The environmental fate of polycyclic aromatic hydrocarbons (PAH) is a significant issue, raising interest in its clean up using remediation. However, the physical, chemical, and biological properties of soils can drastically influence degradation of pollutants. The effect of soil pH on degradation of PAHs with a view to modify soil pH to enhance the degradation of PAH's was studied. The degradation rate of key model PAHs was monitored in topsoil modified to a range of pH 4 to 9 at half pH intervals. Photo-oxidation of PAHs in presence of catalyst under UV light at two different wavelengths was studied. The degradation of PAHs during photo-oxidation was carried out at varying soil pH, whilst the degradation rate of individual PAH was monitored using HPLC. Photo-degradation of PAHs at 375 nm showed higher rate of degradation compared at 254 nm. Higher degradation was observed at pH 6.5, whilst in general, acidic soil had greater photo-degradation rates than basic pH of soil. pH 7.5 and pH 8 had slowest photo-degradation. Phenanthrene at both the wavelengths had highest degradation rate and pyrene had slowest degradation rate. Therefore, photo-catalysis can be used as alternative process to eliminate PAHs by manipulating soil pH to enhance remediation.
The research that we present here are related to a study for the design and implementation of a follow-up survey of students via an interactive voice response (IVR) using VoiceXML, a W3C standard language. We present a corpus of questions and answers obtained in natural language, and we validate scientific hypotheses concerning the use of modes of interaction (voice versus direct manipulation). Then, we explain how we passed from a mechanism of exogenous traces (with a monitoring system performed by external tools recordings) to an endogenous mechanism (with a monitoring system made from within the IVR) to provide tools and instruments more adapted to the evaluation of multimodal applications that use speech and gesture (telephone keypad or mouse click on hyperlink). The trace mechanism for telephone interactions using VoiceXML presented here increases the quality of the evaluation of human-machine telephone interactions, because these traces are automatically recorded and reusable. Furthermore, we show that it is possible to get instant statistics (histograms and graphs made in real time, in PHP) using the method presented here. Thus, we have shown that pedagogical surveys, which traditionally are laborious, complex to implement and very time consuming can be facilitated through the methods and tools we recommend.
Measuring the effectiveness of bank mergers and acquisitions has been the subject of several studies mainly on Anglo-Saxon and European markets. The aims of this paper is to examine the performance of these operations realized on emerging markets and appreciate the creation of financial and strategic values of a bank merger, in this particular case, the merger between the Commercial Bank (BCM) and Wafabank who took place in Morocco on 2003. In this research, the method of event study, which measures stock performance in the short term, and the method of pairing, which assesses accounting performance, were used. The analysis of empirical results shows that at the announcement of the transaction a negative abnormal return for the acquirer and positive for the target firm. These first results are consistent with other empirical studies who emphasized the negative impact of mergers and acquisitions on shareholder wealth of the acquiring and positive impact on shareholder wealth of the target firm. Also, the financial ratio analysis shows an improvement in profitability and productivity of the combined entity in the medium term, which is consistent with research confirming that mergers lead to a better use of assets, and can benefit from operational synergies and efficiency gains.
The products introduced to the market that make use of the technology developed require ensuring the integration between the technologies and the products developed, minimizing risks and maximizing results. This article aims to contribute to a new planning policy in the development of innovative products. To do so, it presents a new modeling proposal to integrate technological innovation and new product development (NPD) in high tech environments, carried out according to the following stages: Phase 1: Modeling of the information needs in PDP; Phase 2: Determining of technology integration dimensions to the product; Phase 3: Evaluation of performance of technology integration dimensions to the product. To demonstrate the feasibility and plausibility of the modeling, a study case was conducted in a high tech company in Brazil. The investigation was helped by the intervention of specialists with technical and scientific knowledge about the research object. In order to reduce the subjectivity in the obtained results, the methods of Categorical Judgment Law (CJL) of Thurstone from 1927, Artificial Neural Networks (ANN), the multicriteria Electre III methods, Compromise Programinng and Promethee II; Multivaried Analysis and the neurofuzzy technology were used. Few studies have investigated the Product-Integration Technology. It is hoped that this study will stimulate a broad debate on the issue and it is acknowledged that more studies are needed to build more robust results in the near future. The results were satisfactory, validating the present proposal.
