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      • KCI등재

        Optimization of Sand-Bentonite Mixture for the Stable Engineered Barriers using Desirability Optimization Methodology: A Macro-Micro-Evaluation

        Khalid Farooq,Zia ur Rehman,Muqadas Shahzadi,Hassan Mujtaba,Usama Khalid 대한토목학회 2023 KSCE JOURNAL OF CIVIL ENGINEERING Vol.27 No.1

        In this paper, Desirability Optimization Methodology (DOM) is employed to achieve optimum sand bentonite mixture (SBM) based on multiple antagonist macro-geotechnical responses of the compacted SBM prepared using poorly graded sand with the mean grain size around 0.2 mm and bentonite with plasticity index around 157% for the stable engineered barriers (EBs). For this purpose, varying mix designs of SBM compacted at compaction energy of 2,700 kN-m/m3 are initially tested to determine their mechanical properties, volumetric-change behavior, and hydraulic conductivity. The unconfined compressive strength, cohesion, angle of internal fiction, swell pressure, compression index, and hydraulic conductivity are taken as the geotechnical design parameters for the SBM. Mathematical models are developed and statistically validated for these design parameters using sand content (SC) and bentonite content (BC) as the predictors. In addition, models are also developed to predict compression curves for compacted SBMs. Moreover, microstructural evaluation is conducted through scanning electron microscope (SEM) analysis to determine the SBM having a desirable microstructure for stable EB. It is observed that a major shift in the microstructure from medium pores to micro-pores occurs for the BC between 20% and 30%. Afterward, optimization of SBM is carried out by integrating developed models for the geotechnical design parameters in a desirability function (D) algorithm, which is subsequently simulated by setting maximization of strength and minimization of swell pressure, compressibility and hydraulic conductivity of compacted SBM as the goals. A reasonably high D-value is achieved for the SBMs having SC:BC in a range of 74:26 to 78:22 with the highest at 75.63:24.37 against the set goals. This study manifests an effective and pragmatic strategy for designing the SBM for a stable EB considering its antagonist hydraulic, volumetric change, and mechanical responses.

      • KCI등재

        Optimal Planning of Distributed Generators for Integration of Electric Vehicles in a Korean Distribution System

        Khalid Mousa Hazazi,Khawaja Khalid Mehmood,Chul-Hwan Kim 한국조명·전기설비학회 2018 조명·전기설비학회논문지 Vol.32 No.3

        Due to the rising concerns about global warming, Korean government is encouraging the penetration of electrical vehicles (EVs). Integrating a large number of EVs may expose the distribution systems to high voltage drops and increased energy losses. In this paper, we have carried out the optimal planning of distributed generators (DGs) in a Korean distribution feeder to enhance the penetration of EVs. The optimization problem is formulated as a mix-integer non-linear programming for minimizing the energy losses in the distribution feeder. The real traffic volume of Seoul, Korea is used for modelling the power demand of EVs. Wind and dispatchable DGs are considered as the DG-types, and Weibull distribution is applied to model the probabilistic behavior of wind speed. In order to estimate the parameters of Weibull distribution from the wind speed data, maximum likelihood estimation method is employed. The optimization problem is solved using genetic algorithm. Moreover, four test cases are considered for the simulation on the distribution system to validate the performance of the proposed planning approach. The results show that the energy losses caused by the integration of EVs are reduced while the voltage profile of the distribution feeder is enhanced.


        Effect of Spore-Forming Probiotics on the Poultry Production: A Review

        Khalid, Anam,Khalid, Fatima,Mahreen, Nida,Hussain, Syed Makhdoom,Shahzad, Muhammad Mudassar,Khan, Salman,Wang, Zaigui Korean Society for Food Science of Animal Resource 2022 한국축산식품학회지 Vol.42 No.6

        Due to the bad aspects associated with the use of antibiotics, the pressure on poultry production prompted the efforts to find out suitable growth-promoting and disease-preventing alternatives. Although many cost-effective alternatives have been developed, currently, one of the most auspicious alternatives for poultry feed is spore-forming probiotics, which can exert more beneficial effects as compared to normal probiotics, because of their ability to withstand the harsh external and internal conditions which result in increased viability. Many studies have already used spore-forming probiotics to improve different parameters of poultry production. Our laboratory has recently isolated a spore-forming bacterial strain, which has the potential to be used as a probiotic. So, to provide a detailed understanding, the current review aimed to collect valuable references to describe the mechanism of action of spore-forming probiotics and their effect on all the key aspects of poultry production.

