Algal extracts based biogenic synthesis of reduced graphene oxides (rGO) with enhanced heavy metals adsorption capability

Shahbaz Ahmad,Aftab Ahmad,Sikandar Khan,Shujaat Ahmad,Idrees Khan,Shah Zada,Pengcheng Fu 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.72 No.-

Efficient reduction of GO was performed, using cellular extracts of three algal strains. The rGO werecharacterized by SEM, TEM, UV-Visible spectroscopy, XRD, FTIR, Raman spectroscopy, Zeta potential andredox potentials. The rGO were then used as decontaminating agents for heavy metals (Cu and Pb), inwaste water. GO reduced via JSC-1 have removed up to 93% Cu and 82% Pb (adsorption capacity of93 mg g 1 and 82 mg g 1, respectively), by 211-9a have removed 74% (74 mg g 1) Cu and 89% (89 mg g 1)Pb, while by 211-11n have adsorbed 91% (91 mg g 1) Cu and 95% Pb (95 mg g 1), within 30 min.

Functional fruit market centres: Their spatial distribution and hierarchical organization

Shahbaz Rashid,Javeed Ahmad Rather,Ferooz Ahmad Hajam 대한공간정보학회 2023 Spatial Information Research Vol.31 No.2

Fruit marketing is more challenging than other agricultural commodities due to the product’s high perishability, seasonality, and bulkiness, all of which necessitate special attention and early disposal. Market centres are supposed to be the farmer’s initial point for marketing-related tasks. This work aims to identify the location, spatial arrangement, and hierarchical organization of functional fruit market centres in Kashmir Valley, India. Both primary and secondary data sources were used to achieve the objective’s fundamental premises. By handheld Global Positioning System (GPS), the coordinates of selected fruit market centres were collected, and their distributional pattern was evaluated using Nearest Neighbour Analysis. The result indicates that the selected sites follow a “random distributional pattern” with an Rn value of 1.12. The hierarchical classification was evaluated using functional composite indices calculated by the Davies location quotient method and annual turnover. Among the ten functional fruit market centres, only one is in the highest (1st) order of Hierarchy, two in the 2nd, two in the 3rd, and five in the lowest (4th), depicting the region’s asymmetrical hierarchical organization. The study findings could be influential in formulating strategies to enhance the marketing efficiency of fruit market centres in the region.

Preventive and Emergency Control of Power System for Transient Stability Enhancement

Shahbaz A. Siddiqui,Kusum Verma,K. R. Niazi,Manoj Fozdar 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.1

This paper presents preventive and emergency control measures for on line transient stability (security) enhancement. For insecure operating state, generation rescheduling based on a real power generation shift factor (RPGSF) is proposed as a preventive control measure to bring the system back to secure operating state. For emergency operating state, two emergency control strategies namely generator shedding and load shedding have been developed. The proposed emergency control strategies are based on voltage magnitudes and rotor trajectories data available through Phasor Measurement Units (PMUs) installed in the systems. The effectiveness of the proposed approach has been investigated on IEEE-39 bus test system under different contingency and fault conditions and application results are presented.

Some extensions of Enestrom-Kakeya theorem for quaternionic polynomials

Shahbaz Mir,Abdul Liman 강원경기수학회 2022 한국수학논문집 Vol.30 No.4

In this paper, we will prove some extensions of the Enestr\"{o}m-Kakeya theorem to quaternionic polynomials which were already valid for the classical Enestr\"{o}m-Kakeya theorem to complex polynomials. Our kind of extensions have considerably improved the bounds by relaxing and weakening the hypothesis in some cases.

User Authentication Using Neural Network in Smart Home Networks

Shahbaz Zahr Reyhani,Mehregan Mahdavi 보안공학연구지원센터 2007 International Journal of Smart Home Vol.1 No.2

Security has been an important issue in the smart home applications. In home networks with distributed architectures that consist of a broad range of wired or wireless devices, it is likely that unauthorized access to some restricted data or devices may occur. Therefore, it becomes important to consider issues of security, authentication and access control. The authentication and authorization of users in smart environments are the key factors in the security of home networks. User authentication has been traditionally based on PIN, password, key, smart card or biometrics. Password-based authentication is widely used to identify legitimate users, because passwords are cheap, easy and reasonably accurate. In conventional password-based authentication methods, passwords store as a password or verification table. These methods use some encryption algorithms to prevent the passwords from being revealed, but they are still vulnerable. In this paper, we train a neural network to store encrypted passwords and use it instead of the password or verification table. This proposed method can solve the security problems in some authentication system and can be used to store the user profiles and access controls in smart home networks.