This research demonstrates the relationship between the brand engagement, depending on the structure of values and level of self-esteem in adolescents. The research methods was used: Rosenberg
Currently fields of optics and photonics have urgent problem of fast and accurate simulation of photonic crystal fibers with different fillings. Although significant progress has been made from the time of first method founding, the rigorous analysis of light propagation remains problematic because of the large index contrast, the vectorial nature of the Maxwell equations and the complicated cross-sections of the hole geometries involved. This paper presents improved fast multipole method for low birefringence materials used in photonic crystal fiber core. Using this method, abruptly growth of modeling speed and accuracy is provided. Previously some research in the field of this method implementation in photonic crystal modeling have carried out, but suitable results for low birefringence fillings have not been reached yet. Implementation of this method for low birefringence fillings on photonic crystals is the main goal of this article. Modeling is implemented in Maple and show next results: monotonic decreasing of refraction index real part and linear character of refractive index imaginary part, attenuation has a plateau in bandwidth range and zero velocity group dispersion at 780 nm. Dissimilarity between numerical results and results presented in datasheet caused by nonideal cylindrical shape of air holes, but not by implemented theoretical method.
The forthcoming wireless communication networks, commonly referred to as fourth generation (4G) systems, are expected to support extremely high data rates as close as possible to the theoretical channel capacity while satisfying quality of service (QoS) constraints. The development of these systems must take into account the problem of limited radio resources and the harshness of wireless channel conditions. Two emerging technologies that are potential candidates for 4G wireless networks are multiuser multiple-input multiple-output (MU-MIMO) wireless systems and orthogonal frequency division multiplexing (OFDM). The MU-MIMO technique allows the spatial multiplexing gain at the base station to be obtained without the need for multiple antenna terminals, thereby allowing multiple users to receive data over the downlink simultaneously. The use of OFDM provides protection against intersymbol interference (ISI) and allows high data rates to be achieved. Linear precoding schemes for MU-MIMO wireless systems, e.g., zero forcing beamforming (ZF-BF) and minimum mean squared error beamforming (MMSE-BF), have been widely concerned for their high performance in single-carrier MU-MIMO networks where a base station attempts to communicate simultaneously with multiple users. In this paper, we evaluate and extend the ZF-BF and MMSE-BF schemes from single-carrier MU-MIMO to multicarrier MU-MIMO architecture based on OFDM, i.e., MU-MIMO-OFDM system, assuming the availability of channel state information (CSI) at the transmitter. Numerical results demonstrate that both introduced linear precoding strategies provide a higher sum-rate capacity improvement compared to a conventional MU-MIMO-OFDM system where the users are served on a time division multiple access (TDMA) basis.
In this paper, planar monopole antenna for wireless applications with triple band has been proposed. It simply consists of hexagonal meander-line structure and defected ground plane, which occupy a small PCB area of 50
Seven strains were collected for phosphate solubilizing and potassium decomposing activities from Microbiology Laboratory, Department of Biotechnology, Shweziwa Biofertilizer Plant. When phosphate solubilizing activity of selected strains was qualitatively determined, all strains except from B1 strain, gave clear zone formation on NBRIP media. But when quantitatively determined by spectrophotometric method, all strains solubilized insoluble tricalcium phosphate. Among seven strains, Ps strain gave the highest soluble phosphate concentration (386 ppm). Potassium decomposing activity was also determined for qualitatively and quantitatively. For qualitative determination, potassium decomposing activity was screened for clear zone formation on potassium decomposing media. Among seven strains, B1 and Y strains cannot give clear zone around their colonies. But when determined by AAS method, all strains can decompose potassium mica by giving soluble potassium concentration. Y strain gave the highest soluble potassium concentration (8.45 ppm). Phosphate solubilizing and potassium decomposing strains were combined differently for four treatments to study their effects on tomato cultivation. Chemical fertilizer was also applied to compare with selected strains. Among all treatments, T-4 showed better result on total yield although yields were not significantly different.
