Optimized Biodiesel Production and Environmental Assessment of Produced Biodiesel

Muhammad Saqib,Muhammad Waseem Mumtaz,Asif Mahmood,Muhammad Imran Abdullah 한국생물공학회 2012 Biotechnology and Bioprocess Engineering Vol.17 No.3

Present study deals with the optimization of biodiesel production using rapeseed oil as feedstock and NaOCH3 as a catalyst. Optimization of different reaction parameters, such as catalyst concentration, reaction temperature,reaction time. and alcohol to oil molar ratio, was done using response surface methodology (RSM). The optimal experimental conditions for biodiesel production were as follows: catalyst concentration (%) 0.30, reaction temperature 55oC, molar ratio 6.75, and reaction time 60 min. Under these optimal conditions, 97.5 percentage yield of biodiesel was obtained. The observed and predicted values of rapeseed oil methyl esters (ROMEs) yield showed a linear relationship. The fuel properties such as specific gravity 0.876 ± 0.01, flash point 168 ± 0.48oC, fire point 197.8 ±0.31oC, pour point -7 ± 0.060oC, cloud point -2 ± 0.10oC kinematic viscosity 4.42 ± 0.26 mm2/sec, and sulfur content 0.002 mg/Kg of the produced biodiesel show the suitability of rapeseed oil biodiesel, as fuel. Moreover, engine performance test of the Rapeseed oil biodiesel (rapeseed oil methyl esters, ROME) was examined. The results showed that CO and particulate matter (PM) emissions of the ROME were lower than those of diesel fuel. NOX emissions of the ROME were lower for B5, B20, B40, and B50, while higher for B80 and B100. These results show the environment benefits of biodiesel.

Regulated Peak Power Tracking (RPPT) System Using Parallel Converter Topologies

Muhammad Saqib Ali,Hyun-Su Bae,Seong-Jun Lee,Bo-Hyung Cho 전력전자학회 2011 JOURNAL OF POWER ELECTRONICS Vol.11 No.6

Regulated peak power tracking (RPPT) systems such as the series structure and the series-parallel structures are commonly used in satellite space power systems. However, these structures process the solar array power or the battery power to the load through two cascaded regulators during one orbit cycle, which reduces the energy transfer efficiency. Also the battery charging time is increased due to placement of converter between the battery and the solar array. In this paper a parallel structure has been proposed which can improve the energy transfer efficiency and the battery charging time for satellite space power RPPT systems. An analogue controller is used to control all of the required functions, such as load voltage regulation and solar array stabilization with maximum power point tracking (MPPT). In order to compare the system efficiency and the battery charging efficiency of the proposed structure with those of a series (conventional) structure and a simplified series-parallel structure, simulations are performed and the results are analyzed using a loss analysis model. The proposed structure charges the battery more quickly when compared to the other two structures. Also the efficiency of the proposed structure has been improved under different modes of solar array operation when compared with the other two structures. To verify the system, experiments are carried out under different modes of solar array operation, including PPT charge, battery discharge, and eclipse and trickle charge.

Temperature Annealing Effect on Poly(vinylidene fluoridetrifluoroethylene) film with β-Phase

Muhammad Saqib,Shenawar Ali Khan,Woo Young Kim 대한전자공학회 2020 대한전자공학회 학술대회 Vol.2020 No.8

Acacia Species for the Rehabilitation and Utilization of Salt-affected Lands and Waters

Muhammad Saqib,Ghulam Abbas,Javaid Akhtar,Muhammad Kashif Ali 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Evaluating the importance of different computed tomography scan-based factors in predicting the outcome of extracorporeal shock wave lithotripsy for renal stones

Muhammad Waqas,Imad-ud-din Saqib,Muhammad Imran Jamil,Mohammad Ayaz Khan,Saeed Akhter 대한비뇨의학회 2018 Investigative and Clinical Urology Vol.59 No.1

Purpose: To evaluate the impact of various computed tomography scan-based parameters of renal stones on the outcome of extracorporeal shock wave lithotripsy (ESWL). Materials and Methods: We conducted a retrospective study of patients who underwent ESWL for renal stones (sized 5–20 mm) from January 2013 to December 2016. We evaluated body mass index, location of the stone, skin-to-stone distance (SSD), stone attenuation value (SAV), stone diameter, Hounsfield density, stone area, and stone volume. Statistical analysis was done and significance was confirmed by multivariate logistic regression analysis. Results: Of the 203 patients 122 (60.1%) had successful clearance of the stone. The presence of a double J stenting, a lower pole location, a higher SAV, higher Hounsfield density, larger stone area, larger stone diameter, and higher stone volume were negative predictors of ESWL outcome. When these parameters were analyzed with multivariate logistic regression analysis, stone location, SSD, and SAV were the only significant independent predictors of the outcome of ESWL. Conclusions: Stone location, SSD, and SAV are reliable and strong predictors of ESWL outcome for the treatment of renal stones.

