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The present study numerically investigated the effect of variations in the twisting angle and perimeter of diamond-shaped perforation on the heat transfer of twisted fin heat sinks. The study showed a possible configuration of a heat sink design, aiming to improve heat transfer and the hydrothermal performance factor (HTPF). ANSYS/FLUENT computational fluid dynamics software was used to perform the simulations, and the Reynolds-averaged Navier–Stokes-based k−ε turbulence model was used. Results revealed that a maximum of 46 % enhancement in the Nusselt number and a 25 % increase in (HTPF) could be attained with a twisting angle of 540° in comparison with conventional cylindrical fins. Furthermore, the variation in perforation perimeter at a twisting angle of 540° resulted in a maximum of 28 % enhancement in the Nusselt value and a 36 % enhancement in HTPF in comparison with the twisted fins with no perforations. Therefore, this configuration is recommended as the optimal heat sink configuration.

Schiff-base fluorescent chemosensor (E)-N-(4-(dimethylamino)benzylidene)quinolone-3-amine (DBQA) was synthesized and characterized by FT-IR,1H NMR,13C NMR, ESI-MS spectrometry and Single X-ray crystallographic studies. The synthesized chemosensor (DBQA) was used for the detection of Fe3+ successfully. UV-visible and fluorescence spectra of (DBQA) exhibits a ratiometric behaviour along with a bathochromic shift upon the successive addition of Fe3+. The fluorescence spectra of chemosensor (DBQA) were recorded followed by addition of concentrations of different metal ions and NH3. The chemosensor (DBQA) showed a favourable linear relationship between the fluorescence intensity and concentration of Fe3+ ion. DBQA exhibits a ratiometric response and illustrates high sensitivity (with a detection limit of 0.4 ​μM) and good selectivity for the Fe3+ ion over other transition metal ions. DBQA shows 0.6 ​μM detection limit for NH3 along with ratiometric behaviour also. The association constant (Ka) of chemosensor (DBQA) was found to be 1.455×102 ​M-1/2 for Fe3+. The mechanism of sensing of the present ratiometric fluorescent chemosensor (DBQA) was explained by ICT (Intra-molecular charge transfer) using DFT calculations. The interaction model of chemosensor (DBQA) with Fe3+ was determined to be 2:1 stoichiometry using Job's plot analysis and ESI-MS spectra which further confirms DFT studies. Moreover, tested DBQA ​+ ​Fe3+ was showed that remarkable anticancer activity against the HCT116 colon cancer cells by MTT assay. Novelty and importance of DBQA as it can be investigate, test or analyse of detect Fe3+ rapidly as compared to other tested ions. Lastly, DBQA can be investigate, test or analyse of Fe3+ in environmental and biological samples.

Rampant discharge of industrial wastes containing non-biodegradable colored dyes to water bodies has prompted the development of an environment-friendly photocatalytic process using nontoxic, photostable water soluble photocatalyst. In this work, bare undoped carbon dots (CDots) based photocatalyst has been reported. The carbon dots were synthesized via the pyrolysis method using a single source, ammonium citrate; the reported carbon dots were characterized using HR-TEM, XRD, FTIR, XPS, Photoluminescence (P.L.), TGA, and UV–Vis spectroscopy. The catalytic behavior of the synthesized carbon dots was tested against two water-soluble industrial dyes (Methylene Blue (M.B.) and Congo Red (C.R.)). The synthesized carbon dots exhibited excellent photocatalytic activity under visible light irradiation facilitating 96% degradation of MB within 55 min and 98% degradation of C.R. within 60 min. A plausible mechanism for the photocatalytic degradation of studied dyes was proposed based on comprehensive active species trapping experiments. The photogenerated holes (h+) and superoxide radicals (O2 .−) were the main active species responsible for the degradation of studied dyes. The kinetic studies revealed that the cationic methylene blue dye degradation by BUCDs followed the modified Freundlich kinetic model with rate constant 0.063 and anionic congo red dye depicted closed correlation with both parabolic diffusion model and modified Freundlich kinetic model with rate constants 0.256 and 0.196. The synthesized BUCDs showed no cytotoxicity in HCT human colon cancer cell lines, thus establishing their nontoxic nature.

