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Search Results: 1 - 10 of 14 matches for " Sirajuddin "
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Cure Characteristics, Mechanical and Swelling Properties of Marble Sludge Filled EPDM Modified Chloroprene Rubber Blends  [PDF]
Khalil Ahmed, Shaikh Sirajuddin Nizami, Nudrat Zahid Raza, Khaula Shirin
Advances in Materials Physics and Chemistry (AMPC) , 2012, DOI: 10.4236/ampc.2012.22016
Abstract: In the present study, attempts have been made to modify Marble Sludge (MS) filled Ethylene-propylene-diene monomer (EPDM) with Chloroprene rubber (CR). Compounding was carried out on a two-roll mill and vulcanized at 155℃. The modified blend of MS filed EPDM/CR was characterized on the basis of the effect of blend ratio on cure characteristics, mechanical and swelling properties of blends were investigated. The effect of thermal aging on mechanical and swelling behavior in aromatic, aliphatic and chlorinated solvents of cured MS filled EPDM/CR blend was also examined. The minimum torque and maximum torque of the blend first increased and then slightly decreased after the increasing of CR content in MS filled EPDM/CR blends. Scorch time, cure time, cure rate index, tensile strength, tear strength, hardness increased with increasing CR content in the MS filled EPDM compound, but elongation at break, resilience, abrasion loss, mole % uptake, swelling index and percentage of soluble fraction decreased, resilience, abrasion loss, mole % uptake, swelling index and percentage of soluble fraction decreases. Accelerated aging performance of cured composites also influenced by increasing CR content in MS filled EPDM compound.
On a Curvature Tensor for the Spacetime of General Relativity
Zafar Ahsan,Musavvir Ali,Sirajuddin
Mathematics , 2015,
Abstract: In the differential geometry of certain F-structures, the role of W-curvature tensor is very well known. A detailed study of this tensor has been made on the spacetime of general relativity. The spacetimes satisfying Einstein field equations with vanishing W-tensor have been considered and the existence of Killing and conformal Killing vector fields has been established. Perfect fluid spacetimes with vanishing W-tensor have also been considered. The divergence of W-tensor is studied in detail and it is seen, among other results, that a perfect fluid spacetime with conserved W-tensor represents either an Einstein space or a Friedmann-Robertson-Walker cosmological model.
1-(2-Methoxyphenyl)-1H-pyrrole-2,5-dione
Muhammad Sirajuddin,Saqib Ali,M. Nawaz Tahir
Acta Crystallographica Section E , 2012, DOI: 10.1107/s1600536812026888
Abstract: In the title compound, C11H9NO3, the dihedral angle between the methoxybenzene and 1H-pyrrole-2,5-dione rings is 75.60 (10)°. The C atom of the methoxy group is close to coplanar with its attached ring [deviation = 0.208 (2) ]. In the crystal, weak aromatic π–π stacking [centroid–centroid separation = 3.8563 (13) ] occurs between inversion-related pairs of benzene rings.
Assay of Aliphatic Phthalates in Polymer Products by Sensitive Polarographic Method: Health and Environmental Issue
Munawar Saeed,Sirajuddin,Abdul Niaz2,,Afzal Shah
Pakistan Journal of Analytical and Environmental Chemistry , 2010,
Abstract: A faster, simpler and sensitive method was developed for determination of aliphatic phthalates using differential pulse polarography (DPP) as standard technique. The choice and concentration of base electrolyte, solvent, initial potential, effect of water addition and interference by other phthalates were the main parameters to optimize for enhancement of peak current and to obtain well-defined polarogram with lower background current using 1.3 x 10-4 M di-butyl phthalate (DBP) solution. Best results were obtained in the presence of tetra methyl ammonium bromide (TMAB) as electrolyte in methanol solvent with initial potential, -1.4 V. A linear calibration plot was observed in the range of 3 x 10-7 – 1.6 x 10-4 M DBP solution as aliphatic phthalates with lower detection limit of 5.9 x 10-8 M and linear regression coefficient of 0.9987. The developed polarographic method was successfully applied for analysis of aliphtaic phthalates in various samples of locally available polymer products such as baby toys, nipples, teethers, infusion blood bags and shopping bags. The results of the current method were compared with those obtained by a reported method and good agreement was found between them.
