• Title/Summary/Keyword: premix

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Laminar Burning Velocities and Flame Stability Analysis of Hydrocarbon/Hydrogen/Carbon Monoxide-air Premixed Flames (탄화수소/수소/일산화탄소-공기의 예혼합화염에서 층류화염전파속도와 화염안정성)

  • Vu, Tran Manh;Song, Won-Sik;Park, Jeong;Lee, Kee-Man
    • Journal of the Korean Society of Combustion
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    • v.16 no.2
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    • pp.23-32
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    • 2011
  • To investigate cell formation in hydrocarbon/hydrogen/carbon monoxide-air premixed flames, the outward propagation and cellular instabilities were experimentally studied in a constant pressure combustion chamber at room temperature and elevated pressures. Unstretched laminar burning velocities and Markstein lengths of the mixtures were obtained by analyzing high-speed schlieren images. In this study, hydrodynamic and diffusional- thermal instabilities were evaluated to examine their effects on flame instabilities. The experimentally-measured unstretched laminar burning velocities were compared to numerical predictions using the PREMIX code. Effective Lewis numbers of premixed flames with methane addition decreased for all of the cases; meanwhile, effective Lewis numbers with propane addition increased for lean and stoichiometric conditions and increased for rich and stoichiometric cases for hydrogen-enriched flames. With the addition of propane, the propensity for cell formation significantly was diminished, whereas cellular instabilities for hydrogen-enriched flames were promoted. However, similar behavior of cellularity was obtained with the addition of methane to the reactant mixtures.

Effect of Growell on Performance, Organ Weight and Serum Trace Element Profile of Broilers

  • Kalorey, D.R.;Kurkure, N.V.;Sakhare, P.S.;Warke, Subhangi;Ali, Murtuza
    • Asian-Australasian Journal of Animal Sciences
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    • v.14 no.5
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    • pp.677-679
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    • 2001
  • Effect of Growell a herbomineral premix was evaluated on performance, organ weight, humoral immune response, tissue and serum trace element profile of boilers. Day old 50 Babcock broiler chicks were randomly divided in two groups (C and T) and reared on deep litter system for 6 weeks of age. Chicks from group C were given basal diet while chicks from T group were fed basal diet supplemented with Growell at the rate 0.35 g/Kg. The chicks were vaccinated with Lasota strain of NCDV at $4^{th}$ and $28^{th}$ day of age. The birds receiving Growell treatment had higher body weight with better feed conversion ratio as compare to that of control chicks. Growell treatment had significantly reduced per cent weight of spleen and kidney, whereas that of bursa was increased. There was no effect of treatment on relative weight of thymus. HI antibody titer against NCDV in Growell treated chicks were higher as compare to untreated chicks indicating better humoral immune status. Growell treatment had no effect on serum Fe and Zn concentration. Dietary supplementation of Growell had significantly increased iron content of liver, kidney and muscle; zinc content of kidney and muscle; copper content of kidney and muscle and Mn content of kidney. Growell treatment improved the body weight, FCR and humoral immune status of broilers. Similarly, deposition of trace minerals in various organs was also increased in comparison to control.

Effects of Using Monensin and Different Levels of Crude Protein on Milk Production, Blood Metabolites and Digestion of Dairy Cows

  • Ghorbani, B.;Ghoorchi, T.;Amanlou, H.;Zerehdaran, S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.24 no.1
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    • pp.65-72
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    • 2011
  • Twenty-four Holstein dairy cows were used to evaluate the single and combined effects of different levels of crude protein (CP) and monensin treatment during early lactation on blood metabolites, milk yield and digestion of dairy cows. The experiment was designed as a completely randomized block with a $3{\times}2$ factorial arrangement of treatments. The factors were three concentrations of CP supplement (19.5, 21.4, and 23.4% of dry matter) and two levels of monensin (0 and 350 mg per cow per day). The experiment consisted of three phases and each phase was 3 wk in length. Monensin did not affect milk yield, lactose, solids-non-fat (SNF), blood glucose, triglyceride and DMI, but increased blood cholesterol, blood urea nitrogen (BUN), insulin and reduced blood ${\beta}$-hydroxybutyrate (BHBA), milk fat and protein percentage. Monensin premix significantly decreased rumen ammonia, but rumen pH and microbial protein synthesis were not affected by monensin treatment. Increasing dietary CP improved milk and protein production, but did not alter the other components of milk. Digestibility of NDF, ADF, CP were improved by increasing dietary CP. Increasing dietary CP from 19.5 to 21.4% had no significant effect on ruminal ammonia, but increasing CP to 23.4% significantly increased ruminal ammonia. There was a linear relationship between level of crude protein in the diet and volume of urine excretion. Microbial protein synthesis was affected by increasing CP level; in this way maximum protein synthesis was achieved at 23.4% CP.

