Title: |
Two constraint preconditioners for generalized saddle point problems+ |
Authors: |
Cui-Xia Li || Shi-Liang Wu |
Source: |
International Journal of Precious Engineering Research and Applications, Volume 4, Issue 3 (May-June) 2019), PP. 01-04 |
Abstract: |
In this paper, we consider two new constraint preconditioners for generalized saddle point problems. The eigenvalue distribution of the related preconditioned matrix is discussed in detail. Theoretical analysis shows that all the eigenvalues of the preconditioned matrix are strongly clustered. |
Keywords: |
Generalized saddle point problems; eigenvalue; constraint preconditioner |
 |
Download Full Article |
Title: |
Thevenin analysis of alternating current R-C circuit for teaching and learning of electric circuit subject |
Authors: |
Ishak Annuar |
Source: |
International Journal of Precious Engineering Research and Applications, Volume 4, Issue 3 (May-June) 2019), PP. 05-08 |
Abstract: |
The paper presents the calculated and simulated of R-C alternating current (ac) circuit solved by using Thevenin method used for electric circuit subject. A MATLAB-Simulink (R2017b) was used for simulation purposes. A selected value of R-C ac circuit is developed for calculation and simulation, respectively. The simulation results of Vth and Zth using Simulink achieved lower percentage error Vth (0.102%) Zth (0.524% and 0.106%). The result showed simulated of Thevenin equivalent circuit is consistent with the calculated value with small error percentage. The first method of calculation of Zth achieved best result with the lowest percentage error of 0.106%. The result showed the successfully simulation by Simulink for Thevenin voltage and Thevenin impedance. |
Keywords: |
Simulink, Thevenin impedance, Thevenin voltage. |
|
Download Full Article |
Title: |
Optimization of culture conditions and process parameter (pH)to enhance the production of DHA by using Schizochytrium sp. in submerged batch fermentation |
Authors: |
Ved Prakash Jangir || Anjali Pande || Snehlata || Ranjana || Deepak Prasad || Muskan Choudhary || HarshpalSingh |
Source: |
International Journal of Precious Engineering Research and Applications, Volume 4, Issue 3 (May-June) 2019), PP. 09-13 |
Abstract: |
Docosahexaenoic acid (DHA) is an important omega-3 fatty acid with many beneficial health effects on humans. Microalgae derived DHA has several advantages as compared to fish oil. Therefore, most of the commercial production is done now-a-days through fermentation using microalgae and Schizochytrium species are well studied in this regard. In the current study, Schizochytriumlimacinumwas used for optimization of culture conditions and process parameters for enhanced biomass and yield of DHA in fermentation. Our study highlights the use of initial culture growth attained after 28hours with pH and packed cell volume (PCV) values 5.8±0.2 and 05±1.0, respectively as lab inoculum for seed and production batch. Moreover, we studied the effect of varying pH(5.7±0.2, 6.2±0.2 and 6.8±0.2) on DHA production. Our results suggest that the optimal pH for maximum DHA production is 6.2±0.2 duringproduction fermentation batch. |
Keywords: |
Microalgae,DHA, fermentation, pH, extraction, HPLC |
|
Download Full Article |
Title: |
Optimization of Separant Displacement in Artificial Barrier Height-Control Hydraulic Fracture |
Authors: |
Lu Haibing || Wang Xin || Yi Xinbin || Jiang Wei || Wang Tian || Sun Ting |
Source: |
International Journal of Precious Engineering Research and Applications, Volume 4, Issue 3 (May-June) 2019), PP. 14-22 |
Abstract: |
The main mechanism of artificial barrier height control is to change the stress difference between pay layer and barrier layers, but the artificial barriers method is mainly studied by experiment, and rarely in theoretical till now. Based on the hypothesis of (that) artificial barrier can be treated as a porous filter cake, this paper studied the laws of separant floating or sinking, and the porosity, permeability and specific resistance of the composition medium of separant. With the 3D fracture extent model, it can be developed into the theoretical model of artificial barrier laying optimization, programmed the model. At last use the oilfield data to verify the program. |
Keywords: |
Artificial Barrier; Fracture Height Control; Hydraulic Fracture; Separant Optimization |
|
Download Full Article |
Title: |
Classification, Properties and Applications of titanium and its alloys used in aerospace, automotive, biomedical and marine industry- A Review |
Authors: |
Sani A. Salihu || Y.I. Suleiman || A. I. Eyinavi || Abdullahi Usman |
Source: |
International Journal of Precious Engineering Research and Applications, Volume 4, Issue 3 (May-June) 2019), PP. 23-36 |
Abstract: |
Titanium and its alloys are attractive engineering materials used in aerospace, automotive, biomedical, and marine industry because of their outstanding mechanical properties such as high specific strength and physical properties with excellent corrosion resistance and excellent elevated temperature properties. This paper presents a brief reviewonthe classification of titanium and its alloys associated with their chemical composition, properties and applications of titanium and its alloys used in aerospace, automotive, marine, and biomedical industry.The mechanical and physical properties were highlighted. Aerospace industry has been the major area of application of titanium alloys............ |
Keywords: |
Titanium alloys, classification, applications, aerospace and automotive industry, chemical composition |
|
Download Full Article |
Title: |
Qualities Requirement forTeachers of Metal Works Technologyfor Efficient ServicesDelivery for Global Competitiveness |
Authors: |
beako, Y. T || okagwa P. O || dr Hillary Wordu |
Source: |
International Journal of Precious Engineering Research and Applications, Volume 4, Issue 3 (May-June) 2019), PP. 37-43 |
Abstract: |
The study assessed qualities required of Metal Works Technology teachersfor efficient services delivery for global competitiveness in Rivers State.Population of the study consists of16 VTE doctorate degree Students of Rivers State University, Port Harcourt and 19VTE doctorate degree Students of Ignatius Ajuru University of Education, Rumuolumeni, Port Harcourt. No sampling was taken considering the small size of the population. Self-structured instrument was designed to elicit information from the respondents. Test re-test method was used to determine the Reliability Co-efficient of the instrument where the results were correlated using Pearson Product Moment coefficient to determine the reliability coefficient which yielded a value of 0.86. The findings revealed that teachers who are regular and punctual to classes, teach according to set objectives, posse qualified academic credentials, grounded in method and procedure relevant to build capacity and among others............. |
Keywords: |
Qualities, Efficient services, Metal work Technology, Global Competitiveness |
|
Download Full Article |
Title: |
Financial Support for Social Entrepreneur in Engineering Project for the Community |
Authors: |
Rohanna Rajan || Ishak Bin Annuar |
Source: |
International Journal of Precious Engineering Research and Applications, Volume 4, Issue 3 (May-June) 2019), PP. 44-47 |
Abstract: |
Financial problems among Social Entrepreneurs (SEs) is one of the top challenging issues faced.