Above sea gas dispersion resulting from subsea release could cause explosion risk to a nearby offshore platform. Past researchers performed a CFD-based assessment of above sea gas dispersion under the varying sea and environment conditions, but the resulting expected overpressure consequences due to the potential ignition of dispersing flammable on an offshore platform under such varying conditions were not investigated. Overpressure estimates under varying sea and weather parameters could support the practitioners in determining the most critical conditions that correspond to the worst consequences on the offshore platform thus, the research could contribute to process safety. Therefore, in this study, above sea gas dispersion under varying wind speeds in range 2-6 m/s and sea surface release rates of 390 kg/s and 872 kg/s were performed using a Fire Dynamics Simulator (FDS), and expected overpressure consequences in each case are estimated based on the flammable concentration distribution on the platform. It was found that low wind speed and less release rate do not pose a danger to the platform. However, compared to the low wind-low release rate, 35% greater platform area was covered by flammable gas cloud at a high wind speed of 6 m/s and a high release rate of 872 kg/s. This could cause overpressure of 70 kPa in 7.5% of the platform region, which is identified as the most dangerous release rate and wind speed condition. It is suggested that the operators on the offshore platform take special care in high wind and release rate scenarios to avoid flammable cloud accumulation and resulting overpressure consequences.

Applying sinusoidal vibration to heat sinks has proven to be a promising technique for improving heat transfer by disrupting the thermal boundary layer. However, applying sinusoidal vibration to the base of thin plate-fin heat sinks can cause a flapping motion within the fins, further enhancing heat transfer. Therefore, the current study numerically investigates and compares the effects of sinusoidal vibrations on the thermal performance of conventional and thin plate-fin heat sinks. The study concludes that increased vibrational amplitude and frequency (f ˃ 30 Hz) increases the vibration-assisted thermal performance. It was found that the thin plate-fin heat sink provides higher thermal performance compared to the conventional heat sink at every level of vibrational characteristics. The study found that the application of vibration enhances the Nusselt number up to a maximum of 20% and 15% in thin plate-fin and conventional heat sinks, respectively. Furthermore, the Reynolds number is reduced by 33.3% and 28% with thin plate-fin and conventional heat sinks compared with non-vibrating heat sinks, indicating a potential reduction of the size of the cooling system or fin size.

T-junction is broadly utilized for phase separation, as it has a notable function as a conduit to distribute fluid, due to its simple design, low maintenance cost and adaptability to offshore industries. The geometrical parameters that influence phase separation make the phase re-distribution unpredictable. Even though the diameter ratio of the T-junction has a prominent effect on phase separation, it was not thoroughly and comprehensively reviewed specifically. This review article intends to fill in that gap, focusing solely on the effect of the diameter ratio on phase separation, specifically for two-phase flow in branching T-junction. Initially, the inversely proportional relation between diameter ratio and phase separation is discussed, reported first in the 1970s. Besides, a critical analysis in 1998, is reported which challenged the inverse proportionality. Unfortunately, their disagreement was not addressed for more than a decade. Lastly, two different criteria to determine the separation efficiency, state-of-the-art T-junction design and side arm modifications are summed up with conclusions. The primary contribution of this research is that it takes into account the agreement and disagreements among the researchers for inverse proportionality between phase separation and diameter ratio, including some critical findings that were not reported in the past in review articles. Some recommendations for future research in this domain are also reported.

Pool fires cause immense damage to fuel storage tank farms. Reduced fire escalation risk in tank farms improves fire safety. Computational fluid dynamics (CFD) has proven effective in assessing escalation of fire-related domino effects and is being utilized for pool fire consequences in tank farms. The past CFD-based analysis focused on primary fire effects on secondary targets. This study used fire dynamics simulator (FDS) to model complete evolution of the domino effect under different wind speeds and primary pool fire locations. Dynamic escalation probability (DEP) and fire spread probability of the tank farm were calculated. Offset tank failure increased by 3% and 31%, while inline tank failure dropped by 36% and 90%, at 2 and 8 m/s, respectively. An artificial neural network (ANN) incorporating the Levenberg–Marquardt algorithm is used to predict fire spread probability based on numerical data set. The use of ANNs for this purpose is one of the first attempts in this regard. ANNs can reliably predict dynamic fire spread probability and could be utilized to manage fire-induced domino effects. Moreover, dynamic fire spread probability in tank farms obtained from ANN modelling can be used for safety applications, such as updating mitigation time when fire spread probability is unacceptable for a specific wind speed.

