The solution of mixed integral equation of the first kind using toeplitz matrix method

In this work, the existence and uniqueness of the solution of mixed integral equation (MIE) of the first kind is considered in the  L2  *C[0,T], T<1 ,  is the domain of integration with respect to position and T is the time. Then, a numerical method is used to obtain a system of Fredholm integral equations (SFIE). The discontinuous kernel of the SFIE takes the form of Carleman function and logarithmic kernel. The existence and uniqueness of the solution SFIE can be proved. Moreover, Toeplitz matrix method (TMM) is used to obtain a linear algebraic system (LAS). The LAS is solved numerically, to get the eigenvalues and eigenfunctions of SFIE

EFFECT OF NITROGEN FERTILIZATION AND GROWTH REGULATORS ON DELONIX REGIA SEEDLINGS GROWN IN SANDY SOIL

A pot experiment was carried out at the Fac. of Agric. Nursery, Minia Univ. to explore the response of Delonix regia seedlings to three nitrogen fertilization rates (10, 20 and 30 g/plot of ammonium sulphate (20.5 % N) and seven growth regulator treatments (0, GA3 at 50, 100 and 150 ppm and IAA at 25, 50 and 75 ppm). The studied vegetative growth characters (plant height, stem thickness, crown diameter, number of leaves and dry weight of leaves, stem and roots) were gradually increased parallel to the increase in N fertilization rate. A similar trend, in response to N fertilization was observed for total chlorophylls content (a + b) and nitrogen % in the leaves. Concerning growth regulators, both GA3 and IAA effectively induced different vegetative growth traits and chemical determinations, except, for stem thickness, total chlorophylls and N % which were reduced due to GA3. The effectiveness of either GA3 or IAA was parallel to its concentration. The best growth of Delonix regia seedlings was achieved by supplying the plants with the high N fertilization rate (30 g/pot) along with either GA3 at 150 ppm or IAA at 75 ppm

EFFECT OF NPK FERTILIZATION AND MICRONUTRIENTS ON DELONIX REGIA SEEDLINGS GROWN IN SANDY SOIL

A pot experiment was carried out to study the effect of different NPK fertilization rates and various Mn and Zn treatments on sandy soil-grown Delonix regia seedlings at the Nursery of Fac. of agric., Minia Univ. during 2016 and 2017 seasons. The obtained results showed that following: all studied vegetative growth characters, i.e. plant height, stem thickness, crown diameter and leaves, stem and roots dry weights, as well as, the three photosynthetic pigments and leaves % of N, P and K were gradually increased upward parallel to the increase in the applied rate of NPK fertilizers. Similarly, the prementioned vegetative growth and chemical parameters were augmented due to the use of Mn + Zn micronutrient treatments with the effective one being Mn 75 ppm + Zn 75 ppm. It was found that supplying the seedlings with either the medium or high NPK  rate combined with Mn at 75 ppm + Zn at 75 ppm was capable of producing the best growth of Delonix regia seedlings grown in sandy soil

Wheat Germ Oil Restores Testicular Function Through Modulation of Oxidative Stress in Male Adult Rats Exposed to Chromium VI

This research was outlined to assess the protective and therapeutic role of wheat germ oil against chromium VI -induced oxidative stress and testicular dysfunction in male adult rats through evaluation of semen picture, measuring the sex hormone levels, oxidative stress markers, DNA fragmentation percentage and histopathological changes in the testes. Twenty-eight adult Wister male rats were assigned into four equal groups: Group 1; Control, group 2; Cr VI, group 3; Cr VI + WGO, and group 4; WGO. WGO showed a significant increment in the RBC, Hb, Ht, WBC and Plts. WGO restored the levels of testicular antioxidant enzymes, NO, MDA as well as GSH. Also, WGO in-combination with Cr VI showed a significant (p<0.05) increase in the levels of testosterone, LH, GnRH hormones and 17β-HSD enzyme, while, FSH was decreased. Data showed that treatment of male rats with WGO and Cr VI caused an increase in sperm count, motility, and decrease in sperm abnormality. Combination of WGO with Cr VI revealed a decrease in the levels of TL, TC, TG and LDL–C, while, HDL–C was increased. Rats administrated with WGO in-combination with Cr VI exhibited a slight improvement in testicular DNA integration compared to Cr VI-treated group. Further, co-administration of WGO + Cr VI revealed a slight improvement in the pathological alterations; the cellular layers of the seminiferous tubules more or less near to the normal structure. It was concluded that wheat germ oil can be an effective antioxidant in modulating Cr VI-induced male infertility, and may lead to improve the male reproductive performance

Vibrational spectroscopy and DFT calculations of 1,​3-​dibromo-​2,​4,​6-​trimethylbenzene: Anharmonicity, coupling and methyl group tunneling

