Because they contain water, an essential constituent, food products have to be refrigerated for their conservation. In refrigeration processes, heat transfers are generally coupled with mass transfers and phase changes of water, which have consequences on product quality and also on refrigerating equipment itself. Refrigeration processes have to put up with these phenomena. However, if they can be controlled they can be played as winning cards for better quality of food products. We discuss their characteristics and ways opened for their application in industry. | L'eau, constituant essentiel des produits alimentaires, rend nécessaire leur réfrigération ou leur congélation pour assurer leur conservation. Or, dans les procédés frigorifiques, les transferts de chaleur sont généralement couplés à des transferts de matière et à des changements de phase de l'eau, qui ont des conséquences sur la qualité des produits, mais également sur le fonctionnement des installations frigorifiques. Souvent subis, ces phénomènes peuvent au contraire, s'ils sont maîtrisés, devenir des atouts pour améliorer la qualité des produits. Nous présenterons donc leurs caractéristiques essentielles et les perspectives ouvertes par une meilleure maîtrise.

A key aspect of modeling contaminant uptake by animals is knowledge of the route taken by the contaminant to enter the animal. To determine the relative importance of food and water as Cd sources for benthic insects, we measured Cd accumulation by the predatory alderfly Sialis velata (Megaloptera) from either water alone or from chironomid prey (Cryptochironomus sp.). We determined that Cd uptake from prey was far more important than that from water. Chironomid prey fed to S. velata also appeared to take up the bulk of their Cd from food (meiobenthic organisms). The efficiency with which Cd was assimilated by the predator from its prey is high (50%) and comparable with values reported for several other insects. In the predator, Cd taken up from food was largely stored in gut tissues (as is the case for insect larvae in nature), whereas a greater proportion of the metal taken up from water was stored in other animal parts.

A novel method was used to estimate assimilation efficiencies (AEs) of dissolved and food associated PCBs (IUPAC 31, 49, and 153) by the Baltic Sea blue mussel (Mytilus edulis). Mussels were exposed to radiolabeled PCBs in a series of short-term toxicokinetic experiments at different algal food concentrations, both at apparent steady-state (ASS) and non-steady-state (NSS) conditions in respect to PCB partitioning between water and algae. The PCB AEs were calculated using a physiologically based bioaccumulation model where experimentally determined uptake and exposure rates at ASS and NSS conditions were combined into linear equation systems, which were solved for PCB AE from water and food. A positive relationship between PCB uptake and algae clearance by the mussels was observed for all three PCBs. The PCB AEs from both water and food increased with congener hydrophobicity (octanol/water partition coefficient [K(ow)]), but AEs decreased with increases in water pumping and filtration rate of the mussels, respectively, The average contribution of food-associated PCB to the total uptake also increased with K(ow) from approximately 30% for PCB 31 and PCB 49 to 50% for PCB 153, mainly as a consequence of increased sorption to the algal food.

Most of secondary crops in Indonesia are grown on dry land and rainfed lowland condition. Under dry land condition maize, peanut and soybean are planted in early wet season; and late wet season under rainfed lowland in order to make use of available moisture. However, insufficient rainfall often occurs during the growing season of the crops. Application of water pump is necessary to provide enough moisture for plants, particularly in intensification program of production system. Appropriate use of water pump is determined by its type and engine, discharge capacity, irrigation method, and crops. Several types of water pump have been developed by RIMC (previously, MORIF). This paper describes and reviews some technical specification of water pumps and irrigation method for maize, soybean, and peanut. Financial analysis of the water pump application is presented. A modified axial pump, 8 inches in diameter (PS-3), used under riverbank of less than 30 deg. in slope, suction lift of less than 4 m has discharge less than capacity of 134.1 cubic meter/h. Provided that water requirement for maize, peanut, and soybean were 420, 351, 271 mm/ha/season, respectively, application of the water pump would be able to irrigate 26.4 ha, 31.6 ha, and 40.9 ha of maize, peanut, and soybean crops, respectively. Effective use of the water pump in maize is attairable when 50 percent ETA of water requirement is supplied during the first four weeks after planting then all (100 percent ETA) of the water need should be supplied for the later stages of the crop. In peanut effective application is achievable when water is pumped every 14 days (70 mm/ha/season) during vegetative stage followed by more frequent every 7 days (35 mm/ha/season) pumping during generative stage. In soybean, application of water pump is recommended every 14 days beginning post emergence up to maturity stages. All of the mentioned practice water distribution apply furrow irrigation method. The result of the financial analysis for water pump rental business showed B/C ratio 2.06; IRR 106.55 percent and BEP 5.60 ha/season/year | Sebagian besar produksi tanaman pangan (palawija) di Indonesia pada lahan kering dan sawah tadah hujan. Pada umumnya, tanaman jagung, kacang tanah dan kedelai tumbuh pada awal musim hujan di lahan kering dan akhir musim hujan pada sawah tadah hujan. Selama satu tahun pertanaman, palawija mengalami keterbatasan ketersediaan lengas tanah. Intensifikasi pertanaman palawija pada lahan kering dan sawah tadah hujan perlu penggunaan pompa air. Penggunaan pompa air ditentukan antara lain: tipe pompa dan enjin, kapasitas pemompaan, cara pemberian air dan jenis tanaman. Beberapa tipe pompa air telah dikembangkan oleh Balittan atau Balitjas. Makalah ini menyajikan spesifikasi pompa air, cara pemberian air pada tanaman jagung, kedelai dan kacang tanah dan analisis finansial. Modifikasi pompa aksial (pompa sepak) ukuran diameter 8 (PS-3) inchi pada kondisi tebing sungai kurang dari 30 derajat, daya capai kurang dari 4 m, dan mempunyai kapasitas pemompaan 134,1 meter kubik/jam. Pemberian air dengan pompa ini (420 mm/ha/musim, jagung); (351 mm/ha/musim, kacang tanah); (271 mm/ha/musim, kedelai) adalah cukup untuk mengairi seluas 26,40 ha tanaman jagung; 31,58 ha tanaman kacang tanah; dan 40,93 ha tanaman kedelai. Kinerja pompa ini menjadi baik dan dapat meningkatkan hasil dan berat berangkasan pada saat pemberian air 50 persen ETA mulai perkecambahan sampai dengan pemantapan tumbuh untuk tanaman jagung setiap 14 hari sekali (70 mm/ha/musim) pada fase vegetatif kemudian 7 hari sekali (35 mm/ha/musim) pada fase generatif untuk tanaman kacang tanah, setiap 14 hari sekali pada saat fase perkecambahan sampai dengan menjelang panen untuk tanaman kedelai. Metode pemberian air umumnya adalah alur terbuka. Analisis finansial untuk pemilik pompa air menunjukkan bahwa B/C ratio 2,06, IRR 106,55 persen dan BEP 5,60 ha/musim/tahun