Search results for: analysis of elemental composition of hair

Authors: Enrique Nunez L., Maria Cortes L., Sandra Laffon L., Ana M. Cupul V.

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The phytoplankton community composition was studied in a tropical coastal lagoon of Mexico and relationships with environmental variables were evaluated. Six sites inside the tropical Terminos Lagoon were sampled in order to determine abundances and ecological indexes for phytoplankton from May to December 2017. Water samples were also collected to determine the values of pigments, nutrients, and water solids. Results showed that the composition and abundance of the phytoplankton community were influenced by physicochemical factors, nutrients, water solids, and climate seasons. Sixty-six species were identified as potential HAB producers (44.29% from total). However, abundances were not related to the occurrence of HAB during the study. Multidimensional ANOVA indicated no significant differences between sites while some months revealed significant differences. The canonical analysis suggested that environmental variables explained 49% of community variation of potential phytoplankton species producers of HAB.

Keywords: phytoplankton, environment, lagoon, biodiversity

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Authors: A. M. Pashayev, A. S. Samedov, T. B. Usubaliyev, N. Sh. Yusifov

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Different types of coating technologies are widely used for gas turbine blades. Thermal barrier coatings, consisting of ceramic top coat, thermally grown oxide and a metallic bond coat are used in applications for thermal protection of hot section components in gas turbine engines. Operational characteristics and longevity of high-temperature turbine blades substantially depend on a right choice of composition of the protective thermal barrier coatings. At a choice of composition of a coating and content of the basic elements it is necessary to consider following factors, as minimum distinctions of coefficients of thermal expansions of elements, level of working temperatures and composition of the oxidizing environment, defining the conditions for the formation of protective layers, intensity of diffusive processes and degradation speed of protective properties of elements, extent of influence on the fatigue durability of details during operation, using of elements with high characteristics of thermal stability and satisfactory resilience of gas corrosion, density, hardness, thermal conduction and other physical characteristics. Forecasting and a choice of a thermal barrier coating composition, all above factors at the same time cannot be considered, as some of these characteristics are defined by experimental studies. The implemented studies and investigations show that one of the main failures of coatings used on gas turbine blades is related to not fully taking the physical-chemical features of elements into consideration during the determination of the composition of alloys. It leads to the formation of more difficult spatial structure, composition which also changes chaotically in some interval of concentration that doesn't promote thermal and structural firmness of a coating. For the purpose of increasing the thermal and structural resistant of gas turbine blade coatings is offered a new approach to forecasting of composition on the basis of analysis of physical-chemical characteristics of alloys taking into account the size factor, electron configuration, type of crystal lattices and Darken-Gurry method. As a result, of calculations and experimental investigations is offered the new four-component metallic bond coat on the basis of chrome for the gas turbine blades.

Keywords: gas turbine blades, thermal barrier coating, metallic bond coat, strategic metals, physical-chemical features

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Authors: Abrehet Kahsay Mehari

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Aquatic plants provide the physical structure of wetlands and increase their habitat complexity and heterogeneity, and as such, have a profound influence on other biotas. In this study, we investigated how human disturbance activities influenced the species richness and community composition of aquatic plants in the wetlands of Lake Tana, Ethiopia. Twelve wetlands were selected: four lacustrine, four river mouths, and four riverine papyrus swamps. Data on aquatic plants, environmental variables, and human activities were collected during the dry and wet seasons of 2018. A linear mixed effect model and a distance-based Redundancy Analysis (db-RDA) were used to relate aquatic plant species richness and community composition, respectively, to human activities and environmental variables. A total of 113 aquatic plant species, belonging to 38 families, were identified across all wetlands during the dry and wet seasons. Emergent species had the maximum area covered at 73.45 % and attained the highest relative abundance, followed by amphibious and other forms. The mean taxonomic richness of aquatic plants was significantly lower in wetlands with high overall human disturbance scores compared to wetlands with low overall human disturbance scores. Moreover, taxonomic richness showed a negative correlation with livestock grazing, tree plantation, and sand mining. The community composition also varied across wetlands with varying levels of human disturbance and was primarily driven by turnover (i.e., replacement of species) rather than nestedness resultant(i.e., loss of species). Distance-based redundancy analysis revealed that livestock grazing, tree plantation, sand mining, waste dumping, and crop cultivation were significant predictors of variation in aquatic plant communities’ composition in the wetlands. Linear mixed effect models and distance-based redundancy analysis also revealed that water depth, turbidity, conductivity, pH, sediment depth, and temperature were important drivers of variations in aquatic plant species richness and community composition. Papyrus swamps had the highest species richness and supported different plant communities. Conservation efforts should therefore focus on these habitats and measures should be taken to restore the highly disturbed and species poor wetlands near the river mouths.

Keywords: species richness, community composition, aquatic plants, wetlands, Lake Tana, human disturbance activities

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Authors: Otuu O. Obasi, Jude C. Ajaraogu, Happiness C. Anthony-Ikpe

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Women in Igbo land generally experience culture-related mistreatment in the event of the death of their husbands. The mistreatment ranges from scraping of widows’ hair to denial of the right to see their husbands’ corpses. The objectives of the study were to determine the forms and prevalence of widowhood practice in the studied communities, the effects of the socio-cultural attributes of the people on the practice, and the perceived effect of the practice on the victims. Data for the study were collected from 64 randomly selected communities out of 640 communities in Imo State, Nigeria. 450 copies of the researcher-made-questionnaire were distributed across the three senatorial zones of the State. A total of 418 or 92.8% were completely filled and returned. The result of the study showed, among other things, that the majority of males and females recognized widowhood practice as dehumanizing, but opined that it cannot be stopped because it is rooted in culture. However, 30.2% of the female population did not agree that the practice is dehumanizing to women since it was their cultural practice. The study also revealed that scrapping of widows’ hair was the commonest practice while sleeping alone with the husband’s corpse was the least practice. Regarding the effect which this practice has on widows, emotional trauma topped the list; and was followed by economic hardship and health deterioration. Also shown by the study was that the level of education and religion did not have a notable effect on widowhood practice. With regard to possible stoppage measures, greater number of the respondents (38%) indicated that a synergy of efforts was needed to curb the social scourge.