A significant rise in bone-related defects affects the quality of life which impels researchers to facilitate the new approaches for bone regeneration. Herein, we have explored the bioactive nature of nano-titania for its utilization in bone tissue engineering. The titania-doped ternary nanocomposite film (PVA/NC-TiO2) was prepared by the fusion of Polyvinylalcohol (PVA), nano-cellulose (NC), and TiO2 (0.01 wt%) nanoparticles via sol-gel casting and compared with its binary nanocomposite film (PVA/NC). The simple and low-cost synthesis of these nanocomposite films, together with remarkable bioactive and thermo-mechanical properties, makes them a good candidate for their applications in human bone regeneration. The fabricated nanocomposite films were characterized through Fourier transform infra-red, Ultra-violet spectroscopy, and X-ray diffraction analysis to study complex formation and intermolecular interactions between the molecular entities.The SEM and TEM micrographs revealed the smooth surface of the developed binary and ternary nanocomposite films along with homogenous particle distribution. The thermo-mechanical stability was significantly improved when the nanocomposite film was modified with TiO2 nanoparticles indicating an enhancement of intermolecular interactions in PVA/NC-TiO2 film as compared to PVA/NC film. The Dynamic mechanical analysis results show higher storage modulus and glass transition temperature for PVA/NC-TiO2 film (9131.26 MPa, 74.3 °C) than PVA/NC film (7588 MPa, 64.3 °C). A comparative analysis of nanocomposite films revealed that PVA/NC-TiO2 film exhibited a thick and more uniformed layer of Ca–P mineral on its surface than PVA/NC film when incubated in Simulated Buffer Saline. The low loading of TiO2 nanoparticles resulted in a positive reinforcement effect on the bioactivity of the PVA/NC-TiO2 film (cell viability higher than 80%, hemolysis less than 1.7%) which provides an effective gateway for polymer nanocomposites in the dynamic orthopedic application by serving a better bone template for the regeneration of bone tissue.

l-Tryptophan derived Schiff base ligand and its complexes of the type, [ML(H2O)2]·H2O [M = Co(II), Ni(II), Zn(II)] and [CuL] have been synthesized and characterized on the basis of results obtained from elemental analysis, conductivity measurements, ESI-Mass spectral studies, FT-IR, 1H and 13C NMR, UV–Vis spectroscopy and magnetic moment data. The synthesized complexes were subjected to thermogravimetric analysis to study their decomposition pattern and stability. The fluorescence and viscosity measurements reveal that complexes have significant CT-DNA binding. However, upon comparing the DNA binding analyses, Cu(II) complex exhibited significant binding affinity. Keywords: l-Tryptophan based Schiff base complexes, Spectroscopic studies, DNA-binding

Among numerous electronic cooling methods, a vibrating heat sink using sinusoidal wave vibration effectively enhances the heat transfer by disturbing the thermal boundary layer. However, sinusoidal wave vibration has reached its limits in enhancing heat transfer. The present study utilizes a new square wave-shaped vibration and numerically investigates the thermal performance of a heat sink subjected to sinusoidal and square waves vibration. It is found that using the square wave vibration is more beneficial to the thermal performance of the heat sink than the sinusoidal wave. The sudden impulsive motion of square wave vibration induces a higher randomness of the airflow profile and recirculation zones than the sinusoidal wave, causing the air flow to impinge directly into the fin surfaces, and further enhances the heat transfer. Furthermore, increasing the frequency and amplitude leads to a higher heat transfer enhancement. Moreover, square wave vibration achieves a 25% increase in Nusselt values compared to the nonvibrating fins and it is 11% higher than the Nusselt number recorded by the sinusoidal vibration. Consequently, Reynolds number values can be reduced by 42.2% to achieve the Nusselt number values of nonvibrating fins, potentially reducing the cooling system or fin size. This reduction may contribute to solving the challenges of electronic systems compactness.

