dietary fmctose is available (25). 

There is a fixed relation between the measure of a quantity of work and that of the quantity of heat obtained from it by complete conversion. If these- two measures are expressed in terms of the erg and the calorie respectively as units, there will also be a relation between the erg and the calorie. Heat, considered as a form of energy, may be measured in ergs, i.e., in work units, and to convert the measure of a quantity of heat expressed in calories into the measure. of the same quantity expressed in ergs, we must find the number of times the erg is contained in the calorie, and multiply this by the measure of the given quantity of heat in calories. It is a relation between units which is involved. 

The only quantity considered here is the enthalpy of formation, A fH°, at 298.15 K. Data are given in units of kJmol-1. The conversion factor 1 thermochemical calorie = 4.1840 joules was used. 

The use of non-SI units is strongly discouraged. For these units there often do not exist standards, and for historical reasons the same denomination may mean sundry units. For example, it is common practice in theoretical chemistry to state energy values in kilocalories. However, to convert a calorie to the SI unit Joule, there exist different conversion factors ... 

We now wish to examine the heat capacity per unit mass to determine if it varies significantly with conversion. At the inlet conditions, the molal heat capacity of the gaseous feed will be equal to X(y CPi). Hence at / = 0, with Cp in units of calories per gram degree Kelvin and T in degrees Kelvin. 

Table 1.3 gives some commonly used non-SI units for certain quantities, together with conversion factors relating them to SI units. We use these in some examples and problems, except for the calorie unit of energy. This last, however, is frequently encountered. 

Calculate the conversion factor for changing liter atmosphere to (a) erg, (b) joule, and (c) calorie. Calculate the conversion factor for changing atmosphere to pascal and atmosphere to bar. 

Calculate the conversion factor for changing calorie to (a) cubic meter atmosphere and (b) volt faraday. 

The fat content of the US diet has increased very substantially over the past few decades. Currently more than 40% of dietary calories are consumed in the form of fat. This can easily lead to weight gain. The energy required for conversion of dietary fat to fat in adipose tissue involves the loss of only 3% of the calories in the dietary fat. In contrast, the energy requirement for conversion of dietary carbohydrate to fat in adipose tissue involves the loss of 23% of the calories in the dietary carbohydrate. Clearly, dietary fat is a great source of body fat. 

Don t forget that both the calorie and Tins, joule are units of energy in published charts, so you will often have to do a conversion to obtain the unit that you want. 

For conversion of values expressed in terms of the defined calorie to other desired units, the following factors can be used ... 

Although SI is the internationally accepted system of measurement in science, other units are encountered. Useful conversion factors are found in Table 1-4. For example, common non-SI units for energy are the calorie (cal) and the Calorie (with a capital C, which stands for 1 000 calories, or 1 kcal). Table 1-4 states that 1 cal is exactly 4.184 J (joules). 

A bimolecular reaction which would proceed with comparable velocity at the same temperature as this reaction would have a heat of activation of about 60,000 calories, as may be inferred from the table on page 96. Now termolecular collisions are about 1,000 times less frequent than bimolecular collisions at atmospheric pressure. Thus if we have a bimolecular reaction and a termolecular reaction with equal heats of activation, the rate of the latter should be at least 1,000 times smaller than that of the former at the same temperature. It will probably be more nearly 10,000 times slower, since a larger proportion of the ternary collisions are likely to be ineffective on account of unfavourable orientation of the molecules during impact. Conversely, if a termolecular reaction and a bimolecular reaction are to take place at equal rates at the same temperature, then the heat of activation of the termolecular reaction would need to be the smaller by an amount AE, such that e ElRT = 1,000 to 10,000. Thus, other things being equal, the heats of activation of termolecular reactions ought to be about 5,000 calories less at the ordinary temperature, and about 15,000 calories less at 1,000° abs., than those of bimolecular reactions. We have also to allow for the diminished duration of collisions at higher temperatures, which we can do by comparison with the nitric oxide oxidation. 

