Mid Infrared Spectroscopy and Partial Least-Squares Regression: A Rapid and Cost-Effective Approach to Estimate Soil Arsenic Content

Nabeel Khan Niazi,Balwant Singh,Budiman Minasny 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Quad-Active-Bridge Converter with Integrated Magnetic Current Balancing Cell for DC Distribution System

Nabeel Naseem,Honnyong Cha,Ubaid Ahmad,Heung-Geun Kim 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

In this paper integrated magnetic current balancing (IMCB) cell-based asymmetrically configured Quad-Active-Bridge (QAB) converter is proposed. QAB converter provides high-frequency isolation for a dc-dc stage of solid-state-transformer (SST), as well as provides a modular solution to the SST medium-voltage (MV) dc link. The proposed IMCB cell ensures the current balancing among the three active H-bridges without using any dedicated controller when transferring equal power from MV to low voltage (LV) side. The proposed IMCB cell is the integration of three inductors of the active H-bridges required for power transfer and zero voltage switching (ZVS), which doesn’t require extra magnetic volume. Simulation and experimental results are presented to validate the performance.

The Effect of Personality Traits on Employee Job Satisfaction with Moderating Role of Islamic Work Ethics

Raja Nabeel-Ud-Din JALAL,Naveeda ZEB,Um-E-Roman FAYYAZ 한국유통과학회 2019 The Journal of Asian Finance, Economics and Busine Vol.6 No.2

Personality factors and ethical values are considered as vital element in social and professional life. This present research aims to explore the relationship between Personality and Job Satisfaction. Further, we tried to test the moderating effect of Islamic work ethics (IWE) in the relationship of Personality traits with Job satisfaction. Convenience sampling was used in defining sample as in Pakistan there is no data base which provides information regarding number of employees. Due to moderating variable the data has been collected from respondents who identify themselves as Muslim. To collect data from respondents Self-administered, close-ended questionnaires and e-questionnaire were used in this study and respondents were targeted in the normal working environment. Correlation and regression analysis was used to analyze the data statistically. The results of study indicated that neuroticism exhibits significant negative effect on job satisfaction. Also, openness to experience, agreeableness and conscientiousness showed positive effect on job satisfaction. Whereas, extraversion exhibits no effect on job satisfaction and IWE has a negative effect on job satisfaction. However, the output indicates that IWE do not act as moderator in the relation of agreeableness and conscientiousness with job satisfaction moderation effect of IWE is observed between the relationship of neuroticism, extraversion and openness to experience with job satisfaction.

Utility of 24-hour ambulatory blood pressure monitoring in potential living kidney donors

Aslam Nabeel,Memon Sobia H.,Wadei Hani,Lesser Elizabeth R.,Niazi Shehzad K. 대한고혈압학회 2021 Clinical Hypertension Vol.27 No.4

Introduction: Hypertension (HTN) is a risk factor for cardiovascular disease; therefore, it is imperative to risk stratify potential kidney donors during evaluation. Clinic blood pressure (CBP) measurement is inaccurate in assessing presence or absence of HTN. There is paucity of data about utility of 24-h ambulatory blood pressure monitoring (ABPM) during kidney donor evaluation. Methods: 24-h ABPM is performed on all kidney donors at Mayo Clinic Florida. We conducted retrospective review of 264 consecutive potential kidney donors from 1/1/2012 to 12/31/2017. Demographic, comorbid conditions, laboratory results and 24-h ABPM data were collected. Subjects were divided into two groups: Group1: Subjects with no prior history of HTN and new diagnosis of HTN using 24-h ABPM; Group 2: Subjects with no prior history of hypertension and normal BP on 24-h ABPM. Results: Baseline demographic included mean age 46.40 years, 39% males, 78.4% Caucasians, and mean BMI was 26.94. Twenty one subjects (8.0%) had prior diagnosis of HTN. Among 243 subjects without prior HTN, 62 (25.5%) were newly diagnosed with HTN using 24-h ABPM. CBP was high only in 27 out of 62 (43.6%) of newly diagnosed HTN subjects. Thirty-five subjects (14.4%) had masked HTN and 14 subjects (5.8%) had white-coat HTN. Newly diagnosed hypertensive subjects were more likely to be males as compared to Group 2 (53.2% vs 34.3% P = 0.008). There was a trend of more non-Caucasians subjects (30.6% vs 19.9% P = 0.08) and more active smokers (17.7% vs 11.6%, P = 0.054) in Group1 as compared to Group 2. Only 17 (27.4%) out of 62 newly diagnosed hypertensive subjects were deemed suitable for kidney donation as compared to 105 (58.0%) out of 181 normotensive subjects (P < 0.001). Conclusion: In our cohort, use of ABPM resulted in new diagnosis of HTN in 1 out of 4 potential kidney donors. Newly diagnosed HTN was more common in men, those with non-Caucasian race, and in active smokers. There was a significantly reduced acceptance rate for kidney donation among newly diagnosed HTN subjects. Further studies are needed to determine the value of 24-h ABPM among these high risk groups.