Transverse myelitis (TM) is a rare neurological disorder characterized by acute or subacute bilateral inflammation and myelin destruction in the spinal cord. A 14-year-old, primigravida with idiopathic TM presented to us with 38 weeks gestation for emergency cesarean section. There are potential anesthetic concerns with general anesthesia in the form of hyperkalemia following succinylcholine and delayed reversal from nondepolarizing muscle relaxants. Taking into consideration, the above-mentioned facts and level of sensory deficit of our patient; we successfully conducted the case under monitored anesthesia care with minimal analgesic support keeping our conventional anesthetic techniques as standby.

Slug multiphase flow is known to be the most prevalent regime because of its extensive encounters associated with chaotic behaviour, complexity and instability that cause significant fluctuations in operating conditions and thus lead to undesirable effects. In this study, the effect of varying crude oil grades on slug characteristics is numerically investigated. A partitioned one-way coupling framework of fluid–structure interaction (FSI) one-way coupling framework is adopted to investigate the influence of changing oil grades and slug characteristics on the maximum induced stresses in horizontal carbon steel pipe. It was found that increasing crude oil density causes frequent slugging and promotes the formation of liquid slugs further upstream near the inlet with high translational velocity and short wavelength. Therefore, the maximum induced stresses resulting from the interaction between slugs and the inner surface of pipes are strongly dependent on crude oil grade. In modelling extra heavy crude oil, a 40% increase in maximum induced stresses is recorded when the liquid superficial velocity decreases from 1 to 0.86 m/s at a constant natural gas superficial velocity.

A novel Schiff base ligand, N,N′-bis (glyoxalicacidcarboxaldiimine)-1,8-diaminonaphthalene [H2L] obtained by the condensation of glyoxalic acid and 1,8-diaminonaphthalene and its mononuclear complexes of type, [ML] [M = Co(II), Ni(II), Cu(II), Zn(II)] have been synthesized and characterized on the basis of elemental analysis, molar conductance, magnetic susceptibility measurements and spectroscopic studies viz., FT-IR, EPR, 1H NMR, FAB-Mass, UV–vis and magnetic moment data. A square planar geometry has been assigned on the basis of UV–vis and magnetic susceptibility around Co(II), Ni(II) and Cu(II) ions while conductivity data showed non electrolytic nature of all the complexes. The synthesized ligand, H2L and its complexes have been tested against Streptococcus mutans, Staphylococcus pyogenes, MRSA (Gram positive bacteria), Pseudomonas aeruginosa, Salmonella typhimurium, Escherichia coli (Gram negative bacteria), Candida albicans, Candida krusei, Candida parapsilosis and Candida neroformans and results suggested that Cu(II) complex has significant antimicrobial activity.

A series of two new Zn(II) complexes derived from 3-aminoquinoline are reported. The complexes were synthesized by the interaction of 3-aminoquinoline and Zn(II) ions in 2:1 molar ratio. The structure of synthesized complexes is investigated by elemental analyses, ESI-MS, FT-IR, 1H and 13C NMR and UV–Vis spectroscopic studies. A single crystal X-ray diffraction measurement study reveals tetrahedral geometry around the zinc ion, and existence as a neutral discrete molecule.

This paper presents the experimental analysis of the effects of simulated hydrocarbon fire exposure on the mechanical properties and the heat transmission in fiber-reinforced self-compacting concrete, FR-SCC. For that purpose, 300-mm thick, and 1200-mm square-shaped slabs were cast. Basalt and polyvinyl alcohol (PVA) fibers were added using the content of 1, 1.5, and 2% in self-compacting concrete. For investigating the heat transmission within 300-mm thick slabs, five external thermocouples were installed at the unexposed face to the fire of the slabs. Similarly, eleven internal thermocouples were installed at an interval of 25 mm throughout the slab thickness. It has been found that fibers have shown better insulation than the controlled concrete; the unexposed to fire surface of FR-SCC showed temperatures lower by ten degree Celcius than the controlled concrete. Compressive strength results showed that fiber addition caused a higher reduction in strength because of softening and stiffness reduction due to high-temperature exposure. After 120 min of fire exposure, basalt fibers caused an average reduction of 30% in the compressive strength, and PVA fibers caused an average reduction of 25%. Whereas, the addition of fibers improved the split cylindrical tensile strength even after exposure to 120 min of fire exposure in comparison with the unreinforced samples.

