Bio-capped and green synthesis of ZnO/g-C_(3)N_(4) nanocomposites and its improved antibiotic and photocatalytic activities: An exceptional approach towards environmental remediation

In this research study, we have synthesized the bio-capped ZnO/g-C_(3)N_(4) nanocomposites by employing lemon juice(Citrus limon) as a stabilizer and mediator. Fruitfully, lemon juice which contains various acidic functional groups and citric acid has the capability to block the surface of g-C_(3)N_(4) from chemical reactivity and activated the surface of g-C_(3)N_(4) for various reactions. Consequently, the agglomeration behavior and controlled shape of g-C_(3)N_(4) has also been achieved. Our experimental results i.e. XRD,TEM, HRTEM, PL, FS, XPS, and PEC have confirmed that the lemon juice mediated and green g-C_(3)N_(4)(L-CN) have good performances and remarkable visible light photocatalytic activities as compared to the chemically synthesized g-C_(3)N_(4)(CN). Furthermore, the small surface area and low charge separation of g-C_(3)N_(4) is upgraded by coupling with Zn O nanoparticles. It is proved that the coupling of Zn O worked as a facilitator and photoelectron modulator to enhance the charge separation of g-C_(3)N_(4). Compared to pristine lemon-mediated green g-C_(3)N_(4)(L-CN), the most active sample 5Zn O/L-CN showed ~ 5-fold improvement in activities for ciprofloxacin(CIP) and methylene blue(MB) degradation. More specifically,the mineralization process and degradation pathways, and the mineralization process of ciprofloxacin(CIP) and methylene blue(MB) are suggested. Finally, our present novel research work will provide new access to synthesize the eco-friendly and bio-caped green g-C_(3)N_(4)nanomaterials and their employment for pollutants degradation and environmental purification.

Thermal conductivity of soils with heavy metals concentration from the Niger Delta region of Nigeria

This paper presents the characteristic thermal and chemical properties of some surface soil samples from the oil-producing regions of Nigeria. A microprocessor-based thermal analyzer was used to determine the thermal conductivity while spectrophotometric procedure was employed to conduct the heavy metal concentration analysis. Thermal conductivity values were compared with heavy metal concentrations in each soil sample. The values of lead and cadmium and their respective measured thermal conductivities were highly correlated, with their correlation coefficients both greater than 0.900, while other metals showed no correlation.

Assessment of Heavy Metals Concentration in Shore Sediments from the Bank of River Benue, North-Central Nigeria

Heavy metals are elements, whose density is greater than water. They are generated from our environment. Rocks, sediments, plants, water and aerosol particles represent the carriers of heavy metals. An accumulated amount of heavy metal in the body, either by inhalation, food or drinking water, can cause an adverse health effect to human. The Benue river passed through the town of makurdi, was high population of the inhabitant of Benue State dwells. The industrial and agricultural activities carried out in this region, increase the concentration of heavy metals. This may result to adverse health effect on the inhabitant of Makurdi. The objectives of this work were to determine the heavy metal concentration and its site contaminations along the bank of river Benue, Makurdi. An inductively coupled plasma optical emission spectrometry (ICP-OES) was used to determine the heavy metals concentration. The metals concentrations (Iron, Copper, Manganese, Lead, Zinc, Chromium, Arsenic, and Cadmium) of the three stations were found. This ranges from 3.55 - 9454.0 mg/kg, 0.20 - 8928.0 mg/kg and 2.80 - 13,657 mg/kg for stations 1, 2 and 3. With Fe recorded as the highest concentration in the sediment, this value is compared with the World Health Organisation (WHO) and World Surface Rock Average (WSRA) standard. The assessment on contamination status of heavy metals in the riverbank, showed low degree of contamination in stations 1 and 2, and moderate degree in station 3. The degree of enrichment to heavy metals in all the stations is deficient to minimal. The evaluation of the results of pollution load index (PLI) from this present study indicated PLI 1 in stations 1 and 3. Hence stations 1 and 3 are polluted, while station 2 is not polluted with heavy metals.

