Moisture loss

Pre-Production Handling. Salt-cured catde hides, when received at the tannery, are individually bundled to prevent excessive moisture loss. The bundles are tied with ropes that are later cut and removed the hides may be sorted for different weight or quaUty classification at this point. It is best to have hides of similar size and thickness in a given production batch to assure an even reactivity of the processing chemicals and to avoid frequent adjustments in the machinery to compensate for size and thickness variations. In the modem large tannery, the size/quaUty classification is not necessary because the hides arrive in carload quantities under specifications as to size, type, and month of slaughter. 

Briquettes have a heating value of 16.7-23.4 MJ/kg (7, 200-10,000 Btu/lb) or from 2—3 times the value of a typical brown coal primarily because of the moisture loss. 

The hygroscopic and humectant properties of com symps are of great importance in many apphcations. Depending on the type of symp and on the specific conditions of temperature and humidity, the products may either resist or facihtate moisture loss or moisture absorption. The abihty to attract moisture or retard its loss increases with increasing DE value. Prevention of moisture pickup is more characteristic of symps having low DE values. 

If water losses from the surrounding area are a major component of the total evaporative losses of the pond, then soil moisture conditions will be expected to be high. Under non-limiting soil moisture conditions vegetative moisture losses are often defined as "potential" losses. Evaporative losses in this case would not be expected to differ greatly from free water evaporation. The literature recommends... 

Clothing affects heat and moisture loss. Increasing the thickness or number of layers of clothing increases its insulating capability and reduces body heat loss. Clothing insulation is usually described with the do unit. Originally, t do was defined as the thermal resistance necessary for comfort while sedentary in a uniform still air environment of 21 °C. In conventional SI nomenclature I do has a thermal resistance of 0.155 K m-/W. Some ensembles do values and associated comfort temperatures are shown in Fig. 5.4. 

Barrier plastics using oxifluorination are widely used for foods. With these, barriers are needed to protect them against spoilage from oxidation, moisture loss or gain, and changes or losses in favor, aroma, or color. Most plastics can be considered barrier types to some degree, but as barrier properties are maximized in one area (as the gases such as O2, N2, or CO2), such other properties as permeability and moisture resistance diminish. 

Any material used for packaging natural cheeses must prevent moisture loss, maintain good product appearance, protect against microorganisms, and act as an oxygen barrier. Aluminum foil laminates provide this type of protection for cheese. Cream cheese is packed in lami-... 

When moisture loss was to be determined, each packet was weighed initially and at intervals of 2-4 weeks through the holding time. Moisture loss rates were calculated on the basis of grams/100 sq. in./24 hours (excluding the first 24 hours which constitutes a packaging material conditioning time). 

Mustard. Mustard has been packaged in PVDC-coated cellophane/ polyethylene pouch material which was recognized to have a 3-6 month shelf life. In this case, the moisture loss rate was diminished by using the PVDC-coated cellophane. The main drawback of this package was the moisture loss, since the flavor was not markedly changed by the oxygen traces allowed by the PVDC cellophane coating. 

The thermo-gravimetric (TG) and differential thermo-gravimetric (DTG) curves of the gingko nut shell are shown in Fig. 2 where the moisture losses take place up to 200°C followed by the pyrolysis reaction. Then, the major weight loss due to the main degradation occurs at around 360°C. This zone is referred to as the active pyrolysis zone where the evolution of volatile compounds occurs during decomposition of the primary hemi-cellulose and cellulose [5]. 

RCF itself is not a good barrier, nor can it be heat-sealed. Barrier and heat-sealing are conferred by coatings of nitrocellulose or polyvinylidene chloride on one or both sides. RCF has poor dimensional stability due to moisture loss or gain. Its principal use is in laminates and over wrapping. 

Figure 4.26 further illustrates why the 5% weight loss level was a good choice for this system. This level provides the best compromise between avoiding simple moisture loss if a lower level selects intersections too early in the TG experiments, or mixed-mechanistic... 

Powers, D.H. and Fox, C. (1957). A study of the effect of cosmetic ingredients, creams and lotions on the rate of moisture loss. Proc. Sci. Sect. Toilet Goods from the Skin Ass. 28 21. Racy, I. (1989). Drug Formulation. Wiley, New York. 

Migration of nitrosamines into consumer products can occur via direct contact of materials such as waxed containers, elastic and rubber etc.81. Morpholine is used extensively as an industrial solvent for wax formulations. The wax formulations are used for coating fruits and vegetables to prevent moisture loss and increase shelf-life of the products. Paper and cardboard packed with morpholine was also found to give rise to NDMA, as these packaging materials were found to be contaminated with NDMA as well. Besides this, rubber products also provided a migratory source for both nitrosamines and nitros-able amine precursors, as trace levels of NDEA and TV-nitrosodibutylamine (NDBA) have been reported in cured meats with amine-based accelerators in the rubber nettings82. 

Improper use of dryers to enhance cleaning can result in shorter staple because of fiber breakage and in lower marketable weight because of excessive moisture loss (40). Conclusions and recommendations for optimum dryer operation are as follows ... 

Containers, media and seeds. Glass Petri dishes, 100 x 15 cm, were used with two sheets of 75-mm Whatman 41 filter paper as the absorptive medium. Ten seeds of TAM105 wheat were placed in a radial pattern with the micropyle end toward the center between the two sheets of filter paper. Seeds were hand-selected for normal size and absence of damage. TAM105 was selected because it is the variety used in the ongoing field research on conservation tillage practices. The bottom section of each Petri dish cover was covered with a square of kitchen-type plastic wrap to retard moisture loss before the lid was pressed on. 

Since Ppore depends heavily on vapor pressure, this is expected to occur after some cooling takes place. As Ppore decreases and vapor condenses, the pressure difference is expected to force the oil within the structure. The condensation mechanism should predominate in thick samples and short frying times, since in thinner samples or longer frying times, moisture loss rate may diminish considerably (and therefore Pp0re)> allowing oil absorption to begin early. 

Gamble, M. H., Rice, P., and Selman, J. D. (1987). Relationship between oil uptake and moisture loss during frying of potato slices from c.v. Record U.K. tubers. Int. J. Food Sci. Technol. 22, 233-241. 

Some workers use 20 g air-dry soil, add 12 ml water and incubate in the dark at 22°C for 28 days, making good any moisture loss. Others extract the air-dry soil directly. The given method uses the fresh (or thawed) soil sample. The usual extractant for moist soils is 2 M KCI, but for dry soil, 10% m/v KCI (1.34 M) may be used. The amount of nitrite-N in the soil is usually so small that it can be neglected, but it will be incorporated in the amount of nitrate recorded. 

The volume deformations of concrete are shrinkage, which occurs under drying conditions, and creep, which is the additional deformation obtained under an applied stress. Creep does occur under saturated conditions (basic creep) but increases considerably under conditions of moisture loss. The picture is rather complicated in that creep is made up of a recoverable and irrecoverable portion on removal of the applied stress. 

Fig. 5.37 CaCl2 increases drying shrinkage of concrete, although the moisture loss is decreased (Shideler).

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