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1.
By using an UF apparatus equipped with new mineral membranes making it possible to reach a protein content of 21% and a T.S. content of 45%, making semi-hard cheese such as the French variety St. Paulin was studied. Properties of precheeses were characterized for defining optimum parameters of the proposed process. Acidification, addition of salt, renneting pH, and temperature were studied for their influence regarding the rheological behavior of the precheese and/or the organoleptic qualities of young and ripened cheese. Advantages of the process: increase of 199 of the cheese yield, no in vat processing, possible addition of flavouring substances are discussed. Performances observed with the new UF equipment (30 l of milk treated per hour and m2) and its cleanability offer sufficient reliability to envisage an industrial scale up.  相似文献   
2.
Polylactide (PLA) is the most used biodegradable and biobased food packaging polymer for rigid containers and films. However, its low ductility is a hurdle for increasing its applications in flexible food packaging. A solution is the use of additives. Palm oil deodorizer distillate (PODC) is revealed to be an excellent additive promoting PLA ductility. PODC is a by‐product of vegetable oil refining, which is available in stable quality and in sufficient amounts. Amorphous PLA/PODC blends had an elongation at break of around 130% and that of semi‐crystalline blends was still around 55% compared to the initial 5% of neat PLA. At the same time the PLA rigidity and high glass transition temperatures were kept. PODC was also a very efficient processing aid, allowing for film blow extrusion. The blends were stable in properties during six months without exudation. They complied with legal norms of Food Contact Materials (EU 10/2011) and induced no sensorial alteration of packed food. Therefore PODC is a very interesting alternative to common plasticizers for the production of flexible PLA packaging films. © 2016 Society of Chemical Industry  相似文献   
3.
The evolution of aroma compounds from orange juice made from concentrate and stored in glass, standard monolayer polyethylene terephthalate (PET 1), multilayer PET (PET 2) and plasma-treated PET (internal carbon coating) (PET 3) was investigated. Bottles were stored at room temperature (20 degrees C) under artificial light. Volatile compounds in orange juice samples and corresponding packaging materials were analysed at zero time and after 2, 3 and 5 months of storage. After 5 months of storage, from 0.2 to 0.3% of the initial amounts of limonene and beta-myrcene in the orange juice had been absorbed by the plastic packaging materials. Statistical analyses showed that the evolution of aroma compounds was strongly correlated to the duration of storage, but not to the type of packaging material. Indeed, whatever the stored orange juice samples, the same evolutions were observed, with a decrease in aldehydes and ketones, esters, aliphatic alcohols, sesquiterpene and monoterpene alcohols, and an increase in two aliphatic and monoterpene alcohols (i.e. furfural and 4-vinylguaicol). The results suggest that the losses of aroma compounds from the juice could be attributed to the high acidity of the matrix, implying acid-catalysed reactions. Finally, PET packaging materials and their corresponding oxygen permeabilities showed no correlation with the loss of aroma compounds.  相似文献   
4.
Qualitative and quantitative agreement between experimental and theoretical results for binary error probability for a coherent QPSK system degraded by intersymbol interference is given. The source of intersymbol interference is a delayed and attenuated replica of the transmitted signal which may represent several forms of observed multipath. Although the experimental results pertain to a particular 1 Gbit/s modem, the theory is applicable for any data rate.  相似文献   
5.
Eighteen students (K-11th grade) with emotional/behavioral disorders who were at-risk for change of placement to more restrictive settings participated. Construct validity of functional behavioral assessment (FBA) was assessed with a multifunction-multimethod matrix that showed excellent convergent and divergent agreement with combined FBA methods and functional analysis results. Treatment validity was assessed with random assignment to either a FBA with consultation condition (FBC) or to a behavioral consultation without FBA condition (BC). Growth curve analysis showed a significant decrease in inappropriate behavior from baseline to treatment for both treatment groups compared to a control group. The efficiency of teachers' implementation effected treatment validity. Effect sizes showed that regardless of treatment condition that interventions with good fidelity realized the largest effect (d = -1.14). Social and habilitative validity was assessed with telephone interviews conducted a year after treatment. Sixty-five percent attributed the students' problem behaviors to their thoughts or feelings, whereas only 25% attributed it to classroom variables. Many (57%) indicated the most helpful intervention would be individual counseling, whereas only 14% indicated a more involved classroom management plan would be useful. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
6.