Antispasmodic, Bronchodilator and Vasodilator Activities of (+)-Catechin, a Naturally Occurring Flavonoid

Muhammad Nabeel Ghayur,Hassan Khan,Anwarul Hassan Gilani 대한약학회 2007 Archives of Pharmacal Research Vol.30 No.8

Catechin is a well-known flavonoid found in many food plants and often utilized by naturopaths for the symptomatic treatment of several gastrointestinal, respiratory and vascular diseases. Our aim was to explore the biological basis for the medicinal use of this flavonoid by investigating whether catechin exhibits any pharmacological activity on smooth muscle preparations. We found that catechin dose-dependently relaxes both spontaneous and high K+ (80 mM)-induced contraction in rabbit jejunum, showing specificity for the latter by causing a rightward shift in the Ca2+ dose-response curve. Similar results were observed with verapamil, a standard Ca2+ channel blocker (CCB). Catechin also inhibited high K+-induced contraction in intact smooth muscle preparations from rat stomach fundus, guinea-pig ileum and guinea-pig trachea. In rat aorta, catechin inhibited phenylephrine (PE, 1 μM) and K+-induced contractions in a similar fashion. In PE-contracted, endothelium-intact aorta, this vasodilator effect was partially blocked by Nù-nitro-L-arginine methyl ester and atropine, indicating activity at cholinergic receptors and possibly a CCB effect at higher doses of catechin. In guinea-pig atria catechin was found inactive. These data suggest that catechin may possess Ca2+ antagonist activity - in addition to an endothelium-dependent relaxant component in blood vessels - thus providing a pharmacological basis for the efficacy of catechin in hyperexcitability disorders of gastrointestinal, respiratory and vascular smooth muscle.

Studies on Cardio-suppressant, Vasodilator and Tracheal Relaxant Effects of Sarcococca saligna

Muhammad Nabeel Ghayur,Anwarul Hassan Gilani 대한약학회 2006 Archives of Pharmacal Research Vol.29 No.11

Sarcococca saligna is a shrub that is traditionally used for its medicinal properties in Pakistan. In this study we report the cardio-suppressant, vasodilator and tracheal relaxant activities of the aqueous-methanolic extract (Ss.Cr) of the plant. Ss.Cr, that tested positive for the presence of saponins, flavonoids, tannins, phenols, and alkaloids, exhibited a dose-dependent (0.3-5 mg/mL) negative inotropic and chronotropic effect on the isolated guinea-pig atrium which was resistant to atropine (1 μM) and aminophylline (10 μM) pretreatment. In rabbit thoracic aorta, Ss.Cr dose-dependently (0.1-3 mg/mL) relaxed the high K+ (80 mM) and phenylephrine (PE, 1 μM)-induced contractions, indicating a possible Ca++ channel blocking (CCB) effect. When tested against PE (1 μM) control peaks in normal Ca++ and Ca++-free Kreb’s solution, Ss.Cr exhibited dose-dependent (0.1-3 mg/mL) inhibition, being more potent in relaxing the PE responses in Ca++-free Kreb’s solution, thus indicating specific blockade of Ca++ release from the intracellular stores. Ss.Cr also relaxed the agonist-induced contractions in: a) rat aorta irrespective of the presence of endothelium or nitric oxide synthase inhibitor L-NAME and b) rabbit and guinea-pig tracheal strips. The data shows that Ss.Cr possesses possible Ca++ channel blocking activity which might be responsible for its observed cardio-suppressant, vasodilator and tracheal relaxant effects though more tests are required to confirm this Ca++ channel blocking effect.

Commodity Prices, Tax Purpose Recognition and Bitcoin Volatility: Using ARCH/GARCH Modeling

Raja Nabeel-Ud-Din JALAL,Massimo SARGIACOMO,Najam Us SAHAR 한국유통과학회 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.11

The study investigates the role of commodity prices and tax purpose recognition on bitcoin prices. Since the introduction of bitcoin in 2008, emphasis has focused on economists, policy-makers and analysts drastically increasing bitcoin’s accessibility and commodity values (Dumitrescu & Firică, 2014). This study employs GARCH and EGARCH from ARCH/GARCH family on daily nature data. We measure the volatile behavior of bitcoin by employing auto-regressive conditional heteroscedasticity model with the aim to explore the relationship between major commodities and bitcoin volatility. We focus on major commodities like gold, silver, platinum, and crude oil to be regressed with bitcoin. The daily prices of commodities were retrieved from www.investing.com and bitcoin prices from www.coindesk.com for the period from 29 April 2013 to 16 October 2018. Results confirmed the currency’s long-term volatile behavior, which is due to its composition and market dynamics, whereas the existence of asymmetric information effect is not confirmed. Tax recognition by other countries may in future help in controlling the volatility as bitcoin is not a country-specific security. But, only silver impacts on volatility in comparison to oil prices and platinum, which is due to its similar features with gold. Eventually, bitcoin can be used for risk diversification and money making.

