The need of alternate clean transport fuels is exponentially increasing due to stringent environmental regulations of vehicular emissions and alarmingly depleting the current resources of traditional transport fuels such as gasoline, diesel fuels. The world statistical data depicts that public transport vehicles are increasingly converted to Compressed Natural Gas (CNG) due to its environment friendly nature. The literature survey depicts that research mainly focused on fluid dynamics aspects (such as turbulence) and flame features (flame development, flame propagation, flame geometry etc) of combustion in various combustions systems. In this regard, a number of studies are reported in the literature in which the combustion of fuels (mostly single component such as methane, ethane, propane, octane, ethanol, pentane, hydrogen etc) was simulated using the kinetic reactions mechanisms. The limited work is reported in the literature related to the formation of pollutants due to the combustion of CNG (a multi component gas mixture) in automobile engines (powered by IC engines). In present research, the combustion of CNG is simulated using the kinetic reaction mechanisms in Internal Combustion (IC) engines. These mechanisms are primarily investigated to predict the formation of gaseous pollutant such as Carbon monoxide (CO), Oxides nitrogen (NO & NO 2 ) and ammonia (NH 3 ) due to combustion of CNG in IC engine. A number of reaction mechanisms were developed and analyzed under the selected simulation conditions describing the practical operating conditions of the automobile engine. The reaction mechanisms were developed by the coupling of two reaction mechanisms (i) a hydrocarbon reaction mechanism generated by EXGAS (an automatic mechanism generation tool) and (ii) Leeds NO x mechanisms. Each of the mechanisms was consisting of the hundreds of the elementary reactions of types including Unimolecular viiiinitiations, Bimolecular Decompositions to initiations, Additions, Isomerization, Beta-scissions, o-rings, Branching, Metatheses, Combination, Dismutation. These mechanism also contain a number of the species/radicals/intermediates such as Monohydroperoxides (OOH), Dihydroperoxydes (OOH) 2 , Allylic molecules YH, , Ethers (O), Ketones (CO), aldehydes (CHO). Each of the reaction was containing the kinetic data (Arrhenius rate parameters; A, b or β and E a ) required to determine the rate constant (k) using the Arrhenius Rate Law and the species thermo-chemical data (NASA Coefficients). Each of the proposed mechanisms was implemented in IC engine module of Chemkin 4.1.1 (a kinetic simulation package) for further analysis and the four detailed reaction mechanisms successfully predicted the combustion profiles of pressure, temperature and selected pollutant species. These are represented by Mechanism-I, Mechanism-II and Mechanism-III Mechanism-IV in this report. Mechanism-I is a comprehensive reaction mechanism containing reactions feasible at range of temperature conditions (below 800 K and above 1000 K). This mechanism is composed of 935 elementary reactions and 185 species. Mechanism-II is a high temperature (above 1000 K) reaction mechanism and consists of 124 species and 792 elementary reactions. This mechanism composed of that type of reaction feasibly at high temperature during the combustion of natural gas. Mechanism-III is a low temperature (below 800 K) reaction mechanism and consists of 152 species and 864 elementary reaction. Mechanism-IV is developed by the simplification of Mechanism-I by the chemical lumping technique and is consisting of only 72 species and 208 elementary reactions. In the simulation study, the common inputs were; (i) fuel composition (CH 4 , 89.03; C 2 H 6 , 1.5; C 3 H 8 , 0.27%; C 4 H 10 , 0.17 %, N 2 , 7.20% & CO 2 ; 2.60% by vol.); (ii) engine geometrical parameters (cylinder displacement volume, 63.0 cm 3 , connecting rod to crank radius ratio, 1.632 etc). Each of the proposed mechanisms of were investigated by (a) ixParametric Analysis (b) Rate of Production Analysis (ROP) (c) Sensitivity Analysis and (d) Uncertainty Analysis. In Parametric Analysis of proposed mechanism, the effect of engine operating parameters such as engine speed, fuel to air equivalence ratio, compression ratio, initial inlet temperature and pressure of feed mixture on the in-cylinder pressure, temperature and pollutant species profiles were analyzed. This analysis determined that output simulation profiles (of in-cylinder pressure, temperature, pollutant species) is greatly affected by the engine speed and fuel to equivalence ratio under the selected simulation condition. The rate of production analysis of each the mechanisms was carried out to identify the reactions involved in the formation of selected pollutant species in addition to the major combustion products (i.e. CO 2 & H 2 O). In this analysis, the total rate of production and normalized rate of production coefficient were calculated for each of the elementary reaction of each mechanism at two temperature condictions of 1500 K and 4000 K. The Sensitivity Analysis showed the dependency (sensitivity) of the output concentrations of pollutant species to the rate constants of the reactions involved. This effect was quantified by determined the “Logarithmic Normalized Sensitivity Coefficients” for each of the reaction involved and