Keywords: widowhood practice, socio-cultural attributes, violence, impact

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Authors: M. Jerold, V. Sivasubramanian, A. George, B.S. Ashik, S. S. Kumar

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Bioethanol is a sustainable biofuel that can be used alternative to fossil fuels. Today, third generation (3G) biofuel is gaining more attention than first and second-generation biofuel. The more lignin content in the lignocellulosic biomass is the major drawback of second generation biofuels. Algae are the renewable feedstock used in the third generation biofuel production. Algae contain a large number of carbohydrates, therefore it can be used for the fermentation by hydrolysis process. There are two groups of Algae, such as micro and macroalgae. In the present investigation, Macroalgae was chosen as raw material for the production of bioethanol. Two marine algae viz. Ulva Lactuca and Sargassum swartzii were used for the experimental studies. The algal biomass was characterized using various analytical techniques like Elemental Analysis, Scanning Electron Microscopy Analysis and Fourier Transform Infrared Spectroscopy to understand the physio-Chemical characteristics. The batch experiment was done to study the hydrolysis and operation parameters such as pH, agitation, fermentation time, inoculum size. The saccharification was done with acid and alkali treatment. The experimental results showed that NaOH treatment was shown to enhance the bioethanol. From the hydrolysis study, it was found that 0.5 M Alkali treatment would serve as optimum concentration for the saccharification of polysaccharide sugar to monomeric sugar. The maximum yield of bioethanol was attained at a fermentation time of 9 days. The inoculum volume of 1mL was found to be lowest for the ethanol fermentation. The agitation studies show that the fermentation was higher during the process. The percentage yield of bioethanol was found to be 22.752% and 14.23 %. The elemental analysis showed that S. swartzii contains a higher carbon source. The results confirmed hydrolysis was not completed to recover the sugar from biomass. The specific gravity of ethanol was found to 0.8047 and 0.808 for Ulva Lactuca and Sargassum swartzii, respectively. The purity of bioethanol also studied and found to be 92.55 %. Therefore, marine algae can be used as a most promising renewable feedstock for the production of bioethanol.

Keywords: algae, biomass, bioethaol, biofuel, pretreatment

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Authors: S. O. Oladeji, I. Saleh, A. U. Adamu, S. A. Fowotade

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The proximate composition, trace metal level and amino acid composition of Amaranthus hybridus, Celosia argentea and Solanum nigrum were determined. These vegetables were high in their ash contents. Twelve elements were determined: calcium, chromium, copper, iron, lead, magnesium, nickel, phosphorous, potassium, sodium and zinc using flame photometer, atomic absorption and UV-Visible spectrophotometers. Calcium levels were highest ranged between 145.28±0.38 to 235.62±0.41mg/100g in all the samples followed by phosphorus. Quantitative chromatographic analysis of the vegetables hydrolysates revealed seventeen amino acids with concentration of leucine (6.51 to 6.66±0.21g/16gN) doubling that of isoleucine (2.99 to 3.33±0.21g/16gN) in all the samples while the limiting amino acids were cystine and methionine. The result showed that these vegetables were of high nutritive values and could be adequate used as supplement in diet.

Keywords: proximate, amino acids, Amaranthus hybridus, Celosia argentea, Solanum nigrum

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Authors: I. Sani, F. Bello, I. M. Fakai, A. Abdulhamid

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Abelmoschus esculentus L. fruit is very common especially in northern part of Nigeria, but people are ignorant of its medicinal and pharmacological benefits. Preliminary phytochemical screening, antioxidant potential and mineral composition of the dried form of this fruit were determined. The Phytochemical screening was conducted using standard methods. Antioxidant potential screening was carried out using Ferric Reducing Antioxidant Power Assay (FRAP) method, while, the mineral compositions were analyzed using an atomic absorption spectrophotometer by wet digest method. The result of the qualitative phytochemical screening revealed that the fruits contain saponins, flavonoids, tannins, steroids, and terpenoids, while, anthraquinone, alkaloids, phenols, glycosides, and phlobatannins were not detected. The quantitative analysis revealed that the fruits contain saponnins (380 ± 0.020 mg/g), flavonoids (240±0.01 mg/g), and tannins (21.71 ± 0.66 mg/ml). The antioxidant potential was determined to be 54.1 ± 0.19%. The mineral composition revealed that 100 g of the fruits contains 97.52 ± 1.04 mg of magnesium (Mg), 94.53 ± 3.21 mg of calcium (Ca), 77.10 ± 0.79 mg of iron (Fe), 47.14 ± 0.41 mg of zinc (Zn), 43.96 ± 1.49 mg of potassium (K), 42.02 ± 1.09 mg of sodium (Na), 0.47 ± 0.08 mg of copper (Cu) and 0.10 ± 0.02 mg of lead (Pb). These results showed that the Abelmoschus esculentus L. fruit is a good source of antioxidants, and contains an appreciable amount of phytochemicals, therefore, it has some pharmacological attributes. On the other side, the fruit can serve as a nutritional supplement for Mg, Ca, Fe, Zn, K, and Na, but a poor source of Cu, and contains no significant amount of Pb.