I Sec also Chemical Reaction Rate.) For the qualitative effect temperature change, one may visualize the heat ol an equilibrium reaction as material, and an increase of temperature (hem intensity) as operating to increase the concentration of "heal material." thus shifting the equilibrium away from the side ol its increased concentration, and conversely. It is possible, knowing the heal of reaction. Q. on the assumption that the heat nf reaction is constant between two given (absolute) temperatures. 7j and T . to calculate the equilibrium constant A (at 73) when the equilibrium constant A tat 7j I and the gas constant, R (equals 2 calories per mole) are known, by the application of van l Holt s equation ... 

PLi represents any polymeric organolithium. For 4 mmoles of organolithium these cumulative heats are 61.6 calories, 37.6 calories, and 32.4 calories for PSLi, PILi, and PBDLi, respectively. Therefore, the total heats involved correspond to 15.4 kcal/mole, 9.4 kcal/mole, and 8.1 kcal/mole for PSLi, PILi, and PBDLi, respectively. Thus, the conversion shown in Eq. (21) is 6.0 kcal/mole more exothermic for PSLi versus PILi, and 7.3 kcal/mole more exothermic for PSLi versus PBDLi. The process shown in Eq. (21) can be dissected conceptually into two thermodynamic steps (Eqs. (22) and (23)),... 

The 5-deiodinase enzyme activity necessary for liver conversion of T-4 into T-3 requires adequate levels of zinc and selenium. During calorie restricted periods lasting more than 2-3 weeks T-4 conversion to the more active T-3 decreases dramatically greatly reducing fat loss. Adequate zinc intake and absorption prevents the decline in 5-deiodinase that causes this negative by about 67% and adequate selenium levels prevents the decline by about 47%. Obviously both in sufficient amounts are best. 

An advantage of T-3/L-triiodothyronine administration over T-4/L-thyroxine was the lack of dependence upon the liver enzyme responsible for T-4/T-3 conversion. During diet restricted periods the liver naturally decreases the liver enzyme levels as a control measure to prevent metabolic rate induced starvation. Just as the liver increases production of this enzyme in response to elevated calorie intake it also reduces levels in response to decreased calorie intake. Remember that T-4 /L-thyroxine is only 20% as active as T-3/L-triiodothyronine. 

A high protein diet providing 1.5-2 g of protein and 17-20 calories per pound of bodyweight daily was commonly considered a must with this cycle example. Post cycle protein intake levels were continued while total calories are reduced to 15-17 calories per pound of bodyweight by those who retained the greatest lean mass tissue and the least adipose (fat) tissue. Since Testosterone converts to DHT fairly easily, hair loss of the scalp was monitored. If this became a concern, 1 mg of Finasteride (Proscar) was often co-administered and believed to be quite prudent (to block DHT conversion). It was almost unanimously said to be mandatory that Deca and Testosterone injections were alternated (Deca on Monday / Testosterone on Thursday) to avoid androgen build-up. By beginning Clenbuterol and Nolvadex/Proviron on week 25, this was noted to be an excellent contest prep cycle. 

Calorie (nonnutritional) The amount of heat required to raise the temperature of 1 g of pure water by 1 °C (for conversions, see Appendix A). 

To convert into dry or fresh weights or calorie content, the same coefficients are used in the equation, while conversion into protein requires different coefficients. The inverse relationship between AT, and K2 on die one hand and the ration on the other has been pointed out by several workers (Paloheimo and Dickie, 1966 Kitchell et al., 1977 Paloheimo and Plowright, 1979). 

The requirements set out in this publication and taken mainly from the report on the Nutrient Requirements of Poultry (NRC, 1994) are based on ME (AME), expressed as kilocalories (kcal) or megacalories (Meal)/kg feed. This energy system is used widely in North America and in many other countries. Energy units used in some countries are based on joules (J), kilojoules (kj) or megajoules (MJ). A conversion factor can be used to convert calories to joules, i.e. IMeal = 4.184 MJ 1MJ = 0.239 Meal and 1MJ = 239 kcal. Therefore, the tables of feedstuff composition in this publication show ME values expressed as MJ or kj as well as keal/kg. 

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