This paper presents a study for analyzing and improving research productivity of Malaysian Research University (RU). In literature there are various general models for research and development analysis. Although many prior researchers have studied factors that influence research productivity, only a few have examined it from the behavioral perspective. From the behavioral perspective, it becomes apparent that motivation theory is the predominant theory that researchers utilized when studying research productivity. Further scrutinized of the previous studies have identified that the expectancy theory analysis was used by most of them either solely or with other theories. It has been proven that the expectancy theory when properly employed will most likely bring success to organizational change. This paper addresses the development of the proposed model to be applied at Malaysian RU.

The performance of a membrane-based heat exchanger utilizing porous paper as the heat and moisture transfer media is presented. The measured performance is compared with a plastic film heat exchanger. This novel heat exchanger is used in ventilation energy recovery systems. The results show that the sensible effectiveness is higher than the latent effectiveness. When a similar experiment was conducted using a plastic film heat exchanger surface instead of paper, where only heat is transferred, the sensible effectiveness values were lower than the effectiveness values recorded when the paper heat exchanger is used. Furthermore, energy analysis shows that utilizing a paper surface heat exchanger in a standard air conditioning system will lead to significant energy savings.

Energy performance of buildings has attracted much attention among building physicists and engineers worldwide. The effects of building heating; ventilation; and air conditioning (HVAC) systems’ design upgrade on the building energy performance are the focus of the current study. The adopted HVAC system consisted of chilled ceiling and chilled beam systems served by a centrifugal water chiller. An energy simulation study was undertaken in accordance with the national Australian built environment rating system-rules for collecting and using data. A three-dimensional simulation study was carried out utilizing the virtual environment-integrated environmental solutions software. Results from the current study have shown the importance of utilizing energy-efficient HVAC systems and HVAC strategies for achieving a high building energy star rating. Recommended strategies in order to achieve the nominated star rating; as predicted by the simulation analysis; were presented. Moreover; the effects of solar radiation inside the building atrium were significant; which cannot be overcome by simply installing a low shading coefficient glazing type at the atrium skylight. In addition to providing chilled ceiling technology; a high efficiency chiller and low energy lighting; it is recommended that the building be well tuned during the commissioning period. The current approach could be extended to accommodate higher energy ratings of commercial buildings at different locations worldwide.

A series of 16- and 18-membered binuclear octaazamacrocyclic complexes, [M2L1(NO3)4] and [M2L2(NO3)4] (M = Co(II), Ni(II), Cu(II), Zn(II), L1 = 3,8,11,16-tetramethyl-1,2,4,7,9,10,12,15-octaaza-3,7,11,15-cyclohexadecatetraene and L2 = 3,9,12,18-tetramethyl-1,2,4,8,10,11,13,17-octaaza-3,8,12,17-cyclooctadecatetraene) were synthesized by metal template condensation of N,N’-diacetylhydrazine with 1,2-diaminoethane and 1,3-diamino¬pro¬pane in methanol. The formation of macrocyclic ligand frameworks, the bonding of the macrocyclic moieties in the complexes and the overall geometry of the complexes were deduced based on the results obtained from elemental analyses as well as molar conductivity, FTIR, 1H-, 13C-NMR, EPR, ESI-mass, UV–Vis spectral studies and magnetic measurements. An octahedral geometry is proposed for all the complexes, while a distortion in the octahedral geometry was registered for the Cu(II) complexes. Comparative fluorescence and UV–Vis studies on the Cu(II) complexes proved a significant binding to calf thymus DNA.