In situ prepared polyamide 6/DOPO-derivative nanocomposite for melt-spinning of flame retardant textile filaments

Abstract A novel flame retardant polyamide 6 (PA6)/bridged 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO)-derivative (PHED) nanocomposite textile filament yarns were developed. The scalable production approach includes in situ water-catalyzed ring-opening polymerization of e-caprolactam in the presence of the flame retardant PHED followed by melt-spinning of nanocomposite filament yarns and production of knitted fabrics. The specific chemical structure of the PHED additive enabled its excellent miscibility with molten e-caprolactam and the uninterrupted polymerization of e-caprolactam. The produced PA6/PHED nanocomposite was characterized by the preserved molecular structure of the polyamide 6 and uniformly distributed nano-dispersed FR at concentrations of 10 and 15 wt %. The PA6/PHED nanocomposite structure was successfully preserved after the melt-spinning processing. The PA6 nanocomposite filament yarns at the applied 15 wt %. loading of PHED showed (a) increased thermo-oxidative stability compared to neat PA6 up to 500 °C, with a 43% higher residue at 500 °C and (b) self-extinguishment of fiber strand and knitted samples within 1 s in standard vertical flame spread tests (ASTM D6413), followed by the significant reduction of the melt-dripping and the melt-drop flammability. Additionally, 1.2 mm-tick PA6/PHED bar samples achieved a V0 rating in UL94 vertical burning test at the applied 10 wt % concentration of PHED. This innovative and scalable approach could pave the way for the production of new-generation nanocomposite PA6 filament yarns with self-extinguishing properties at the macro-scale, which would be highly beneficial for increasing fire safety, whilst maintaining the use of a DOPO derivative at the minimum level

Livestock Farming in Rural Areas

Serbia has favorable natural conditions for the development of livestock despite the third decade of recording negative trends. Autochthonous breeds are closely connected to geographical and cultural diversity in Serbian rural areas. Unfortunately, number of autochthonous breeds significantly decreased during the last 5 - 6 decades. This is the potential threat for further decrease in production and loss of agro-biodiversity in Serbia. There are 400 - 500 companies in Serbia which are involved in the breeding of rare, autochthonous, domestic animal breeds. According to the 2012 Agricultural Census, total number of cattle in the Republic of Serbia on the family farms had a share of 91.7%. In the last ten years, poultry and pig production is 20% of total number of pigs and 37% of poultry is grown on the farms of legal entities. The paper aims to point out the need for defining measures that should be adopted in the near future (special programs and developing legal, administrative and technical instruments) for preservation and support of the animal resources of Serbia

Surface and thermomechanical characterization of polyurethane networks based on poly(dimethylsiloxane) and hyperbranched polyester

Two series of polyurethane (PU) networks based on Boltorn® hyperbranched polyester (HBP) and hydroxyethoxy propyl terminated poly(dimethylsiloxane) (EO-PDMS) or hydroxy propyl terminated poly(dimethylsiloxane) (HPPDMS), were synthesized. The effect of the type of soft PDMS segment on the properties of PUs was investigated by Fourier transform infrared spectroscopy (FTIR), contact angle measurements, surface free energy determination, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), atomic force microscopy (AFM), dynamic mechanical thermal analysis (DMTA) and differential scanning calorimetry (DSC). The surface characterization of PUs showed existence of slightly amphiphilic character and it revealed that PUs based on HP-PDMS have lower surface free energy, more hydrophobic surface and better waterproof performances than PUs based on EO-PDMS. PUs based on HPPDMS had higher crosslinking density than PUs based on EO-PDMS. DSC and DMTA results revealed that these newlysynthesized PUs exhibit the glass transition temperatures of the soft and hard segments. DMTA, SEM and AFM results confirmed existence of microphase separated morphology. The results obtained in this work indicate that PU networks based on HBP and PDMS have improved surface and thermomechanical properties