A numerical investigation has been carried out for an MHD mixed convection problem to realize the influence of solid fluid thermal conductivity ratio as well as diameter of the centered obstacle on the flow and thermal fields in a ventilated cavity. The basis of the current paper is the numerical solutions of the Navier-Stokes equation along with the energy equation, wherein Galerkin weighted residual finite element technique is adopted with the help of Newton
For effective degradation of agricultural residues into more useful forms, cellulolytic nitrogen fixing bacteria were isolated from soil samples of central region of Myanmar. Among 32 isolated strains, six best isolates (three strains of Azomonas agilis, two strains of Azotobacter chroococcum, and one strain of Alcaligenes sp.) were selected. Best strains were selected by their nitrogen fixing activities. Nitrogen fixing bacteria cannot excrete significant amount of ammonia into their environment. To improve cellulolytic nitrogen fixing activities, Alcaligenes sp. among six isolates was muatgenized with chemical mutagen, MNNG. From treatment of Alcaligenes sp. with three concentrations of MNNG (7.5 ppm, 10 ppm and 12.5 ppm), six potential mutant colonies were obtained. After screening of nitrogen fixing activities of wild type and mutagenized strains, four out of six mutant strains excreted higher amount of ammonium concentration than wild type strain. Although wild type strain of Alcaligenes sp. excreted 46.64 ppm of ammonium concentration, 101.35 ppm of ammonium concentration was excreted by mutant strain (M2-F) of Alcaligenes sp. According to results obtained, 10 ppm of MNNG was more effective for obtaining better mutant strain for nitrogen fixing activity. Although nitrogen fixing activities of mutant strains were increased, cellulolytic activities were decreased than those of wild type strain. Reducing sugar concentrations produced by all mutant strains were decreased using cellulose and CMC as substrates than wild type strain.
In this paper, a design of small sized, low profile patch antenna is proposed for BLUETOOTH applications at 2.4GHz frequency with coaxial feeding technique. The patch is H-shaped and different parameters like return loss, VSWR, gain along two directions, radiation pattern in 2-D and 3-D, axial ratio, E and H Field Distributions, Current Distributions are simulated using Ansoft HFSS. The measured parameters satisfy required limits hence making the proposed antenna suitable for BLUETOOTH applications in 2.4GHz band.
The full-field electroretinogram (ffERG) was used as an electrophysiological test of retinal function. The electrophysiology activity of the photoreceptors in the retina was investigated using photopic adapted full-field electroretinogram (ffERG) in a sample of Malay ethnic (Melayu), (mean 21.72
Capital structure represents one of the most discussed concepts in financial management. Capital structure refers to how a company finances its operations whether through shareholders equity-fund or debt or a combination of both. Various internal and external factors contribute to the choice of these sources of fund. The external factors include factors such as tax policy, capital market conditions and tax policy, among others. Meanwhile, the internal factors are those that relate to individual firm characteristics. This study examines the determinants of capital structure in Nigeria using the descriptive research design. The population comprised of the eighty-six manufacturing firms that are listed in the Nigerian Stock Exchange. The sample firms were selected using the simple random sampling method. Secondary data obtained from the annual accounts of 24 randomly selected manufacturing firms for 10 years period culminating in 240 firm-year observations. The results of the regression analysis revealed that leverage (a measure of capital structure) has a negative relationship with firm size and tax on one hand and a positive relationship with tangibility of assets, profitability and growth on the other hand. However, only with tangibility of assets and firm size that significant relationship is established. It is recommended for future researchers to carry out similar studies in multiple sectors.
