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In this paper, the two positive position feedback controllers (PPF) are used to reduce the vertical vibration in the vertical conveyors. An investigation is presented of the response of a four-degree-of-freedom system (4-DOF) with cubic nonlinearities and external excitations at primary resonance $$(\Omega _1 \cong \omega _1 ,\Omega _2 \cong \omega _2)$$ in the presence of 1:1 internal resonance $$(\omega _3 \cong \omega _1 ,\omega _4 \cong \omega _2)$$ . Method of multiple scales is applied to the equations of the system to find approximate analytical solutions. Then, we derived the frequency response equation and the stability criteria for the system. Numerical solution show that the time histories of the main system and the PPF controllers to present the response with and without control. The frequency response curves for the system and the controllers are studied numerically. To discuss the validity of the results, we make comparison between the analytical and numerical solutions and also compared them with the available published work.

A new decentralized approach for solving the economic dispatch problem is presented in this paper. The proposed approach consists of either two or three stages. In the first stage, a flooding-based consensus algorithm is proposed in order to achieve consensus among the agents with respect to the units and system data. In the second stage, a suitable algorithm is used for solving the economic dispatch problem in parallel. For cases in which a nondeterministic method is used in the second stage, a third stage is applied to achieve consensus about the final solution of the problem, with a flooding-based consensus algorithm for sharing the information required during this stage. The proposed approach is highly effective for solving the non-convex formulation of the economic dispatch problem and for incorporating transmission losses accurately in a fully decentralized manner. Three case studies that were examined for validation purposes are described. The results obtained demonstrate that the proposed approach aggregates many of the advantages of both centralized and fully decentralized mechanisms for solving the economic dispatch problem.

Objectives/Background The increased complexity of endovascular aortic repair necessitates longer procedural time and higher radiation exposure to the operator, particularly to exposed body parts. The aims were to measure directly exposure to radiation of the bodies and heads of the operating team during endovascular repair of thoracoabdominal aortic aneurysms (TAAA), and to identify factors that may increase exposure. Methods This was a single-centre prospective study. Between October 2013 and July 2014, consecutive elective branched and fenestrated TAAA repairs performed in a hybrid operating room were studied. Electronic dosimeters were used to measure directly radiation exposure to the primary (PO) and assistant (AO) operator in three different areas (under-lead, over-lead, and head). Fluoroscopy and digital subtraction angiography (DSA) acquisition times, C-arm angulation, and PO/AO height were recorded. Results Seventeen cases were analysed (Crawford II–IV), with a median operating time of 280 minutes (interquartile range 200–330 minutes). Median age was 76 years (range 71–81 years); median body mass index was 28 kg/m 2 (25–32 kg/m 2 ). Stent-grafts incorporated branches only, fenestrations only, or a mixture of branches and fenestrations. A total of 21 branches and 38 fenestrations were cannulated and stented. Head dose was significantly higher in the PO compared with the AO (median 54 μSv [range 24–130 μSv] vs. 15 μSv [range 7–43 μSv], respectively; p = .022), as was over-lead body dose (median 80 μSv [range 37–163 μSv] vs. 32 μSv [range 6–48 μSv], respectively; p = .003). Corresponding under-lead doses were similar between operators (median 4 μSv [range 1–17 μSv] vs. 1 μSv [range 1–3 μSv], respectively; p = .222). Primary operator height, DSA acquisition time in left anterior oblique (LAO) position, and degrees of LAO angulation were independent predictors of PO head dose ( p Conclusions The head is an unprotected area receiving a significant radiation dose during complex endovascular aortic repair. The deleterious effects of exposure to this area are not fully understood. Vascular interventionalists should be cognisant of head exposure increasing with C-arm angulation, and limit this manoeuvre.

Torsional vibration characteristics are important information for rotating machinery design and control. Jointed shaft is a commonly used element in drive trains of rolling mill. The torsional vibrations of one- degree -of freedom nonlinear dynamical system are controlled using active control. The multiple scale perturbation technique used to get the approximate solution of the differential equation describes the system. The worst resonance cases were deduced and the frequency response function are obtained. The stability and steady state response of the system are studied and discussed numerically. The numerical solutions are focused on both the effects of the different parameters and the system behavior at different resonance cases. To insure the validity of the results, a comparison between the numerical and analytical solution was presented.

Tyrosine kinases are one of the most critical mediators in the signaling path way. Late studies have proved the part of tyrosine kinases in the pathophysiology of cancer diseases. This current research paper has focused on investigating the novel Pyrazolo[1,5-a]pyrimidines and Pyrido[2,3-d]pyrimidines as a small molecules that can inhibit tyrosine kinase in cancer cells. NCI protocol was applied to test the antitumor activity of such compounds. Leukemia and renal cancer cell lines proved to be sensitive to some derivatives such as 6b–d, 9a and 11 with GI% values ranging from 30.4 to 41.3%. In addition, compound 11 proved to be the most active against MCF-7 with GI% 62.5. The synthesized compounds were also evaluated for their inhibitory effects against EGFR kinase enzyme. Compound 9b proved to be the most active one among the synthesized series with inhibition % value of 81.72 at 25 nM concentration and IC50 8.4 nM which is very close to the reference drug Sorafenib. In vitro cytotoxicity test was also performed using the MCF-7 breast cell line. Computer modeling using the active site of tyrosine kinase as a template and the most active tyrosine kinase inhibitors were calculated. Docking studies of the synthesized compounds into the active site of EGFR kinase domain showed good agreement with the obtained biological results.