Mogućnost izbora između alternativnih investicija u preduzeću

Expected profitability level of particular alternative investments could be quite different, so in the case of some investments it is even lower than the one investor likes to obtain for the total invested amount of money. In that situation it is necessary to be calculated expected minimal profitability level, which should serve as the basis in the process of selection the possibly accepted investment projects. In the process of investment decision making it is not only the question should some investment has to be implemented, but it has frequently appeared a problem of selection the best project between two or more alternative investment projects in an enterprise. The investor will decide to implement those investment projects, which have real possibilities for as great as possible contribution to the enterprise development goal. That is why the solving of such problem has been deduced onto the economic analysis, calculation of economic parameters as well as their comparison among alternative investments. Such problem could be solved according to the methodological procedure applied in the models analyzed in this paper. On the basis of determined indicators, the investor could make decision on economically most profitable project.Očekivani stepen rentabilnosti pojedinih alternativnih investicija može da bude dosta različit, tako da je kod nekih investicija čak niži od stepena rentabilnosti koji investitor želi da postigne za ukupno uložena sredstva. Tada je potrebno da se utvrdi željeni minimalni stepen rentabilnosti, koji bi trebao da posluži kao osnova pri izboru mogućih investicionih projekata. Prilikom donošenja investicionih odluka ne postavlja se samo pitanje da li neka investicija treba da bude realizovana, već se često javlja problem izbora između dve ili više alternativnih investicionih projekata u preduzeću. Investitor će se odlučiti za realizaciju onih investicionih projekata za koje postoje realne mogućnosti da bi mogli u najvećoj meri da doprinesu ostvarenju cilja razvoja preduzeća. Zato se rešavanje ovakvog problema svodi na ekonomsku analizu, utvrđivanju ekonomskih pokazatelja i njihovom poređenju za alternativne investicije. Dati problem se može rešiti prema metodološkom postupku analiziranih modela u ovom radu. Na osnovu utvrđenih pokazatelja investitor može da donese odluku o ekonomski najcelishodnijem projektu

Plasma treatment in textile industry

Plasma technology applied to textiles is a dry, environmentally- and worker-friendly method to achieve surface alteration without modifying the bulk properties of different materials. In particular, atmospheric non-thermal plasmas are suited because most textile materials are heat sensitive polymers and applicable in a continuous processes. In the last years plasma technology has become a very active, high growth research field, assuming a great importance among all available material surface modifications in textile industry. The main objective of this review is to provide a critical update on the current state of art relating plasma technologies applied to textile industryFernando Oliveira (SFRH/BD/65254/2009) acknowledges Fundacao para a Cioncia e Tecnologia, Portugal, for its doctoral grant financial support. Andrea Zille (C2011-UMINHO-2C2T-01) acknowledges funding from Programa Compromisso para a Cioncia 2008, Portugal

Régularisation de problèmes inverses à l'aide de l'équation de diffusion, avec application à l'assimilation variationnelle de données océaniques

En assimilation de données, les modèles de corrélation permettent de caractériser les structures d'erreurs pour les variables définies sur une grille numérique. L'équation de diffusion fournit un cadre flexible et efficace pour représenter des fonctions de corrélation pour des problèmes de grande dimension tels que ceux rencontrés en assimilation variationnelle pour l'atmosphère ou l'océan. Des produits d'opérateurs de diffusion implicite 1D sont ensuite utilisés pour construire des modèles de corrélation en dimension deux et trois pour des configurations globales d'un système d'assimilation variationnelle pour le modèle océanique NEMO. Leurs performances sont comparées au modèle de diffusion explicite existant, et des exemples de structures de corrélation où les échelles sont soit paramétrées, soit issues d'une méthode d'ensemble, sont montrés. Enfin, les performances de différentes techniques de normalisation sont comparées.Correlations models are required in data assimilation to characterize the error structures of variables defined on a numerical grid. The diffusion equation provides a flexible and efficient framework for representing correlation functions for problems of large dimension such as those encountered in variational atmospheric or ocean data assimilation. Products of 1D implicit diffusion operators are then used for constructing two-and three-dimensional correlation models for global configurations of a variational assimilation systems for the NEMO ocean model. Their efficiency are compared to the exixting explicit diffusion model, and examples using an ensemble method. Finally, the efficiency of different normalization techniques are compared

