SYNTHESIS, CHARACTERIZATION AND BIOLOGICAL STUDY OF MANNICH BASES AND THEIR COPPER (II) COMPLEXES

Objective: The present study is focused on the synthesis of novel Mannich bases and their metal complexes, and to characterize them by physical, chemical and biological methods. Mannich bases, 2-(piperazin-1-yl(thiophen-2-yl)methyl)hydrazinecarboxamide (PTMHC), 2-(piperazin-1-yl(thiophen-2-yl)methyl)hydrazinecarbothioamide (PTMHCT), and 2-((4-methylpiperazin-1-yl)(thiophen-2-yl)methyl)hydrazinecarboxamide (MPTMHC) and 2-((4-methylpiperazin-1-yl)(thiophen-2-yl)methyl)hydrazinecarbothioamide (MPTMHCT), were prepared by Mannich condensation method.Methods: The compounds and complexes were prepared by known literature methods. Characterizations were carried out through physical methods such as elemental analyses, melting point and TLC. IR, 1H NMR, [13]C NMR and Mass spectral studies were carried out to characterize the ligands. The methods like EPR, magnetic susceptibility measurements, conductance measurements and thermal analysis were carried out for complexes besides the UV-Vis and IR spectral studies. Anti-cancer activity of synthesized ligands was performed using human lung and colon cancer cell lines.Results: Eight compounds have been prepared and characterized. Four among the eight compounds were used as ligands for the preparation of metal complexes. The results of physical and chemical methods show all the complexes act as bidentate ligands. The coordination with the metal ion takes place through N, S and O atoms. The results of molar conductivity and magnetic susceptibility measurements reveal the electrolytic and non-electrolytic nature of the metal complexes. EPR and TG-DTA studies also support the other spectral data.Conclusions: Copper (II) complexes of PTMHC, PTMHCT, MPTMHC, and MPTMHCT were prepared and their structures were determined. The anti-cancer activity of the synthesized ligands and their complexes was evaluated. The synthesized novel ligands of Mannich bases can serve as a potential anti-cancer agent.Â

Disorder mediated splitting of the cyclotron resonance in two-dimensional electron systems

We perform a direct study of the magnitude of the anomalous splitting in the cyclotron resonance (CR) of a two-dimensional electron system (2DES) as a function of sample disorder. In a series of AlGaAs/GaAs quantum wells, identical except for a range of carbon doping in the well, we find the CR splitting to vanish at high sample mobilities but to increase dramatically with increasing impurity density and electron scattering rates. This observation lends strong support to the conjecture that the non-zero wavevector, roton-like minimum in the dispersion of 2D magnetoplasmons comes into resonance with the CR, with the two modes being coupled via disorder.Comment: accepted to PRB Rapid Com

Non-parabolicity of the conduction band of wurtzite GaN

Using cyclotron resonance, we measure the effective mass, $m$*, of electrons in AlGaN/GaN heterostructures with densities, $n_{2D}\sim 1-6\times10^{12}$cm$^{-2}$. From our extensive data, we extrapolate a band edge mass of $(0.208\pm0.002) m_e$. By comparing our $m$* data with the results of a multi-band \textbf{k.p} calculation we infer that the effect of remote bands is essential in explaining the observed conduction band non-parabolicity (NP). Our calculation of polaron mass corrections -- including finite width and screening - suggests those to be negligible. It implies that the behavior of $m*(n_{2D})$ can be understood solely in terms of NP. Finally, using our NP and polaron corrections, we are able to reduce the large scatter in the published band edge mass values

Quasicontinuum γ\gamma-decay of 91,92^{91,92}Zr: benchmarking indirect (n,γn,\gamma) cross section measurements for the ss-process

Nuclear level densities (NLDs) and $\gamma$-ray strength functions ($\gamma$SFs) have been extracted from particle-$\gamma$ coincidences of the $^{92}$Zr($p,p' \gamma$)$^{92}$Zr and $^{92}$Zr($p,d \gamma$)$^{91}$Zr reactions using the Oslo method. The new $^{91,92}$Zr $\gamma$SF data, combined with photonuclear cross sections, cover the whole energy range from $E_{\gamma} \approx 1.5$~MeV up to the giant dipole resonance at $E_{\gamma} \approx 17$~MeV. The wide-range $\gamma$SF data display structures at $E_{\gamma} \approx 9.5$~MeV, compatible with a superposition of the spin-flip $M1$ resonance and a pygmy $E1$ resonance. Furthermore, the $\gamma$SF shows a minimum at $E_{\gamma} \approx 2-3$~MeV and an increase at lower $\gamma$-ray energies. The experimentally constrained NLDs and $\gamma$SFs are shown to reproduce known ($n, \gamma$) and Maxwellian-averaged cross sections for $^{91,92}$Zr using the {\sf TALYS} reaction code, thus serving as a benchmark for this indirect method of estimating ($n, \gamma$) cross sections for Zr isotopes.Comment: 10 pages and 9 figure

Enhancing properties of iron and manganese ores as oxygen carriers for chemical looping processes by dry impregnation

