Search results for: thermal stressed test

Authors: Sini George

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Active learning pedagogies are valued for their success in increasing 21st-century learners’ engagement, developing transferable skills like critical thinking or quantitative reasoning, and creating deeper and more lasting educational gains. 'Blended learning' is an active learning pedagogical approach in which direct instruction moves from the group learning space to the individual learning space, and the resulting group space is transformed into a dynamic, interactive learning environment where the educator guides students as they apply concepts and engage creatively in the subject matter. This project aimed to develop a blended learning instructional approach to teaching concepts around pharmaceutical calculations to year 1 pharmacy students. The wrong dose, strength or frequency of a medication accounts for almost a third of medication errors in the NHS therefore, progression to year 2 requires a 70% pass in this calculation test, in addition to the standard progression requirements. Many students were struggling to achieve this requirement in the past. It was also challenging to teach these concepts to students of a large class (> 130) with mixed mathematical abilities, especially within a traditional didactic lecture format. Therefore, short screencasts with voice-over of the lecturer were provided in advance of a total of four teaching sessions (two hours/session), incorporating core content of each session and talking through how they approached the calculations to model metacognition. Links to the screencasts were posted on the learning management. Viewership counts were used to determine that the students were indeed accessing and watching the screencasts on schedule. In the classroom, students had to apply the knowledge learned beforehand to a series of increasingly difficult set of questions. Students were then asked to create a question in group settings (two students/group) and to discuss the questions created by their peers in their groups to promote deep conceptual learning. Students were also given time for question-and-answer period to seek clarifications on the concepts covered. Student response to this instructional approach and their test grades were collected. After collecting and organizing the data, statistical analysis was carried out to calculate binomial statistics for the two data sets: the test grade for students who received blended learning instruction and the test grades for students who received instruction in a standard lecture format in class, to compare the effectiveness of each type of instruction. Student response and their performance data on the assessment indicate that the learning of content in the blended learning instructional approach led to higher levels of student engagement, satisfaction, and more substantial learning gains. The blended learning approach enabled each student to learn how to do calculations at their own pace freeing class time for interactive application of this knowledge. Although time-consuming for an instructor to implement, the findings of this research demonstrate that the blended learning instructional approach improves student academic outcomes and represents a valuable method to incorporate active learning methodologies while still maintaining broad content coverage. Satisfaction with this approach was high, and we are currently developing more pharmacy content for delivery in this format.

Keywords: active learning, blended learning, deep conceptual learning, instructional approach, metacognition, pharmaceutical calculations

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Authors: Gholamreza Koochaki

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This paper presents the buckling analysis of functionally graded beams with various boundary conditions. The first order shear deformation beam theory (Timoshenko beam theory) and the classical theory (Euler-Bernoulli beam theory) of Reddy have been applied to the functionally graded beams buckling analysis The material property gradient is assumed to be in thickness direction. The equilibrium and stability equations are derived using the total potential energy equations, classical theory and first order shear deformation theory assumption. The temperature difference and applied voltage are assumed to be constant. The critical buckling temperature of FG beams are upper than the isotropic ones. Also, the critical temperature is different for various boundary conditions.

Keywords: buckling, functionally graded beams, Hamilton's principle, Euler-Bernoulli beam

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Authors: Yasmeen F. Pervez, Etesh K. Janghel, Santosh Kumar Sar

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Simple and sensitive analytical thermal gradient-thin layer chromatography technique has been developed for the simultaneous determination of phenolic pesticides like carbaryl, propoxur and carbofuran. It is based on the differential migration of colored derivatives formed by the reaction of hydrolysed phenolic compound with diazotized 3, 4 dimethyl aniline on a silica gel plate. Quantitative evaluation of hydrolyzed phenolic compound is made by visual comparison of intensities of color by spectrophotometry. The color system obeys Beer’s law in the following working range in ppm : carbaryl, 0.5-6.6; propoxur, 0.8-7.2; and carbofuran, 0.2-3.3 respectively. The Molar absorptivity, Sandell’s sensitivity, Correlation coefficient have been determined. The effects of analytical parameters on migration and analysis have been evaluated. The methods are highly reproducible and have been successfully applied to determination of phenolic pesticides in environmental and biological samples.

Keywords: phenolic pesticides (carbaryl, propoxur and carbofuran), 3.4 dimethyl aniline, environmental, biological samples

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Authors: B. Sadek, N. Khan, D. Łażewska, K. Kieć-Kononowicz

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The effects of the non-imidazole histamine H3 receptor (H3R) antagonist DL77 in passive avoidance paradigm (PAP) and novel object recognition (NOR) task in MK801-induced cognitive deficits associated with schizophrenia (CDS) in adult male rats, and applying donepezil (DOZ) as a reference drug were investigated. The results show that acute systemic administration of DL77 (2.5, 5, and 10 mg/kg, i.p.) significantly improved MK801-induced (0.1 mg/kg, i.p.) memory deficits in PAP. The ameliorating activity of DL77 (5 mg/kg, i.p.) in MK801-induced deficits was partly reversed when rats were pretreated with the centrally-acting H2R antagonist zolantidine (ZOL, 10 mg/kg, i.p.) or with the antimuscarinic antagonist scopolamine (SCO, 0.1 mg/kg, i.p.), but not with the CNS penetrant H1R antagonist pyrilamine (PYR, 10 mg/kg, i.p.). Moreover, the memory enhancing effect of DL77 (5 mg/kg, i.p.) in MK801-induced memory deficits in PAP was strongly reversed when rats were pretreated with a combination of ZOL (10 mg/kg, i.p.) and SCO (1.0 mg/kg, i.p.). Furthermore, the significant ameliorative effect of DL77 (5 mg/kg, i.p.) on MK801-induced long-term memory (LTM) impairment in NOR test was comparable to the DOZ-provided memory-enhancing effect, and was abrogated when animals were pretreated with the histamine H3R agonist R-(α)-methylhistamine (RAMH, 10 mg/kg, i.p.). However, DL77(5 mg/kg, i.p.) failed to provide procognitive effect on MK801-induced short-term memory (STM) impairment in NOR test. In addition, DL77 (5 mg/kg) did not alter anxiety levels and locomotor activity of animals naive to elevated-plus maze (EPM), demonstrating that improved performances with DL77 (5 mg/kg) in PAP or NOR are unrelated to changes in emotional responding or spontaneous locomotor activity. These results provide evidence for the potential of H3Rs for the treatment of neurodegenerative disorders related to impaired memory function, e.g. CDS.