Keywords: Abelmoschus esculentus Fruits, antioxidant potential, mineral composition, phytochemical screening

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Authors: Uzaira Rafique, Kousar Parveen

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The discharge volume and composition of Textile effluents gains scientific concern due to its hazards and biotoxcity of azo dyes. Azo dyes are non-biodegradable due to its complex molecular structure and recalcitrant nature. Serious attempts have been made to synthesize and develop new materials to combat the environmental problems. The present study is designed for removal of a range of azo dyes (Methyl orange, Congo red and Basic fuchsine) from synthetic aqueous solutions and real textile effluents. For this purpose, Metal (cobalt) doped alumina hybrids are synthesized and applied as adsorbents in the batch experiment. Two different aluminium precursor (aluminium nitrate and spent aluminium foil) and glucose are mixed following sol gel method to get hybrids. The synthesized materials are characterized for surface and bulk properties using FTIR, SEM-EDX and XRD techniques. The characterization of materials under FTIR revealed that –OH (3487-3504 cm-1), C-H (2935-2985 cm-1), Al-O (~ 800 cm-1), Al-O-C (~1380 cm-1), Al-O-Al (659-669 cm-1) groups participates in the binding of dyes onto the surface of hybrids. Amorphous shaped particles and elemental composition of carbon (23%-44%), aluminium (29%-395%), and oxygen (11%-20%) is demonstrated in SEM-EDX micrograph. Time-dependent batch-experiments under identical experimental parameters showed 74% congo red, 68% methyl orange and 85% maximum removal of basic fuchsine onto the surface of cobalt doped alumina hybrids probably through the ion-exchange mechanism. The experimental data when treated with adsorption models is found to have good agreement with pseudo second order kinetic and freundlich isotherm for adsorption process. The present study concludes the successful synthesis of novel and efficient cobalt doped alumina hybrids providing environmental friendly and economical alternative to the commercial adsorbents for the treatment of industrial effluents.

Keywords: alumina hybrid, adsorption, dopant, isotherm, kinetic

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Authors: Bahor Bahriddinovna Turaeva

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The article provides a structural analysis of the titles of the famous Kyrgyz writer Chingiz Aitmatov’s creative works “The Day Lasts More Than a Hundred Years”, “Doomsday”. The author’s creative purpose in naming the work of art, the role of the elements of the plot, and the composition of the novels in revealing the essence of the title are explained. The criteria that are important in naming the author’s works in different genres are classified, and the titles that mean artistic time and artistic space are studied separately. Chronotope is being concerned as the literary-aesthetic category in world literary studies, expressing the scope of the universe interpretation, the author’s outlook and imagination regarding the world foundation, defining personages, and the composition means of expressing the sequence and duration of the events. A creative comprehension of the chronotope as a means of arranging the work composition, structure and constructing an epic field of the text demands a special approach to understanding the aesthetic character of the work. Since the chronotope includes all the elements of a fictional work, it is impossible to present the plot, composition, conflict, system of characters, feelings, and mood of the characters without the description of the chronotope. In the following development of the scientific-theoretical thought in the world, the chronotope is accepted to be one of the poetic means to demonstrate reality as well as to be a literary process that is basic for the expression of reality in the compositional construction and illustration of the plot relying on the writer’s intention and the ideological conception of the literary work. Literary time enables one to cognate the literary world picture created by the author in terms of the descriptive subject and object of the work. Therefore, one of the topical tasks of modern Uzbek literary studies is to describe historical evidence, event, the life of outstanding people, the chronology of the near past based on the literary time; on the example of the creative works of a certain period, creators or an individual writer are analyzed in separate or comparative-typological aspect.

Keywords: novel, title, chronotope, motive, epigraph, analepsis, structural analysis, plot line, composition

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Authors: Lina Lauciene, Vaida Andruleviciute, Ingrida Sinkeviciene, Mindaugas Malakauskas, Loreta Serniene

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Dairy product manufacturers constantly are looking for new markets for their production. And in most cases, the problem of product compliance with the composition requirements of foreign products is highlighted. This is especially true of the composition of milk fat in dairy products. It is well known that there are many factors such as feeding ratio, season, cow breed, stage of lactation that affect the fatty acid composition in milk. However, there is less evidence on the impact of the technological process on the composition of fatty acids in raw milk and products made from it. In this study the influence of the technological process on fat composition in 82% fat butter, 15% fat curd, 3.6% fat yogurt and 2.5% fat UHT milk was determined. The samples were collected at each stage of production, starting with raw milk and ending with the final product in the Lithuanian milk-processing company. Fatty acids methyl esters were quantified using a GC (Clarus 680, Perkin Elmer) equipped with flame ionization detector (FID) and a capillary column SP-2560, 100 m x 0.25 mm id x 0.20 µm. Fatty acids peaks were identified using Supelco® 37 Component FAME Mix. The concentration of each fatty acid was expressed in percent of the total fatty acid amount. In the case of UHT milk production, it was compared raw milk, cream, milk mixture, and UHT milk but significant differences were not estimated between these stages. Analyzing stages of the yogurt production (raw milk, pasteurized milk, and milk with a starter culture and yogurt), no significant changes were detected between stages as well. A slight difference was observed with C4:0 - a percentage of this fatty acid was less (p=0.053) in the final stage than in milk with the starter culture. During butter production, the composition of fatty acids in raw cream, buttermilk, and butter did not change significantly. Only C14:0 decreased in the butter then compared to buttermilk. The curd fatty acid analysis showed the increase of C6:0, C8:0, C10:0, C11:0, C12:0 C14:0 and C17:0 at the final stage when compared to raw milk, cream, milk mixture, and whey. Meantime the increase of C18:1n9c (in comparison with milk mixture and curd) and C18:2n6c (in comparison with raw milk, milk mixture, and curd) was estimated in cream. The results of this study suggest that the technological process did not affect the composition of fatty acids in UHT milk, yogurt, butter, and curd but had the impact on the concentration of individual fatty acids. In general, all of the fatty acids from the raw milk were converted into the final product, only some of them slightly changed the concentration. Therefore, in order to ensure an appropriate composition of certain fatty acids in the final product, producers must carefully choose the raw milk. Acknowledgment: This research was funded by Lithuanian Ministry of Agriculture (No. MT-17-13).