The use of naturally occurring ores as oxygen carriers in CLC processes is attractive because of their relative abundance and low cost. Unfortunately, they typically exhibit lower reactivity and lack the mechanical robustness required, when compared to synthetically produced carriers. Impregnation is a suitable method for enhancing both the reactivity and durability of natural ores when used as oxygen carriers for CLC systems. This investigation uses impregnation to improve the chemical and mechanical properties of a Brazilian manganese ore and a Canadian iron ore. The manganese ore was impregnated with Fe2O3 and the iron ore was impregnated with Mn2O3 with the goal of forming a combined Fe/Mn oxygen carrier. The impregnated ore’s physical characteristics were assessed by SEM, BET and XRD analysis. Measurements of the attrition resistance and crushing strength were used to investigate the mechanical robustness of the oxygen carriers. The impregnated ore’s mechanical and physical properties were clearly enhanced by the impregnation method, with boosts in crushing strength of 11–26% and attrition resistance of 37–31% for the impregnated iron and manganese ores, respectively. Both the unmodified and impregnated ore’s reactivity, for the conversion of gaseous fuel (CH4 and syngas) and gaseous oxygen release (CLOU potential) were investigated using a bench-scale quartz fluidised-bed reactor. The impregnated iron ore exhibited a greater degree of syngas conversion compared to the other samples examined. Iron ore based oxygen carrier’s syngas conversion increases with the number of oxidation and reduction cycles performed. The impregnated iron ore exhibited gaseous oxygen release over extended periods in an inert atmosphere and remained at a constant 0.2% O2 concentration by volume at the end of this inert period. This oxygen release would help ensure the efficient use of solid fuels. The impregnated iron ore’s reactivity for CH4 conversion was similar to the reactivity of its unmodified counterpart. The unmodified manganese ore converted CH4 to the greatest extent of all the samples tested here, while the impregnated manganese ore exhibited a decrease in reactivity with respect to syngas and CH4 conversion.EPSR

Efficient Model Learning for Human-Robot Collaborative Tasks

We present a framework for learning human user models from joint-action demonstrations that enables the robot to compute a robust policy for a collaborative task with a human. The learning takes place completely automatically, without any human intervention. First, we describe the clustering of demonstrated action sequences into different human types using an unsupervised learning algorithm. These demonstrated sequences are also used by the robot to learn a reward function that is representative for each type, through the employment of an inverse reinforcement learning algorithm. The learned model is then used as part of a Mixed Observability Markov Decision Process formulation, wherein the human type is a partially observable variable. With this framework, we can infer, either offline or online, the human type of a new user that was not included in the training set, and can compute a policy for the robot that will be aligned to the preference of this new user and will be robust to deviations of the human actions from prior demonstrations. Finally we validate the approach using data collected in human subject experiments, and conduct proof-of-concept demonstrations in which a person performs a collaborative task with a small industrial robot

Fisher profiles and perceptions of sea turtle-fishery interactions: case study of East Coast Peninsular Malaysia

The paper focuses on coastal fisheries, particularly examining sea turtle-fishery interactions and determining the socioeconomic profile and perception of local fishers about sea turtle issues along the East Coast of Peninsular Malaysia.Turtle fisheries, Nature conservation, Coastal fisheries, Man-induced effects, ISEW, Malaysia, Malaya, Pahang, Malaysia, Malaya, Kelantan, Malaysia, Malaya, Terengganu,

Extraction of thermal and electromagnetic properties in 45Ti

The level density and gamma-ray strength function of 45Ti have been determined by use of the Oslo method. The particle-gamma coincidences from the 46Ti(p,d gamma)45Ti pick-up reaction with 32 MeV protons are utilized to obtain gamma-ray spectra as function of excitation energy. The extracted level density and strength function are compared with models, which are found to describe these quantities satisfactorily. The data do not reveal any single-particle energy gaps of the underlying doubly magic 40Ca core, probably due to the strong quadruple deformation

Study of surgical management of fracture of proximal humerus by PHILOS plate and screws

Background: Proximal humerus fracture accounts for about 5% of all fractures in recent advances proximal humerus fractures are often managed operatively with PHILOS plate which provides greater angular stability and study was aimed at to assess functional outcome of PHILOS plate fixation in proximal humerus fractures.Methods: Prospective study of 31 cases of proximal humerus fractures admitted and operated in Kempegowda Institute of Medical Sciences Hospital November 2017 to May 2019 of which 4 patients died due to medical comorbidities so 27 patients were studied. Follow-up of these patients was done at 6 weeks, 12 weeks and 24 weeks with functional evaluation was done using Constant and Murley (CM) scoring and disabilities of the arm, shoulder and hand (DASH) scoring.Results: CM scoring and DASH scoring was applied to analyze the functional outcome among the cases. Most of the patients had excellent outcome (52%) followed by good (26%), fair (8%) and poor (15%) outcome according to CM scoring and according to DASH scoring 20.21 was mean score and mean CM score was 77.62. Complications observed were impingement in 1 patient, avascular necrosis in 2 patient and non union in 1 case.Conclusions: We conclude that the use of PHILOS plate for the fixation of proximal humerus fractures is a good device as it provides rigid fixation and early mobilisation and prevented complications. Precontoured locking plates work on the principle of angular stability, divergent screws, less disruption of vascularity and less chances of plate failure

Modeling Sustainable Traffic Behavior: Avoiding Congestion at a Stationary Bottleneck

Sustainable traffic behaviour is increasing in importance as traffic volume rises due to population growth. In this paper, a model for traffic flow at a stationary bottleneck is developed to determine the parameters that cause congestion. Towards this goal, traffic density, speed, and delay were acquired during peak and off-peak periods in the morning and afternoon at a stationary bottleneck in Peshawar, KPK, Pakistan. The morning and afternoon peak periods have high densities, low speeds, and considerable delays. Regression models are developed using this data. These results indicate that there is a linear relationship between density and time at the stationary bottleneck and a negative linear relationship between density and speed. Thus, an increase in density increases the time delay and reduces the speed. I comprehensive traffic delay model is characterized by a stationary bottleneck. The Kolmogorov-Smirnov (KS) test and P-values were used to identify the best-fit distribution for speed and density. The binomial and generalized extreme values are considered the best fits for density and speed. The results presented can be used to develop accurate simulation models for stationary bottlenecks to reduce congestion. Doi: 10.28991/CEJ-2022-08-11-02 Full Text: PD