A Survey of Rate-Adaptation Schemes for IEEE 802.11 Compliant WLANs

( Shahbaz Khan ),( Sadiq Ullah ),( Aziz Ahmed ),( Sahibzada. A. Mahmud ) 한국인터넷정보학회 2013 KSII Transactions on Internet and Information Syst Vol.7 No.3

The IEEE 802.11 compliant stations can transmit at multiple transmission rates. Selection of an appropriate transmission rate plays a significant role in determining the overall efficiency of a communication system. The technique which determines the channel state information and accordingly selects an appropriate transmission rate is called rate-adaptation protocol. The IEEE 802.11 standard does not provide standard specification for implementing a rate-adaptation protocol for its multi-rate capable wireless stations. Due to the lack of standard specification, there is a myriad of rate-adaptation protocols, proposed by industry and various research institutes. This paper surveys the existing rate-adaptation schemes, discusses various features which contribute significantly in the process of rate-adaptation, the timing constraints on such schemes, and the performance gains in terms of throughput, delay and energy efficiency; which can be gained by the use of rate-adaptation. The paper also discusses the implication of rate-adaptation schemes on the performance of overall communication and identifies existing research challenges in the design of rate-adaptation schemes.

Long-term Outcomes of Augmentation Cystoplasty in a Pediatric Population With Refractory Bladder Dysfunction: A 12-Year Follow-up Experience at Single Center

Shahbaz Mehmood,Hamdan Alhazmi,Mohammed Al-Shayie,Ahmed Althobity,Ahmed Alshammari,Waleed Mohamed Altaweel,Ahmed Almathami,Santiago Vallasciani 대한배뇨장애요실금학회 2018 International Neurourology Journal Vol.22 No.4

Purpose: Augmentation cystoplasty (AC) is a surgical procedure used in adults and children with refractory bladder dysfunction, including a small bladder capacity and inadequate bladder compliance, and in whom conservative and medical treatment has failed. This study was aimed to determine the long-term outcomes of AC in children. Methods: A retrospective analysis was conducted of 42 patients (31 males; mean age, 14.2±6.2 years) who underwent AC for neurogenic and nonneurogenic bladder dysfunction, with a median 12.0±1.5 years of follow-up. All patients underwent AC using the ileum with or without continent reconstruction. Pre-AC, concurrent, and post-AC procedures and complications were analyzed. Patients who underwent ureterocystoplasty, were lost to follow-up, or had less than 10 years of follow-up were excluded. The primary outcomes were the complication and continence rates, the post-AC linear rate of height and weight gain, and renal function. The Student t-test was used to evaluate between-group differences and the paired t-test was used to evaluate longitudinal changes in measured variables. Results: Renal function was stable or improved in 32 of 42 patients (76.2%), with a post-AC continence rate of 88.1%. Thirty patients (71.4%) required 72 procedures post-AC. There was no statistically significant difference in the mean percentile of height (P=0. 212) or weight (P=0.142) of patients in the pre- and post-AC periods. No cases of bladder perforation or malignancy were detected. Conclusions: We consider AC to be a safe and effective procedure that does not negatively affect future physical growth, while achieving a good rate of stable renal function. Patients need long-term follow-up to address long-term complications.