Keywords: dairy products, fat composition, fatty acids, technological process

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Authors: Philemon Rakoto

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Most executive compensation packages consist of four major components: base fixed salary, annual and long-term non-equity incentive plans, share-based and option-based awards and pension value. According to agency theory, the relative composition of executive compensation packages is one of the mechanisms that firms use to align the interests of executives and shareholders in order to mitigate agency costs. This paper tests the effect of the relative composition of executive compensation packages on financial reporting quality. Financial reporting quality is measured by the value relevance of accounting earnings. Corporate governance is a moderating variable in the model. Using data from Canadian firms composing S&P/TSX index of the year 2013 and governance scores based on Board Games, the analysis shows that, only for firms with good governance, there is an optimal level of the proportion of executive equity-based compensation in relation to total compensation that enhances the quality of financial reporting.

Keywords: Canada, corporate governance, executive compensation packages, financial reporting quality

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Authors: Jyh-Cherng Chen, Yu-Zen Lin, Wei-Zhi Chen

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Torrefaction is one of waste to energy (WTE) technologies developing in Taiwan recently, which can reduce the moisture and impurities and increase the energy density of biowaste effectively. To understand the torrefaction characteristics of different biowaste and the influences of different torrefaction conditions, four typical biowaste were selected to carry out the torrefaction experiments. The physical and chemical properties of different biowaste prior to and after torrefaction were analyzed and compared. Experimental results show that the contents of elemental carbon and caloric value of the four biowaste were significantly increased after torrefaction. The increase of combustible and caloric value in bamboo was the greatest among the four biowaste. The caloric value of bamboo can be increased from 1526 kcal/kg to 6104 kcal/kg after 300oC and 1 hour torrefaction. The caloric value of torrefied bamboo was almost four times as the original. The increase of elemental carbon content in wood was the greatest (from 41.03% to 75.24%), and the next was bamboo (from 47.07% to 74.63%). The major parameters which affected the caloric value of torrefied biowaste followed the sequence of biowaste kinds, torrefaction time, and torrefaction temperature. The optimal torrefaction conditions of the experiments were bamboo torrefied at 300oC for 3 hours, and the corresponding caloric value of torrefied bamboo was 5953 kcal/kg. This caloric value is similar to that of brown coal or bituminous coal.

Keywords: torrefaction, waste to energy, calorie, biofuel

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Authors: Valerija Dunkić, Nada Bezić

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Salvia is a genus of the well-known medicinal plant of Lamiaceae family and growing wild throughout the world. This abstract reports the comparation of the essential oils from leaves and flowers composition of Salvia pratensis L. from mountain Velebit, Croatia. Water distilled essential oils from aerial parts of investigation plant have been analysed by GC and GC/MS using VF-5ms capillary column. Fifty-three constituents, representing 99.4% of the leaf oil composition; 51 constituents, representing 86.8% of the flower oil composition. Essential oil yield varied from 0.9% to 1.3% in the leaf and flower parts of the plant. The flower essential oil was characterized by a high concentration of E-caryophyllene (21.9%) and germacrene D (10.2%). Major constituents of the leaf oil were linalool (17.7%), linalool acetate (15.3%) and limonene (9.8%). The comparative results clearly indicated that the leaf and flower oil compositions of S. pratensis were quite different in terms of major components content. The present study gives additional knowledge about secondary metabolites contents on the genus Salvia.

Keywords: essential oil, leaf, flower, Salvia pratensis L.

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Authors: Christian C. Vaso, Rinlee Butch M. Cervera

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Solid oxide electrolysis cell (SOEC) is a promising technology for hydrogen production that will contribute to the sustainable energy of the future. An important component of this SOEC is the anode material and one of the promising anode material for such application is the Sr-doped LaMnO3 (LSM) and Yttrium-stabilized ZrO2 (YSZ) composite material. In this study, LSM/YSZ with different weight percent compositions of LSM and YSZ were synthesized using solid-state reaction method. The obtained samples, 60LSM/40YSZ, 50LSM/50YSZ, and 40LSM/60YSZ, were fully characterized for its microstructure using X-ray diffraction, FTIR, and SEM/EDS. EDS analysis confirmed the elemental composition and distribution of the synthesized samples. Surface morphology of the sample using SEM exhibited a well sintered and densified samples and revealed a beveled cube-like LSM morphology while the YSZ phase appeared to have a sphere-like microstructure. Density measurements using Archimedes principle showed relative densities greater than 90%. In addition, AC impedance measurement of the synthesized samples have been investigated at intermediate temperature range (400-700 °C) in an inert and oxygen gas flow environment. At pure states, LSM exhibited a high electronic conductivity while YSZ demonstrated an ionic conductivity of 3.25 x 10-4 S/cm at 700 °C under Oxygen gas environment with calculated activation energy of 0.85eV. The composite samples were also studied and revealed that as the YSZ content of the composite electrode increases, the total conductivity decreases.