      • KCI등재

        Potential of Bacillus velezensis as a probiotic in animal feed: a review

        Fatima Khalid,Anam Khalid,Yuechi Fu,Qian Hu,Yunfang Zheng,Salman Khan,Zaigui Wang 한국미생물학회 2021 The journal of microbiology Vol.59 No.7

        Bacillus velezensis is a plant growth-promoting bacterium thatcan also inhibit plant pathogens. However, based on its properties,it is emerging as a probiotic in animal feed. This reviewfocuses on the potential characteristics of B. velezensisfor use as a probiotic in the animal feed industry. The reviewwas conducted by collecting recently published articles frompeer-reviewed journals. Google Scholar and PubMed wereused as search engines to access published literature. Basedon the information obtained, the data were divided into threegroups to discuss the (i) probiotic characteristics of B. velezensis,(ii) probiotic potential for fish, and (iii) the future potentialof this species to be developed as a probiotic for theanimal feed industry. Different strains of B. velezensis isolatedfrom different sources were found to have the ability toproduce antimicrobial compounds and have a beneficial effecton the gut microbiota, with the potential to be a candidateprobiotic in the animal feed industry. This review providesvaluable information about the characteristics of B. velezensis,which can provide researchers with a better understandingof the use of this species in the animal feed industry.

      • Perception of Patients with Cancer towards Support Management Services and Use of Complementary Alternative Medicine - a Single Institution Hospital-Based Study in Saudi Arabia

        Sait, Khalid Hussain,Anfinan, Nisrin Mohammad,Eldeek, Basem,Al-Ahmadi, Jawher,Al-Attas, Maha,Sait, Hesham Khalid,Basalamah, Hussain Abdullah,Al-Ama, Nabeel,El Sayed, Mohamed Ezzat Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.6

        Background: To evaluate the perception of cancer patients toward treatment services and influencing factors and to inquire about the use of complementary alternative medicine (CAM). Materials and Methods: Information was obtained through pre-tested structured questionnaires completed by cancer patients during treatment at King Abdulaziz University Hospital, Jeddah, Saudi Arabia. Results: Of 242 patients, 137 (64.6%) accepted to enter this study. Most were Saudi (n=93, 68%), female (n=80, 58%), educated at university (n=71, 52%), married (n=97, 72%) and with breast cancer (n=36, 26%). One-hundred (73%) patients were satisfied with the services provided; 61% were Saudi. Ninety-four (68%) respondents were satisfied with the explanation of their cancer. Twenty-eight (21.6%) patients received CAM, of them 54.0% received herbal followed by rakia (21.0%), nutritional supplements/vitamins (7.0%) and Zamam water (18.0%), with significant differences among them (p =0.004). Seven (5%) patients believed this therapy could be used alone; 34 (25%) patients believed it could be used with other treatments, regardless of whether they themselves used this therapy. Fifty-three (53%) satisfied patients felt they received enough support; 31 (58%) patients received support from family and friends; 22 (41.6%) patients received support from the health-care team. Patients who received information about their disease from their physicians and those who felt they had enough support were more satisfied. The patients who took alternative treatment were older age, mostly female and highly educated but values did not reach significance. Conclusions: We stress enhancing the educational and supportive aspects of cancer-patient services to improve their treatment satisfaction and emphasize the need for increasing the educational and awareness programs offered to these patients.

      • KCI등재

        AVO-derived attributes to differentiate reservoir facies from non-reservoirs facies and fluid discrimination in Penobscot area, Nova Scotia

        Perveiz Khalid,Nisar Ahmed,Khalid Amin Khan,Mustansar Naeem 한국지질과학협의회 2015 Geosciences Journal Vol.19 No.3

        The discrimination of hydrocarbon (gas or oil) facies from non-hydrocarbon (wet sands) facies is an important goal in quantitative seismic interpretation and reservoir estimation. The differentiation of hydrocarbon facies from non-hydrocarbon in Mississauga Formation of early Cretaceous in Penobscot area is a difficult task due to smaller net pay thickness and shaly sand intervals. Based on seismic interpretation and wireline logs, five sand plays are identified in the middle of Mississauga Formation. Four sands have hydrocarbons while top of sand 5 represents hydrocarbon water transition zone. Among these four, the pay sand 4 is analyzed for hydrocarbon facies. Wireline logs and seismic data are used to derive various amplitude versus offset (AVO) based attributes such as: acoustic (IP) and shear (IS) impedances, Poisson ratio (σ) etc. Further, the combined attributes e.g., product of Lamé parameters (μ, λ) with density (ρ), their ratio (λ/μ), difference between bulk modulus (K) and shear modulus (μ), Δμρ/μρ, Δ(λ/μ + 2)(λ/μ + 2) and the pore space modulus (ΚP) are also analyzed to find out the best attribute as a hydrocarbon facies discriminator from non-hydrocarbon facies in the shale imbedded pay sand 4 of Mississauga Formation. First, petrophysical parameters such as P and S wave impedances, Lamé’s parameters etc. are extracted from log data. Then, appropriate pairs of seismic attributes are crossplotted so that the hydrocarbon and non-hydrocarbon facies cluster together for quick identification and interpretation. Gamma ray index is crossplotted against spontaneous potential log to mark sand and shale facies. Fluid substitution modeling for various fluid types and saturation is also done which demonstrate that the cross-plots between different rock physics parameters can be used to distinguish between reservoir fluids. Our analysis reveals single P-wave based attributes are not sufficient to discriminate fluids thus the use of multi-attributes such as KP, λρ and Κ-μ is more effective to discriminate the hydrocarbon and non-hydrocarbon facies. The analysis of these cross-plots was done to map the reservoir sands and the hydrocarbon-water contact.