Keywords: histamine H3 receptor, antagonist, learning, memory impairment, passive avoidance paradigm, novel object recognition

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Authors: Nazila Dehbari, Javad Tavakoli, Yakani Kambu, Youhong Tang

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Superabsorbent hydrogels (SAP), as an enviro-sensitive material have been widely used for industrial and biomedical applications due to their unique structure and capabilities. Poor mechanical properties of SAPs - which is extremely related to their large volume change – count as a great weakness in adopting for high-tech applications. Therefore, improving SAPs’ mechanical properties via toughening methods by mixing different types of cross-linked polymer or introducing energy-dissipating mechanisms is highly focused. In this work, in order to change the intrinsic brittle character of commercialized Poly Acrylic Acid (here as SAP) to be semi-ductile, a commercial available highly branched tree-like dendritic polymers with numerous –OH end groups known as hyper-branched polymer (HB) has been added to PAA-SAP system in a single step, cost effective and environment friendly solvent casting method. Samples were characterized by FTIR, SEM and TEM and their physico-chemical characterization including swelling capabilities, hydraulic permeability, surface tension and thermal properties had been performed. Toughness energy, stiffness, elongation at breaking point, viscoelastic properties and samples extensibility were mechanical properties that had been performed and characterized as a function of samples lateral cracks’ length in different HB concentration. Addition of HB to PAA-SAP significantly improved mechanical and surface properties. Increasing equilibrium swelling ratio by about 25% had been experienced by the SAP-HB samples in comparison with SAPs; however, samples swelling kinetics remained without changes as initial rate of water uptake and equilibrium time haven’t been subjected to any changes. Thermal stability analysis showed that HB is participating in hybrid network formation while improving mechanical properties. Samples characterization by TEM showed that, the aggregated HB polymer binders into nano-spheres with diameter in range of 10–200 nm. So well dispersion in the SAP matrix occurred as it was predictable due to the hydrophilic character of the numerous hydroxyl groups at the end of HB which enhance the compatibility of HB with PAA-SAP. As the profused -OH groups in HB could react with -COOH groups in the PAA-SAP during the curing process, the formation of a 2D structure in the SAP-HB could be attributed to the strong interfacial adhesion between HB and the PAA-SAP matrix which hinders the activity of PAA chains (SEM analysis). FTIR spectra introduced new peaks at 1041 and 1121 cm-1 that attributed to the C–O(–OH) stretching hydroxyl and O–C stretching ester groups of HB polymer binder indicating the incorporation of HB polymer into the SAP structure. SAP-HB polymer has significant effects on the final mechanical properties. The brittleness of PAA hydrogels are decreased by introducing HB as the fracture energies of hydrogels increased from 8.67 to 26.67. PAA-HBs’ stretch ability enhanced about 10 folds while reduced as a function of different notches depth.

Keywords: superabsorbent polymer, toughening, viscoelastic properties, hydrogel network

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Authors: Junior Akunzi

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In the matter of patient treatment planning quality assurance in 3D conformational therapy (3D-CRT) and volumetric arc therapy (VMAT or RapidArc), the independent monitor unit verification calculation (MUVC) is an indispensable part of the process. Concerning 3D-CRT treatment planning, the MUVC can be performed manually applying the standard ESTRO formalism. However, due to the complex shape and the amount of beams in advanced treatment planning technic such as RapidArc, the manual independent MUVC is inadequate. Therefore, commercially available software such as RadCalc can be used to perform the MUVC in complex treatment planning been. Indeed, RadCalc (version 6.3 LifeLine Inc.) uses a simplified Clarkson algorithm to compute the dose contribution for individual RapidArc fields to the isocenter. The purpose of this project is the validation of RadCalc in 3D-CRT and RapidArc for treatment planning dosimetry quality assurance at Antoine Lacassagne center (Nice, France). Firstly, the interfaces between RadCalc and our treatment planning systems (TPS) Isogray (version 4.2) and Eclipse (version13.6) were checked for data transfer accuracy. Secondly, we created test plans in both Isogray and Eclipse featuring open fields, wedges fields, and irregular MLC fields. These test plans were transferred from TPSs according to the radiotherapy protocol of DICOM RT to RadCalc and the linac via Mosaiq (version 2.5). Measurements were performed in water phantom using a PTW cylindrical semiflex ionisation chamber (0.3 cm³, 31010) and compared with the TPSs and RadCalc calculation. Finally, 30 3D-CRT plans and 40 RapidArc plans created with patients CT scan were recalculated using the CT scan of a solid PMMA water equivalent phantom for 3D-CRT and the Octavius II phantom (PTW) CT scan for RapidArc. Next, we measure the doses delivered into these phantoms for each plan with a 0.3 cm³ PTW 31010 cylindrical semiflex ionisation chamber (3D-CRT) and 0.015 cm³ PTW PinPoint ionisation chamber (Rapidarc). For our test plans, good agreements were found between calculation (RadCalc and TPSs) and measurement (mean: 1.3%; standard deviation: ± 0.8%). Regarding the patient plans, the measured doses were compared to the calculation in RadCalc and in our TPSs. Moreover, RadCalc calculations were compared to Isogray and Eclispse ones. Agreements better than (2.8%; ± 1.2%) were found between RadCalc and TPSs. As for the comparison between calculation and measurement the agreement for all of our plans was better than (2.3%; ± 1.1%). The independent MU verification calculation software RadCal has been validated for clinical use and for both 3D-CRT and RapidArc techniques. The perspective of this project includes the validation of RadCal for the Tomotherapy machine installed at centre Antoine Lacassagne.

Keywords: 3D conformational radiotherapy, intensity modulated radiotherapy, monitor unit calculation, dosimetry quality assurance

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Authors: K. P. Gogoi

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The current research study investigates the motivational pattern viz Power motivation among the tribal college students of Assam. The sample consisted of 240 college students (120 tribal and 120 non-tribal) ranging from 18-24 years, 60 males and 60 females for both tribal’s and non-tribal’s. Attempts were made to include all the prominent tribes of Assam viz. Thematic Apperception Test, Power motive Scale and a semi structured interview schedule were used to gather information about their family types, parental deprivation, parental relations, social and political belongingness. Mean, Standard Deviation, and t-test were the statistical measures adopted in this 2x2 factorial design study. In addition to this discriminant analysis has been worked out to strengthen the predictive validity of the obtained data. TAT scores reveal significant difference between the tribal’s and non-tribal on power motivation. However results obtained on gender difference indicates similar scores among both the cultures. Cross validation of the TAT results was done by using the power motive scale by T. S. Dapola which confirms the results on need for power through TAT scores. Power motivation has been studied in three directions i.e. coercion, inducement and restraint. An interesting finding is that on coercion tribal’s score high showing significant difference whereas in inducement or seduction the non-tribal’s scored high showing significant difference. On the other hand on restraint no difference exists between both cultures. Discriminant analysis has been worked out between the variables n-power, coercion, inducement and restraint. Results indicated that inducement or seduction (.502) is the dependent measure which has the most discriminating power between these two cultures.