Keywords: ceramic composites, fuel cells, strontium lanthanum manganite, yttria partially-stabilized zirconia

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Authors: Lucja Rodzik, Joanna Lewandowska-Lancucka, Michal Szuwarzynski, Krzysztof Szczubialka, Maria Nowakowska

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The analysis of nucleobases is of great importance for bioscience since their abnormal concentration in body fluids suggests the deficiency and mutation of the immune system, and it is considered to be an important parameter for diagnosis of various diseases. The presented conjugate meets the need for development of the effective, selective and highly sensitive sensor for nucleobase/nucleoside detection. The novel, highly fluorescent cadmium telluride quantum dots (CdTe QDs) functionalized with thymine and stabilized with thioglycolic acid (TGA) conjugates has been developed and thoroughly characterized. Successful formation of the material was confirmed by elemental analysis, and UV–Vis fluorescence and FTIR spectroscopies. The crystalline structure of the obtained product was characterized with X-ray diffraction (XRD) method. The composition of CdTe QDs and their thymine conjugate was also examined using X-ray photoelectron spectroscopy (XPS). The size of the CdTe-thymine was 3-6 nm as demonstrated using atomic force microscopy (AFM) and high resolution transmission electron microscopy (HRTEM) imaging. The plasmon resonance fluorescence band at 540 nm on excitation at 351 nm was observed for these nanoparticles. The intensity of this band increased with the increase in the amount of conjugated thymine with no shift in its position. Based on the fluorescence measurements, it was found that the CdTe-thymine conjugate interacted efficiently and selectively not only with adenine, a nucleobase complementary to thymine, but also with nucleosides and adenine-containing modified nucleosides, i.e., 5′-deoxy-5′-(methylthio)adenosine (MTA) and 2’-O-methyladenosine, the urinary tumor markers which allow monitoring of the disease progression. The applicability of the CdTe-thymine sensor for the real sample analysis was also investigated in simulated urine conditions. High sensitivity and selectivity of CdTe-thymine fluorescence towards adenine, adenosine and modified adenosine suggest that obtained conjugate can be potentially useful for development of the biosensor for complementary nucleobase/nucleoside detection.

Keywords: CdTe quantum dots, conjugate, sensor, thymine

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Authors: John M. Basey, Clinton D. Francis, Maxwell B. Joseph

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After gathering data from experimental procedures, inquiry-oriented-science labs often allow students the freedom to stay and complete the write up in class or leave lab early and complete the write up later. Teachers must decide whether to allow students this freedom to self-regulate this time. Student interviews have indicated four time-target strategies that may influence how students utilize this time: grade-target-A, grade-target-C, time-limited, and proficiency. The hypothesis tested was that variability in class composition relative to the four grade-target strategies has an impact on when students leave class, which in turn may influence their overall learning as exemplified by grades. Students were divided into the four indicated groups with a survey. Class composition and the GTA teaching the class had significant impacts on how long students stayed in class with class composition having the greatest impact. A factor analysis identified two factors. Factor 1 included classes with percentages of grade-target students opposite time-limited/proficiency students and explained 43% of the variance. Factor 2 included classes with percentages of grade-target-A/proficiency students opposite grade-target-C students and explained 33% of the variance. Students who stayed longer received significantly higher grades (P = 0.008) with no significant relationships between grade and Factor 1 or Factor 2 (P > 0.05). The time students stayed in class was significantly positively related to Factor 1 (P = 0.006) and significantly negatively related to Factor 2 (P = 0.008). These results support the hypothesis and indicate that teachers may want to know the composition of student-target strategies before deciding on how to have students allocate study time at the end of inquiry-oriented labs. According to these results, ideal classes for self-regulation have a high proportion of proficiency and time-limited students and a low proportion of grade-target students, or a high proportion of grade-target-A and proficiency students and a low proportion of grade-target-C students. Non-ideal classes for self-regulation were comprised of the inverse proportions.

Keywords: grades, inquiry lab design, synergism in student motivation, class composition

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Authors: Sibel Karacaoglu, Fatma Ç. Kayapinar

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The aim of the study is to investigate the effect of the core training program on physical fitness characteristics and body composition in male volleyball players. 26 male university volleyball team players aged between 19 to 24 years who had no health problems and injury participated in the study. Subjects were divided into training (TG) and control groups (CG) as randomly. Data from twenty-one players who completed all training sessions were used for statistical analysis (TG,n=11; CG,n=10). A core training program was applied to the training group three days a week for 10 weeks. On the other hand, the control group did not receive any training. Before and after the 10-week training program, pre- and post-testing comprised of body composition measurements (weight, BMI, bioelectrical impedance analysis) and physical fitness measurements including flexibility (sit and reach test), muscle strength (back, leg and grip strength by dynamometer), muscle endurance (sit-ups and push-ups tests), power (one-legged jump and vertical jump tests), speed (20m sprint, 30m sprint) and balance tests (one-legged standing test) were performed. Changes of pre- and post- test values of the groups were determined by using dependent t test. According to the statistical analysis of data, no significant difference was found in terms of body composition in the both groups for pre- and post- test values. In the training group, all physical fitness measurements improved significantly after core training program (p<0.05) except 30m speed and handgrip strength (p>0.05). On the hand, only 20m speed test values improved after post-test period (p<0.05), but the other physical fitness tests values did not differ (p>0.05) between pre- and post- test measurement in the control group. The results of the study suggest that the core training program has positive effect on physical fitness characteristics in male volleyball players.

Keywords: body composition, core training, physical fitness, volleyball

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Authors: Stephen J. Mitchual, Kwasi Frimpong-Mensah, Nicholas A. Darkwa

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The fuel potential of six tropical hardwood species namely: Triplochiton scleroxylon, Ceiba pentandra, Aningeria robusta, Terminalia superba, Celtis mildbreadii and Piptadenia africana were studied. Properties studied include the species density, gross calorific value, volatile matter, ash, organic carbon, N, H, S, Cu, Pb, As and Cd content. Fuel properties were determined using standard laboratory methods. The result indicates that the Gross Calorific Value (GCV) of the species ranged from 20.16 to 22.22 MJ/kg and they slightly varied from each other. Additionally, the GCV of the biomass materials were higher than that of other biomass materials like; wheat straw, rice straw, maize straw and sugar cane. The ash and volatile matter content varied from 0.6075 to 5.0407%, and 75.23% to 83.70% respectively. The overall rating of the properties of the six biomass materials suggest that Piptadenia africana has the best fuel property to be used as briquettes and Aningeria robusta the worse. This study therefore suggests that a holistic assessment of a biomass material needs to be done before selecting it for fuel purpose.