Sustainable self compacting acid and sulphate resistance RAC by two stage mixing approaches

  • Rajhans, Puja;Kisku, Nishikant;Nayak, Sanket;Panda, Sarat Kumar
    • Advances in concrete construction
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    • v.9 no.1
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    • pp.55-70
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    • 2020
  • In this research article, acid resistance, sulphate resistance and sorptivity of self compacted concrete (SCC) prepared from C&D waste have been discussed. To improve the above properties of self compacted recycled aggregate concrete (SCRAC) along with mechanical and durability properties, different two stage mixing approaches (TSMA and TSMAsfc) were followed. In the proposed two stage mixing approach (TSMAsfc), silica fume, a proportional amount of cement and a proportional amount of water were mixed in premix stage which fills the pores and cracks of recycled aggregate concrete (RAC). The concrete specimen prepared using above mixing approaches were immersed in 1% concentration of sulphuric acid (H2SO4) and magnesium sulphate (MgSO4) solution for 28, 90 and 180 days for evaluating the acid resistance of SCRAC. Experimental results concluded that the proposed two stage mixing approach (TSMAsfc) is most suitable for acid resistance and sulphate resistance in terms of weight loss and strength loss due to the elimination of pores and cracks in the interfacial transition zone (ITZ). In modified two stage mixing approach, the pores and cracks of recycled concrete aggregate (RCA) were filled up and make ITZs of SCRAC stronger. Microstructure analysis was carried out to justify the reason of improvement of ITZs by electron probe micro analyser (EPMA) analysis. X-ray mapping was also done to know the presence of strength contributing elements presents in the concrete sample. It was established that SCRAC with modified mixing approach have shown improved results in terms of acid resistance, sulphate resistance, sorptivity and mechanical properties.

Quality Characteristics of Pancake Premix with Dioscorea batatas Powder by Steaming Process (증숙 공정을 이용한 마 분말 첨가 팬케익 프리믹스의 품질특성)

  • Kang, Moon-Kyung;Kim, Jin-Sook;Kim, Gi-Chang;Choi, Song-Yi;Kim, Kyung-Mi
    • Korean journal of food and cookery science
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    • v.32 no.5
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    • pp.593-599
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    • 2016
  • Purpose: The aim of this study was to investigate the quality characteristics of pancake mix containing Dioscorea batatas powder. In order to optimize the formulation ratio of the pancakes, steaming process was used to develop health-oriented products by adding D. batatas saponin and improved blood circulation. Methods: D. batatas powder was substituted into pancake at 0%, 10%, 20%, 30% and 40% of the total weight of wheat flour. Results: The viscosity of batter tended to increase as the ratio of D. batatas powder increased whereas the measures of spreadability were not significantly changed. In addition, the L-value and b-values decreased gradually while a-value increased. Among the textural characteristics cohesiveness tended to increase in proportion to the amount of D. batatas powder. Conclusion: The results of the sensory evaluation showed that pancake made with 20% D. batatas powder was the most preferable in appearance, flavor, taste, texture, and overall acceptability.