Assessment of Radionuclide Content of Shore Sediments Collected from the Bank of River Benue, North-Central Nigeria

Ionizing Radiation emitted from radionuclide has an adverse effect on human health. A continuing population exposure to naturally occurring radioactive materials (NORMS) found in our environment is one of the major scientific subjects that attract public attention. The assessment of radionuclide content of shore sediments of river Benue-North Central Nigeria was carried out using gamma-ray spectrometry. The activity concentrations of U-238, Th-232 and K-40 were found to have an average concentration of 1.17, 3.31 and 405.95 Bq·kg-1 respectively. The values gotten from present study were compared with the world average values. World average values of U-238, Th-232 and K-40 are 50 Bq·kg-1, 50 Bq·kg-1 and 500 Bq·kg-1 respectively. The mean concentration of daughter radionuclides generated from U-238, Th-232 was 4.32, 10.37, 5.24, 3.86, 11.87, and 6.52 for Bi-212, Pb-212, Bi-214, Pb-214, Ra-226 and Ac-228, respectively. The mean of the absorbed dose, Annual effective dose equivalent, for radium equivalent activity, and external hazard index, were evaluated to be 19.45 nGy·h-1, 23.82 μSv·y-1, 37.16 Bq·kg-1, 0.10 mSv·y1, below the permissible limit of 57 nGy·h-1, 70 μSv·y-1, 370 Bq·kg-1 and 1 mSv·y-1 respectively. These shore sediments from river Benue are therefore, radiologically safe for construction and other domestic and industrial purposes.

Neutron Induced Fission Track Estimation of Uranium Concentration and Its Associated Health Hazards in Drinking Water of the Faisalabad Industrial City

Drinking water plays a major role regarding quality of human life because polluted water is the main cause of many types of diseases. Besides other pollutants, high concentration of uranium above a certain level in drinking water is also hazardous. As water and food are the main sources of uranium intake, it is absolutely imperative that their level of concentrations is monitored regularly for safety of the general public. In this regard, trace amount of uranium in drinking water samples collected from different locations of Faisalabadcity has been carried out using Neutron Induced Fission Track Technique. The water samples along with the standard of known uranium concentration were poured and dried over Lexan track detectors and then irradiated with thermal neutrons in Reactor. After etching, the tracks produced in the detectors as a result of 235U (n, f) reaction were counted under an optical microscope. The uranium concentration was determined by counting and comparing the observed fission track density in the samples and the standard. The observed uranium concentration in the studied water samples varied from (1.04 ± 0.30) μg·L-1 to (21.08 ± 2. 95) μg·L-1 with an average value of (7.39 ± 1.30) μg·L-1 and is found to be within safe limits as far as uranium related health hazards are concerned.

Analytical Study of Band Structure of Material Using Relativistic Concept

In this paper, we present the study of band structure relativistically. Here, Dirac equation is formulated from Hamilto-nian in which the formulation is found to contain a correction term known as spin-orbit coupling given as that modifies the non-relativistic expression for the same formulation. This term leads to double spin-degeneracy within the first Brillioun zone which is a concept that is not found in other method of study of band structure of material.

Magnetism,optical,and thermoelectric response of CdFe_2O_4by using DFT scheme

Comparative analysis of electronic, magnetic, optical, and thermoelectric properties of CdFe2O4, calculated by em- ploying PBEsol ＋ mBJ has been done. The PBEsol reveals metallic nature, while TB-mBJ illustrates ferromagnetic semiconducting behavior. The reasons behind the origin of ferromagnetism are explored by observing the exchange, crystal field, and John-Teller energies. The optical nature is investigated by analyzing dielectric constants, refraction, absorption coefficient, reflectivity, and optical conductivity. Finally, thermoelectric properties are elaborated by describing the electri- cal and thermal conductivities, Seebeck coefficient, and power factor. The strong absorption for the visible energy and high power factor suggest CdFe2O4 as the potential candidate for renewable energy applications.

The effect of replacing pnictogen elements on the physical properties of SrMg_2X_2(X=N,P,As,Sb,Bi) Zintl compounds

The effect of replacing the anion from N to Bi down the group in the periodic table is investigated on SrMg2X2（X = N,P,As,Sb,Bi）.A full potential linearized augmented plane wave plus local orbitals method is used along with different exchange–correlation potentials to obtain the lattice constants,phonons,electronic,and optical properties of the Sr Mg2X2（X = N,P,As,Sb,Bi） Zintl compounds.A good agreement is achieved and our calculations are validated by previous experimental and theoretical data.All compounds have shown stable dynamical behavior with gamma centered longitudinal response having no imaginary frequencies.Electronic band structures reveal the semiconducting nature of the compounds.The Pnictogen（X）-p state contributed mainly in the valence band and the Sr-d state forms the conduction of the compounds.Relative charge transfer and low overlapping of the atomic densities indicates the preferable ionic bonding character of these materials.In the optical properties,real and imaginary parts of dielectric function,complex refractive index,birefringence,reflectivity,and optical conductivity are calculated.These compounds can be utilized in the optical and optoelectronic devices.

