Time and cost play an important role in project completion for both developing and developed countries. This study aims to identify the critical factors that influence the time and cost of commercial ...projects in Malaysia. A detailed questionnaire survey was conducted with industry professionals, and the results were analyzed based on the survey responses. The average index method was used to determine critical factors based on responses from professionals. The critical factors that affect time are poor contract management, client fund shortages, late drawing submissions, land acquisition problems, and inadequate surveying before construction. The critical factors identified for cost are delayed client payments, shortage of skilled workers, design changes, errors in the construction process, and changes in top management. This study raises awareness by identifying critical factors to minimize their impact so that construction can be completed on time and according to the defined budget, and maximize the benefits of future projects.
Nitrogen doped graphene modified WO3 nanocomposites were synthesized through an effective methodology. The prepared photocatalysts were employed as active candidates for degradation of highly toxic ...organics i.e., 2, 4 dichloro phenol (2, 4-DCP) and methyl orange (MO). XRD profile of N-graphene showed complete reduction of GO into N-graphene. All diffraction peaks of WO3 along with N-graphene indicated monoclinic phase of WO3. SEM and TEM images of 3.0% N-graphene/WO3 have demonstrated the mixed morphology of irregular massive rod like blocks and round shaped particles of WO3 distributed on cracked sheets of N-graphene. Nitrogen defects in graphene altered zero band gap semi-metallic graphene to semiconducting material and increased the absorption edge of N-graphene/WO3 nanocomposites towards visible region as studied in DRS analysis. FTIR and Raman studies showed the strong connection between N-graphene and WO3 by making W−O−C surface linkage. The noticeable reduction in PL emission peaks of 3.0% N-graphene/WO3 indicated obvious separation of photo induced charge carriers. The study of radical scavengers suggested that holes (h+) and •OH are the main elements for the decontamination of both MO and 2, 4-DCP. XPS analysis shows all possible C−N bonding configurations in 3.0% N-graphene/WO3. 3.0% N-graphene/WO3 composite showed the maximum photo degradation of MO (~94.0%) and 2, 4-DCP (~81.0%). The synergism between N-graphene and WO3 results into more sporty sites on catalyst and restoring of sp2 structural defects in N-graphene lattice improve the transportation of charge carriers during photocatalysis. This work provides innovative strategies for designing the N-graphene/semiconductor nanosystems with enhanced photocatalytic phenomena in the environmental cleanup remedies.
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•Nitrogen doped graphene/WO3 nanocomposite functioned as energetic photocatalyst.•Nitrogen atoms in graphene produce unstable charge zone leading to polarization.•Graphene in WO3 provides conductive channels for the passage of charge carriers.•3.0% N-graphene/WO3 nanosystem showed the superior photocatalytic efficiency.•OH•and h+ radicals emerged as main active species for photocatalysis.
In an effort to develop new organotin materials for investigation and biocidal evaluation, a series of compounds with the general formula $R_{4_n}SnL_n$ (where R = $CH_3$, $n-C_4H_9$, $C_6H_5$, ...$C_6H_5CH_2$ and L = 3-(N-naphthylaminocarbonyl)-2-propenoic acid) were synthesised, and characterised by elemental analysis, IR, multinuclear ($^1H$, $^{13}C$ and $^{119 }Sn$) NMR, $^{119m}Sn$ Mössbauer spectroscopy and mass spectrometry. The biological activity of these compounds against various bacteria and fungi was investigated. All of the compounds were active against the fungi tested with a few exceptions. These compounds also showed significant antibacterial activity. $LD_{50}$ data show that the investigated compounds have significant toxicity.
Organotin carboxylates of the general formulae $R_2SnL_2$ and $R_3SnL$, where $R = CH_3$, $n-C_4H_9$, $C_6H_5$, $CH_2C_6H_5$ and L = 1-ethyl-1,4-dihydro-7-methyl-4-oxo-1,8-naphthyridine-3-carboxylic ...acid (nalidixic acid), have been prepared. These compounds were characterized by FT-IR, mass and multinuclear NMR ($^1H$, $^{13}C$ and $^{119}Sn$) spectroscopy. The geometry around the tin atom is compared both in solution and in solid state. These compounds were also screened for their antifungal and antibacterial activities.
The structure of the title compound, Sn(CH3)3(C8H8NO4), is composed of two independent monomers in the asymmetric unit, which form polymeric chains involving both O atoms of the acid moieties lying ...parallel to the b axis, and are separated by one half unit cell along the a axis. The geometry around the Sn atoms in both monomers is distorted trigonal‐bipyramidal, where three methyl C atoms occupy the equatorial positions with almost identical Sn—C distances, and O atoms from two symmetry‐related ligands are in the axial positions with significantly different Sn—O distances.
The molecules of the title compound, Sn(CH3)3(C13H10NO4), form polymeric chains involving both O atoms of the acid moiety. The geometry around the Sn atom is distorted trigonal bipyramidal, whith ...three methyl C atoms occupying the equatorial positions and O atoms from two symmetry‐related molecules at axial positions.
In an effort to develop new organotin materials for investigation and biocidal evaluation, a series of compounds with the general formula R
4−n
SnL
n
(where R=CH
3
, n-C
4
H
9
, C
6
H
5
, C
6
H
5
CH
...2
and L=2-(N-maleoyl)-3-phenylpropanoic acid anion) have been synthesized, and characterized by elemental analyses, IR, multinuclear (
1
H,
13
C and
119
Sn) NMR and mass spectrometry. The biological activity of these compounds against various bacteria and fungi has been investigated. All of the compounds were found to be active against the tested fungi with a few exceptions. These compounds also showed significant antibacterial activity. LD
50
data show that the investigated compounds also have significant toxicity.
In this study, a new hybrid model, bootstrap multiple linear regression (BMLR) is suggested to investigate the potential of bootstrap resampling technique for daily reservoir inflow prediction. The ...proposed model compares with three other models: Multiple linear regression (MLR), wavelet multiple linear regression (WMLR) and wavelet bootstrap multiple linear regression (WBMLR). River stage data of monsoon season (1st July 2010 to 30 September 2010) from three gauging stations of Chenab river basin are used. In wavelet transformation, input vectors are decomposed using discrete wavelet transformation (DWT) into discrete wavelet components (DWCs). Then suitable DWCs are used to provide input to MLR model to develop WMLR model. Bootstrap technique coupled with MLR model to build up BMLR model. While WBMLR model is the conjunction of suitable DWCs and bootstrap technique to MLR model. Performance indices namely root mean square error (RMSE), mean absolute error (MAE), Nash-Sutcliffe coefficient of efficiency (NSC), and persistence index (CP) are used in study to evaluate the performance of model. Results showed that hybrid model BMLR produce significantly better results on performance indices than other models MLR, WMLR and WBMLR.