The objective of this study is to examine the Fluid Structure Interaction (FSI) effect on transient dynamic response and failure of sandwich composite structures under impact loading. The primary sandwich composite used in this study consisted of a 6.35?mm balsa core and a multi-ply symmetrical plain weave 6?oz E-glass skin. Both clamped sandwich composite plates and beams were studied using a uniquely designed vertical drop-weight testing machine. There were three impact conditions on which these experiments focused. The first of these conditions was completely dry (or air surrounded) testing. The second condition was completely water submerged. The final condition was also a water submerged test with air support at the backside of the plates. The tests were conducted sequentially, progressing from a low to high drop height to determine the onset and spread of damage to the sandwich composite when impacted with the test machine. The study showed the FSI effect on sandwich composite structures is very critical such that impact force, strain response, and damage size are generally much greater with FSI under the same impact condition. As a result, damage initiates at much lower impact energy conditions with the effect of FSI. Neglecting to account for FSI effects on sandwich composite structures results in very non-conservative analysis and design. Additionally, it was observed that the damage location changed for sandwich composite beams with the effect of FSI.  相似文献   
7.
This article presents synthesis and mechanical characterization of carbon nanotube (CNT)‐reinforced syntactic foams. Following a dispersion approach (comprising ultrasonic, calendering, and vacuum centrifugal mixing), single‐ and multi‐walled functionalized CNTs (FCNTs) were incorporated into two foam composites containing various commercially available microballoon grades (S38HS, S60HS, and H50 from 3M). The FCNT‐reinforced composites were tested for compressive strength and apparent shear strength before and after hot/wet conditioning. The results showed that the FCNT‐reinforced composites' mechanical properties depended on the vacuum pressure used during processing. Compared with pristine and commercially available syntactic foam (EC‐3500 from 3M), the FCNT‐reinforced composites processed at high vacuum (0.2 kPa) showed significant increase in compressive strength and apparent shear strength before and after hot/wet conditioning. Dynamic mechanical analysis showed an increase of about 22°C in glass transition temperature for composites processed at high vacuum with 0.5 wt % FCNT and 45 wt % S38HS–5 wt % S60HS microballoons. Thermogravimetric analysis indicated water absorption and lower decomposition temperature for the FCNT‐reinforced composite mixed at atmospheric pressure, whereas no significant change was observed for the compound processed at high vacuum. Fracture analysis showed matrix failure for the composite processed at high vacuum and microballoon crushing for the composite mixed at atmospheric pressure. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012  相似文献   
8.
Microwave/millimeter-wave propagation in woods and forests was investigated at 9.6, 28.8, and 57.6 GHz. The experiments were repeated over the same transmission paths, under both summer and winter conditions, i.e. with tree in leaf and without leaves. Of particular interest were the range dependence, beam broadening, and depolarization of millimeter-wave beams in vegetation and frequency dependence of these effects. The experiments have shown, in particular, that the range dependence is characterized by a high attenuation rate at short vegetation depths and a reduced attenuation rate at large depth. For trees fully in leaf, the transition between the two regimes can be abrupt and the change in attenuation rate substantial. Just after the transition significant beam broadening (and depolarization) occurs. A theory of millimeter-wave propagation in vegetation was derived using transport theory  相似文献   
9.
Mitogaligin is a mitochondrion‐targeting protein involved in cell death. The sequence of the protein is unrelated to that of any known pro‐ or antiapoptotic protein. Mitochondrial targeting is controlled by an internal sequence from residues 31 to 53, and although this sequence is essential and sufficient to provoke cell death, the precise mechanism of action at the mitochondrial membrane remains to be elucidated. Here, by focusing on the [31–53] fragment, we first assessed and confirmed its cell cytotoxicity by microinjection. Subsequently, with the aid of membrane models, we evaluated the impact of the membrane environment on the 3D structure of the peptide and on how the peptide is embedded and oriented within membranes. The fragment is well organized, even though it does not contain a canonical secondary structure, and adopts an interfacial location. Structural comparison with other membrane‐interacting Trp‐rich peptides demonstrated similarities with the antimicrobial peptide tritrpcidin.  相似文献   
10.
The influence of packaging polymers (polypropylene or polystyrene) on the sensory and physicochemical characteristics of flavoured stirred yogurts with either 0% or 4%-fat content was investigated during the 28 days of storage at 4 °C. Regardless of the packaging type, complex viscosity and thickness perception increased during storage due to exopolysaccharide production, whereas the pH of yogurts decreased. Packaging type had a greater impact on 0%-fat yogurts than on 4%-fat yogurts for both sensory and physicochemical characteristics. During storage, 0%-fat yogurt conditioned in glass displayed the lowest aroma quantity decrease of the three types of packaging, in accordance with the olfactory properties. However, between the two polymer types, polystyrene packaging seemed to be preferable for limiting aroma compound losses and subsequent fruity note intensities, and for avoiding the development of odour and aroma defects. Less significant packaging effect was observed for 4%-fat yogurts.  相似文献   
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