A Comparison of Higher-Order Active Band-Pass R-Filter Response with Equivalent Band-Pass RC-Filter Response at Varying Q-Factors

In this paper a comparison of a sixth-order active band pass R-filter output response with the output response of a sixth-order band pass RC-filter at different quality factors (Q = 2, 5, 7, 8 and 10) was carried out at a fixed frequency of 10 KHz. The architecture used in the design is the multiple feedbacks for both filter networks. The simulated response characteristics show that both filters (R- and RC-filters) have their mid-band gains increasing with Q, while their bandwidths monotonically decreased with Q-values. The bandwidths are in the range of 22.23 dB to 62.97 dB and –55.49 dB to –50.81 dB (Q = 2 to 10) for R- and RC-filters respectively. At higher Q-values, R-filter showed better selectivity with a smaller bandwidth (400 Hz) at the edge of the pass band, when compared to 450 Hz for the RC-filter. The roll-off rate around –58.9 dB/decade for the R-filter appears to be that of a third-order filter response, while the RC-filter has its response in the range –106 to –132 dB/decade which is in the neighbourhood of an ideal sixth-order response (roll-off of 120 db/decade). A shift in the center frequency with Q was observed for the RC-filter only.

Synthesis of yttrium and cerium doped ZnO nanoparticles as highly inexpensive and stable photocatalysts for hydrogen evolution

Yttrium and cerium co-doped ZnO nanoparticles were synthesized by combustion route and characterized using X-ray diffraction(XRD),scanning electron microscopy(SEM),Brunauer-Emmett-Teller(BET),energy dispersive spectroscopy(EDS),X-ray photoelectron spectroscopy(XPS),UV-visible diffuse reflectance spectroscopy(UV-vis DRS),photoluminescence(PL)and electrochemical impedance spectroscopy(EIS)techniques.The introduction of yttrium ions has efficiently increased the relative percentage of Ce^(3+)ions in ZnO.Yttrium and cerium co-doped ZnO shows efficient photo activity for hydrogen evolution(10.61 mmol/((g·h))higher than previously reported optimal value for rare earth codoped ZnO photocatalysts.This remarkably increased hydrogen evolution can be ascribed to the synergy between electronic anchoring effect of Y^(3+)/Y^(2+)and Ce^(4+)/Ce^(3+)redox couples.This report presents new idea for the synthesis of efficient photocatalyst using economical route and ion anchoring effect.The hydrogen evolution was also tested using Na_(2)S and Na_(2)SO_(3)as electron donors under visible light illumination.The synthesized photocatalysts also exhibit high stability.

Moisture and Temperature Response of Structural and Lithology based Thermophysical and Energy Saving Traits of Limestone using Experimental and Least-Square Fitting Methods

Thermophysical analysis of the crustal rocks is important for heat transfer determination and insulation purposes to save energy in buildings.In the presented work,thermophysical properties of four limestones were investigated in dry and moist state under ambient conditions by using a transient plane source method.A thermal constant analyzer was used to raise the sample temperature and to measure the thermal properties in the temperature range of 300 K to 433 K.Thermal conductivity and diffusivity were measured by developing a linear relationship between temperature response of TPS (transient plane source) sensor and dimensionless time function through least-square fitting method.The experimental observations and predicted thermal conductivity of samples have shown that in-situ observations are important to determine the thermal properties accurately.The effect of temperature on thermal properties of limestone was defined by considering the chemical composition of the samples and associated heat transfer mechanism.Both thermal conductivity and diffusivity of limestone decreased while specific heat capacity increased with a rise in temperature.The overall findings indicate that the spinoff of this research is useful in studying the reliance of thermophysical properties of rocks on their structures and lithology.