Keywords: power motivation, tribal, social, political, predictive validity, cross validation, coercion, inducement, restraint

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Authors: Muna Khethier Abbass, Khairia Salman Hussan, Huda Mohummed AbdudAlaziz

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This work aims to study the effect of shot peening on the mechanical properties of welded joints which performed by two different welding processes: Tungsten inert gas (TIG) welding and friction stir welding (FSW) processes of aluminum alloy 6061 T6. Arc welding process (TIG) was carried out on the sheet with dimensions of (100x50x6 mm) to obtain many welded joints with using electrode type ER4043 (AlSi5) as a filler metal and argon as shielding gas. While the friction stir welding process was carried out using CNC milling machine with a tool of rotational speed (1000 rpm) and welding speed of (20 mm/min) to obtain the same butt welded joints. The welded pieces were tested by X-ray radiography to detect the internal defects and faulty welded pieces were excluded. Tensile test specimens were prepared from welded joints and base alloy in the dimensions according to ASTM17500 and then subjected to shot peening process using steel ball of diameter 0.9 mm and for 15 min. All specimens were subjected to Vickers hardness test and micro structure examination to study the effect of welding process (TIG and FSW) on the micro structure of the weld zones. Results showed that a general decay of mechanical properties of TIG and FSW welded joints comparing with base alloy while the FSW welded joint gives better mechanical properties than that of TIG welded joint. This is due to the micro structure changes during the welding process. It has been found that the surface hardening by shot peening improved the mechanical properties of both welded joints, this is due to the compressive residual stress generation in the weld zones which was measured using X-Ray diffraction (XRD) inspection.

Keywords: friction stir welding, TIG welding, mechanical properties, shot peening

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Authors: Cyril O. Ehi-Eromosele, Ajayi Kayode

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The Li-rich layered metal oxides (LLO) are the most promising candidates for promising electrodes of high energy Li-ion battery (LIB). In literature, these electrode system has either been designed as a hetero-structure of the primary components (composite) or as a core-shell structure with improved electrochemistry reported for both configurations when compared with its primary components. With the on-going efforts to improve on the electrochemical performance of the LIB, it is important to investigate comparatively the structural and electrochemical characteristics of the core-shell like and ‘composite’ forms of these materials with the same compositions and synthesis conditions which could influence future engineering of these materials. Therefore, this study concerns the structural and electrochemical properties of the ‘composite’ and core-shell like LLO cathode materials with the same nominal composition of 0.5Li₂MnO₃-0.5LiNi₀.₅Mn₀.₃Co₀.₂O₂ (LiNi₀.₅Mn₀.₃Co₀.₂O₂ as core and Li₂MnO₃ as the shell). The results show that the core-shell sample (–CS) gave better electrochemical performance than the ‘composite’ sample (–C). Both samples gave the same initial charge capacity of ~300 mAh/g when cycled at 10 mA/g and comparable charge capacity (246 mAh/g for the –CS sample and 240 mAh/g for the –C sample) when cycled at 200 mA/g. However, the –CS sample gave a higher initial discharge capacity at both current densities. The discharge capacity of the –CS sample was 232 mAh/g and 164 mAh/g while the –C sample is 208 mAh/g and 143 mAh/g at the current densities of 10 mA/g and 200 mA/g, respectively. Electrochemical impedance spectroscopy (EIS) results show that the –CS sample generally exhibited a smaller resistance than the –C sample both for the uncycled and after 50th cycle. Detailed structural analysis is on-going, but preliminary results show that the –CS sample had bigger unit cell volume and a higher degree of cation mixing. The thermal stability of the –CS sample was higher than the –C sample. XPS investigation also showed that the pristine –C sample gave a more reactive surface (showing formation of carbonate species to a greater degree) which could result in the greater resistance seen in the EIS result. To reinforce the results obtained for the 0.5Li₂MnO₃-0.5LiNi₀.₅Mn₀.₃Co₀.₃O₂ composition, the same investigations were extended to another ‘composite’ and core-shell like LLO cathode materials also with the same nominal composition of 0.5Li₂MnO₃-0.5LiNi₀.₃Mn₀.₃Co₀.₃O₂. In this case, the aim was to determine the electrochemical performance of the material using a low Ni content (LiNi₀.₃Mn₀.₃Co₀.₃O₂) as the core to clarify the contributions of the core-shell configuration to the electrochemical performance of these materials. Ni-rich layered oxides show active catalytic surface leading to electrolyte oxidation resulting in poor thermal stability and cycle life. Here, the core-shell sample also gave better electrochemical performance than the ‘composite’ sample with 0.5Li₂MnO₃-0.5LiNi₀.₃Mn₀.₃Co₀.₃O₂ composition. Furthermore, superior electrochemical performance was also recorded for the core-shell like spinel modified LLO (0.5Li₂MnO₃-0.45LiNi₀.₅Mn₀.₃Co₀.₂O₂-0.05LiNi₀.₅Mn₁.₅O₄) when compared to the composite system. These results show that the core-shell configuration can generally be used to improve the structural and electrochemical properties of the LLO and spinel modified LLO materials.