The difficulties arise once the team built without any funding and how do they create business plan for the
project. SEs are one of those function like non-profit organization, the target to help improving selected
community's life. So, as the target is for the community grow, there is a need to build an organizational with
people who can dedicate themselves, their time and effort for the project. All this is impossible to do without
funding. This article would like to discuss the difficulties to get funding to develop SE project especially in
engineering. Thus, this paper aims to discuss the relationship and influence of financial aspect itself and the implication and areas for future research to be discussed. |
Keywords: |
Financial Support, Social Entrepreneur, Funding Engineering Project |
|
Download Full Article |
Title: |
Effects of pH and substrate availability on the half saturation coefficient and kinetics of ammonium oxidizing bacteria |
Authors: |
Junmin Park || Wookeun Bae |
Source: |
International Journal of Precious Engineering Research and Applications, Volume 4, Issue 3 (May-June) 2019), PP. 48-49 |
Abstract: |
The controversial arguments on the true substrate in nitritation kinetics might be due to the cells' dual substrate-transport system. Our experiments revealed that, under ammonia-rich environments, it diffused into the membrane (ammonia was the direct substrate); but, under oligotrophic, ammonium ion was actively transported (ammonium was the direct substrate). Facilitating this change-over, the bacterial composition in the sludge was altered, although the predominant was Nitrosomonaseutrophain most of the six chemostats. Also, the substrate affinity constant (Ks) fell resulting in partial compensation for the reduced availability of substrate........... |
Keywords: |
Ammonia oxidizing bacteria (AOB),True substrate, Dual ammonia transport, Ammonia leakage,Intracellular TAN reserve, Affinity constant |
|
Download Full Article |
Title: |
Partial Oxidation of Ammonium and Methane by Ammonia Oxidizing Bacteria in a Membrane Aerated Biofilm Reactor |
Authors: |
JunminPark || WookeunBae |
Source: |
International Journal of Precious Engineering Research and Applications, Volume 4, Issue 3 (May-June) 2019), PP. 50-52 |
Abstract: |
Although anaerobic wastewater treatment is being evaluated as an innovative technology for the future, to maximize its benefits, a revolutionary post-treatment technology must be developed that consumes less energy and minimizes the supply of external carbon sources. In this study, we implemented both aerobic and anaerobic reactions, without any collision, by forming stratified biofilms on the surface of an aerated membrane. We also investigated the possibility of simultaneous treatment of ammonia, methane, and organic matters in a single reaction tank by adding microaerophilic AME-D biofilms in the middle of the stratified biofilms. Moreover, before seeding methane-oxidizing bacteria, we tested the methane oxidizing ability of ammonia oxidizing bacteria (AOB). Approximately 1.3 mM of methane was oxidized by AOB when approximately 2.5 mM of ammonia was oxidized, indicating an active cometabolic oxidation of methane by AOB.In the future, we plan to study the denitrification of hydrogen sulfide to remove H2S simultaneously. In addition, we will verify the dominant microbial community at each layer of biofilm through a microbial community analysis. |
Keywords: |
Aerobic/facultative/anaerobic co-reaction, Anaerobic sewage treatment, Membrane aerated biofilm reactor (MABR), Stratified biofilms |
|
Download Full Article |
Title: |
The question of school failure in the Republic of Congo |
Authors: |
Elenga BibianeDorothée |
Source: |
International Journal of Precious Engineering Research and Applications, Volume 4, Issue 3 (May-June) 2019), PP. 53-59 |
Abstract: |
School failure, for these fragile young children, is particularly overwhelming and very difficult to avoid by its own forces. These learners are therefore condemned, as sometimes fragile adults, or also placed in situations with no way out, to defend themselves from failure by ways not really adapted, but not strictly pathological either, because they will preserve the essence of their selves, to preserve their personality , avoiding depressive or psychotic collapses. It is these median pathways between serious pathology and realistic adaptation that constitute the mechanisms of defense of the self in the face of failure, as against other types of difficulties. This chapter summarizes a selection of quantitative data on equity in education and also serves............ |
Keywords: |
Question of school,education,failure,management, Republic of Congo |
|
Download Full Article |