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991.
Hasan Huseyin Erdem Ahmet Dagdas Suleyman Hakan Sevilgen Burhanettin Cetin Ali Volkan Akkaya Bahri Sahin Ismail Teke Cengiz Gungor Selcuk Atas 《Applied Thermal Engineering》2010,30(2-3):181-187
In a conventional coal-fired power plant, which is only designed for electricity generation, 2/3 of fuel energy is wasted through stack gases and cooling water of condensers. This waste energy could be recovered by trigeneration; modifying the plants in order to meet district heating/cooling demand of their locations. In this paper, thermodynamical analysis of trigeneration conversion of a public coal-fired power plant, which is designed only for electricity generation, has been carried out. Waste heat potentials and other heat extraction capabilities have been evaluated. Best effective steam extraction point for district heating/cooling system; have been identified by conducting energetic and exergetic performance analyses. Analyses results revealed that the low-pressure turbine inlet stage is the most convenient point for steam extraction for the plant analyzed. 相似文献
992.
Yeek Chia Ho Norli Ismail Abbas F. M. Alkarkhi Norhashimah Morad 《Canadian Metallurgical Quarterly》2010,136(11):1267-1276
The performance of two flocculants on turbidity reduction was studied. The two flocculants were: a biopolymeric flocculant which was extracted from fruit waste and a commercial industrial flocculant. The effect of the flocculants’ average molecular weight on turbidity treatment, the treatment efficiency of both flocculants and the flocculants’ degradability were investigated. Response surface methodology was carried out using Box Behnken design to find the optimal pH, cation concentration, and flocculant dosage to maximize the turbidity reduction. The results showed that the maximum turbidity reduction by industrial flocculant occurs between pH 7.5 and pH 8.2, cation concentration between 0.02 and 0.06 mM, and industrial flocculant dosage between 6.5 and 8.0 mg/L. While with biopolymeric flocculant, maximum turbidity reduction occurred between pH 4.6 and pH 7.5, cation concentration between 0.60 and 0.95 mM, and biopolymeric flocculant dosage between 4 and 6 mg/L. 相似文献
993.
Hilda Ismail Rute Madeira Lau Fred van Rantwijk RogerA. Sheldon 《Advanced Synthesis \u0026amp; Catalysis》2008,350(10):1511-1516
A fully enzymatic methodology for the resolution of chiral amines has been demonstrated. Candida antarctica lipase B (CaLB)‐catalyzed acylation with N‐methyl‐ and N‐phenylglycine, as well as analogues having the general formula R1 X CH2CO2R2 (R1=Me, Ph; X=O, S) afforded the corresponding enantioenriched amides, which were subsequently enzymatically hydrolyzed. Surprisingly, CaLB also proved to be the catalyst of choice for this latter step. The heteroatom in the acyl donor profoundly influences both the enzymatic acylation and deacylation; the O‐substituted reagents performed best with regard to enantioselectivity as well as reaction rate in synthesis and hydrolysis. 相似文献
994.
Naghmouchi K Fliss I Drider D Lacroix C 《Journal of Bioscience and Bioengineering》2008,105(5):513-517
Pediocin PA-1 production by Pediococcus acidilactici UL5 cells immobilized in kappa-carrageenan/locust bean gum gel beads was studied during repeated-cycle batch (RCB) culture with pH control in Man Rogosa and Sharpe (MRS) broth supplemented with 1% glucose and whey permeate (SWP) medium. The pediocin PA-1 production by free P. acidilactici cells pH-controlled batch culture has reached 2048 and 4096 AU ml(-1) after 11 and 12 h of incubation, with volumetric productivities of 187 and 342 AU ml(-1) h(-1) in SWP and MRS media, respectively. In RCB culture, immobilized cells reached a maximum concentration of 7.3+/-0.2 x 10(10) and 4.3+/-0.9 x 10(10) cfu g(-1) of beads in MRS and SWP media, respectively. The maximum pediocin PA-1 activity obtained during RCB fermentation was 4096 AU ml(-1); it was attained after only 0.75 and 2 h of incubation in MRS and SWP media, respectively. The corresponding volumetric productivities were 5461 and 2048 AU ml(-1) h(-1). Pediocin PA-1 production in the RCB culture was highly stable over 12 fermentation cycles carried out over 3 d in SWP media. 相似文献
995.
Yusuf Kayalı Ismail Ucun Kubilay Aslantaş 《Journal of Failure Analysis and Prevention》2009,9(3):288-294
Tapered roller bearings, which are also known as angular-contact bearing, are suitable for supporting radial and axial loads.
The more frequent types of defects in such bearings are caused by contact fatigue in these machine components, and this examination
focuses on a contact fatigue failure in a tapered rolling bearing. The examination included visual inspection, microscopic
analysis (optical and scanning electron microscope), and microhardness measurements. These measurements were conducted to
help understand the failure mechanisms. Based on the results of visual examination and microstructure and fracture surface
analysis, it was determined that the tapered roller bearing failed by contact fatigue that was caused by overloading of the
bearing. 相似文献
996.