BIMs (bis-indolylmethanes) ( 1 a–n ) were synthesized using glacial acetic acid as a protic acid for promotion of the condensation reaction of indoles with aldehydes in high yields (86–98 %). Corresponding tetrahydroindolo[2,3- b ]carbazoles ( 2 a–m ) were synthesized via condensation of BIMs with aldehydes. Ten synthesized compounds have been submitted to the national cancer institute in the USA where all the submitted samples have been selected for one dose screening . As a result of the one dose screening of BIMs ( 1 e,f,h,i,n ) and of the indolocarbazoles ( 2 e,f,h,i,j ) the average highest cytostatic effects was recorded here for the BIM 1 h and the indolocarbazole ( 2 e ) that showed the lowest mean values of “47.39%” and of “21.63%” respectively. Both compounds ( 1 h and 2 e ) were further tested in five dose screening with the tested substance ( 1 h ) being significantly more sensitive for several cancers cell line as corresponding to their GI 50 values. Furthermore, the basically substituted derivative 2 e showed the highest antipoliferative activity in a nanomolar scale towards the three selected cancers cell lines Non small lung cell NCI–H460 with GI 50 “616 nM”, Ovarian Cancer cell line OVCAR-4 with GI 50 “562 nM” and Breast Cancer cell line MCF7 with GI 50 “930 nM”.

As a part of a directed program for development of new active agents, novel heterocyclic derivatives with antipyrine and pyrazolone moieties -incorporated in- have been designed and synthesized. Starting with 4-arylidene-3-methyl-1-phenyl-5-pyrazolone derivative 2a,b novel Mannich bases derivatives have been synthesized and biologically evaluated for their anti-inflammatory activity. Furthermore, the activity of such compounds has been tested interestingly as COX-1 and COX-2 inhibitors. Structure elucidation of the synthesized compounds was attained by the use of elemental analysis, IR, 1H NMR, 13C NMR, and Mass spectrometry techniques. Compounds 3b, 3d and 4b represent the high % inhibition values for both COX-1 and COX-2. On the other hand, compound 8 showed little selectivity against COX-2 while compound 10 showed good selectivity against COX-1 only. Structure activity relationship has been discussed and the results were confirmed by molecular docking calculations.

This paper presents a new approach for solving the energy management problem of utility microgrids. In this approach, the rolling horizon concept is utilized to constitute a framework, in which an efficient metaheuristic technique known as the social spider algorithm is used for solving the problem. Before presenting the proposed approach, the mathematical formulation of the problem has been introduced, and the problem is formulated as a mixed-integer dynamic optimization problem. The proposed approach has been applied for solving the energy management problem of a utility microgrid with specifications obtained from the previous literature. The results obtained from using the social spider algorithm are promising.

Inflammation is a fundamental physiological process that is essential for survival of human being but at the same time is one of the major causes of human morbidity and mortality. In the past decade, numerous advances have taken place in the understanding and development of novel anti-inflammatory drugs. Therefore, investigation of newest anti-inflammatory agents is still a major challenge. In this study, novel and successfully synthesized naproxen-derivatives indicated powerful anti-inflammatory properties as potent of COX-1 and/or COX-2 inhibitors are reported. Results obtained revealed the presence of very potent derivatives with% inhibition of the oedema by 100% in addition to enzyme inhibition values that can reach 92%. The molecular docking and molecular dynamic calculations have been studied. Thus, new potent candidates for further investigation as prospective non-steroidal anti-inflammatory drug were proposed. Furthermore, twenty of the synthesized derivatives have been selected by the NCI, USA for anti-cancer screening and some of the tested compounds showed good% growth inhibition and some selectivity against some cell lines such as melanoma, non-small cell lung and colon cancer with GI% values ranging from 60.9 to 82.8%. Structure activity relationship has been performed and molecular modeling studies and molecular dynamic simulations have been performed for more explanation of the action of the synthesized compounds.

Metal organic frameworks (MOFs) represent an excellent material for chemical species sensors because they contain various optically-active centers, different ligands, variable metals, porosity and various guest species. This may be rationally chosen to afford the desired light emission properties. Unlike other porous crystalline solids, MOFs may be post-synthetically modified (PSM) with various types of chemical compounds embedded in the pore walls. Here, Eu-IRMOF-3-EBA is built up via post-synthetic modification of IRMOF-3 with ethylbenzoylacetate followed by coordination with Eu3+ ions. The main point of this work is not to report yet another MOF sensor. Rather, it is to show, for the first time, that PSM is an interesting route to tune the optically-active organophosphorus insecticides (prothiofos and profenofos) sensors. The complexation behavior of ethion, prothiofos, or profenofos with Eu-IRMOF-3-EBA has been computationally investigated.

