Cold contacts

A thermopile sensor generates an output voltage that depends on the temperature difference between its hot and cold contacts. For infrared temperature measurement, the hot contacts are normally thermally insulated and placed on a thin membrane, whereas the cold contacts are thermally connected to the metal housing. Infrared radiation, which is absorbed by the hot contacts of the thermopile, causes a temperature difference between hot and cold contacts. The resulting output voltage is a measure for the temperature difference between radiation source and cold contacts of the thermopile sensor. It is therefore necessary to measure also the temperature of the cold contacts by an additional ambient temperature sensor in order to determine the temperature of the radiation source. 

Working conditions (noise, dust, heat, cold, contact with irritating or unhealthy substances,... 

Beer, on the other hand, is produced by more complex biochemical and technological processes, which all affect its flavor. Yeast amino acid metabolism, a key to the development of beer flavor as described earlier, is affected by process temperature and use of cell immobilization techniqnes. Therefore, technologies based on these features as well as other process conditions and strain selection have been developed to control beer flavor. The combination of immobilized yeast and low-temperature primary fermentation was found to produce beers with low diacetyl amounts, therefore indicating potential of low-cost industrial application since maturation is a high-energy-consuming process. Finally, Perpete and Collin showed that during alcohol-free beer production, the enzymatic reduction of worty flavor (caused by Strecker aldehydes) by brewer s yeast was improved by cold contact fermentation. 

Perpete P. and Collin S. How to improve the enzymatic worty flavour reduction in a cold contact fermentation. Food Chemistry 70 (4) (2000) 457-462. 

Fermentation itself can be stopped when the desired alcohol content is reached, either by removal of yeast (filtration, centrifugation) or by their deactivation (pasteurization). A further possibility is to create fermentation conditions, which suppress yeast metabolism (Narziss, Miedaner, Kem, Leibhard, 1992). The most practical tool to suppress yeast metabolism is low temperature. This method is called the cold contact process (CCP) , which ensures very slow ethanol prodnction while other metabolic processes, snch as formation of higher alcohols and esters or reduction of carbonyls, may exhibit moderate activities (Perpete Collin, 1999). After interrupting the fermentation at an alcohol content less than 0.5% voL, the AFB is usually matured for at least 10 days at 0-1 °C to enrich flavour and improve the colloidal stability. Then the product is filtered, carbonated, stabilized and sterilized (Branyik, Silva, et al., 2012 Burberg Zamkow, 2009). 

Perpete, R, Collin, S. (1999). Fate of the worty flavours in a cold contact fermentation. Food Chemistry, 66, 359-363. 

A potential injury source arising from exposure to a machine, equipment, or a process system that contains sharp surfaces, sharp projections, heat, or extreme cold. Contact Stress... 

Cold contact Cold urticaria 2-5 min 1-3 Cold objects (ice), fluid (bath), wind or air... 

Localized cold contact urticaria Immediate cold urticaria Delayed cold urticaria Cold-dependent dermographic urticaria Localized cold urticaria Localized reflex cold urticaria Perifollicular cold urticaria Familial delayed cold urticaria Generalized cold urticaria Cold wind and air urticaria Cholinergic cold urticaria... 

Lesions of delayed cold urticaria (Table 4) appear after a latency of 3 h to maximally 24 h after cold exposure and can persist over many hours. In cold induced dermographic urticaria, small wheals appear in skin exposed to the cold only after additional mechanical irritation such as scratching or rubbing. Localized cold urticaria can only be elicited in certain skin areas. In cold reflex urticaria, small transient, but also larger wheals develop only in the vicinity of the area of contact. Follicular cold urticaria is a rare, recently described subtype of cold urticaria, with wheals appearing at sites of cold contact in a perifollicular distribution. In autosomal-dominant delayed familial cold urticaria, deep red swellings appear only after 9-18 h at sites of contact, without previous early reactions. 

To put the N -iso transition line into a nonequilibrium situation, we force it to move at a velocity, v, through a temperature gradient G v. The temperatures at the hot and cold contacts are chosen so that Jchi is in the middle of the field of view of a polarizing microscope (Figure 15.1). We force v on the interface by displacing the sample at speed, —v, toward the cold contact. As the transition temperature is fixed in the lab frame, displacing the sample toward colder temperatures forces the N -iso phase boundary to move toward the hot contact to maintain Tcu. 

Graft copolymers of polychloroprene and a cationic starch imparted wet-strength properties to paper when applied as wet-end additives to pulp, and they also exhibited cold-contact adhesive properties without pressure being applied. Poly(styrene-n//-acrylonitrile) has been grafted onto starch. ... 

The Cold Contact Method as a Simple Drug Interaction Detection 162 System... 

Figure 3 (a) Cold contact observation results (i) the cociystal grew from clavulanate crystal to amoxicillin solution in NaOH> (ii) amoxicillin melted at 194°C, clavulanate oxidized at 203°C> while the cocrystal oxidized least, (b) DSC data of amoxicillin trihydiate (top), potassium clavulanate (middle), and the physical mixture 1 1 (bottom). The exothermic peak of I 1 mixture shows that amoxicillin and clavulanate overlay and become 1 peak at 202°C which indicates a solid solution interaction. 

Figure 4. Cold contact preparation (1) solution A dropped on clean object glass, (2) let it be crystallized, (3) then solution B dropped near the crystal A, (4) if it interacted, the new habit with different melting point will be formed on the contact area.

The results prove strong relation between cold contact method data and DSC. The simple eutectic interaction of pseudoephedrine hcl-acetaminophen, the peri-tectic interaction between methampyrone-phenylbutazon, and solid solution formation between amoxicillin trihydrate-clavulanate have been early detected by this simple method. Therefore, this method has high possibility to be used as a simple method to evaluate the other drug interactions [10—13]. 

The acceptability of the cold contact method as a simple method to identify the physical interaction of drug combination has been proved by coherency between the cold contact method data with the DSC evaluation. 

I. Nugrahani, S. N. Soewandhi, S. Asyarie, and S. Ibrahim, The cold contact method to detect physical interaction of amoxicillin-clavulanate, in Proceeding of International Chemical Conference and Seminar, Yogyakarta, Indonesia, 2007. 

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