Keywords: lithium-ion battery, lithium rich oxide cathode, core-shell structure, composite structure

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Authors: Hidayah Triana, Mahir S. Gani, Asmi Citra Malina, Hamka

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This study was conducted to determine genetic diversity of tiger groupers that are resistant to V. parahaemolyticus and tolerant to low extreme salinities. This research is useful to obtain superior broodstock of fish. Tiger grouper used were 6 to 8 cm obtained from Brackish Water Aquaculture Research Center Gondol (Bali). This study consists of four stages: preliminary stage was adaptation of fish exposed to several concentrations of V. parahaemolyticus (103, 104, 105, 106, and 107 CFU / ml); second stage was test of Lethal Concentration (LC50) of bacteria to fish; third stage was salinity tolerance test (low salinity 12, 14 and 16 ppt) and fourth stage was analysis of DNA profiles. For DNA profiles analysis, genomic DNA of fish were extracted for PCR using primers YNZ-22 and UBC-122 and visualized by electrophoresis method. The results showed that Lethal concentration of bacteria (LC50) to fish was 1,56x106 CFU/ml. Furthermore, survival rate of groupers exposed with low salinities (12, 14, 16 ppt) survival rates were found to be 54,17 %, 66,67 % and 79,16 % respectively. Average of DNA fragment (5 fragments) generated from primer UBC-122 in the group of fish resistant to V.parahaemolyticus and tolerant to low salinities was similar to group of susceptible to low salinities. Primer YNZ-22 generated more diverse of DNA fragments (8,0 and 5,8 fragments) both in the group of fish tolerant and susceptible to low salinities compared to primer UBC-122 (5,0 fragments). Size of DNA 1.5 kb resulted from primer YNZ-22. Primer YNZ-22 generated 4 (50 %) and 3 (42,8 %) polymorfic fragments in the group of fish tolerant and susceptible to low salinities, respectively. Four (4) monomorfic fragments were found both in the group of fish tolerant and susceptible to low salinities. Primer UBC-122 generated 6 (85,7 %) and 9 (90,0 %) polymorfic fragments in the fish tolerant and susceptible to low salinities, respectively.

Keywords: genetic diversity, epinephelus fuscoguttatus, V. parahaemolyticus, PCR-RAPD, low extreme salinity

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Authors: Nicolas Lipchak, Franco Aiducic, Santiago Baieli

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The present work is a part of the research project called ‘Testing of gas turbine KingTech with biodiesel’, carried out by the Department of Industrial Engineering of the National Technological University at Buenos Aires. The research group aims to experiment with biodiesel in a gas turbine Kingtech K-100 to verify the correct operation of it. In this sense, tests have been developed to obtain real data of parameters inherent to the work cycle, to be used later as parameters of comparison and performance analysis. In the first instance, the study consisted in testing the gas turbine with a mixture composition of 50% Biodiesel and 50% Diesel. The parameters arising from the measurements made were compared with the parameters of the gas turbine with a composition of 100% Diesel. In the second instance, the measured parameters were used to calculate the power generated and the thermal efficiency of the Kingtech K-100 turbine. The turbine was also inspected to verify the status of the internals due to the use of biofuels. The conclusions obtained allow empirically demonstrate that it is feasible to use biodiesel in this type of gas turbines, without the use of this fuel generates a loss of power or degradation of internals.

Keywords: biodiesel, efficiency, KingTech, turbine

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Authors: Hilary Limo Rutto

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To better understand the application of diatomite as an adsorbent for the removal of Pb2+ from heavy metal-contaminated water, in this paper, diatomite was used to adsorb Pb2+ from aqueous solution under various conditions. The intrinsic exchange properties were further improved by heating the raw diatomite with fluxing agent at different temperatures and modification with manganese oxides. It is evident that the mass of the adsorbed Pb2+ generally increases after thermal treatment and modification with manganese oxides. The adsorption characteristics of lead on diatomite were studied at pH range of 2.5–12. The favourable pH range was found to be 7.5-8.5. The thermodynamic parameters (i.e.,∆H° ∆G° ∆S°) were evaluated from the temperature dependent adsorption isotherms. The results indicated that the adsorption process of Pb2+ on diatomite was spontaneous, endothermic and physical in nature. The equilibrium data have been analyzed using Langmuir and freundlich isotherm. The Langmuir isotherm was demonstrated to provide the best correlation for the adsorption of lead onto diatomite. The kinetics was studied using Pseudo- first and second-order model on the adsorption of lead onto diatomite. The results give best fit in second-order studies and it can be concluded that the adsorption of lead onto diatomite is second order reaction.

Keywords: thermally modified, diatomite, adsorption, lead

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Authors: Rui Huang, Thomas Richard, Masood Mostofi

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The lifetime of impregnated diamond bits and their drilling efficiency are in part governed by the bit wear conditions, not only the extent of the diamonds’ wear but also their exposure or protrusion out of the matrix bonding. As much as individual diamonds wear, the bonding matrix does also wear through two-body abrasion (direct matrix-rock contact) and three-body erosion (cuttings trapped in the space between rock and matrix). Although there is some work dedicated to the study of diamond bit wear, there is still a lack of understanding on how matrix erosion and diamond exposure relate to the bit drilling response and drilling efficiency, as well as no literature on the process that governs bit sharpening a procedure commonly implemented by drillers when the extent of diamond polishing yield extremely low rate of penetration. The aim of this research is (i) to derive a correlation between the wear state of the bit and the drilling performance but also (ii) to gain a better understanding of the process associated with tool sharpening. The research effort combines specific drilling experiments and precise mapping of the tool-cutting face (impregnated diamond bits and segments). Bit wear is produced by drilling through a rock sample at a fixed rate of penetration for a given period of time. Before and after each wear test, the bit drilling response and thus efficiency is mapped out using a tailored design experimental protocol. After each drilling test, the bit or segment cutting face is scanned with an optical microscope. The test results show that, under the fixed rate of penetration, diamond exposure increases with drilling distance but at a decreasing rate, up to a threshold exposure that corresponds to the optimum drilling condition for this feed rate. The data further shows that the threshold exposure scale with the rate of penetration up to a point where exposure reaches a maximum beyond which no more matrix can be eroded under normal drilling conditions. The second phase of this research focuses on the wear process referred as bit sharpening. Drillers rely on different approaches (increase feed rate or decrease flow rate) with the aim of tearing worn diamonds away from the bit matrix, wearing out some of the matrix, and thus exposing fresh sharp diamonds and recovering a higher rate of penetration. Although a common procedure, there is no rigorous methodology to sharpen the bit and avoid excessive wear or bit damage. This paper aims to gain some insight into the mechanisms that accompany bit sharpening by carefully tracking diamond fracturing, matrix wear, and erosion and how they relate to drilling parameters recorded while sharpening the tool. The results show that there exist optimal conditions (operating parameters and duration of the procedure) for sharpening that minimize overall bit wear and that the extent of bit sharpening can be monitored in real-time.