showed by the sensitivity bar plot. The Uncertainty Analysis was carried out to determine the uncertainties in the output concentrations of pollutant species due to (i) operating parameters (such as engine speed, fuel to air equivalence ratio and compression ratio) and (ii) due to kinetic parameters (Arrhenius parameters, A, β, E a ) for each reaction was studied. In simulation studies, the adiabatic flame temperature of natural gas combustion predicted are order of ~6300 K, 4400 K, 6200 K and 8200 K for Mechanism-I, Mechanism- II, Mechanism-III and Mechanism-IV respectively. It was also observed that adiabatic flame temperatures increase with increasing initial gas temperature. The in-cylinder xtemperature and pressure were predicted as 4554.738 K and 39.776 atm when compression ratio was 10.51 for Mechanism-I at equivalence ratio of 1.3 (under fuel rich operation), compression ratio of 10.5 (design value for the tested engine), about 3000 rpm engine speed. When combustion in IC engine was simulated with kinetic Mechanism-II (High temperature mechanism), the maximum peak temperature and pressure was achieved at equivalence ratio of 1.3, compression ratio of 10.51, and low engine speed of about 2000 rpm, and initial inlet temperature of 1500 K. The simulation with Mechanism-III illustrates that the maximum peak temperature (3526.161 K) and pressure (31.27 atm) in the combustion chamber were achieved at equivalence ratio of 1.4, compression ratio of 10.51, engine speed of 1500 rpm (low speed) and at initial inlet temperature of 2300 K. and pressure. The Mechanism-IV shows that the maximum peak temperature (4277.804 K) and pressure (41.84569 atm) was achieved when equivalence ratio (Fuel/air) was ≈1.3, compression ratio of ≈10.51, engine speed of ≈ 3000 rpm and initial inlet temperature of ≈1000 K. For experimental measurements, an experimental setup was developed to study the effect of various operating parameters on the CNG combustion in an automobile engine (a type an IC engine) and to validate the simulation result obtained by the proposed kinetic mechanisms. In this experimental study, the in-cylinder profiles of temperature, pressure and pollutant species (CO, NO, NO 2 & NH 3 ) were recorded under various operating conditions of an automobile engine. The simulation data for each of the proposed mechanism is compared with experimental data for and an appropriate mechanism of CNG combustion is selected which showed the closer agreement with the experimental results. The average measured cylinder pressure varied from 0.61 atm to 32.62 atm for six consecutive engine cycles. The highest concentrations of NO x were near the stoichiometric conditions and then become lower while CO level shows increasing trend. The modeled xidata was compared with the experimental data (measured when engine was operated at 3000 rpm, φ=1.0, P inlet =0.67 atm) for each proposed mechanisms. The simulated pressure & temperature profiles of Mechanism-I exhibited the closer agreement with those of the experimental measured profiles while the pollutant species profiles significantly deviated. The deviation in the species profile caused because of the reactions involved in the formation/destruction under given conditions. Similarly, the profiles of Mechanism-II (high temperature above 1000K) and Mechanism-III (low temperature below 800 K) exhibited the early start of the combustion which was not supported by the experimental measurements. On the basis of these discrepancies, it is conclude that Mechanism-I, Mechanism-II & Mechanism-III were failed in the viable prediction of the formation pollutants and the experimental measurements did not validated simulation result. In spite of the existence of some discrepancies among the simulation profiles, Mechanism-IV (consisting of 208 elementary reactions & 72 species) exhibits the closer agreement with the experimental data under the given engine operating conditions. This mechanism is containing the reactions feasible at range of temperature conditions of low (below 800 K) to high (1000 K). In this mechanism, major primary types of reactions include; Unimolecular initiations, Bimolecular initiations, Beta-scissions, Oxidation, Branching, Metatheses, Combination and Dismutation. On the basis of this, it is concluded that Mechanism-IV is consisting of those kinds elementary reactions (both primary & secondary type) involved in the combustion of CNG in the automobile engine and is capable of predicting the formation of the selected criteria gaseous pollutants." xml:lang="en_US
The Immensely Merciful to all, The Infinitely Compassionate to everyone.
31:01 a. Alif. Lam. Mim.
31:02 a. These are the Messages of the Book - The Divine Qur’an – full of Wisdom.
31:03 a. It is a source of Guidance and a Mercy for those who seek excellence in virtue.
31:04 a. Those who - establish the Salat/Prayer, and - pay out the Zakat/annual charity, and - believe with certainty in the realm of the Hereafter.
31:05 a. It is they who are upon Guidance from their Rabb -The Lord, and b. it is also they who are going to be the successful in the Hereafter.
31:06 a. And from among the people, there are some who engage in diverting talk over Allah’s Message - misleading others from the Path of Allah without knowledge, and - taking it in mockery as well. b. Those - for them will be a humiliating punishment.