Water hammer is defined as a pressure surge or wave caused when a fluid in motion is forced to stop or change direction suddenly. This pressure wave can cause major problems to transmission pipes.. The present study aims to investigate problems resulting from unsteady flow and then investigate the effect of using a protection device; air vessel only, surge tank only and air vessel with surge tank; to protect pipelines against water hammer. Through this work, the study is applied using Water Hammer Software Wanda V3.30. In the present study for transient condition caused by pump failure, it is found that using the proposed an air vessel as a protection device proved to be effective for prevent column separation, using of air vessel with two surge towers will not effect the total volume of protection. Increases the diameter of the pipeline reduces the surge pressures and decrease the total volume required to protect the system. Otherwise, change of pipe material type from Glass Reinforced Plastic to steel decreases the minimum pressure but does not effect the total volume required to protect the system and change of pipe material type from Glass Reinforced Plastic to concrete decreases the minimum pressure and the total volume required to protect the system. Finally found that as the air vessel volume is reduced the number of used air vessels is increased and the negative pressure of the pipe line not affected.

In this paper, the linear absorber is proposed to reduce the vibration of a nonlinear dynamical system at simultaneous primary resonance and the presence of 1:1 internal resonance. This leads to a two-degree-of-freedom system subjected to external excitation force. The method of multiple scales perturbation technique is applied throughout to determine the analytical solution up to first-order approximations. The stability of the system near the one of the worst resonance case is studied using the frequency response equations. The effects of the different system and absorber parameters on the behavior of the main system are studied numerically. For validity, the numerical solution is compared with the analytical solution and gets a good agreement. Effectiveness of the absorber ( $$E_{a})$$ is about 800 for the nonlinear vibrating system. The simulation results are achieved using MATLAB programs. At the end of the work, the comparison with the available published work is reported.

In most metals and alloys, the evolution of voids has been generally recognized as the basic failure mechanism. Furthermore, stress triaxiality has been found to influence void growth dramatically. Besides strain intensity, it is understood to be the most important factor that controls the initiation of ductile fracture. We include sensitivity of stress triaxiality in a variational porous plasticity model, which was originally derived from hydrostatic expansion. Under loading conditions rather than hydrostatic deformation, we allow the critical pressure for voids to be exceeded so that the growth due to plasticity becomes dependent on the stress triaxiality. The limitations of the spherical void growth assumption are investigated. Our improved constitutive model is validated through good agreements with experimental data. Its capacity for reproducing realistic failure patterns is also indicated by a numerical simulation of a compact tensile (CT) test.

The present study investigated the gonads alterations of mature female Oreochromis niloticus caused by different concentrations (0, 40, 60, 100 μg/L) of 4-nonylphenol (NP) and also its effect on steroidogenesis. A tendency for a dose-dependent reduction in the gonadosomatic index, fecundity and oocytes diameter in the NP-exposed groups was observed. Histological examination revealed that NP impairs gonadal growth clearly shown in the oocyte development and differentiation. Also, the estrogenic activity of such NP was identified through 11-ketotestosterone, 17b-estradiol and vitellogenin which were affected significantly by the applied concentrations. The study indicates that NP has estrogenic potency-induced marked alteration in the sexual development including gonadal maturation, spawning time and egg production.

Deriving bulk materials with ultra-high mechanical strength from nanometer-sized single metalic crystals depends on the consolidation procedure. We present an accurate molecular dynamics study to quantify microstructure responses to consolidation. Aluminum single crystals with an average size up to 10.7 nm were hydrostatically compressed at temperatures up to 900 K and pressures up to 5 GPa. The consolidated material developed an average grain size that grew exponentially with the consolidation temperature, with a growth rate dependent on the starting average grain size and the consolidation pressure. The evolution of the microstructure was accompanied by a significant reduction in the concentration of defects. The ratio of vacancies to dislocation cores decreased with the average grain size and then increased after reaching a critical average grain size. The deformation mechanisms of poly-crystalline metals can be better understood in the light of the current findings.