CMOS spiral inductors suffer from a number of drawbacks including a low Q factor, a low self- resonant frequency, and a small and non-tunable inductance and require a large chip area. On the other hand active inductor offers many unique advantages over their spiral counterparts including small chip area, large and tunable inductance and high quality factor. These active inductors have been used successfully in many applications such as in radio frequency (RF) front end integrated circuits, filters, and phase shifter and oscillator circuits. The effectiveness of these active inductors is however affected by a number of limitation including small dynamic range, a high noise level and high power consumption. High speed applications such as preamplifier of data transceiver require large bandwidth hence there is a need for technique that achieve larger bandwidth without increased power consumption and design complexity. In this paper, bandwidth extension techniques are used to extend the bandwidth of the bandpass filter. Active inductors are used in the designing of the bandpass filter. A swing independent quality factor, called constant-Q active inductor is used as an active element in the designing of the bandpass filter. Bandpass filter is implemented on both 0.5
This paper presents the way to form other set of natural numbers from a given set of natural numbers and formulae to determine the sum of resulting numbers. The other set of natural numbers can be formed either by arranging a given natural numbers in specific order that is by using the principles of permutation rule or by using the principle of product rule provided that a given set of natural numbers should contain equal number of digits. The major areas of study to carry out this particular research work are probability rule, counting principles like permutation rule and product rule, and geometric series. Paper contains some essential theorems that help to arrive at main findings. The objective of this paper is to contribute additional knowledge to the Mathematical and Statistical science. The research results are two fundamental theorems and their applications in Mathematics, Statistics and other expected field of study. They are used to analyze complex numerical data computation and to create a password for a given numerical data with its importance to protect information flow management within a socio economic organization. The findings are foot step for the other related findings and applications that will be presented in the future. The future expected formulas or equations help to solve some difficult scientific and socio economic problems and also to derive approximation formula.
Vehicular ad hoc networks (VANETs) are the flaming topic of research. VANET comprises of moving vehicles communicating with each other. VANETs involve three types of communication: vehicle to vehicle (V2V), vehicle to roadside (V2R) or vehicle to infrastructure (V2I) communication. VANETs consist of some vital components: RSU, OBU and Trusted Authority. Among them Roadside units (RSUs) are one of the fundamental components of Vehicular ad hoc network (VANET). Roadside Units (RSUs) are placed across the road for infrastructure communication. But the deployment cost of RSUs is very high, so to deploy more and more number of RSUs across roads is quite expensive. Thus, there is a need to optimally place a limited number of RSUs in a given region or road in order to achieve maximum performance. In this paper, we present a solution to this problem using parallel processing. A so-called scalable TDB based RSUs deployment algorithm with a goal of minimizing the parallel time taken to place roadside units in a given area and to attain high efficiency and cover maximum area has been presented. The performance of the proposed algorithm and optimization strategy is assessed by evaluating different parameters like efficiency, power consumption, serial elapsed time, parallel elapsed time, speedup and overheads incurred in running the algorithm in parallel.
In this paper, a band pass filter structure using Ansoft designer software and Matlab software simulation tool are presented. The filter is operated at U Band range in higher order 50 GHz edge-coupled Stripline band pass filter for different microwave application. For the proposed work we consider simulation using Roger R03203 substrate with dielectric constant of 3.02, Conductor Thickness 0.035 mm and Substrate Height 0.787 mm. This filter is design at a center frequency of 50 GHz with 8 GHz bandwidth. Simulation results show that the filter operation is optimum & best in this range and results show good performance and agree well with the high frequency EM full wave simulation. In this paper, band pass filter development with the assistance of the Richards-Kuroda Transformation method, is used. Moreover, measured S parameters denote the center frequency is also strongly influenced by the variation of Roger's material's dielectric constants. By analyzing the characteristics at center frequency of the filter, both theoretical and simulated data are accumulated for broadening application filed. The band pass filter exhibits advantages of small size and high reliability compared to conventional planar filter structure, which makes the band pass filter suitable for U Band communicational application. This filter shows attractive characteristics for BPF applications.
The conversion of sulfur dioxide into sulfur trioxide is a reaction which interests not only the industry of sulfuric acid production but also the processes of pollution control of certain gas effluents containing SO2. This exothermic reaction needs a very good control of temperature, that's why it is led in the industry in a multistage converter with intermediate heat exchangers. Microreactors represent a good alternative for such reaction due to their intensification of mass and heat transfer and enhancement of temperature control. In this study, this reaction was conducted in a stainless steel tubular (4mm ID) packed bed reactor using particles of vanadium pentoxide as catalyst at atmospheric pressure. Experiments were performed with different inlet SO2 concentration in 3-9% range and reaction temperature between 685-833K. We noticed that the conversion decreases with the amount of SO2 and increases with the temperature until an optimum, above this value the conversion drop according to the shape of the equilibrium curve. Controlling rate mechanism is studied by varying temperature. Pseudohomogeneous perfect plug flow is used to describe this small tubular reactor. Numerical simulations with MATLAB were performed to validate the experimental results. Good agreement between the model predictions and the experimental results is achieved. Fluid flow description inside the packed bed reactor was performed by using the free fluid and porous media flow model. This model was solved by the commercial software COMSOL Multiphysics. Velocity profile inside the reactor is theoretically obtained.