      • KCI등재

        Comparison of characteristics and ventilatory course between coronavirus disease 2019 and Middle East respiratory syndrome patients with acute respiratory distress syndrome

        Imran Khalid,Romaysaa M Yamani,Maryam Imran,Muhammad Ali Akhtar,Manahil Imran,Rumaan Gul,Tabindeh Jabeen Khalid,Ghassan Y Wali 대한중환자의학회 2021 Acute and Critical Care Vol.36 No.3

        Background: Both coronavirus disease 2019 (COVID-19) and Middle East respiratory syndrome (MERS) can cause acute respiratory distress syndrome (ARDS); however, their ARDS course and characteristics have not been compared, which we evaluate in our study. Methods: MERS patients with ARDS seen during the 2014 outbreak and COVID-19 patients with ARDS admitted between March and December 2020 in our hospital were included, and their clinical characteristics, ventilatory course, and outcomes were compared. Results: Forty-nine and 14 patients met the inclusion criteria for ARDS in the COVID-19 and MERS groups, respectively. Both groups had a median of four comorbidities with high Charlson comorbidity index value of 5 points (P>0.22). COVID-19 patients were older, obese, had significantly higher initial C-reactive protein (CRP), more likely to get trial of high-flow oxygen, and had delayed intubation (P≤0.04). The postintubation course was similar between the groups. Patients in both groups experienced a prolonged duration of mechanical ventilation, and majority received paralytics, dialysis, and vasopressor agents (P>0.28). The respiratory and ventilatory parameters after intubation (including tidal volume, fraction of inspired oxygen, peak and plateau pressures) and their progression over 3 weeks were similar (P>0.05). Rates of mortality in the ICU (53% vs. 64%) and hospital (59% vs. 64%) among COVID-19 and MERS patients (P≥0.54) were very high. Conclusions: Despite some distinctive differences between COVID-19 and MERS patients prior to intubation, the respiratory and ventilatory parameters postintubation were not different. The higher initial CRP level in COVID-19 patients may explain the steroid responsiveness in this population.


        Interfacial bond behavior of FRP fabrics bonded to fiber-reinforced geopolymer mortar

        Khalid, Hammad R.,Ha, S.K.,Park, S.M.,Kim, G.M.,Lee, H.K. Elsevier 2015 COMPOSITE STRUCTURES -BARKING THEN OXFORD- Vol.134 No.-

        <P><B>Abstract</B></P> <P>This paper presents the experimental investigation of composite-mortar three-point bending beam test setup, used to characterize the bond behavior between concrete/mortar and fiber-reinforced polymers (FRPs). With this aim, a series of experimental studies have been conducted by considering different FRP fabric types (carbon/glass and carbon/aramid), epoxy adhesives (E-1 and E-2), and notch depths (50 and 33mm). In addition, a fiber-reinforced mortar, with different fiber contents (0, 0.5, 1 and 1.5wt.%) was also used to investigate the effects of short fibers on the interface behavior. From the load–displacement curves in three-point bending beam tests, peak load (<I>P<SUB>peak</SUB> </I>), ultimate mid-span deflection (<I>δ<SUB>ult</SUB> </I>), and interfacial fracture energy (<I>G<SUB>F</SUB> </I> <SUB>,</SUB> <I> <SUB>int</SUB> </I>) of different bonded interfaces were evaluated. It is concluded from this study that this test setup is useful for the comparison of different bonded interfaces as true interfacial failure was observed, but the interfacial fracture energy (<I>G<SUB>F</SUB> </I> <SUB>,</SUB> <I> <SUB>int</SUB> </I>) obtained from these tests showed sensitivity to the notch depth. The incorporation of short steel fibers into mortar was not effective to improve the interfacial bond strength as not much fiber action was observed (near the bond line) during testing.</P>

      • KCI등재

        저강도 강우시 절토사면의 흡인력 분포와 안정성에 대한 투수계수의 효과

        Khalid Mahmood,김진만 한국지반공학회 2012 한국지반공학회논문집 Vol.28 No.6

        The authors discuss the effect of hydraulic conductivity on the suction profile and stability of a typical cut-slope subjected to low intensity rainfall. The initial suction value above the ground table in the unsaturated zone is assumed to be 15 kPa. The uncoupled approach of finite element and limit equilibrium method is used to evaluate the stability of the cut-slope at different elapsed times of rainfall. The finite element seepage analysis shows that the soil in the unsaturated zone always remains unsaturated during the course of low intensity rainfall. Furthermore, the slope stability remains practically unchanged so long as the wetting front remains in the unsaturated zone but it decreases noticeably when the wetting front reaches and elevates the ground water table level.

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