31:07 a. And whenever OUR Messages from The Qur’an are recited to such a person, b. he turns away arrogantly, as if he had not heard them – almost as if there was deafness in his ears. c. So give him the good news of a painful punishment.
31:08 a. As for those - believe, and - practice righteousness,
b. for them will be Gardens of Delight in Paradise -
31:09 a. living therein forever: never to leave, never to die. b. This is Allah’s true Promise, c. for HE is The Almighty, The Wise.
This writing discusses the health assessment of Sharia Banks. The legal basis for regulating the health assessment of Sharia Banks (BUS and BPRS) refers to the regulations of the Law, PP, PBI, POJK, and BI, as well as OJK circulars. The article explains the RGEC assessment of Sharia Banks, using a qualitative approach with a literature study research design. This writing presents a literature review of various sources related to assessing the health of Sharia Banks, the legal basis of BUS and BPRS, and RGEC. The discussion explains that bank health assessment reflects the bank's performance and is the result of assessing the bank's condition to overcome risks and improve performance. The logical structure and causal connections between statements ensure a clear and balanced presentation of the topic. The health assessment of Sharia Commercial Banks (BUS) is regulated by Law Number 21 of 2008 concerning Sharia Banking. According to this law, banks are required to maintain their level of soundness. Article 1, paragraph 6 of POJK No. 8 of 2014 pertains to the evaluation of the soundness level of sharia commercial banks and sharia units. The health assessment of Sharia Rural Banks (BPRS) is regulated by Bank Indonesia Regulation No.9/17/PBI/2007, which is based on the Health Assessment System Rural Credit Bank using Sharia Principles. The RGEC method is an advancement of the CAMELS method. The RGEC method involves inherent risks, and quality risk management is applied to bank operations across eight factors: credit risk, market risk, liquidity risk, operational risk, legal risk, strategic risk, compliance risk, and reputation risk.
The purpose of this research is to present efficient novel techniques in contactless thermal surveillance by devising and developing two prototype Thermal Infrared Field Gradient Detection Scanning Systems by using thermal sensors. Signals from Pyroelectric Infrared (PEIR) sensors based Scanning System-1 are analyzed for recognition of thermal gradient patterns to surveil for thermally contrasted stationary and dynamic objects in multiple active Fresnel zones (AFZs) including subzones. The advantage of surveillance in thermal infrared perspective over the visible spectrum realm lies in the fact that all objects above absolute zero emit thermal radiations, with thermal contrast in an AFZ the gradient can be effectively determined by using multi-element pyroelectric infrared sensors. Another prototype open-air thermal gradient scanning system is developed based on Non-Dispersive Infrared (NDIR) thermopile sensing array. This system is used to steer the trespasser in a quiescent vicinity by the detection of wave flow in the gravity induced carbon dioxide, which causes phase delay in density gradients at three spatial locations. The objective of this research is to analyze the first scanning system for up to four active monitoring Fresnel regions for static thermal gradients caused by thermal absorption or emission by living and non-living things and due to the movement of homeothermic body or its constituents in thermally contrasted regions in 8–14μm wide infrared bandwidth. The second scanning system analyze concentration gradient in 4.26μm narrow-band infrared region. In the first thermal scanning system, the gyratory mask-aperture maps a narrow scanning beam on the pyroelectric sensing elements through each lens of a linear Fresnel lens array. The signals from the system are linear field thermograms that are used for localization and thermal field gradients signatures analysis of stationary and dynamic objects. Discrete multilevel and continuous level thermal field analysis have been performed using three different types of pyroelectric sensors, LHI-968, LHI-1148, LHI- 1128 and NDIR thermopile sensor TPD-2T-0625-G2G20, have been used in the Scanning System-2. Thermal analysis of the pyroelectric sensor, transient and harmonic V mathematical models for the sensors and the systems are also presented to establish theoretical basis and to understand the operation of the systems. Robust Dynamic Time Warping (DTW) and Multiclass Support Vector Machines (MSVMs) algorithms with Sequential Minimal Optimization (SMO) heuristic have been utilized with distinctive lower bounded Short-Time Fourier-Transform (STFT) vector reduction algorithm to abridge recognition time in measuring dynamic distances and feature extraction. In second scanning system the direction of intrusion is determined by numerically estimating Time Difference of Arrival (TDOA) of the wave at three sensing nodes that utilized generalized correlation with phase transform technique. Scanning System-1 has been demonstrated to identify thermal gradient of stationary objects in multiple AFZs and recognized thermal patterns with over 95% true recognition rate using only one pyroelectric sensor. Dynamic objects across Fresnel zones and within sub Fresnel zones and their intermission state have been successfully identified with recognition rate of more than 94% using three pyroelectric sensors. For Scanning System- 2, the steering angle of the source is successfully estimated with recognition rate of more than 92%. Evaluation of these scanning systems shown promising results and the author suggests further research can be made in this field.