Numerical and experimental evaluation of the mechanical behavior of Kevlar/glass fiber reinforced epoxy hybrid composites

Muhammad Nabeel,Muhammad Ali Nasir,Mariyam Sattar,Rizwan Ahmed Malik,Meshal Alzaid,Muhammad Shoaib Butt,Mohsin Saleem,Hussein Alrobei 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.11

Flexural, tensile, and impact strength of hybrid Kevlar/glass reinforced epoxy composite is studied. Six different types of hybrid composite material were manufactured by hand layup process using different compositions of Kevlar and glass fiber. Tensile, flexural and impact strengths of manufactured samples were investigated using standard tests and compared. It is observed that tensile strength is greater for combinations with higher percentage (%) of Kevlar fabric and decreases with an increase in the glass fabric %age. Flexural strength is higher for combinations with greater %age of glass fabric and decreases with an increase in the Kevlar fabric %age. From drop weight test, it is found from visual inspection that damaged area is increased with an increase in the glass fabric percentage. Numerical simulation model incorporated with elastoplastic material data successfully predicts tensile and flexural experimental results.

Force–displacement model for analysis of pulsed-GMAW

Arif, Nabeel,Lee, Jae Hak,Yoo, Choong Don Institute of Physics [etc.] 2009 Journal of physics. D, applied physics Vol.42 No.3

<P>A force–displacement model (FDM) is introduced in this work to analyse pulsed gas metal arc welding (GMAW). The drop detaching criterion is established based on the displacement of the pendant drop instead of the previous force balance criterion. The displacement of the drop is calculated by integrating the acceleration of the drop, and the force exerted on the drop is predicted using the modified force balance model coupled with wire melting. When the peak current, base current and time of pulsed-GMAW are given, the peak time for the one-drop one-pulse condition is determined using the FDM. While the peak current has the most significant effect on drop detachment, the initial drop mass prior to the peak time also influences the drop transfer. The FDM is applied to the dc as well as pulsed-GMAW, and the calculated results show good agreement with the experimental data.</P>

Arsenic removal by perilla leaf biochar in aqueous solutions and groundwater: An integrated spectroscopic and microscopic examination

Niazi, Nabeel Khan,Bibi, Irshad,Shahid, Muhammad,Ok, Yong Sik,Burton, Edward D.,Wang, Hailong,Shaheen, Sabry M.,Rinklebe, Jö,rg,Lü,ttge, Andreas Elsevier 2018 Environmental pollution Vol.232 No.-

<P><B>Abstract</B></P> <P>In this study, we examined the removal of arsenite (As(III)) and arsenate (As(V)) by perilla leaf-derived biochars produced at 300 and 700 °C (referred as BC300 and BC700) in aqueous environments. Results revealed that the Langmuir isotherm model provided the best fit for As(III) and As(V) sorption, with the sorption affinity following the order: BC700-As(III) > BC700-As(V) > BC300-As(III) > BC300-As(V) (<I>Q</I> <SUB> <I>L</I> </SUB> = 3.85–11.01 mg g<SUP>−1</SUP>). In general, As removal decreased (76–60%) with increasing pH from 7 to 10 except for the BC700-As(III) system, where notably higher As removal (88–90%) occurred at pH from 7 to 9. Surface functional moieties contributed to As sequestration by the biochars examined here. However, significantly higher surface area and aromaticity of BC700 favored a greater As removal compared to BC300, suggesting that surface complexation/precipitation dominated As removal by BC700. Arsenic K-edge X-ray absorption near edge structure (XANES) spectroscopy demonstrated that up to 64% of the added As(V) was reduced to As(III) in BC700- and BC300-As(V) sorption experiments, and in As(III) sorption experiments, partial oxidation of As(III) to As(V) occurred (37–39%). However, XANES spectroscopy was limited to precisely quantify As binding with sulfur species as As<SUB>2</SUB>S<SUB>3</SUB>-like phase. Both biochars efficiently removed As from natural As-contaminated groundwater (As: 23–190 μg L<SUP>−1</SUP>; <I>n</I> = 12) despite in the presence of co-occurring anions (e.g., CO<SUB>3</SUB> <SUP>2−</SUP>, PO<SUB>4</SUB> <SUP>3−</SUP>, SO<SUB>4</SUB> <SUP>2−</SUP>) with the highest levels of As removal observed for BC700 (97–100%). Overall, this study highlights that perilla leaf biochars, notably BC700, possessed the greatest ability to remove As from solution and groundwater (drinking water). Significantly, the integrated spectroscopic techniques advanced our understanding to examine complex redox transformation of As(III)/As(V) with biochar, which are crucial to determine fate of As on biochar in aquatic environments.</P> <P><B>Highlights</B></P> <P> <UL> <LI> BC700 (high temperature) perilla leaf biochar removed more arsenite at pH 7–9 than BC300 (low temperature). </LI> <LI> Langmuir model efficiently delineated sorption affinity for arsenite and arsenate, notably by BC700. </LI> <LI> FTIR spectroscopy and elemental maps indicated arsenic association with surface functional groups. </LI> <LI> XANES spectroscopy revealed redox transformation/fate of arsenite and arsenate on biochars. </LI> <LI> Both biochars depleted arsenic in groundwater, with slightly higher removal by BC700. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>