This work is a part of research of rare Actinomycetal bacteria producing antimicrobial substances that may be used in agricultural, food and pharmaceutical fields. Among the 77 strains of actinomycetes isolated from different types of Moroccan ecosystems, 25 were selected according to their biological activity for molecular identification by sequencing the 16S rDNA fragment. After DNA extraction from isolates, amplification of 16S rDNA fragments by PCR technique (Polymerase Chain Reaction), sequencing of the amplified fragments and comparison of characteristic sequences obtained with the contents of a database and phylogenetic studies using special programs were used to develop phylogenetic trees of the twenty-five isolates. The results Analysis showed the taxonomic affiliation of all isolates to the genus Streptomyces and assign each of them to one or more species. This shows the abundance of this kind in relation to others in the studied ecosystems. While the absence of other types of actinomycetes can be explained either by the absence of these genera in these ecosystems, or by the isolation techniques used, or by the fact that microbial population in the sample is non-culturable. Thus, in the last case, the confirmation of the presence of other types in these ecosystems could be performed by amplification of the 16S rDNA PCR from DNA mixture obtained directly from samples.
The growing worldwide energy demand associated with several inter related complex environmental as well as economical issues are driving the increase of the share of uranium in energy mix. Subsequently, over the last few years, the interest for uranium extraction and recovery from unconventional resources has gained considerable importance. Phosphate rock has been the most suitable alternative source for the uranium recovery because of its uranium content. Solvent extraction has been found to be a successful process for uranium separation from phosphoric acid. The synergistic solvent mixture of Di-2-EthylHexyl Phosphoric Acid (DEHPA) and TriOctyl Phosphine Oxid (TOPO) diluted in kerosene has been the favored because of its high efficiency and selectivity for uranium extraction. In the present work, uranium extraction from Tunisian Wet Process Phosphoric Acid (WPA) using DEHPA in combination with synergistic reagent TOPO is presented. An experimental study was conducted in order to optimize the operating parameters affecting uranium recovery from phosphoric acid. The effect of temperature, solvent ratio, acid concentration and extractants concentrations were considered. The experiments were performed at a laboratory scale with batch extractions. Overall extraction yields are reported in this work. High uranium extraction yields exceeding 95% were obtained in all extraction steps but one where the yield was 92%. The overall recovery yield was 81%.
Now day selection of optimum quay Sid equipment for loading and discharging the dry bulk cargo can maximize the overall efficiency of Terminal. For this end the current applied study was implemented by the aim to choose the best equipment for discharging dry bulk cargoes in BIK Grain terminal using TOPSIS and Shannon entropy method in three phases. In the 1st phase, the most important decision-making criteria for choosing the most appropriate equipment were identified by using experts' interview and investigating the previous researches and holding brain storm meetings with the Grain Terminal's experts. Then in the 2nd phase, the weight of every identified criteria using Shannon entropy method, Was determined. The abstained result from Shannon entropy method indicates that service facility criterion with the scale of 0.06 has earned the maximum and operator cost criterion with the scale of 0.034 obtained the least. In the 3rd phase, using scale 1-9 of each equipment regarding shall be scored based on the criteria and according to the obtained scores for each equipment of the decision- making matrix of the TOPSIS method was established and finally, with respect to the weight of each earned criteria, the equipment shall be scored in the 2nd phase and the most optimum shall be selected. The final results from TOPSIS method indicates that unloader with (Ci=0.91346) enjoys the 1st and the vacuum with (Ci=0.26382) the 2nd and grab with (Ci=0.00000) ranks.