Modification of Oxygen-Ionic Transport Barrier of BaCo_0.4Zr_0.1Fe_0.4Y_0.1O₃Steam (Air) Electrode by Impregnating Samarium-Doped Ceria Nanoparticles for Proton-Conducting Reversible Solid Oxide Ce

Saqib, Muhammad,Lee, John-In,Shin, Ji-Seop,Park, Kwangho,Kim, You-Dong,Kim, Ki Buem,Kim, Jung Hyun,Lim, Hyung-Tae,Park, Jun-Young Electrochemical Society 2019 Journal of the Electrochemical Society Vol.166 No.12

<P>A reliable and high performance proton-conducting reversible solid oxide cell (P-RSOCs) is developed to generate electricity in a protonic ceramic fuel cell (PCFC) mode and to generate hydrogen gas in a protonic ceramic electrolysis (PCEC) mode in a single electrochemical device. Herein we propose a modified triple conducting (H<SUP>+</SUP>/O<SUP>2−</SUP>/e<SUP>−</SUP>) steam (air) electrode through the infiltration of an Sm<SUB>0.2</SUB>Ce<SUB>0.8</SUB>O<SUB>2-δ</SUB> (SDC) oxygen-ionic conductor, because the polarization resistance (<I>R<SUB>p</SUB></I>) of P-RSOCs mainly comes from the steam (air) electrode in both the operational modes. The SDC-infiltrated nanoparticles on the composite BaCo<SUB>0.4</SUB>Zr<SUB>0.1</SUB>Fe<SUB>0.4</SUB>Y<SUB>0.1</SUB>O<SUB>3+δ</SUB> (BCZFY)-BaCe<SUB>0.7</SUB>Zr<SUB>0.1</SUB>Y<SUB>0.2-x</SUB>Yb<SUB>x</SUB>O<SUB>3-δ</SUB> (BCZYYb) electrode result in a considerable improvement in the oxygen reduction reaction and oxygen evolution reaction catalytic activity at 600–700°C due to the extension of electrochemical active sites with the increasing of surface area. In addition, the enhanced ionic conduction of a triple conducting composite using infiltrated oxygen-ionic SDC conductors leads to an effective decrease in the <I>R<SUB>p</SUB></I> (1.388→1.079 Ω·cm<SUP>2</SUP> at 600°C symmetric cell) with improved cell performance in both the PCFC and PCEC modes. Furthermore, the NiO-BCZYYb anode-supported cell with the SDC-infiltrated composite BCZFY-BCZYYb air electrode shows excellent durability in the PCFC and PCEC modes without any degradation during 250 h each at 650°C.</P>

Distributed SDN Based Network State Aware Architecture for Flying Ad-hoc Network

Muhammad Saqib,Asif Mehmood,Adeel Rafiq,Afaq Muhammad,Wang-Cheol SONG 한국통신학회 2020 한국통신학회 APNOMS Vol.2020 No.09

Flying networks are resource constraints while the nature of nodes’ mobility is very dynamic and unpredicted. Therefore, these networks are very prone to link failure and performance degradation. By considering the existing limitations, this work proposes a new approach consists of proactive and reactive network failure mitigation techniques that have been named as a hybrid approach. In the proposed architecture, the SDN controllers are distributed where each one controls its local domain nodes. The controller node continuously monitors the network state information and proactively adjusts the near-future changes to the topology. Each local domain also contains a sink node that directly connects to the controller. The sink node is used to forward the network state information to the controller and keep the controller defined flow rules for local domain nodes. The sink node can also request a new path in case of any link failure or any topology updates cause by nodes’ movement. Besides, a distributed routing protocol also runs on domain nodes to establish connectivity toward the sink node.

자체전원공급 가능한 시스템을 위한 유연한 저전력 저항 메모리 소자

Muhammad Muqeet Rehman,Hafiz Mohammad Mutee ur Rehman,Shenawer Ali Khan,Muhammad Saqib,Woo Young Kim 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.4