Screening Methods for the Identification of Irradiated Foods

Shahbaz, Hafiz Muhammad,Ahn, Jae-Jun,Akram, Kashif,Kwon, Joong-Ho Institute of Agricultural Science and Technology 2013 慶北大農學誌 Vol.31 No.1

The exposure of food to ionizing radiation has been recognized as a safe and effective mode of food preservation in more than 55 countries. The benefits include eradication of insect pests, inactivation of food pathogens, extension of shelf-life, and improvement in food hygiene. Regulatory authorities around the world have emphasized the implementation of various national and international regulations to facilitate trade and development of consumers' confidence in purchasing irradiated foods. Therefore, the need for reliable irradiation detection methods has increased to enforce these regulations. At present, a number of promising analytical approaches have been developed and evaluated. Moreover, about 10 European Standards have been adopted as General CODEX Alimentarius methods for the detection of irradiated foodstuffs. However, most of these methods demand relatively expensive equipment and prolonged sample preparation. Therefore, simple and cost-effective approaches would be advantageous for rapid screening of foodstuffs. The suspected samples need to be analyzed further with more validated techniques to confirm the screening results. In this review, existing screening methods (i.e. physical, chemical, and biological) for the identification of irradiated foods have been outlined along with their principles, scopes and limitations.

Worldwide Status of Fresh Fruits Irradiation and Concerns about Quality, Safety, and Consumer Acceptance

Shahbaz, Hafiz Muhammad,Akram, Kashif,Ahn, Jae-Jun,Kwon, Joong-Ho Taylor Francis 2016 Critical reviews in food science and nutrition Vol.56 No.11

<P>Development of knowledge-based food preservation techniques have been a major focus of researchers in providing safe and nutritious food. Food irradiation is one of the most thoroughly investigated food preservation techniques, which has been shown to be effective and safe through extensive research. This process involves exposing food to ionizing radiations in order to destroy microorganisms or insects that might be present on and/or in the food. In addition, the effects of irradiation on the enzymatic activity and improvement of functional properties in food have also been well established. In the present review, the potential of food irradiation technology to address major problems, such as short shelf life, high-initial microbial loads, insect pest management (quarantine treatment) in supply chain, and safe consumption of fresh fruits was described. With improved hygienic quality, other uses, such as delayed ripening and enhanced physical appearance by irradiation were also discussed. Available data showed that the irradiation of fruits at the optimum dose can be a safe and cost-effective method, resulting in enhanced shelf life and hygienic quality with the least amount of compromise on the various nutritional attributes, whereas the consumer acceptance of irradiated fruits is a matter of providing the proper scientific information.</P>

Combination of TiO2-UV Photocatalysis and High Hydrostatic Pressure to Inactivate Bacterial Pathogens and Yeast in Commercial Apple Juice

Shahbaz, Hafiz Muhammad,Yoo, Sungyul,Seo, Bohyun,Ghafoor, Kashif,Kim, Jeong Un,Lee, Dong-Un,Park, Jiyong Springer-Verlag 2016 Food and bioprocess technology Vol.9 No.1

<P>The purpose of this study was to investigate the effect of combined treatments using TiO2-UV photocatalysis (TUVP) and high hydrostatic pressure (HHP) on inactivation of microorganisms in commercial apple juice as model liquid food. A synergistic effect was observed for combined treatments to inactivate microorganisms. Gram-positive bacteria, Listeria monocytogenes and Staphylococcus aureus, were completely inactivated from initial loads of 7.1 and 6.7 log CFU/mL, respectively, when treated with a combination of TUVP (8.45 J/cm(2)) and HHP (500 MPa). In contrast, reductions of only 4.8 log CFU/mL (L. monocytogenes) and 2.4 log CFU/mL (S. aureus) were achieved with 500 MPa HHP alone. Gram-negative bacteria, Escherichia coli O157:H7 and Salmonella Typhimurium, were reduced by 7.1 and 7.2 log CFU/mL, respectively, after a combined treatment using 8.45 J/cm(2) TUVP and 600 MPa (E. coli) or 400 MPa (S. Typhimurium) HHP which were significantly higher than the effects of HHP alone. A 6.2 log CFU/mL reduction in Saccharomyces cerevisiae count was monitored after treatment with a combination of 8.45 J/cm(2) TUVP and 500 MPa HHP whereas even 600 MPa alone could not achieve complete S. cerevisiae inactivation. Combined treatments (TUVP + HHP) were more effective for microbial inactivation than alone treatments. Scanning electron microscopic images of microorganisms showed highly deformed morphologies after TUVP + HHP treatment. In conclusion, pretreatment of commercial apple juice using TUVP before HHP processing results in better disinfection and may assure complete disinfection.</P>