The minimum inhibitory concentration (MIC) value of Aspergillus awamori for Cd(II) was 700 mg/l. A complete inhibition of biomass production was observed at 400 mg/l concentration of Cd(II). A significant deformation in Cd(II)-stressed conidiophores and conidia was observed by Scanning electron microscopy (SEM) investigation. Quantification of Cd(II) was performed by EDX microanalysis. Transmission electron microscopy investigation (TEM) confirmed the involvement of extracellular adsorption, intracellular penetration through the cell wall and vacuolation. Cadmium(II) stress induced noticeable changes in the activities of polyphenol oxidase (PPO), glutathione reductase (GR) and peroxidase (POD), and in the concentrations of total antioxidants, soluble protein and thiols. High performance liquid chromatography analysis (HPLC) revealed that Cd(II) stress stimulated the production of oxalic acid. Maximum Cd(II) uptake capacity was achieved at pH 5.0, initial metal ion concentration 500 mg/l and biomass dosage 1 g/l. Maximum Cd(II) uptake capacity was reached after 6 h for live biomass and after 2 h for dead biomass. Fourier transform infrared spectroscopy (FTIR) results gave an indication on chelation between oxygen-, nitrogen-, phosphorus- and especially sulphur-containing ligands of biomass with metal ions. X-ray diffraction analysis (XRD) revealed the presence of CdSO4 .H2O by live and dead biomass. EDX confirmed the occurrence of sulphur, oxygen and Cd(II) on the cell wall.

The aim of this work was to determine the antimicrobial activity of chitooligosaccharides (chito) and comparing them with that of the standards broad spectrum antibiotic flomox and kluacid. The chito were prepared by enzyme hydrolysis of chitosan. They were fractionated into four groups (1, 2, 3 and 4) according to their molecular weights (MW) by ultrafiltration. Specific growth rate of the tested microorganisms was determined in the presence of chito. The potential antimicrobial activity of chito was evaluated as minimum inhibitory concentration (MIC) towards Gram positive bacteria (B. cereus), Gram negative fungi (P. aeruginosa) and Gram positive yeast (C. albicans). MIC was determined by8 serial dilution methods. The inhibitory activities of chito 1 and 3 were identified as being as strong as broad spectrum flomox and kluacid against B. Cereus. The specific growth rate of C. albicans was completely inhibited by chito (4) at concentration of 0.11 mg/ml with molecular weight less than 1.0 KDa and was stronger than that of broad spectrum kluacid (0.42 mg/ml). Chito (3) with molecular weight 1–10 KDa had MIC 1.67 mg/ml against P. aeruginosa. The results of this study suggested that chito can be a potent factor affecting as an antimicrobial activity. They could be considered as a possible alternative/additive to known antimicrobial agents in pharmaceutical compositions.

The aim of the present study was to prepare novel monophenolase inhibitory peptides from Vicia faba (broad bean) pods. Isolated protein was hydrolysed by immobilized protease at pH 10. For maximum production of hydrolysate (peptides), an optimized hydrolysis process, including incubation temperature and protein concentration, was established. Broad bean peptides had higher tyrosinase inhibitor potency than that of the parent protein. They were fractionated by ultrafiltration into three fractions: F1, F2, and F3. With high monophenolase inhibitor potency, F2 was further fractionated by reversed-phase high-performance liquid chromatography (RP-HPLC) three times, followed by high-performance size-exclusion chromatography (HPSEXC) to finally achieve a single peak, confirming its purity with a molecular weight of 26.102 kDa. It had superior monophenolase inhibitor potency compared to that of the original protein. The Michaelis-Menten constant (Km) values of tyrosinase activity toward l -tyrosine in the presence of a broad bean monophenolase inhibitor increased when its concentration increased, while the maximum velocity (Vmax) value was unchanged. The monophenolase inhibitor exhibited a competitive type of inhibition. The results of this study suggest that broad bean pods are a good source of monophenolase inhibitory peptides, which exhibit therapeutic potential for curing or preventing some diseases.

In this paper, passive and active control methods are applied to reduce the torsional vibration of a nonlinear dynamical system. This system is subjected to multi parametric excitation forces and modeled by the coupled nonlinear differential equations. This leads to two degrees of freedom and three degrees of freedom when the torsional absorber is connected to the system. A multiple scale perturbation technique is applied to obtain an approximate solution and investigate the response of the system. The stability and the steady-state response of the system near the simultaneous sub-harmonic and internal resonances are studied and discussed using the frequency response function method. The numerical solution and chaotic response of the nonlinear dynamical system for different parameters are also studied. The simulation results are achieved using MATLAB 7.0 programs.

Clear understanding of the superior mechanical strength of nanometer-sized metal single crystals is required to derive advanced mechanical components retaining such superiority. Although high quality studies have been reported on nano-crystalline metals, the superiority of small single crystals has neither been fundamentally explained nor quantified to this date. Here we present a molecular dynamics study of aluminum single crystals in the size range from 4.1 nm to 40.5 nm. We show that the ultimate mechanical strength deteriorates exponentially as the single crystal size increases. The small crystals superiority is explained by their ability to continuously form vacancies and to recover them.