Effect of Chemical Parameters on Aqueous Acrylamide Gelcasting (수용성 Acrylamide 겔캐스팅에 대한 화학적 변수의 영향)

  • Yun, Seog-Eun;Woo, Sang-Kuk;Bae, Kang;Kim, Dong-Pyo
    • Applied Chemistry for Engineering
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    • v.10 no.5
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    • pp.748-753
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    • 1999
  • In gelcasting process of the Si powder slurry mixed with acrylamide monomers, it was characterized the effects of chemical parameters such as monomers and additives(polymerization initiator, catalyst and dispersant), Si powder and humidity at drying on processing parameters such as viscosity and idle time as well as on shrinkage and mechanical strength of green bodies. Generally, idle time decreased as initiator and catalyst amounts were increased, but rather depended on initiator. Idle times of the slurries greatly decreased to less than 1/2 time of the premix solutions in which gelation was delayed at higher MBAM portion as a crosslinking monomer. And fluidity of the slurries became worse at greater than 0.6 wt % dispersant. The green bodies showed only less than 7% of linear shrinkage without crack and distortion when dried for longer than 300 hrs under 98% humidity. Typically, the dried bodies containing 40, 50 vol % of Si powder displayed 64 and 36 Mpa in average, respectively.

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Sensory Profiles of Koumiss with added Crude Ingredients extracted from Flaxseed (Linum usitatissimum L.)

  • Kim, Dong-Hyeon;Jeong, Dana;Song, Kwang-Young;Chon, Jung-Whan;Kim, Hyunsook;Seo, Kun-Ho
    • Journal of Dairy Science and Biotechnology
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    • v.35 no.3
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    • pp.169-175
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    • 2017
  • Recently, the health-promoting effects of functional foods have been shown to prevent nutrition-related diseases, improve physical and mental well-being, satisfy hunger, and provide necessary nutrients for the human body. Koumiss is a common type of fermented mare's milk that has been shown to have beneficial therapeutic effects on cardiovascular disease, tuberculosis, and diarrhea as it can nourish vessels, relieve ill mood, and improve digestion. Hence, in this study, we aimed to prepare health-promoting koumiss using different concentrations of flaxseed (Linum usitatissimmum L.), which has the potential to control heart disease, hypertension, inflammation, and lung function. The pH was decreased to around 4.42-4.43, whereas the total anthocyanin (TA) content was increased to around 0.78~0.82% after fermentation of the koumiss premix. There were no significant differences in pH and TA among the three groups, including the control group. In sensory profile analysis, the taste, flavor, color, texture, and overall acceptability decreased in proportion to the added amount of flaxseed. These findings provided the first data describing the effects of flaxseed on koumiss fermentation, establishing a basis for commercial-scale production of koumiss containing fermented flax seed and for improving the health-promoting activity of koumiss.

PAHs Formation Characteristics and Fullerenes $(C_{60},\;C_{70})$ Synthesis in a Low-Pressure $C_6H_6/Ar/O_2$ Flame (저압 $C_6H_6/Ar/O_2$ 화염에서 PAHs 생성 특성 및 플러렌$(C_{60},\;C_{70})$ 합성에 대한 연구)

  • Lee, G.W.;Kim, Y.W.;Hwang, J.;Jrung, J.;Choi, M.
    • Journal of the Korean Society of Combustion
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    • v.7 no.4
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    • pp.36-44
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    • 2002
  • Carbon molecules with closed-cage structures are called fullerenes $(C_{60},\;C_{70})$, whose applications include super-conductors, sensors, catalysts, optical and electronic device, polymer composites, and biological and medical materials. The synthesis of fullerenes has been recently studied with low-pressure benzene/argon/oxygen flames. The formation of fullerene is known as molecular weight growth processes of PAHs (polycyclic aromatic hydrocarbon). This study presents results of PAHs and fullerene measurements performed in a low-pressure benzene/argon/oxygen normal co-flow laminar diffusion flame. Through the central tube of the burner, benzene vapors carried by argon are injected. The benzene vapors are made in a temperature-controlled bubbler. The burner is located in a chamber, equipped with a sampling system for direct collection of condensable species from the flame, and exhausted to a vacuum pump. Samples of the condensable are analyzed by HPLC (High Performance Liquid Chromatography) to determine the yields of PAHs and fullerene. Also, we computed mole fraction of fullerene and PAHs in a nearly sooting low pressure premixed, one-dimensional benzene/argon/oxygen flame (equivalence ratio ${\Phi}=2.4$, pressure=5.33kPa). The object of computation was to investigate the formation mechanism of fullerenes and PAHs. The computations were performed with CHEMKIN/PREMIX. As a result of this study, fullerenes were synthesized in a low pressure (20torr) $C_6H_6/Ar/O_2$ flames and the highest concentration of fullerene was detected just above the visible surface of a flame.