Due to the development of nuclear technology and use of these technologies in various fields of industry, medicine, research and etc, protection against radioactive rays is one of the most important topics in this field .The purpose of this is to reduce the dose rate from radioactive sources. The sources in terms of components are emitted various types of nuclear radiation with different energies. These radiations are involving of alpha particles, beta, and neutron and gamma radiation. Given that alpha and beta particles can be fully absorbed by the shield, the main issue in the debate protection radioactive rays is stopping of gamma rays and neutrons. Accordingly in shield design usually two types of radiation should be considered. First, X-rays and gamma rays, which have great influence, and by the mass of any suitable material, can be more efficiently attenuate the higher the density, the better the potential attenuation effect against gamma rays and the required shielding thickness decreases. The second type of radiation is neutrons. Often a combination of three materials is desirable that include heavy metals, light metals, and neutron-absorbing material to omit the slow neutrons through adsorption to the neutron shield. There are different materials that can be used to shielding against radioactive rays. The main materials that are used in protection include: water, lead, graphite, iron, compounds that contains B, concrete, and polyethylene. Accordingly, the main objective of this paper is evaluating the kind of shield against gamma and neutrons rays.
EOR method evaluation is performing for petroleum gravity, stone type, and tank humectant and tank localities conditions for liquid injection. If the frame is humectant, petroleum exit will perform whenever the pressure is more than threshold; this is controllable by the height of tank block. Experiments and experimental data for recovery capillary absorption are according to data in 1950. Brownscoble & Dyse (1952) studied the ability of water absorption in the sandstone lands. The studies have been done on the tube lines, land and the metal workforces that are related to the oil and gas industries, shows that in most cases, weld lines and edge of a sharp regions has been influencing on location of corrosion and eroding of effective thickness of coating film. In this study we studied EOR methods for dense oil recovery from mold in the breakage tanks. Analyze and comparison of recovery with capillarity of salty water, polymeric solution and hot water on different sample of rocks showed high recovery of dense row oil in the EOR methods, and it is more detected in the diluted row oil. Oil (diluted) can recover by water injection in the sand stone condition and with chemical matter and thermal methods. Hot water recovery is more rapid and higher than chemical recovery.
In this paper a Rectangular Patch Antenna is specifically designed and analysed using metamaterial concepts. Based on an ordinary patch antenna, it has a double C shaped resonant structure embedded in the centre of the substrate of the Rectangular Patch Antenna. The resonant structure has a strong electric response in a certain frequency of interest, and can be used to construct metamaterials with negative permittivity. It is found the great impact on the antenna performance to modify the dimension to 57% of a conventional patch antenna. This antenna has strong radiation in the 45
Stone dust and cement are usually used as filler in asphalt-concrete mixture in Bangladesh. This study has made to prepare asphalt-concrete mixtures using non-conventional fillers which are locally available. Bangladesh is a developing country, where cost is the main concern for any type of constructions. From this point of view, the prime aim of this investigation has been set out to examine the effect of non-conventional filler such as non-plastic sand, brick dust and ash as a filler replacement on the performance of asphalt-concrete mixture and to compare the characteristics of asphalt-concrete mixtures with conventional ones according to the test procedure specified by AASHTO. From the experimental data, it is observed that the value of Marshall Stability is comparatively higher by using non-plastic sand than other non-conventional filler materials. It is also observed that brick dust and ash requires higher asphalt content because of their higher absorption capabilities. The retained strength of the asphalt-concrete mixture using non-plastic sand, brick chips and ash are approximately 89%, 87% and 84% respectively which satisfies the limiting value 75%. Based on this experimental program, it is verified that inclusion of non-conventional filler can be efficiently used in asphalt-concrete mixture as a filler replacement from the viewpoint of stability, deformation and voids characteristics.