When the brittle heterogeneous material is simulated via lattice models, the quasi-static failure depends on the relative magnitudes of [Formula: see text], the characteristic releasing time of the internal forces of the broken elements and [Formula: see text], the characteristic relaxation time of the lattice, both of which are infinitesimal compared with [Formula: see text], the characteristic loading period. The load–unload (L–U) method is used for one extreme, Telem ≪ Tlattice, whereas the force–release (F–R) method is used for the other, Telem ≫ Tlattice. For cases between the above two extremes, we develop a new algorithm by combining the L–U and the F–R trial displacement fields to construct the new trial field. As a result, our algorithm includes both L–U and F–R failure characteristics, which allows us to observe the influence of the ratio of [Formula: see text] to [Formula: see text] by adjusting their contributions in the trial displacement field. Therefore, the material dependence of the snap-back instabilities is implemented by introducing one snap-back parameter γ. Although in principle catastrophic failures can hardly be predicted accurately without knowing all microstructural information, effects of γ can be captured by numerical simulations conducted on samples with exactly the same microstructure but different γs. Such a same-specimen-based study shows how the lattice behaves along with the changing ratio of the L–U and F–R components.

The removal of lead(II) from artificial aqueous solution using live and dead biomass of Saccharomyces cerevisiae AUMC 3875 was investigated. The minimum inhibitory concentration (MIC) value of S. cerevisiae AUMC 3875 for lead(II) was 600 mg/l. For live and dead biomass, maximum lead(II) uptake capacities were achieved at pH 5.0, initial metal ion concentration 300 mg/l, and biomass dosage 3 g/l. Maximum biosorption capacities were reached after 3 h and 20 min for live and dead cells, respectively. Fourier Transform Infrared spectroscopy (FTIR) results revealed the important role of C = O,ـ OH,ـ NH, protein amide II band, $$ \mathrm{PO}_2^{-} $$ , mannans, sulphur and sulphur-oxygen compounds in lead(II) uptake. Scanning electron microscopy analysis (SEM) showed that the cell surface morphology and surface area/volume ratio changed greatly after lead(II) uptake. Transmission electron microscopy analysis (TEM) confirmed the involvement of both extracellular adsorption and intracellular penetration through the cell wall. X-ray powder diffraction (XRD) analysis revealed the presence of Pb(SO4),Pb2OSO4 by dead biomass and Pb3O2(SO4),Pb2OSO4 by live biomass. Energy dispersive X-ray microanalysis (EDAX) confirmed the occurrence of sulphur, oxygen and lead(II) on the cell wall. The removal of lead(II) from storage battery industry wastewater was performed by dead biomass efficiently.

Cichlids represented about 54.51% of the total landed catch in Nozha Hydrodrome during 2008. The present work aims to give useful information on the stocks of Cichlid species ( Oreochromis niloticus, Sarotherodon galilaeus, Oreochromis aureus and Tilapia zillii ) and their management in the Hydrodrome. Length weight relationship, condition factor, length composition of the catch, length scale relationship, total length by the end of each year of life, growth in weight, Von Bertalanffy parameters, the values of total, natural and fishing mortalities, survival rates, length and age at first capture, length and age at recruitment, yield per recruit, biomass per recruit, determination of the biological reference points were studied. The present study concluded that, the fisheries status of the four cichlid species in Nozha Hydrodrome is not in an over exploited condition.

In this paper, the dynamic oscillation of a rectangular thin plate under parametric and external excitations is investigated and controlled. The motion of a rectangular thin plate is modeled by coupled second-order nonlinear ordinary differential equations. The formulas of the thin plate are derived from the von Kármán equation and Galerkin's method. A control law based on negative acceleration feedback is proposed for the system. The multiple time scale perturbation technique is applied to solve the nonlinear differential equations and obtain approximate solutions up to the second-order approximations. One of the worst resonance case of the system is the simultaneous primary resonances, where Ω1≅ω1 and Ω2≅ω2. From the frequency response equations, the stability of the system is investigated according to the Routh–Hurwitz criterion. The effects of the different parameters are studied numerically. It is also shown that the system parameters have different effects on the nonlinear response of the thin plate. The simulation results are achieved using matlab 7.0 software. A comparison is made with the available published work.

Ultrastructural study of oogenesis of the Scarus ferrugineus was carried out during the period of oocyte growth, particularly the changes in nuclear morphology, cytoplasmic organelles, and wall formation. Materials produced in the nucleus and transported to the cytoplasm known as nuage were observed in the oogonia and primary oocytes at premeiotic and perinucleolar stages. This material gives rise to germ plasma in the growing oocytes. In the perinucleolar oocyte, the cytoplasm appears loaded with free ribosomes and dense bodies. Short strands of endoplasmic reticulum (ER), perinuclear mitochondrial ring, and a simple layer of flattened granulosa cells were also detected. Protrusion of short buds from oocyte and granulose surfaces to the perioocyte space was clearly detected in the oocyte. From the early vitellogenic stage (yolk vesicle oocyte) the vitelline envelope was observed as a single electron-dense mesh pattern layer, becoming thicker during the vitellogenic stage. The granulosa cells (GCs) become...