최근 유기 비휘발성 메모리 장치는 주목받고 있다 1, 2. 본 연구에서, 두 고분자 물질(오렌지 염료, 폴리 3-헥실티오핀)의 합성물로 제작된 비휘발성 메모리 소자를 보고한다. 이 메모리 소자는 유연기판 상에 은(Ag)/유기복합체/은(Ag)의 샌드위치 구조를 가지도록 제조되었다. 제작된 메모리 소자는 -1.5V에서 +1.5V 까지의 동작전압 범위에서 전류 상한선을 1mA를 가지도록 작동하였고, 그 결과 저전력소모 동작이 가능하게 되었다. 또한 100 번 이상의 반복 측정에서도 고저항 상태와 저저항 상태가 서로 간섭하지 않고 일정한 동작을 유지하였으며, 4시간 이상 연속 동작에서도 정상 동작하였음을 확인하였다. 이 메모리 소자의 동작 메커니즘은 공간전하제한 전류(SCLC) 메커니즘으로 작동함을 이중로그 곡선으로부터 확인할 수 있었고, 오렌지 염료를 추가할수록 메모리동작을 위한 문턱전압의 크기가 감소함을 확인하였다. 폴리 3-헥실티오핀 기반의 기존 연구결과에 비해 굽힘반경 5cm 범위까지 25 번의 굽힘측정에서도 안정적인 결과를 나타내었다. 본 연구 성과는 유기물질을 기반으로 하는 고신뢰성 저전력 메모리 소자를 위한 중요한 진전으로 평가되며, 나노발전소자와도 호환가능한 자체전력공급 가능한 시스템의 중요한 요소로서 기여할 것으로 기대된다. Organic nonvolatile memory devices are of significant interest these days^1,2. In this study we have reported the non-volatile memory behavior of an organic composite based on two polymers i.e. orange dye (OD) and poly(3-hexylthiophene-2,5-diyl) (P3HT). This memory device was fabricated on flexible substrate for the possible application of wearable electronics with a sandwiched structure of silver (Ag)/P3HT-OD/Ag. This device exhibited its memory behavior by applying a small voltage sweep of – 1.5 V to 1.5 V with a current compliance (CC) of 10^-3 A hence, resulting in low power consumption. The obtained electrical results were highly stable as the values of both high resistance state (HRS) and low resistance state (LRS) were not deteriorated for more than 100 voltage sweeps. The device was tested for nearly 4 h without any considerable deterioration in its electrical characteristics. The conduction mechanism of this device was based on space charge limited current (SCLC) model as depicted form the double logarithmic I-V curve. Addition of OD resulted in the reduction of threshold voltage (V_th) value due to its lower value of work function which provided an easy path for the charge carriers to move from one electrode to another electrode. Significant achievement of this work is that no other P3HT based RRAM device has been characterized for its mechanical robustness, but our memory device showed stable electrical results against 25 bending cycles in the bending diameter range of 15 cm to 5 cm. This device is a significant step forward towards achieving a next generation low power memory device based on organic materials. Also, this low-power device will be expected to combine with nanogenerator for self-powered system in future.

Changes in postpartum metabolites and resumption of ovarian cyclicity in primiparous and multiparous dairy cows

Muhammad Najmus Saqib,Muhammad Subhan Qureshi,Rifat Ullah Khan 한국응용생명화학회 2018 Applied Biological Chemistry (Appl Biol Chem) Vol.61 No.1

The postpartum period in high-yielding dairy cows creates an enormous drain of nutrients in favor of milk yield which antagonizes the resumption of ovulatory cycles. Therefore, a study was undertaken to evaluate the association of changes in postpartum serum metabolites with resumption of ovarian cyclicity. A total of 24 clinically healthy, freshly parturated primiparous (P-1) and multiparous (P-2) Holstein Frisian cows was selected. Cows were further divided on the basis of body condition score (BCS) 1 and 2 having BCS 3 or above 3, respectively. Weekly blood samples were collected and serum glucose, cholesterol, triglycerides, progesterone, and cortisol concentrations were determined for a period of 7 weeks. The glucose concentration was significantly (P\0.05) higher in cows in P-2 during week 7. Cows in parity 2 had significantly (P\0.05) high cholesterol during week 6 and 7. The serum triglyceride concentration in multiparous animals having BCS-2 during week 6 was increased significantly (P\0.05). Serum cortisol was significantly (P\0.05) high in P-1 during week 1 and 2 and significantly (P\0.05) high in P-2 during week 7. Serum progesterone was significantly (P\0.05) higher in cows during week 7 in P-2 having BCS-2. The increased serum progesterone concentration during postpartum period was associated with decreased levels of serum cortisol and more availability of cholesterol and glucose. The multiparous cows maintained the postpartum blood metabolite concentration and showed better adaptability to reproductive cyclicity during the postpartum period as compared to primiparous cows.

Investigation of different aspects of laminar horseshoe vortex system using PIV

Muhammad Yamin Younis,Hua Zhang,Bo Hu,Zaka Muhammad,Saqib Mehmood 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.2

Juncture flow is a classical fluid mechanics problem having wide applications in both aero and hydro dynamics. The flow separatesupstream of the obstacle due to the adverse pressure gradient generated by it, with the formation of the vortical structure called “horseshoevortex.” The current study is carried out for an elliptical leading edge obstacle placed on a flat plate to investigate the horseshoevortex for a range of Reynolds number (ReW) based on maximum width (W) for which the incoming boundary layer is laminar. Fourdifferent types of horseshoe vortex systems were found: the steady, amalgamation, transition and breakaway. The transition vortex systemis one after which the vortex system changes from amalgamation to breakaway. In this phase the vortex system alternatively undergoesboth amalgamation and breakaway vortex cycles. The effect of variation in the chord wise shape of the obstacle is investigated. Thequantitative measurements of PIV show that the vortex system does not undergo any significant change for different chord lengths of themodel with the fixed aspect ratio and maximum width. The most upstream saddle point is also studied for steady horseshoe vortex regionand found that it is the “saddle of attachment” where flow attaches to the plate surface instead of separating from it.