A phase locked loop based indirect frequency synthesizer is designed for S-band frequency. A Phase locked loop is designed and the phase noise response and transient response of the designed PLL is simulated for 2100MHz frequency. The phase noise response of total PLL and its individual components are obtained. A 3rd order low pass passive loop filter is used and by varying the loop bandwidth and phase margin the trade-off between lock time and phase noise is observed and an optimum value of loop bandwidth and phase margin is chosen such that its phase noise contribution is less. The designed phase locked loop has a low phase noise value of -112.4dBc/Hz at 100 kHz offset frequency and has a fast lock time of 119.5 us. The time taken by the designed frequency synthesizer to lock to 10 Hz frequency error and 1
The objective of this work is thus to study the kinetics, thermodynamics and adsorption isotherms of two phenolic compounds phenol (PhOH) and P-hydroxy benzoic acid (4AHB) on a mesoporous material type MCM- 48 functionalized with an organosilane type trimethylchlorosilane (TMCS) (MCM-48-G). At first, the study of the kinetics, thermodynamics and adsorption isotherms of phenolic compounds in each single solution was performed. In a second step, a similar study was performed on a mixture of these two molecules. Several kinetic models (pseudo-first order, pseudo-second order) were used to determine the kinetic parameters of adsorption. Several adsorption models (Langmuir, Freundlich) were also used to determine the thermodynamic parameters of adsorption isotherms. The effect of three-dimensional pores of MCM-48 and comparison of adsorption of PhOH and 4AHB was examined. It was found that MCM-48-G to a significant adsorption capacity for PhOH and 4AHB, this may be related to the hydrophobicity created by the organic function of TMCS in the MCM-48-G.The results of adsorption and PhOH 4AHB were analyzed using the Freundlich and Langmuir models. It was observed that the adsorption of 4AHB was higher than PhOH. Thermodynamics of adsorption showed that the values obtained for our sample confirm well the interactions with phenol and 4AHB are physical in nature. The adsorption of pollutants on our MCM-48 (G) is a spontaneous and exothermic process.
Coconut water extract of Picralima nitida seed and aqueous extract of Tapinanthus bangwensis leaf were investigated for their antidiabetic activities on some biochemical parameters (glucose, protein) associated with diabetes in both the serum and tissues of experimental animals using alloxan-induced diabetic rabbits as model. The rabbits were fasted overnight before they were given a single intraperitoneal injection of aqueous alloxan monohydrate (Sigma, USA) at a dose of 300 mg/kg body weight to make them diabetic. The experimental rabbits (chinchilla) were grouped into six and extracts administered orally, once daily for five weeks. Groups 1 and 2 (non-diabetic) received only distilled water and coconut water respectively, group 3 (diabetic) received 200 mg/kg body weight aqueous extract of T. bangwensis leaf, group 4 received 400 mg/kg body weight of coconut water extract of P. nitida seed, groups 5 and 6 (diabetic) received only distilled water and coconut water respectively. The results revealed that the extracts independently lowered significantly (p<0.05) the blood glucose and protein levels of the diabetic rabbits. Both extracts significantly (p<0.05) increased the tissue protein. Overall, aqueous extract of T. bangwensis leaf and coconut water extract of P. nitida seed independently possesses insulin-like properties as demonstrated by their antidiabetic actions, hence, may be good herbal extracts in the management of diabetes.
This work is a contribution to the numerical modeling and computer implementation of geometrically non-linear vibrations of the thin beams. The spatial distribution over the beam span of the harmonic distortion induced by large vibration amplitudes has been examined, and an analytical investigation has been elaborated to describe this aspect of non-linear vibration. This model allowed us to obtain the explicit analytical expressions for the non-linear response, including the contributions of various spatial functions, associated to the first and higher time harmonics. In the present work, devoted to this particular but practically very important aspect of non-linear vibration, a review is made of some important experimental and theoretical works on the subject. The model is based on an expansion of the transverse displacement function as a sum of series, each series being the product of a given harmonic time function by a series of chosen basic spatial functions, multiplied by the unknown contribution coefficients, to be determined. The explicit analytical expressions obtained for the function contributions corresponding to the first time harmonic are identical to those obtained in the previous works above assuming harmonic motion, which allows one to consider that the present model is a generalization of the previous ones. Also, the results of the model presented here, corresponding to the higher harmonics, are in a very close agreement with each other. They are also in a qualitative agreement with previously published numerical results, based on the hierarchical finite element method.