Noor Ayuni Che Zakaria Takashi Komeda Cheng Yee Low Mohri Makoto Masayuki Kobayashi Ahmad Yusri Ismail Roman Dumitrescu 《Production Engineering》2013,7(1):81-90
Minimally invasive surgery (MIS) is a less invasive procedure compared to traditional open surgery. It usually involves laparoscopic devices and remote control manipulation instruments comprising an endoscope for indirect observation of the surgical field. Interventional radiology (IVR) is one of the MIS methodologies. The IVR procedures include diagnosis such as angiograms, and treatment. The IVR procedures use small tubes called catheters, which are inserted through the body cavity or blood vessel to the treatment area. The IVR procedures lead to the risk of X-ray exposure to surgeon since the procedures is using the digital subtraction angiography device to get clear image of the patient blood vessel. Therefore, we have developed a foolproof tele-operated system to guide the catheter. Hence, the reliability in IVR procedure is crucial. The system is based on a mechatronic design methodology characterized by a principle solution specified in CONSENS® (CONceptual design Specification technique for the ENgineering of complex Systems). This principle solution serves as a basis for the first analysis and verification on the system level. Further, the proposed concept of control system can also be re-used in the other foolproof guidance systems. 相似文献
997.
Ismail Shahin 《Engineering Applications of Artificial Intelligence》2013,26(7):1652-1659
Speaker recognition systems perform almost ideal in neutral talking environments; however, these systems perform poorly in emotional talking environments. This research is devoted to enhancing the low performance of text-independent and emotion-dependent speaker identification in emotional talking environments based on employing Second-Order Circular Suprasegmental Hidden Markov Models (CSPHMM2s) as classifiers. This work has been tested on our speech database which is composed of 50 speakers talking in six different emotional states. These states are neutral, angry, sad, happy, disgust, and fear. Our results show that the average speaker identification performance in these talking environments based on CSPHMM2s is 81.50% with an improvement rate of 5.61%, 3.39%, and 3.06% compared, respectively, to First-Order Left-to-Right Suprasegmental Hidden Markov Models (LTRSPHMM1s), Second-Order Left-to-Right Suprasegmental Hidden Markov Models (LTRSPHMM2s), and First-Order Circular Suprasegmental Hidden Markov Models (CSPHMM1s). Our results based on subjective evaluation by human judges fall within 2.26% of those obtained based on CSPHMM2s. 相似文献
998.
999.
Muhammad Ibrahim Amin Ismail Sadeq Hasan Al-Sheraji Azrina Azlan Azizah Abdul Hamid 《Journal of Functional Foods》2013,5(4):1900-1908
The effects of a bambangan juice powder (BJP) drink on plasma vitamin and antioxidant enzyme levels and liver and kidney function were investigated. Thirty-two healthy subjects (12 male and 20 female) ages 24–28 years were recruited from the Faculty of Medicine and Health Sciences of University Putra Malaysia, Malaysia. Compared with consuming the placebo, consumption of the BJP drink daily for 9 weeks significantly increased the concentration of plasma β-carotene and ascorbic acid. Plasma total antioxidant status was increased, but liver and kidney functions were unaffected after consumption of the BJP drink. The consumption of a BJP drink resulted in a significant improvement in certain cardiovascular biochemical parameters and thus reduced the risk of cardiovascular disease. 相似文献
1000.
Ismail Hameduddin 《International journal of control》2013,86(4):437-450
The nonlinear control problem of aircraft trajectory tracking is tackled in the framework of multiple linear time-varying constrained control using the newly developed paradigm of generalised dynamic inversion. The time differential forms of the multiple constraints encapsulate the control objectives, and are inverted to obtain the reference trajectory-realising control law. The inversion process utilises the Moore–Penrose generalised inverse and the associated nullspace projection, and it predictably involves the problematic generalised inversion singularity. Thus, a singularity avoidance scheme based on a new type of dynamically scaled generalised inverses is introduced that guarantees both asymptotically stable tracking and singularity avoidance. The steady-state closed-loop system allows for two inherently noninterfering control actions working towards a unified goal to exploit the aircraft's control authority over the entire state space. One control action is performed by the particular part of the control law on the range space of the transposed constraint matrix, and it works to impose the prescribed aircraft constrained dynamics. The other control action is performed by the auxiliary part of the control law on the complementary orthogonal nullspace of the constraint matrix, and it provides aircraft's global inner stability using the concept of perturbed feedback linearisation. Numerical simulations of an aggressive multiaxial aircraft coordinated manoeuvre verify the efficacy of designing nonlinear flight control systems via this methodology. 相似文献