Simpler and Faster Spectrophotometric Determination of Diclofenac Sodium in Tablets, Serum and Urine Samples
Abdul Rauf Khaskheli,Sirajuddin,Kamran Abro,S. T. H. Sherazi
Pakistan Journal of Analytical and Environmental Chemistry , 2009,
Abstract: This work describes a simple, sensitive, rapid and economical analytical procedure for direct spectrophotometric evaluation of diclofenac sodium (DS) using aqueous medium without using a chemical reagent. Parameters like time, temperature, acidic and basic conditions and interference by analgesic drugs were studied for a 5μg ml-1 solution of DS at 276 nm. Under optimized parameters, a linear working range of 0.1–30 g ml-1 with regression coefficient of 0.9998 and lower detection limit of 0.01 g ml-1 was obtained. The method was applied for DS contents in tablets, serum and urine samples.
Evaluation of the Iodine Concentration in Serum and Urine of Hypothyroid Males Using an Inexpensive and Rapid Method
Ghulam Abbas Kandhro,Tasneem Gul Kazi,Sirajuddin,Naveed Kazi
Pakistan Journal of Analytical and Environmental Chemistry , 2009,
Abstract: The aim of present study was to evaluate the iodine/iodide status in biological samples (serum and urine) of 172 male hypothyroid patients (HPs) and their supplemental effects on thyroid hormones. For comparison purpose, non-goitrous subjects (n= 220) of same age group and socioeconomic status were also studied. A simple and rapid iodide-ion selective electrode (ISE) was used to measure the concentration of iodine in microwave assisted acid digested serum and urine samples. Quality control for the methodology was established with certified samples and with those obtained by conventional wet acid digestion method on the same certified reference materials (CRMs) and real samples. A linear calibration curve was obtained for a reasonable concentration range of the potassium iodide solutions. The mean concentration of iodine in the serum and urine samples of the HPs was significantly reduced as compared to control male subjects (p< 0.01). The low levels of free triiodothyronine and thyroxin were found in HPs than age matched healthy control (p< 0.005 and 0.002) respectively while high levels of thyroid stimulating hormone were observed in HPs (p< 0.008). The proposed method was relatively efficient as well as cost effective by using inexpensive equipment. It was observed that iodine in biological samples of HPs can play an important role in determining the severity of the hypothyroidism.
Facile Synthesis, Characterization and Catalytic Function of Gelatin Stabilized Gold Nanoparticles
Zulfiqar A. Tagar,Sirajuddin,Najma Memon,Muhammad S. Kalhoro
Pakistan Journal of Analytical and Environmental Chemistry , 2012,
Abstract: In the present investigation, we report a new one phase, one pot method for synthesis of 3.5 ± 0.7 nm average sized gelatin capped gold nano particles (Gel-AuNPs) using strong reductant NaBH4 in aqueous system at room temperature. Size controlled Gel-AuNPs were characterized by UV-Visible, STEM, XRD, DLS and FT-IR. Spherical Gel-AuNPs showed excellent catalytic activity for reduction of three differently charged dyes eosin B (EB), methylene blue (MB) and rose bengal (RB) in the presence of NaBH4. The study revealed that 100% reduction of EB, MB and RB dyes was carried out in just 150 sec. The developed catalyst was easy to recover and capable to be reused three times. The process of reduction rate and kinetics of dyes was monitored using UV-Visible spectrophotometer. A plot of lnC Vs time (sec) showed that reaction follows the first order kinetics. Rate constant (K) was determined for EB, MB and RB reduction at 10 μM, which was found as 2.735 x10-2 sec-1, 2.738 x 10-2 sec-1 and 2.55 x 10-2 sec-1, respectively. The study revealed that catalytic reduction of dyes by Gel-AuNPs in aqueous medium is environmental friendly in terms of recovery of catalyst, is exceptionally fast and hence extremely economical.