Keywords: bit sharpening, diamond exposure, drilling response, impregnated diamond bit, matrix erosion, wear rate

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Authors: Lewis J. Woollin, Robert I. Davidson, Paul Watson, Philip J. Hyde

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Introduction: In-vitro testing of arthroplasty materials is of paramount importance when ensuring that they can withstand the performance requirements encountered in-vivo. One common machine used for in-vitro testing is a pin-on-plate tribometer, an early stage screening device that generates data on the wear characteristics of arthroplasty bearing materials. These devices test vertically loaded rotating cylindrical pins acting against reciprocating plates, representing the bearing surfaces. In this study, a pin-on-plate machine has been developed that provides several improvements over current technology, thereby progressing arthroplasty bearing research. Historically, pin-on-plate tribometers have been used to investigate the performance of arthroplasty bearing materials under conditions commonly encountered during a standard gait cycle; nominal operating pressures of 2-6 MPa and an operating frequency of 1 Hz are typical. There has been increased interest in using pin-on-plate machines to test more representative in-vivo conditions, due to the drive to test 'beyond compliance', as well as their testing speed and economic advantages over hip simulators. Current pin-on-plate machines do not accommodate the increased performance requirements associated with more extreme kinematic conditions, therefore a next-generation pin-on-plate tribometer has been developed to bridge the gap between current technology and future research requirements. Methodology: The design was driven by several physiologically relevant requirements. Firstly, an increased loading capacity was essential to replicate the peak pressures that occur in the natural hip joint during running and chair-rising, as well as increasing the understanding of wear rates in obese patients. Secondly, the introduction of mid-cycle load variation was of paramount importance, as this allows for an approximation of the loads present in a gait cycle to be applied and to test the fatigue properties of materials. Finally, the rig must be validated against previous-generation pin-on-plate and arthroplasty wear data. Results: The resulting machine is a twelve station device that is split into three sets of four stations, providing an increased testing capacity compared to most current pin-on-plate tribometers. The loading of the pins is generated using a pneumatic system, which can produce contact pressures of up to 201 MPa on a 3.2 mm² round pin face. This greatly exceeds currently achievable contact pressures in literature and opens new research avenues such as testing rim wear of mal-positioned hip implants. Additionally, the contact pressure of each set can be changed independently of the others, allowing multiple loading conditions to be tested simultaneously. Using pneumatics also allows the applied pressure to be switched ON/OFF mid-cycle, another feature not currently reported elsewhere, which allows for investigation into intermittent loading and material fatigue. The device is currently undergoing a series of validation tests using Ultra-High-Molecular-Weight-Polyethylene pins and 316L Stainless Steel Plates (polished to a Ra < 0.05 µm). The operating pressures will be between 2-6 MPa, operating at 1 Hz, allowing for validation of the machine against results reported previously in the literature. The successful production of this next-generation pin-on-plate tribometer will, following its validation, unlock multiple previously unavailable research avenues.

Keywords: arthroplasty, mechanical design, pin-on-plate, total joint replacement, wear testing

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Authors: A. M. Gheitaghy, H. Saffari, G. Q. Zhang

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Numerical approach based on the electrical simulation method is proposed to solve a nonlinear transient heat conduction problem with nonlinear boundary for a spherical body. This problem represents a strong nonlinearity in both the governing equation for temperature dependent thermal property and the boundary condition for combined convective and radiative cooling. By analysing the equivalent electrical model using the electrical circuit simulation program HSPICE, transient temperature and heat flux distributions at sphere can be obtained easily and fast. The solutions clearly illustrate the effect of the radiation-conduction parameter Nrc, the Biot number and the linear coefficient of temperature dependent conductivity and heat capacity. On comparing the results with corresponding numerical solutions, the accuracy and efficiency of this computational method are found to be good.

Keywords: convective and radiative boundary, electrical simulation method, nonlinear heat conduction, spherical coordinate

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Authors: Sharmin Sultana, Nicolas Nuns, Pardis Simon, Jean-Marc Giraudon, Jean-Francois Lamonior, Nathalie D. Geyter, Rino Morent

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Environmental issues, especially air pollution, have become a huge concern of environmental legislation as a consequence of growing awareness in our global world. In this regard, control of volatile organic compounds (VOCs) emission has become an important issue due to their potential toxicity, carcinogenicity, and mutagenicity. The research of innovative technologies for VOC abatement is stimulated to accommodate the new stringent standards in terms of VOC emission. One emerging strategy is the coupling of 2 existing complementary technologies, namely here non-thermal plasma (NTP) and heterogeneous catalysis, to get a more efficient process for VOC removal in air. The objective of this current work is to investigate the abatement of trichloroethylene (TCE-highly toxic chlorinated VOC) from moist air (RH=15%) as a function of time by combined use of multi-pin-to-plate negative DC corona/glow discharge with Fe-doped cryptomelanes catalyst downstream i.e. post plasma-catalysis (PPC) process. For catalyst alone case, experiments reveal that, initially, Fe doped cryptomelane (regardless the mode of Fe incorporation by co-precipitation (Fe-K-OMS-2)/ impregnation (Fe/K-OMS-2)) exhibits excellent activity to decompose TCE compared to cryptomelane (K-OMS-2) itself. A maximum obtained value of TCE abatement after 6 min is as follows: Fe-KOMS-2 (73.3%) > Fe/KOMS-2 (48.5) > KOMS-2 (22.6%). However, with prolonged operation time, whatever the catalyst under concern, the abatement of TCE decreases. After 111 min time of exposure, the catalysts can be ranked as follows: Fe/KOMS-2 (11%) < K-OMS-2 (12.3%) < Fe-KOMS-2 (14.5%). Clearly, this phenomenon indicates catalyst deactivation either by chlorination or by blocking the active sites. Remarkably, in PPC configuration (energy density = 60 J/L, catalyst temperature = 150°C), experiments reveal an enhanced performance towards TCE removal regardless the type of catalyst. After 6 min time on stream, the TCE removal efficiency amount as follows: K-OMS-2 (60%) < Fe/K-OMS-2 (79%) < Fe-K-OMS-2 (99.3%). The enhanced performances over Fe-K-OMS-2 catalyst are attributed to its high surface oxygen mobility and structural defects leading to high O₃ decomposition efficiency to give active species able to oxidize the plasma processed hazardous\by-products and the possibly remaining VOC into CO₂. Moreover, both undoped and doped catalysts remain strongly capable to abate TCE with time on stream. The TCE removal efficiencies of the PPC processes with Fe/KOMS-2 and KOMS-2 catalysts are not affected by time on stream indicating an excellent catalyst stability. When using the Fe-K-OMS-2 as catalyst, TCE abatement slightly reduces with time on stream. However, it is noteworthy to stress that still a constant abatement of 83% is observed during at least 30 minutes. These results prove that the combination of NTP with catalysts not only increases the catalytic activity but also allows to avoid, to some extent, the poisoning of catalytic sites resulting in an enhanced catalyst stability. In order to better understand the different surface processes occurring in the course of the total TCE oxidation in PPC experiments, a detailed X-ray Photoelectron Spectroscopy (XPS) and Time of Flight-Secondary Ion Mass Spectrometry (ToF-SIMS) study on the fresh and used catalysts is in progress.