Keywords: ash content, briquette, calorific value, elemental composition, species, volatile matter

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Authors: Wilson Handoko, Farshid Pahlevani, Isha Singla, Himanish Kumar, Veena Sahajwalla

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Aluminium bronze alloys are well known for their superior abrasion, tensile strength and non-magnetic properties, due to the co-presence of iron (Fe) and aluminium (Al) as alloying elements and have been commonly used in many industrial applications. However, continuous exposure to the marine environment will accelerate the risk of a tendency to Al bronze alloys parts failures. Although a higher level of corrosion resistance properties can be achieved by modifying its elemental composition, it will come at a price through the complex manufacturing process and increases the risk of reducing the ductility of Al bronze alloy. In this research, the use of ironmaking slag and waste plastic as the input source for surface modification of Al bronze alloy was implemented. Microstructural analysis conducted using polarised light microscopy and scanning electron microscopy (SEM) that is equipped with energy dispersive spectroscopy (EDS). An electrochemical corrosion test was carried out through Tafel polarisation method and calculation of protection efficiency against the base-material was determined. Results have indicated that uniform modified surface which is as the result of selective diffusion process, has enhanced corrosion resistance properties up to 12.67%. This approach has opened a new opportunity to access various industrial utilisations in commercial scale through minimising the dependency on natural resources by transforming waste sources into the protective coating in environmentally friendly and cost-effective ways.

Keywords: aluminium bronze, waste-based surface modification, tafel polarisation, corrosion resistance

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Authors: Olufunke O. Ezekiel, Adenike O. Ogunshe, Omotola F. Olagunju, Arinola O. Falola

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Studies were conducted on fermentation of tamarind seed for production of food condiment. Fermentation followed the conventional traditional method of fermented locust bean (iru) production and was carried out over a period of three days (72 hours). Samples were withdrawn and analysed for proximate composition, pH, titratable acidity, tannin content, phytic acid content and trypsin inhibitor activity using standard methods. Effects of fermentation on proximate composition, anti-nutritional factors and sensory properties of the seed were evaluated. All data were analysed using ANOVA and means separated using Duncan multiple range test. Microbiological analysis to identify and characterize the microflora responsible for the fermentation of the seed was also carried out. Fermentation had significant effect on the proximate composition on the fermented seeds. As fermentation progressed, there was significant reduction in the anti-nutrient contents. Organisms isolated from the fermenting tamarind seeds were identified as non-pathogenic and common with fermented legumes.

Keywords: condiment, fermentation, legume, tamarind seed

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Authors: Ehsan Alishahi, Chuang Deng

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Materials with microstructural heterogeneity have recently attracted dramatic attention in the materials science community. Although most of the metals are identified as crystalline, the new class of amorphous alloys, sometimes are known as metallic glasses (MGs), exhibited remarkable properties, particularly high mechanical strength and elastic limit. The unique properties of MGs led to the wide range of studies in developing and characterizing of new alloys or composites which met the commercial desires. In spite of applicable properties of MGs, commercializing of metallic glasses was limited due to a major drawback, the lack of ductility and sudden brittle failure mode. Hence, crystalline-amorphous (C-A) composites were introduced almost in 2000s as a toughening strategy to improve the ductility of MGs. Despite the considerable progress reported in previous studies, there are still challenges in both synthesis and characterization of metallic C-A composites. In this study, accumulative roll bonding (ARB) was used to synthesize bulk crystalline-amorphous composites starting from crystalline Cu-Zr multilayers. Due to the severe plastic deformation state, new CuZr phases were formed during the rolling process which was reflected in SEM-EDS analysis. EDS elemental analysis showed the variation in the composition of CuZr phases such as 38-62, 50-50 to 68-32 at Cu-Zr % respectively. Moreover, TEM with electron diffraction analysis indicated the presence of both crystalline and amorphous structures for the new formed CuZr phases. In addition to the microstructural analysis, the mechanical properties of the synthesized composites were studied using the nanoindentation technique. Hysitron Nanoindentation instrument was used to conduct nanoindentation tests with cube corner tip. The maximum load of 5000 µN was applied in load control mode to measure the elastic modulus and hardness of different phases. The trend of results indicated three distinct regimes of hardness and elastic modulus including pure Cu, pure Zr, and new formed CuZr phases. More specifically, pure Cu regions showed the lowest values for both nanoindentation hardness and elastic modulus while the CuZr phases take the highest values. Consequently, pure Zr was placed in the intermediate range which is harder than pure Cu but softer than CuZr phases. In overall, it was found that CuZr phases with higher hardness were nucleated during ARB process as a result of mechanical alloying phenomenon.

Keywords: ARB, crystalline-amorphous composites, mechanical alloying, nanoindentation hardness

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Authors: Amina R. Issae, Godfrey C. Katusi, Beda J. Mwang’Onde, Ladslaus L. Mnyone, Allen L. Malisa

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Background: The fluctuating composition of mosquito species over time, driven by ecological changes in specific regions, plays a pivotal role in the transmission of malaria. Grasping these dynamics is fundamental for establishing a baseline understanding and is crucial for identifying transmission patterns. This knowledge is essential in devising effective strategies for managing and controlling vector populations. Our study focused on examining the species composition and Plasmodium infection rates of malaria vectors, aiming to enhance the health and well-being of communities affected by malaria. Methods: Species composition was determined through a cross-sectional collection of mosquitoes, conducted once in the village, in four selected villages of Kilosa district, Tanzania. Mosquitoes were collected indoors and outdoors using CDC light traps. A sub-sample of all collected mosquitoes was subjected to PCR identification and assayed for Plasmodium porozoites. Results: A total of 6493 female Anophelines mosquitoes were collected, of which eight species were identified as Anopheles gambiaes.l., An. funestus group, An. coustani, An. pharoensis, An. squamosus, and An. rufipes. The abundance of the Anopheles gambiaes.s.and An. funestuss.s. varied with location and village. A total of 5 sporozoite-positive mosquitoes were found, of which 4 were An. funestuss.s. and 1 was An. gambiaes.s. Conclusions: Anopheles gambiaes.s.and An. funestuss.s. were identified as the most abundant malaria vectors, respectively. Sporozoite analysis indicated this for An. funestuss.s. contribute to most of the malaria transmission in the area. Further studies are required to assess the role of seasonal shifts in vector abundance, insecticide resistance and malaria transmission of the vectors.