The effects of feed additive, selenium source, polyphenol, lysine level, and sow lactation feeder type on pigs

Doctor of PhilosophyDepartment of Animal Sciences and IndustryJordan T GebhardtMichael D TokachChapter 1 is a review paper that summarized the effects of 14 feed additive categories on grow-finish pig growth performance and carcass characteristics. The summarized data suggests that most results were positive for each feed additive; however, the magnitude of improvement varied, and most were not statistically significant. For ADG, DFM, Cu, L-carnitine, and multi-enzymes showed relatively large positive effects (> 2.1% improvement) across a reasonable number of articles. Acidifiers, betaine, CLA, multi-enzymes, DFM, L-carnitine, and yeasts showed relatively large positive effects (> 2.5% improvement) on improving G:F. Moreover, except for betaine, Cr, CLA, and L-carnitine, most feed additives showed little and non-significant effects on BF thickness (< 1.7% improvement). Chapter 2 utilized a total of 3,888 nursery pigs to evaluate selenium source on nursery pig growth performance, serum and tissue selenium concentrations, and serum antioxidant status. The results suggested that, compared to sodium selenite and selenium yeast, hydroxy-selenomethionine (OH-SeMet) had greater bioavailability as indicated by increased serum and tissue selenium concentration; however, antioxidant status was similar between treatments and OH-SeMet tended to reduce growth performance compared with pigs fed sodium selenite. Chapter 3 utilized a total of 300 nursery pigs to evaluate the effects of using polyphenols as a partial replacement for vitamin E in nursery pig diets. Increasing vitamin E equivalence improved feed efficiency which may be related to the improved antioxidant status. Providing additional vitamin E equivalence above the basal vitamin E requirement through either vitamin E or polyphenol showed similar benefits. Thus, the polyphenol used in this study can be used as an effective replacement for vitamin E supplemented above the basal requirement. Chapter 4 utilized a total of 702 90-kg finishing pigs to evaluate nutritional strategies for slowing growth rate then inducing compensatory growth. We found feeding Lys-restricted diets reduced the ADG and G:F of finishing pigs. Moreover, compensatory growth can be induced in Lys-restricted finishing pigs, but the duration of restriction and recovery influences the magnitude of compensatory growth. Chapter 5 utilized a total of 600 sows to evaluate sow feeder type and drip cooling on sow bodyweight, litter performance, and feeder cleaning criteria in a hot and humid environment. We determined that sows used SowMax feeders had reduced feed disappearance with no effects on sow and litter performance compared to a PVC tube feeder, and drip cooling improved sow and litter performance during summer in a hot and humid environment

Functionalization of cellulose fibres with DOPO-polysilsesquioxane flame retardant nanocoating

The preparation of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide-functionalised polysilsesquioxane (Si-DOPO)-coating was described and its flame retardant efficiency for cotton fabric was thoroughly investigated. The 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide\u2013vinyltrimethoxysilane (DOPO\u2013VTS) was synthesized and applied to cotton fabrics at different concentrations using a sol\u2013gel process. The structure of the synthesized DOPO\u2013VTS was characterized using Fourier-transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. The characteristics of the Si-DOPO coatings formed on the cotton fibres were investigated using X-ray photoelectron spectroscopy, time-of-flight-secondary ion mass spectrometry and scanning electron microscopy. The flame retardant properties of the Si-DOPO-coated cotton samples were evaluated by thermogravimetric analyses, vertical flame spread tests and cone calorimetry analyses. The Si-DOPO coating increased the thermo-oxidative stability of the cotton fibres by increasing the stability of the protective char and inhibited cellulose fibres degradation. The Si-DOPO coating did not decrease the time of flaming combustion but did completely stop the vigorous combustion of the fibres. The results also suggest that the flame retardation by the Si-DOPO coating is due to the quenching of active radicals from the decomposing cellulose and the cellulose phosphorylation by the DOPO component as well as the silicon oxide formation by the silsesquioxane component on the fibre surface. These findings indicate that the flame retardant efficiency of the Si-DOPO coating can be ascribed to the combined activity of phosphorus acting in both gas and condensed phases and silicon acting in the condensed phase