Keywords: Fe doped cryptomelane, non-thermal plasma, plasma-catalysis, stability, trichloroethylene

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Authors: Augustas Vaitkevicius, Mikhail Korjik, Eugene Tretyak, Ekaterina Trusova, Gintautas Tamulaitis

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Silicate materials are widely used as luminescent materials in amorphous and crystalline phase. Lithium silicate glass is popular for making neutron sensitive scintillation glasses. Cerium-doped single crystalline silicates of rare earth elements and yttrium have been demonstrated to be good scintillation materials. Due to their high thermal and photo-stability, silicate glass ceramics are supposed to be suitable materials for producing light converters for high power white light emitting diodes. In this report, the influence of glass composition and crystallization on photoluminescence (PL) of different silicate glasses was studied. Barium (BaO-2SiO₂) and lithium (Li₂O-2SiO₂) glasses were under study. Cerium, dysprosium, erbium and europium ions as well as their combinations were used for doping. The influence of crystallization was studied after transforming the doped glasses into glass ceramics by heat treatment in the temperature range of 550-850 degrees Celsius for 1 hour. The study was carried out by comparing the photoluminescence (PL) spectra, spatial distributions of PL parameters and quantum efficiency in the samples under study. The PL spectra and spatial distributions of their parameters were obtained by using confocal PL microscopy. A WITec Alpha300 S confocal microscope coupled with an air cooled CCD camera was used. A CW laser diode emitting at 405 nm was exploited for excitation. The spatial resolution was in sub-micrometer domain in plane and ~1 micrometer perpendicularly to the sample surface. An integrating sphere with a xenon lamp coupled with a monochromator was used to measure the external quantum efficiency. All measurements were performed at room temperature. Chromatic properties of the light emission from the glasses and glass ceramics have been evaluated. We observed that the quantum efficiency of the glass ceramics is higher than that of the corresponding glass. The investigation of spatial distributions of PL parameters revealed that heat treatment of the glasses leads to a decrease in sample homogeneity. In the case of BaO-2SiO₂: Eu, 10 micrometer long needle-like objects are formed, when transforming the glass into glass ceramics. The comparison of PL spectra from within and outside the needle-like structure reveals that the ratio between intensities of PL bands associated with Eu²⁺ and Eu³⁺ ions is larger in the bright needle-like structures. This indicates a higher degree of crystallinity in the needle-like objects. We observed that the spectral positions of the PL bands are the same in the background and the needle-like areas, indicating that heat treatment imposes no significant change to the valence state of the europium ions. The evaluation of chromatic properties confirms applicability of the glasses under study for fabrication of white light sources with high thermal stability. The ability to combine barium and lithium glass matrixes and doping by Eu, Ce, Dy, and Tb enables optimization of chromatic properties.

Keywords: glass ceramics, luminescence, phosphor, silicate

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Authors: Yohannes Bisa Biramo

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This study examined the meditational role of surface acting and deep acting on the relationship between calling orientation and work engagement of teachers in secondary schools of Wolaita Zone, Wolaita, Ethiopia. A predictive non-experimental correlational design was performed among 300 secondary school teachers. Stratified random sampling followed by a systematic random sampling technique was used as the basis for selecting samples from the target population. To analyze the data, Structural Equation Modeling (SEM) was used to test the association between the independent variables and the dependent variables. Furthermore, the goodness of fit of the study variables was tested using SEM to see and explain the path influence of the independent variable on the dependent variable. Confirmatory factor analysis (CFA) was conducted to test the validity of the scales in the study and to assess the measurement model fit indices. The analysis result revealed that calling was significantly and positively correlated with surface acting, deep acting and work engagement. Similarly, surface acting was significantly and positively correlated with deep acting and work engagement. And also, deep acting was significantly and positively correlated with work engagement. With respect to mediation analysis, the result revealed that surface acting mediated the relationship between calling and work engagement and also deep acting mediated the relationship between calling and work engagement. Besides, by using the model of the present study, the school leaders and practitioners can identify a core area to be considered in recruiting and letting teachers teach, in giving induction training for newly employed teachers and in performance appraisal.

Keywords: calling, surface acting, deep acting, work engagement, mediation, teachers

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Authors: S. M. Ishtiaque, V. K. Yadav, S. D. Joshi, J. K. Chatterjee

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The DIAMETRIC FAULTS system has been developed that captures a bi-directional image of yarn continuously in sequentially manner and provides the detailed classification of faults. A novel mathematical framework developed on the acquired bi-directional images forms the basis of fault classification in four broad categories, namely, Thick1, Thick2, Thin and Normal Yarn. A discretised version of Radon transformation has been used to convert the bi-directional images into one-dimensional signals. Images were divided into training and test sample sets. Karhunen–Loève Transformation (KLT) basis is computed for the signals from the images in training set for each fault class taking top six highest energy eigen vectors. The fault class of the test image is identified by taking the Euclidean distance of its signal from its projection on the KLT basis for each sample realization and fault class in the training set. Euclidean distance applied using various techniques is used for classifying an unknown fault class. An accuracy of about 90% is achieved in detecting the correct fault class using the various techniques. The four broad fault classes were further sub classified in four sub groups based on the user set boundary limits for fault length and fault volume. The fault cross-sectional area and the fault length defines the total volume of fault. A distinct distribution of faults is found in terms of their volume and physical dimensions which can be used for monitoring the yarn faults. It has been shown from the configurational based characterization and classification that the spun yarn faults arising out of mass variation, exhibit distinct characteristics in terms of their contours, sizes and shapes apart from their frequency of occurrences.