Keywords: mosquito, composition, malaria, sporozoites

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Authors: A. Gilewska, J. Masternak, K. Kazimierczuk, L. Turlej, J. Wietrzyk, B. Barszcz

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Platinum-based drugs are now widely used as chemotherapeutic agents. However the platinum complexes show the toxic side-effects: i) the development of platinum resistance; ii) the occurrence of severe side effects, such as nephro-, neuro- and ototoxicity; iii) the high toxicity towards human fibroblast. Therefore the development of new anticancer drugs containing different transition-metal ions, for example, ruthenium, rhodium, iridium is a valid strategy in cancer treatment. In this paper, we reported the synthesis, spectroscopic, structural and biological properties of complexes of ruthenium, rhodium, and iridium containing N,N-chelating ligand (2,2’-bisimidazole). These complexes were characterized by elemental analysis, UV-Vis and IR spectroscopy, X-ray diffraction analysis. These complexes exhibit a typical pseudotetrahedral three-legged piano-stool geometry, in which the aromatic arene ring forms the seat of the piano-stool, while the bidentate 2,2’-bisimidazole (ligand) and the one chlorido ligand form the three legs of the stool. The spectroscopy data (IR, UV-Vis) and elemental analysis correlate very well with molecular structures. Moreover, the cytotoxic activity of the complexes was carried out on human cancer cell lines: LoVo (colorectal adenoma), MV-4-11 (myelomonocytic leukaemia), MCF-7 (breast adenocarcinoma) and normal healthy mouse fibroblast BALB/3T3 cell lines. To predict a binding mode, a potential interaction of metal complexes with calf thymus DNA (CT-DNA) and protein (BSA) has been explored using UV absorption and circular dichroism (CD). It is interesting to note that the investigated complexes show no cytotoxic effect towards the normal BALB/3T3 cell line, compared to cisplatin, which IC₅₀ values was determined as 2.20 µM. Importantly, Ru(II) displayed the highest activity against HL-60 (IC₅₀ 4.35 µM). The biological studies (UV-Vis and circular dichroism) suggest that arene-complexes could interact with calf thymus DNA probably via an outside binding mode and interact with protein (BSA).

Keywords: ruthenium(II) complex, rhodium(III) complex, iridium(III) complex, biological activity

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Authors: Guillermo Cardoso-Landa, Ana Julita Cuenca-Castro

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The present paper focuses to research the possible causes of curtain failure of dam "El Batan" in Querétaro, Mexico, including the design of the fineness of the employee filter during the construction of the curtain was verified since this depends greatly on the proper functioning of this filter. To carry out the required analysis, it was necessary to document elements provided understanding about the composition and behavior of the land curtain, and the main types of failure in these curtains. The general characteristics of the curtain dam "El Batan", the composition of the filter, as well as possible causes resulted in the failure were also analyzed. Once obtained data starting, the actual analysis was carried out by reviewing the following possible causes of failure: fails due to a poor constructive process of the curtain, failure due to hydraulic suppression, fails due to a structural design wrong, fails due to a geotechnical design wrong, fails due to a hydraulic design wrong, fails due to an inadequate design of the curtain filter. It is concluded that the type of the filter employed in the land dam curtain of "El Batan", located in the municipality of Querétaro, México, do not have adequate characteristics, outside of the ranges of design, using the curves: Terzaghi criteria, Sherard and Dunnigan criteria, UCSCS criteria, and Foster and Fell criteria.

Keywords: failure, dam, filter, curtain

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Authors: Mayandi Ramanathan

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Gas turbine blades see the most aggressive thermal stress conditions within the engine, due to high Turbine Entry Temperatures in the range of 1500 to 1600°C. The blades rotate at very high rotation rates and remove a significant amount of thermal power from the gas stream. At high temperatures, the major component failure mechanism is a creep. During its service over time under high thermal loads, the blade will deform, lengthen and rupture. High strength and stiffness in the longitudinal direction up to elevated service temperatures are certainly the most needed properties of turbine blades and gas turbine components. The proposed advanced Ti alloy material needs a process that provides a strategic orientation of metallic ordering, uniformity in composition and high metallic strength. The chemical composition of the proposed Ti alloy material (25% Ta/(Al+Ta) ratio), unlike Ti-47Al-2Cr-2Nb, has less excess Al that could limit the service life of turbine blades. Properties and performance of Ti-47Al-2Cr-2Nb and Ti-6Al-4V materials will be compared with that of the proposed Ti alloy material to generalize the performance metrics of various gas turbine components. This paper will involve the summary of the effects of additive manufacturing and heat treatment process conditions on the changes in the phase composition, grain structure, lattice structure of the material, tensile strength, creep strain rate, thermal expansion coefficient and fracture toughness at different temperatures. Based on these results, additive manufacturing and heat treatment process conditions will be optimized to fabricate turbine blade with Ti-43Al matrix alloyed with an optimized amount of refractory Ta metal. Improvement in service temperature of the turbine blades and corrosion resistance dependence on the coercivity of the alloy material will be reported. A correlation of phase composition and creep strain rate will also be discussed.