Bistability in Coupled Oscillators Exhibiting Synchronized Dynamics

We report some new results associated with the synchronization behavior of two coupled double-well Duffing oscillators （DDOs）. Some sufficient algebraic criteria for global chaos synchronization of the drive and response DDOs via linear state error feedback control are obtained by means of Lyapunov stability theory. The synchronization is achieved through a bistable state in which a periodic attractor co-exists with a chaotic attractor. Using the linear perturbation analysis, the prevalence of attractors in parameter space and the associated bifurcations are examined. Subcritical and supercritical Hopf bifurcations and abundance of Arnold tongues -- a signature of mode locking phenomenon are found.

High-frequency field intensity along focal point of a long metallic parabolic reflector coated by a magnetized plasma layer using oblique incidence

Theoretical analysis of the electromagnetic field distribution in the focal region of a long metallic parabolic reflector that has its surface covered with a magnetized plasma layer is derived. The incident wave is considered to be with a general oblique incidence for both parallel and perpendicular polarizations. The electromagnetic field intensity expressions along the focal region are obtained accurately using Maslov＇s method. The effects of plasma thickness on the reflected and transmitted field distributions are investigated. The effects of other physi- cal parameters such as the angle of incidence and the plasma and cyclotron frequencies on the transmitted field- intensity distribution along the focal region are also studied. The results obtained by Maslov＇s method and Kirchhoff＇s approximation are found to be in a good agreement.

Effect of low power laser irradiation on bio-physical properties of wheat seeds

The production of quality food is indispensable and essential to overcome its global shortage.In order to exercise the facile route to acquire massive production,a laser irradiation treatment method was established.We have investigated the effects of diode laser irradiation on wheat seeds germination,its early growth and biochemical parameters.The variation in germination parameters,caused by laser treatment were monitored carefully.A comparison study was accomplished to examine the laser irradiation effects on treated and control seeds.The red laser indicated an enhancement of 25%in germination percentage,4.68 cm in shoot length,and 0.64 cm in root length while green laser showed 6.25%less germination percentage than the untreated seeds.Further green laser showed 9.67 cm increase in shoot length,5.39 cm in root length as compared to untreated seeds.It was found that the seeds which were irradiated with green laser showed an amount of superoxide dismutase(SOD),catalase(CAT)and peroxidase(POD),of 11.9,10,and 1.53 per mg of protein,respectively as compared to control seeds.Thus,these investigations are promising and suitable for upcoming research on a large scale.

C-NOT gate based on ultracold Rydberg atom interactions

The Rydberg states of neutral atoms are strongly polarisable and possess long lifetimes because of high energies which can lead to strong and long range dipole-dipole interactions.The energy levels corresponding to these states are shifted because of dipole-dipole interactions and can be used to block transitions of more than one excitation in the Rydberg regime.This reputed Rydberg blockade is obtained when the excitation is shifted out of resonance by these interactions.Electromagnetically induced transparency(EIT)is sensitive to a small detuning.At large distances,up to several micrometers,the interactions can interrupt the EIT consequence.Herein we investigate a novel scheme based on EIT and Rydberg blockade and performed a simulation of a controlled-NOT(C-NOT)quantum gate which is critical for quantum computation by using neutral atoms.

Magnetically treated water irrigation effect on turnip seed germination,seedling growth and enzymatic activities

Pre-sowing magnetic field seed treatment effects on biological characteristics of vegetables and crops have been studied well.However,studies reporting irrigation with magnetically treated water are scanty.Therefore,the effect of irrigation with magnetically treated water on turnip seed germination,seedling growth and enzymatic activities was evaluated.The tap water was treated at 211 mT for 30,45 and 60 min and used for irrigation of turnip seed and seedlings.Uniform and healthy turnip seed was sown under randomized complete block design(RCBD).The germination,emergence rate index,vigor index I and vigor index II increased up to 28.33%,11.54%,57.59%and 32.26%,respectively.The growth parameters such as seedling lengths,fresh&dry weights,chlorophyll content were also enhanced in response of irrigation with magnetically treated water.The seedlings irrigated with magnetically treated water showed 28.92%,11.36%and 14.76%higher protein content,alpha amylase and protease activities,respectively vs control.Results revealed that irrigation with magnetically treated water has potential to improve turnip germination,seedling growth and enzymatic activities and this study is also extendable to other vegetables and crops for the improvement of germination and growth.