Keywords: Euclidean distance, fault classification, KLT, Radon Transform

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Authors: Alicia Carranza, Hildemar Dos Santos, W. Lawrence Beeson, R. Patti Herring, Kimberly R. Freeman, Adam Arechiga

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Early exposure to trauma can impact health-related behaviors later in life, which poses a considerable challenge for young adults transitioning into independence when they are lacking the necessary skills and support to live a healthy life. The study will be a non-experimental, mixed methods pre- and post-test (where subjects will serve as their own controls) to determine the impact of an eight-week trauma-informed healthy lifestyle program on self-efficacy for adopting health-promoting behaviors and health outcomes among young adults. Forty-two adults, ages 18-24 who are living in Orange County, CA will be recruited to participate in the eight-week trauma-informed healthy living program. Baseline and post-intervention assessments will be conducted to assess changes in self-efficacy for nutrition and physical exercise, sleep quality and quantity, body mass index (kg/m2), and coping skills used by comparing pre- to post-intervention. Some of the planned activities include cooking demonstrations, mindful eating activities and media literacy using Instagram. Frequencies analyses, paired t-test, and multiple regression will be used to determine if there was a change in coping skills. The results of this study can serve to assess the potential for mitigating the effects of Adverse Childhood Experiences (ACEs), or other toxic stress, experienced during adolescence across the lifespan. Young adults who learn how to cope with stress in a healthy way and engage in a healthy lifestyle can be better prepared to role model that behavior to their children.

Keywords: nutrition, healthy lifestyle, trauma-informed, stress management

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Authors: M. A. Boukli Hacene, N. E.Chabane Sari, A. Benzair

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This article highlights a method for natural heating and cooling of systems in areas of moderate climate. Movement of air is generated inside a space by an underground piping system. In this paper, we discuss a feasibility study in Algeria of air-conditioning using a ground source heat pump (GSHP) with vertical mounting, coupled with a solar collector. This study consists of modeling ground temperature at different depths, for a clay soil in the city of Tlemcen. Our model is developed from the non-stationary heat equation for a homogeneous medium and takes into consideration the soil thermal diffusivity. It uses the daily ambient temperature during a typical year for the locality of Tlemcen. The study shows the feasibility of using a heating/cooling GSHP in the town of Tlemcen for the particular soil type; and indicates that the duration of air flow in the borehole has a major influence on the outgoing temperature drilling.

Keywords: green building, heat pump, insulation, climate change

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Authors: Salmi-Laouar Sihem, Aouissi Riadh

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The Cenomanian formations of the Bellezma-Batna Range are yielding very diversified fossiliferous beds. Among the abundant and well-preserved fossils stands out Aspidiscus cristatus (Lamarck). This taxon is assigned to the Family Latomeandridae (Alloiteau) for the presence of six symmetry axes. The outer morphology of sampled specimens documents a low-energy environment with a high sedimentary rate and a mud-supported bottom. Its provincialism evidences some characteristic thermal gradients of the marked Tethysian climatic areas. Biometric measurements are given. Coral size increases from the North towards the southeastern Tethysian margin where waters are supposed warmer; this feature is also underlined by a frequent bio-erosion of sampled specimens. Its limited stratigraphic range makes it a good candidate for an index species for the Middle Cenomanian.

Keywords: Aspidiscus cristatus, coral, Middle Cenomanian, Batna, Bellezma, Algeria

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Authors: S. Saadi, S. Benissaad, S. Poncet, Y. Kabar

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In photovoltaic (PV) cells, most of the absorbed solar radiation cannot be converted into electricity. A large amount of solar radiation is converted to heat, which should be dissipated by any cooling techniques. In the present study, the cooling is achieved by inserting triangular ribs in the duct. A comprehensive two-dimensional thermo-fluid model for the effective cooling of PV cells has been developed. It has been first carefully validated against experimental and numerical results available in the literature. A parametric analysis was then carried out about the influence of the number and size of the ribs, wind speed, solar irradiance and inlet fluid velocity on the average solar cell and outlet air temperatures as well as the thermal and electrical efficiencies of the module. Results indicated that the use of triangular ribbed channels is a very effective cooling technique, which significantly reduces the average temperature of the PV cell, especially when increasing the number of ribs.

Keywords: effective cooling, numerical modeling, photovoltaic cell, triangular ribs

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Authors: Mahacine Amrani

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A simple and rapid method for the determination of alcohol in gasoline-alcohol mixtures using density measurements is described. The method can determine a minimum of 1% of alcohol by volume. The precision of the method is ± 3%.The method is more useful for field test in the quality assessment of alcohol blended fuels.

Keywords: gasoline-alcohol, mixture, alcohol determination, density, measurement, Morocco

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Authors: Mahsa Faramarzi Asli, Mina Sarabi

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The important issues that are addressed in most advanced industrial countries in recent decades, discussion of minimizing heat losses through the buildings. And the most influential parameters in the calculation of building energy consumption, is heat exchange, which takes place between the interior and outer space. One of the solutions to reduce heat loss is using materials with low thermal conductivity. The purpose of this article, is the effect of using some frontages with nano-concrete photo catalytic precast materials for reducing energy consumption in buildings. For this purpose, estimating the energy dissipation through the facade built with nano-concrete photo catalytic precast materials on a sample building in Tabriz city by BCS 19 software ( topic 19 simulation) is done and the results demonstrate reduce heat loss through the facade nano- concrete.

Keywords: nano materials, optimize energy consumption, themal, stability

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Authors: Hussain Bohra, Pradyuman Sharma

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This study highlights the significance of Balance Sheet Indicators on the corporate performance in the case of Indian manufacturing companies. Balance sheet indicators show the actual financial health of the company and it helps to the external investors to choose the right company for their investment and it also help to external financing agency to give easy finance to the manufacturing companies. The period of study is 2000 to 2014 for 813 manufacturing companies for which the continuous data is available throughout the study period. The data is collected from PROWESS data base maintained by Centre for Monitoring Indian Economy Pvt. Ltd. Panel data methods like fixed effect and random effect methods are used for the analysis. The Likelihood Ratio test, Lagrange Multiplier test and Hausman test results proof the suitability of the fixed effect model for the estimation. Return on assets (ROA) is used as the proxy to measure corporate performance. ROA is the best proxy to measure corporate performance as it already used by the most of the authors who worked on the corporate performance. ROA shows return on long term investment projects of firms. Different ratios like Current Ratio, Debt-equity ratio, Receivable turnover ratio, solvency ratio have been used as the proxies for the Balance Sheet Indicators. Other firm specific variable like firm size, and sales as the control variables in the model. From the empirical analysis, it was found that all selected financial ratios have significant and positive impact on the corporate performance. Firm sales and firm size also found significant and positive impact on the corporate performance. To check the robustness of results, the sample was divided on the basis of different ratio like firm having high debt equity ratio and low debt equity ratio, firms having high current ratio and low current ratio, firms having high receivable turnover and low receivable ratio and solvency ratio in the form of firms having high solving ratio and low solvency ratio. We find that the results are robust to all types of companies having different form of selected balance sheet indicators ratio. The results for other variables are also in the same line as for the whole sample. These findings confirm that Balance sheet indicators play as significant role on the corporate performance in India. The findings of this study have the implications for the corporate managers to focus different ratio to maintain the minimum expected level of performance. Apart from that, they should also maintain adequate sales and total assets to improve corporate performance.