General summaries on the load–unload and force–release methods indicate that the two methods are efficient for different-charactered quasi-static failures; therefore, it is important to choose the right one for different applications. Then we take, as an example, the case where the release of the ruptured element's internal force is infinitely slower than the relaxation of the lattice system and analyze why the force–release method works better than the load–unload method in this particular case. Different trial deformation fields are used by them to track the next equilibrium state. Force–release method ensures that the deformation throughout the whole failure process coincides exactly with the controlled-displacement boundary conditions and we utilize the ‘left modulus’ concept to prove that this method satisfies the energetic evolution in the force–displacement diagram; both of which are not satisfied by the load–unload method. To illustrate that the force–release method is not just another form of the load–unload method, a tensile test on a specifically designed system is analyzed to further compare the above two methods, showing that their predicted sequences of elemental failures can be different. In closing, we simulate the uniaxial tensile test on a beam lattice system by the load–unload and force–release methods and exploit the details of the resulting fracture processes.

This paper presents an application of passive vibration control to a non-linear spring pendulum system simulating a ship's roll motion. This leads to a four-degree-of-freedom (4-DOF) system subjected to multi external and parametric excitations. Two absorbers in the longitudinal and transverse directions are designed to control the vibration near the simultaneous primary, sub-harmonic and internal resonance where system damage is probable. The theoretical results are obtained to second order approximations applying the multiple scale perturbation technique (MSPT). The stability of the steady-state solution near the simultaneous resonance case is investigated and studied applying frequency response equations. The effects of the absorbers and some system parameters on the vibrating system are studied numerically. The simulation results are achieved using MATLAB 7.0 programs Shampine et al. (2003) [16]. Comparison with the available published work is reported.

Summary Growth and longevity were studied for three species of the family scaridae, the longnose parrotfish (Hipposcarus harid), rusty parrotfish (Scarus ferrugineus) and bullethead parrotfish (Chlorurus sordidus), sampled at the eastern coast of the Red Sea, off Saudi Arabia. The three species are protogynous hermaphrodites presenting two distinct phases whereby the initial phase includes females and primary males, and the terminal phase is exclusively secondary males transformed from females. Annual marks in the ctenoid scales from the three species were used to develop size-at-age plots. Linear relationships were found between the scale radius and standard length for the three species, and the relationships between body weight (w) and standard length (L) were estimated. Scales of these species increased in size consistently throughout life, even though the somatic growth rate decreased with age. Sex-specific growth effects in the three species were demonstrated. Growth of initial phase females was the lowest, followed by the initial phase males and terminal phase males, the latter showing the fastest growth rates. Thus, transition to the terminal male identity was associated with enhanced growth, resulting in larger terminal males than females of equivalent size. The von Bertalanffy growth formula (VBGF) was estimated for H. harid, S. ferrugineus and C. sordidus (L∞ = 43.92, 27.4 and 23.3; K = 0.067, 0.27 and 0.56; t0 = −6.92, −4.98 and −4.6, respectively). The relationship between growth and reproduction of these species is also discussed.

The vibration of a ship pitch-roll motion described by a non-linear spring pendulum system (two degrees of freedom) subjected to multi external and parametric excitations can be reduced using a longitudinal absorber. The method of multiple scale perturbation technique (MSPT) is applied to analyze the response of this system near the simultaneous primary, sub-harmonic and internal resonance. The steady state solution near this resonance case is determined and studied applying Lyapunov’s first method. The stability of the system is investigated using frequency response equations. Numerical simulations are extensive investigations to illustrate the effects of the absorber and some system parameters at selected values on the vibrating system. The simulation results are achieved using MATLAB 7.0 programs. Results are compared to previously published work.

Summary This work analyses the distribution, histology and ultrastructure of chromaffin cells (CCs) and interrenal tissue (It) in the head kidney of Epinephilus tauvina. Histological examination revealed that chromaffin cells are found in small groups under the endothelium of the posterior cardinal vein (PCV) and are mostly closely associated with the interrenal tissue. Ultrastructure examination confirmed the existence of two main chromaffin cell types, distinguished by different types of secretory granules. The first type was characterized by the presence of vesicles with round, strongly electron dense core granules, which were eccentrically located. Such cells were interpreted as being noradrenaline cells. Meanwhile, cells with vesicles that were completely electron lucent or that contained small less dense eccentric granules were identified as adrenaline cells. Nerve endings were invaginated into the chromaffin cells through synaptic junctions. Interrenal tissue consisted of nests, cords, or strands of cells in contact with the posterior cardinal vein (PCV) and interposed with haematopoietic tissue. Ultrastructure analysis revealed only one interrenal cell type, which contained abundant smooth endoplasmic reticulum (sER) and numerous mitochondria with tubulo-vesicular cristae, characteristics of steroid-producing cells. The interrenal tissue cells have different cytological aspects that can be linked to a steroidogenic cell cycle allowing a periodical renewal of organelles.

The general aim of this paper is to develop an accurate fault-location scheme that can solve the problems affecting the accuracy of the existing conventional fault locators achieving easier maintenance and restoration time reduction as well as economical aims. This consequently helps to fit the new deregulation policies and competitive marketing. This investigation successfully applies zero-sequence current (3I 0) from the two terminals for earth high impedance fault (HIF) location, or negative-sequence currents from the two terminals of one faulted phase for line-to-line fault location. The HIF location is determined within only a maximum time of one cycle. The proposed scheme is insensitive to variations of different parameters, such as fault type, HIF behavior, wide-range transmission-line parameters variation, and fault inception angle. Staged fault testing results demonstrate that the proposed algorithm has feasible performance.