2-(2-Methoxyphenyl)-1H-isoindole-1,3(2H)-dione
M. Nawaz Tahir,Muhammad Sirajuddin,Saqib Ali,Khurram Shahzad Munawar
Acta Crystallographica Section E , 2012, DOI: 10.1107/s1600536812027262
Abstract: In the title compound, C15H11NO3, the dihedral angle between the methoxybenzene and isoindole ring systems is 70.21 (3)°. The methoxy C atom is close to being coplanar with its attached ring [deviation = 0.133 (2) ] and is oriented away from the isoindole moiety. In the crystal, inversion dimers linked by pairs of C—H...O hydrogen bonds generate R22(10) loops. Further C—H...O interactions lead to (010) infinite sheets and weak aromatic π–π stacking [centroid–centroid separations = 3.6990 (10) and 3.7217 (10) ] is also observed.
ADOPTION OF BIOSECURITY MEASURES BY LAYER SMALLHOLDERS
V. S. Lestari,S. N. Sirajuddin,K. Kasim
Journal of the Indonesian Tropical Animal Agriculture , 2011,
Abstract: It was indicated that layer smallholders awareness of biosecurity was low. This paper aimed to determine the level of adoption within the South Sulawesi layer smallholders of a range of standard biosecurity measures. Sidenreng Rappang (Sidrap) regency was chosen as a location of the research, because it was famous as a central of layer smallholders. Total sample was 60 respondents. The sample was chosen through random sampling from two districts which were the most populous of layer smallholders, namely Baranti and Maritengae. Data were collected using structured questionnaires and depth-interview. The data were tabulated and analysed using a simple method of scoring with regard to their biosecurity status. The status of biosecurity was used to know the level of biosecurity adoption. Biosecurity status was obtained based on the adoption of biosecurity measures which consisted of 9 stages: farm inputs, traffic onto farms, distance from sources of pathogens to shed, exposure of farm, biosecurity at farm boundary, biosecurity between farm boundary and shed, biosecurity at the shed door, traffic into the shed and susceptibility of the flock. Using adoption index, this research revealed that biosecurity adoption of layer smallholders in South Sulawesi was classified into a partial adopter.
Proximate Composition and Antioxidant Potential of Leaves from Three Varieties of Mulberry (Morus sp.): A Comparative Study
Shahid Iqbal,Umer Younas,Sirajuddin,Kim Wei Chan,Raja Adil Sarfraz,Md. Kamal Uddin
International Journal of Molecular Sciences , 2012, DOI: 10.3390/ijms13066651
Abstract: In this study, leaves of three indigenous varieties of Mulberry namely, Morus alba L., Morus nigra L. and Morus rubra L. were investigated for their antioxidant potential and their proximate composition was determined. The yields of 80% methanolic extracts ranged between 8.28–13.89%. The contents of total phenolics (TPC), total flavonoids (TFC) and ascorbic acid (AA) ranged between 16.21–24.37 mg gallic acid equivalent (GAE)/g, 26.41–31.28 mg rutin equivalent (RE)/g and 0.97–1.49 mg/g, respectively. The antioxidant activity of leaf extracts was evaluated by measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH ?) radical scavenging actity, 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulphonic acid (ABTS ?+) radical cation scavenging capacity and ferric ion reducing power and values ranged between 1.89–2.12, 6.12–9.89 and 0.56–0.97 mM Trolox equivalent/g of dried leaves, respectively. The investigated features reveal good nutritive and antioxidant attributes of all the varieties with mutually significant differences.
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