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Effects of Feeding Licury (Syagrus coronate) Cake to Growing Goats

  • Borja, M.S.;Oliveira, R.L.;Ribeiro, C.V.D.M.;Bagaldo, A.R.;Carvalho, G.G.P.;Silva, T.M.;Lima, L.S.;Barbosa, L.P.
    • Asian-Australasian Journal of Animal Sciences
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    • v.23 no.11
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    • pp.1436-1444
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    • 2010
  • The objectives of this study were to determine the highest inclusion of licury (Syagrus coronate) cake in the diet of growing Boer goats without adverse effects on intake and digestibility and to determine its effects on ingestive behavior and physiological responses. Twenty entire, one year old 3/4 Boer goats, 18.1 kg (DS = 2.2) average body weight (BW), were allocated to dietary treatments in a completely randomized design. Each animal was confined in a $1.0\;m^2$ pen with a suspended floor and given ad libitum access to clean, fresh water. Diets were formulated to meet NRC (2007) requirements and the ingredients were: 50% of Tifton-85 (Cynodon sp.) hay, corn meal, soybean meal, mineral and vitamin premix, and licury cake. The treatments were: i) no addition of licury cake to the diet, ii) 15% (DM basis) addition of licury cake, iii) 30% licury cake and, iv) 45% licury cake. The experiment lasted for 17 days; the first 10 days were used to adapt the animals to the diets and facilities. The inclusion of licury cake increased the fiber concentration of the diets; however, there was no effect on either dry matter (DM) or organic matter (OM) intake. There was a linear increase (p<0.05) in the EE content of the diet as the addition of licury cake increased; however, EE intake did not differ (p>0.05) between treatments. The digestibility of non-fibrous carbohydrates (NFC) decreased with increasing inclusion of licury cake, as did NFC intake. The efficiency of ingestion of DM and NDF presented a negative quadratic effect with the inclusion of licury cake. Results from this study indicate that licury cake can be fed to goats at up to 45% of the diet without adverse effects on either intake or digestibility.

Modeling of Laminar Burning Velocities for Hydrocarbon and 7ethanol Fuels by Using Detailed Chemical Reaction Mechanisms (상세화학반응기구를 이용한 탄화 수소 및 메탄을 층류 화염 속도 모델링)

  • Bae, Sang-Su;Min, Gyeong-Deok
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.25 no.10
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    • pp.1303-1310
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    • 2001
  • In order to be applicable to the combustion modelling of stratified charged combustion like that of - lean burn and GDI engine, the correlations of laminar burring velocities fur several hydrocarbon fuels and methanol are needed over a wide range of equivalence ratio, pressure and temperature. In this study, these correlations are modeled in the 1311owing form based on the experimental and Muller\`s modeling results for several fuels, where $\alpha$, ξ, and ξ are functions of pressure and temperature, $S_{L}$ =$\alpha$ exp[-ξ($\Phi$-$\Phi$$_{m}$)$^{2}$ -exp {-ζ($\Phi$-$\Phi$$_{m}$)}-ζ($\Phi$-$\Phi$$_{m}$)]. By using the results calculated by PREMIX code with Sloane\`s detailed chemical reaction mechanism for propane, it is verified that the coefficients of the abode modeling can be determined by considering laminar burning velocity data only in a range of equivalence ratio less than $\Phi$$_{m}$. Therefore, Muller\`s modeling results can be adopted leer modeling of the pressure and temperature dependency. Compared with the results of the existing Keck'and Gulder's models, those of the present one showed the good agreement of the recent experimental data, especially in the range of lean and rich sides.s.des.s.