The use of passive control strategy is a common way to stabilize and control dangerous vibrations in a nonlinear spring pendulum which is describing the ship’s roll motion. In this paper, a tuned absorber in the transversal direction is connected to a spring pendulum with multi-parametric excitation forces to control the vibration due to some resonance cases on the system. The method of multiple scale perturbation technique (MSPT) is applied to study the periodic solution of the given system near simultaneous sub-harmonic and internal resonance case. The stability of the steady-state solution near the resonance case is investigated and studied using frequency response equations. The effects of the absorber and some system parameters on the vibrating system are studied numerically. Optimal working conditions of the system are extracted when applying passive control methods. Comparison with the available published work is reported.

In this paper, the coupled non-linear differential equations of the non-linear dynamical two-degree-of-freedom vibrating system including quadratic and cubic non-linearities are studied. The system consists of the main system and the absorber. The absorber is used to control the main system vibrations when subjected to multi-external excitation forces at simultaneous primary and internal resonance. This system represents many applications in machine tools, ultrasonic cutting process, etc. The method of multiple scales perturbation technique (MSPT) is applied throughout to determine the solution up to third order approximations. The different resonance cases are reported and studied numerically. Stability is studied applying frequency response functions. The effects of different parameters of the system are studied numerically. Optimum working conditions for the absorber where obtained at internal resonance ratio 1:3. This means smaller mass for the absorber which solves the problem of space limitation. A comparison is made with the available published work.

Properties of polygalacturonase [E.C. 3.2.1.15] (E 1 ) and invertase (E.C. 3.2.1.26] (E 2 ) isolated and purified in powdered form from Endomycopsis fibuligera grown on date wastes were measured. The molecular weights were estimated to be about 32 000 and 69 500, and they were highly specific for hydrolysing (1-4) and (1-2) glycosidic links respectively. The K m value of E 1 was 7.1×10 -2 M for soluble-pectic acid and that for E 2 was 6.7×10 -2 M for sucrose at pH4.5, and optimal pHs were 3.5 for E 1 and 4.0 for E 2 . The purified enzymes are stable on storage for more than one year at -20 o C

Various secondary and primary amines were converted into bis-indolyl Mannich bases with good to excellent yields via double condensation reactions with indole and glutaraldehyde. The expected bis-indolyl Mannich bases (2, 3 and 4) were formed by using piperazinehexahydrate and 4,4′-trimethylenedipiperidine. Whereas, the use of primary amines, phenylhydrazine, amino acids and primary diamine produced the corresponding bis-indolyl-1,2,6-trisubstituted pipridines (5a-e) and indolyl-quinolizine (6) and dibis-indolyl-1,2,6-trisubstituted pipridines (7). All analytical and spectral data of these bis-indolyl Mannich bases have been determined. Six of the synthesized bis-indolyl Mannich bases have been subjected for antiproliferative activity screening at National Cancer Institute (NCI), Egypt, towards three human tumor cell lines representing different tumor types: breast adenocarcinoma cell (MCF-7), non-small lung cancer cell (NCI-H460), and central nervous system (CNS) cancer cell (SF-268). Compound (4) indicated the best and highest inhibitory effect against all three tested tumor cell lines with inhibition of 50% concentration (IC50) for MCF-7 (0.08 µmol/L), NCI-H460 (0.05 µmol/L) and SF-268 (0.01 µmol/L).

This paper is concerned with the vibration of a two degree-of-freedom (2DOF) nonlinear system subjected to multiparametric excitation forces. The vibrating motion of the system is described by the coupled differential equations having both quadratic and cubic terms. The aim of this work is to use a nonlinear absorber to control the vibration of the nonlinear system near the simultaneous subharmonic and internal resonances, where the vibrations are severe. Multiple scale perturbation technique (MSPT) is applied to obtain the averaged equations up to the second-order approximation. The steady-state response and their stability are studied numerically for the nonlinear system at the simultaneous subharmonic and internal resonances. Some recommendations regarding to the different system parameters are given following studying the effects of various parameters. Comparison with the available published work is made.

Pichia pinus was found to be capable of growing on mango wastes, producing pectinase (pectin lyase, EC-4.2.2.10) and lactase (beta-galactosidase, EC-3.2.1.23) enzymes. The two enzymes were successively purified by precipitation with ammonium sulfate followed by chromatography on Sephadex G-120. The purification procedure provided 1,846 and 929 fold purification with 20.6 and 24% yield recovery of pectinase and lactase, respectively. the km value of pectinase was 0.33% for pectin at pH 4.5 and that for lactase was 0.166% for lactose at pH 7.0. The purified enzymes, pectinase and lactase are stable up to 50 degrees C for 60 and 45 min, respectively, with 20 and 35% loss of their activity. Gel filtration on Sephadex G-200 indicated that the molecular weights of the purified pectinase was 90 x 10(3) Dalton and of lactase 115 x 10(3) Dalton. On the basis of the evaluation tests done, the enzymes were considered to have a potential technological interest as treating mango pastes (residues left after mango juice preparation) with the two prepared enzymes resulted in an increase of the colour intensity, total carbohydrate content and juice yield. Treating milk with the purified lactase also showed an increase in the total carbohydrate and reducing sugar produced.