Keywords: high temperature materials, aerospace, specific strength, creep strain, phase composition

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Authors: V. Lokesh, M. Manjunathan, S. Sairam, K. Saithsh Kumar, R. Anantharaj

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The densities of pure and its binary mixtures of 1-Butyl-3-methyl imidazolium bis (trifluoro methyl sulfonyl) imide and 1–Ethyl-3-methyl imidazolium ethyl sulphate at different temperature, over the entire composition range were measured at 293.15, 298.15, 303.15, 308.15, 313.15, 318.15, 323.15, 328.15, 33.15, 338.15, 343.15 K. In this study, the liquid-liquid extraction procedure was used. From this experimental data, the excess molar volumes, apparent molar volume, partial molar volumes and the excess partial molar volumes have been calculated for over the whole composition range. Hence, the effect of temperature and composition on all derived thermodynamic properties of this binary mixture will be discussed in terms of intermolecular interactions.

Keywords: ionic liquid, interaction energy, effect of temperature, effect of composition

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Authors: Semuel Unwakoly, Reinner Puppela, Maresthy Rumalean, Healthy Kainama

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Fish is a kind of food that contains many nutritions, one of those is the long chain of unsaturated fatty acids as omega-3 and omega-6 fatty acids and essential amino acid in enough amount for the necessity of our body. Like pelagic fish that found in the sea of Maluku. This research was done to identify fatty acids and amino acids composition in Moonfish (M. maculata) using transesterification reaction steps and Gas Chromatograph-Mass Spectrophotometer (GC-MS) and High-Performance Liquid Chromatography (HPLC). The result showed that fatty acids composition in Moonfish (M. maculata) contained tridecanoic acid (2.84%); palmitoleic acid (2.65%); palmitic acid (35.24%); oleic acid (6.2%); stearic acid (14.20%); and 5,8,11,14-eicosatetraenoic acid (1.29%) and 12 amino acids composition that consist of 7 essential amino acids, were leucine, isoleucine, valine, phenylalanine, methionine, lysine, and histidine, and also 5 non-essential amino acid, were tyrosine, glycine, alanine, glutamic acid, and arginine.Thus, these fishes can be used by the people to complete the necessity of essential fatty acid and amino acid.

Keywords: Moonfish (M. maculata), fatty acid, amino acid, GC-MS, HPLC

Procedia PDF Downloads 249

Authors: Sandya Mummullage, Prasanna Egodawatta, Ashantha Goonetilleke, Godwin A. Ayoko

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Urban road dust comprises of a range of potentially toxic metal elements and plays a critical role in degrading urban receiving water quality. Hence, assessing the metal composition and concentration in urban road dust is a high priority. This study investigated the variability of metal composition and concentrations in road dust in four different urban land uses in Gold Coast, Australia. Samples from 16 road sites were collected and tested for selected 12 metal species. The data set was analyzed using both univariate and multivariate techniques. Outcomes of the data analysis revealed that the metal concentrations inroad dust differs considerably within and between different land uses. Iron, aluminum, magnesium and zinc are the most abundant in urban land uses. It was also noted that metal species such as titanium, nickel, copper, and zinc have the highest concentrations in industrial land use. The study outcomes revealed that soil and traffic related sources as key sources of metals deposited on road surfaces.

Keywords: metals build-up, pollutant accumulation, stormwater quality, urban road dust

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Authors: Abdu Umar Adamu, Saidu Akun Abdullahi, Al-Hassan Muhammed, Hamisu Abdu

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Leguminous plants such as beans have been considered as a source of protein in this present work. The proximate analysis on beans (Vigna unguiculata) were determined in order to identify the nutritional content as well as presence of some heavy metals accumulation in washed and unwashed beans (white Beans) sold in Kazaure market Jigawa State Nigeria. On the average comparative analysis, the result has indicated that, the Vigna unguiculata had protein content of 61.1%, fibre 4.5%, ash 10.4%, moisture 5%, carbohydrate 15.8% and total lipid 4.9%, therefore it could be suggested that beans has enough nutritional content that helps the people health. The heavy metal analysis of unwashed white beans showed that Fe (17.37 ± 6.71)mg/kg had the highest concentration followed by Zn (6.41 ± 3.09), Cu (5.69 ± 2.42), Cd (0.46 ± 0.65) and Pb (0.57 ± 0.94)mg/kg , while the washed beans shows that Zn (0.11 ± 0.17), Fe (0.01 ± 0.006), Cd (0.02 ± 0.01), Cu (0.03 ± 0.021), Pb (0.01 ± 0.006)mg/kg. The washed white beans are safe for consumption and also the concentration of heavy metal are negligible and of nontoxic effect to human health.

Keywords: white beans, protein, proximate composition, heavy metal

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Authors: Wisitiporn Suksombat, Tanawat Phonkert, Chayapol Meeprom

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The aim of this experiment was to investigate the effect of calcium salt of palm oil fatty acids (Ca-POFA) supplementation on milk production and milk composition of dairy cows. Twenty-four early lactating crossbred Holstein Friesian 87.5% cows (15.4 ± 3.75 kg of milk/d; 93 ± 27 DIM; 369 ± 6 kg of BW), were assigned into 3 treatments in an RCBD. All dairy cows were fed 15.4% CP total mixed ration (TMR). The first group (control) received a basal diet and no supplement. The second group was fed the basal diet supplemented with 150 g/d calcium salt of palm oil fatty acids (Ca-POFA), and the last group was fed the basal diet supplemented with 300 g/d Ca-POFA. The experiment lasted 40 days with the first 10 days is an adaptation period, and measurements were made during the last 30 days in 6 periods with 5-days in each period for milk sample collection. The results found that supplemented calcium salt of palm oil fatty acid had no effect on milk yield, milk composition, milk composition yield, live weight and live weight change. However, Ca-POFA decreased milk protein percentage (P < 0.05).

Keywords: calcium salt of palm oil fatty acid, dairy cow, milk composition, milk production

Procedia PDF Downloads 225