International audienceThe Raman, IR and INS spectra of 1,3-dibromo-2,4,6-trimethylbenzene (DBMH) were recorded in the 80-3200 cm-1 range. The molecular conformation and vibrational spectra of DBMH were computed at the MPW1PW91/LANL2DZ level. Except for the methyl 2 environment, the agreement between the DFT calculations and the neutron diffraction structure is almost perfect (deviations < 0.01 Å for bond lengths, < 0.2° for angles). The frequencies of the internal modes of vibration were calculated with the harmonic and anharmonic approximations; the later method yields results that are in remarkable agreement with the spectroscopic data, resulting in a confident assignment of the vibrational bands. Thus, no scaling is necessary. The coupling, in phase or anti-phase, of the motions of symmetrical C-Br and C-Me bonds is highlighted. Our DFT calculations suggest that the torsion of methyl groups 4 and 6 is hindered in deep wells, whereas methyl group 2 is a quasi-free rotor. The failure of the calculations to determine the frequencies of the methyl torsional modes is explained as follows: DFT does not consider the methyl spins and assumes localization of the protons, whereas the methyl groups must be treated as quantum rotors

Cyber Physical Energy Systems Modules for Power Sharing Controllers in Inverter Based Microgrids

The Microgrids (MGs) are an effective way to deal with the smart grid challenges, including service continuity in the event of a grid interruption, and renewable energy integration. The MGs are compounded by multiple distributed generators (DGs), and the main control goals are load demand sharing and voltage and frequency stability. Important research has been reported to cope with the implementation challenges of the MGs including the power sharing control problem, where the use of cybernetic components such as virtual components, and communication systems is a common characteristic. The use of these cybernetic components to control complex physical systems generates new modeling challenges in order to achieve an adequate balance between complexity and accuracy in the MG model. The standardization problem of the cyber-physical MG models is addressed in this work, using a cyber-physical energy systems (CPES) modeling methodology to build integrated modules, and define the communication architectures that each power sharing control strategy requires in an AC-MG. Based on these modules, the control designer can identify the signals and components that eventually require a time delay analysis, communication requirements evaluation, and cyber-attacks&rsquo; prevention strategies. Similarly, the modules of each strategy allow for analyzing the potential advantages and drawbacks of each power sharing control technique from a cyber physical perspective

Effects of mechanical abrasion challenge on sound and demineralized dentin surfaces treated with SDF

This study evaluated the effect of mechanical abrasion on the surface integrity, color change (Delta E) and antibacterial properties of demineralized and sound dentin surfaces treated with silver-diammine-fluoride (SDF). The dentin specimens were divided into two groups: sound and demineralized dentin, then divided into three sub-groups, control (no-treatment), SDF, and SDF+potassium-iodide (KI). Each sub-group was further divided into two groups, one exposed to mechanical brushing and the other without brushing. Specimens were analyzed for the Delta E, surface roughness/surface loss and antibacterial properties (CFU, optical density and fluorescent microscope). Repeated Measures ANOVA was used for statistical analysis of color change while one-way ANOVA was used for CFU analysis. SDF and SDI+KI groups showed significant reduction in Delta E with brushing in the sound dentin group unlike the demineralized group. The surface roughness values were higher for both SDF and SDF+KI groups but roughness values significantly decreased after brushing. Both SDF and SDF+KI groups revealed significantly less surface loss than control. The SDF group showed high anti-bacterial effect after brushing, unlike SDF+KI group. So, we concluded that mechanical brushing improved the esthetic outcome. While, SDF and SDF+KI could protect the dentin surface integrity. SDF-treated dentin possesses an antibacterial property even after mechanical brushing

Long-term prognostic value of dobutamine stress echocardiography in patients with atrial fibrillation

STUDY OBJECTIVE: To assess the long-term prognostic value of dobutamine stress echocardiography (DSE) for cardiac events (cardiac death, myocardial infarction, and late revascularization) in patients with atrial fibrillation (AF). METHODS: Baseline ECGs were studied in patients undergoing DSE between 1989 and 1998. Sixty-nine patients had AF before DSE. Prognostic value of DSE in these patients was compared with a control group who had sinus rhythm (n = 1,664). The presence of stress-induced ischemia was noted for every patient. The mean follow-up period was 35 months (range, 6 to 84 months). Data are presented as hazards ratio (HR) with 95% confidence interval (CI). RESULTS: Heart rate at rest was higher in patients with AF (77 +/- 15 beats/min vs 73 +/- 14 beats/min; p = 0.04); however, double product at peak stress was not different between patients with AF and sinus rhythm (17,602 vs 17,169, respectively; p = 0.46). In patients with AF, target heart rate was achieved at a lower dobutamine dose (33 +/- 8 microg/kg/min vs 35 +/- 9 microg/kg/min; p = 0.01). Cardiac arrhythmias occurred more frequently (12% vs 5%; p = 0.001) in patients with AF during DSE. During a follow-up period of 7 years, cardiac death occurred in 5 patients, myocardial infarction in 2 patients, and late revascularization in 10 patients. Prognostic value of DSE for all late cardiac events was similar in patients with AF (HR, 3.0; 95% CI, 0.9 to 9.5) and sinus rhythm (HR, 3.4; 95% CI, 2.7 to 4.3; p = 0.85). CONCLUSION: The prognostic value of DSE for late cardiac events is maintained in patients with AF