The present study investigates the effects of different doses (0, 40, 60, 100 μg/L) of 4-nonylphenol (NP) on testis histology and sperms motility of mature Oreochromis niloticus. A tendency for a dose-dependent reduction in the gonado-somatic index (GSI) in the NP-exposed groups was observed. Histological examination revealed that high doses of NP (60 and 100 μg/L) cause hyperplasia of interlobular connective tissue components coincide with decrease in the size of seminiferous lobules and amount of lumen spermatozoa in comparison with the control and low-dose (40 μg/L)-exposed groups. In addition, within the seminiferous lobules, rupture of spermatogenic cysts, vacuolation and necrosis of primary spermatocytes due to damage of sertoli cells were clearly observed and lead to decrease in advanced spermatogenic cells. The highest dose caused significant decrease in the GSI associated with appearance of testis–ova (intersex) state. The percentage of abnormal sperms increased with increasing the dose of NP reaching to 96 % for those subjected to 100 μg NP/L, while it was only 11 % for the control group specimens. The study indicates that NP has estrogenic potency induced marked alteration in the sexual development including inhibition in testicular growth and deformation in the sperms.

Glycosidases namely myrosinase and β-amylase, have been isolated fromBrassicaceae. These enzymes were identified and estimated by the rate of glucose and maltose formation from sinigrin (thioglucosinolate) and amylose (polysaccharides) hydrolysis, respectively. Their activities (U/g dry tissues) varied with the different species of the plant and with the different parts of their tissues. Generally, they were higher in the germinated seeds (3.3-8.0 times) than in powdered or defatted powdered dry seeds. The best amylase and myrosinase extracting solution for radish and white mustard germinated seeds was distilled water, and for turnip germinated seeds, it was 0.1M phosphate buffer, pH 6.0. In the light, the optimum germination temperature for amylase production or activation by radish and white mustard seeds was 25°C, and for turnip seeds, it was 30°C, whereas for myrosinase production or activation by radish and turnip, 25–27°C was the optimum temperature. The highest myrosinase activities in black mustard and radish defatted dry seeds were obtained by extraction with 1% NaCl at 272/30°C and distilled water at 25–27°C, after an incubation period of 4–6 h. Comparative studies indicated that fresh radish roots were the most potent amylase and myrosinase producers compared with radish leaves or roots, stems, and leaves of turnip and cabbage. Amylase and myrosinase were partially purified from water extracts of fresh radish roots by optimum precipitation with ammonium sulfate (100%). Some physicochemical properties were studied.

An investigation into the passive vibration reduction of the nonlinear spring pendulum system, simulating the ship roll motion is presented. This leads to a four-degree-of-freedom (4-DOF) system subjected to multiparametric excitation forces. The two absorbers in the longitudinal and transverse directions are usually designed to control the vibration near the simultaneous subharmonic and internal resonance where system damage is probable. The theoretical results are obtained by applying the multiple scale perturbation technique (MSPT). The stability of the obtained nonlinear solution is studied and solved numerically. The obtained results from the frequency response curves confirmed the numerical results which were obtained using time history. For validity, the numerical solution is compared with the analytical solution. Effectiveness of the absorbers (Ea) are about 13 000 for the first mode (x) and 10 000 for the second mode (ϕ). A threshold value of linear damping coefficient can be used directly for vibration suppression of both vibration modes. Comparison with the available published work is reported.

Indoles are natural products well known for their anticancer activity, which is related to their ability to induce cell death for many cancer cell lines. This review addresses indoles as natural products, mechanism of indoles, facilitated induction and recent studies with indoles and related compounds that were investigated via anticancer screening and that led to drug approval.

Two myrosinase isoenzymes ( EC 3. 2. 3. 1 ) were extracted and purified by (NH 4 ) 2 SO 4 precipitation and DEAE-cellulose and Sephadex G-200 chromatography from radish root tissues with M r s 28 800 and 58 900. The most active one (120 U mg −1 ) was identified and characterized. The yield of the purified myrosinases was 21 mg (2398 U) of pure enzymes from 100 g of dry root tissues. The purity was ascertained by obtaining a single sharp band by disc electrophoresis. Optimal myrosinase activity on sinigrin was recorded in phosphate buffer, pH 6 – 6.5 at 37°. The K m for myrosinase with sinigrin as substrate was 0.47 mM at pH 6. The enzyme was stable for 45 min at 30 and 40° (18% denaturation).