Keywords: balance sheet, corporate performance, current ratio, panel data method

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Authors: Bassant M. M. Ibrahim, Doha H. Abou Baker, Ahmed Abd Elghafour

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Excessive exposure to heavy metals contributes to the occurrence of deleterious health problems that affect vital organs like the brain, liver, kidneys, and heart. The use of natural products that have antioxidant capabilities may contribute to the protection of these organs. In the present study, the essential oil of summer savory (Satureja hortensis) was used to evaluate its protective effects against lead acetate induced damaging effect on rats’ vital organs, due to its high contents of carvacrol, y-terpinene, and p-cymene. Forty female Wister Albino rats were classified into five equal groups, the 1st served as normal group, the 2nd served as positive control group was given lead acetate (60 mg/kg) intra-peritoneal (IP), the third to fifth groups were treated with calcium disodium (EDTA) as chelating agent and summer savory essential oil in doses of (50 and 100mg/kg) respectively. All treatments were given IP concomitant with lead acetate for ten successive days. At the end of the experiment duration electrocardiogram (ECG), an open field test for the evaluation of psychological state, rotarod test as for the evaluation of locomotor coordination ability as well as anti-inflammatory and oxidative stress biomarkers in serum and histopathology of vital organs were performed. The investigations in this study show that the protective effect of high dose of summer savory essential oil is more than the low dose and that the essential oil of summer savory is a promising agent that can contribute to the protection of vital organs against the hazardous damaging effects of lead acetate.

Keywords: brain, heart, kidneys, lead acetate, liver, protective, summer savory

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Authors: Venkatesan Sundaramoorthy

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The field of ceramics has undergone a remarkable transformation with the advent of additive manufacturing technologies. This comprehensive review explores the mechanical properties of additively manufactured ceramic components, focusing on key materials such as Alumina, Zirconia, and Silicon Carbide. The study delves into various authors' review technology into the various additive manufacturing techniques, including Stereolithography, Powder Bed Fusion, and Binder Jetting, highlighting their advantages and challenges. It provides a detailed analysis of the mechanical properties of these ceramics, offering insights into their hardness, strength, fracture toughness, and thermal conductivity. Factors affecting mechanical properties, such as microstructure and post-processing, are thoroughly examined. Recent advancements and future directions in 3D-printed ceramics are discussed, showcasing the potential for further optimization and innovation. This review underscores the profound implications of additive manufacturing for ceramics in industries such as aerospace, healthcare, and electronics, ushering in a new era of engineering and design possibilities for ceramic components.

Keywords: mechanical properties, additive manufacturing, ceramic materials, PBF

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Authors: Genesis F. Dela Cruz, Liza C. Costa

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The study is concerned with the Risk factors of dropping out among Grade VII students for SY 2012-2013. A total of 87 Grade VII Students-At-Risk-of-Dropping Out (SARDOs) were involved in this study. The descriptive survey method was used in this study. A 50-item questionnaire was used in data gathering. Expert validation was done to determine the validity and reliability of the instrument. The study used Chi Square, Kruskal Wallis Test and Mann Whitney Test in the statistical treatment of data. The study revealed that the respondents are within the standard age limit for Grade VII students in the Philippines which is 13 years old. Males more than females usually becomes SARDOs. SARDOs come from low economic status and complete families contrary to the common belief that they came from single-parent families. The study also showed that parent’s involvement in educating their children on family-related factors contributed to the very good perception on the family related factors. Based on age, there are no significant differences in their perception of the four major recognized risk factors for dropping out among all ages. There are no significant differences in their perception of the family, individual and community related factors for dropping out based on sex. However, females have a more favorable perception when it comes to school related factors. No significant differences in their perception of dropping out were also noted when they are classified according to distance of school from home. The respondents do not differ in their perception on family, individual and community related factors when they are classified according to type of family. When surveyed regarding the respondents’ reason for being absent, it was found out that laziness and being late are the two major reasons. Respondents also perceived remedial and tutorial classes as school-initiated intervention measure to prevent school disengagement or dropping out.

Keywords: drop-out, guidance and counseling, school initiated intervention, students at risk of dropping out

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Authors: Niang Mamadou Sileye

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The study turns on the use of the phytase in aquaculture, its zootechnical interests and the possibilities of incorporation in the feed. The goal is to reduce the waste in phosphorus linked to the feeding of fishes, without any loss of zootechnical performances and with a decrease of feed costs. We have studied the literature in order to evaluate the raw materials (total phosphorus, phytate and available phosphorus) used by a company to manufacture feed for rainbow trout; to determine the phosphorus requirements for aquaculture species; to determine the requirements of phosphorus for aquaculture species, to determine the sings of lack of phosphorus for fishes; to study the antagonism between the phosphorus and the calcium and to study also the different forms of waste for the rainbow trout. The results found in the bibliography enable us test several Hypothesis of feed formulation for rainbow trout with different raw materials. This simulation and the calculation for wastes allowed to validate two formulation of feed: a control feed (0.5% of monocalcique phosphate) and a trial feed (supplementation with 0.002% of phytase Ronozyme PL and without inorganic phosphate). The feeds have been produced and sent to a experimental structure (agricultural college of Brehoulou).The result of the formulation give a decrease of the phosphorus waste of 28% for the trial feed compared to the feed. The supplementation enables a gain of 2.3 euro per ton. The partial results of the current test show no significant difference yet for the zootechnical parameters (growth rate, mortality, weight gain and obvious conversion rate) between control feed and the trial one. The waste measures do not show either significant difference between the control feed and the trial one, but however, the average difference would to decrease the wastes of 35.6% thanks to the use of phytase.

Keywords: phosphorus, phytic acid, phytase, need, digestibility, formulation, food, waste, rainbow trout

Procedia PDF Downloads 79