501 research outputs found
Long-Term Yield Prediction of Greenhouse Sweet Pepper Crops
In this paper, a new model for predicting the yield of greenhouse sweet peppers (Capsicum annuum L.) is presented. The model can provide long-term prediction up to 7 weeks in advance with the same accuracy it can predict yield one week in advance. It uses both past and expected environmental readings as well as physiological data as input to a specially designed artificial neural network. The model was tested using 4 years of data that was obtained from commercial pepper growers. Short-term prediction accuracy (one week) is consistent with other predictive models in the literature for sweet peppers. This validates our long-term results
Linear and nonlinear optical properties of the CdSe nanocrystals embedded in PMMA matrix
CdSe nanocrystals (NCs) were prepared using a colloidal solution and dispersed in polymethylmethacrylate (PMMA) matrix. Using spin coating technique, thin films deposited on glass substrates were prepared. Their structural and optical properties were investigated by X-ray diffraction, atomic force microscopy (AFM) and UV-visible absorption, respectively. The absorption spectra of these dispersed NCs exhibit excitonic peaks resulting from the electron-hole coupling transitions. Due to a quantum confinement effect, a blue shift is deduced by comparison of such transition with respect to reported bulk band gap. Assuming a spherical like shape for these NCs, the crystallites radius (R) was estimated by applying the effective mass approximation model and was about 2.92 nm. Such a weak radius value compared to Bohr radius (RB = 5.5 nm) leads to a strong quantum confinement regime. Moreover, the influence of this confinement effect on nonlinear optical (NLO) properties was also studied. Quadratic and cubic NLO properties were investigated by second and third harmonic generation techniques (SHG and THG) with a Q-switched Nd:YAG laser working at 1064 nm fundamental wavelength. The NLO susceptibilities Χ<2>eff, Χ<3>eff were measured to be equal to 2.27.10-10(m/V) and 2.28.10-20(m2/V2), respectively
Quantitative characteristics and chemical composition in Caspian roach (Rutilus rutilus caspicus) sperm
In this study, quantitative characteristics and chemical composition of in roach (Rutilus rutilus caspicus) sperm were investigated. Sperm traits included sperm movement duration, percentage of motile spermatozoa, sperm density, spermatocrit and sperm volume. Some seminal plasma characteristics (sodium, potassium, calcium, magnesium and chloride) were investigated. In addition, some metabolites of seminal plasma (glucose, cholesterol and protein) were measured. The Na+ and K+ ions correlated negatively with spermatozoa motility (r = -0.0518, p<.05 and r =-0.3597, p<.01) respectively. Also, there were significant positive correlations between Ca2+ and Cl- ions with spermatozoa motility (r = 0.2945, p<.05 and r= 0.1379, p<.01), respectively. Mg+2 was positively correlated with glucose and protein (r = 0.046, p<.05 and r = 0.694, p<.05), respectively. On the other hand, a significant positive relationship was found between Na+ and K+ (r = 0.548, p<.01). These parameters can be used to evaluation of sperm quality and collecting information about developing procedures for artificial fertilization of roach
Optical properties of the ZnSe nanocrystals embedded in PMMA matrix
In this paper we report linear and nonlinear optical properties of the thin films based on nanocrystals ZnSe embedded in centrosymmetric matrix PMMA, deposited by spin coating technique. Absorption and emission spectroscopy are shown respectively a blue shift and a strong band emission near the band gap of bulk material ZnSe, which is tunable with particles size. Blue shift of the absorption edge used to evaluate the average size of nanoparticles by using the E.M.A model. The size of NCs of ZnSe was estimated to 1.98 nm, compared to the exciton Bohr radius of bulk material. We established a strong quantum confinement state for the NCS ZnSe. Using Nd:YAG laser at 1064 nm in picoseconds regime, Second order susceptibilities were measured by SHG technique. The obtained value was four order of magnitude larger compared with the bulk (ZnSe) value
The impact of human resource management practices in innovation culture Case Study: Bank of Palestine in Gaza strip
The purpose of this study is to determine the degree of correlation between HRM practices and innovation culture and the degree of the impact of each HRM practice on the innovation culture. Data of this study are obtained from Bank Of Palestine (BoP), triangulation mixed method is used in this study, by using quantitative and qualitative analysis in order to get three points upon the factors being studied through questionnaires distributed to BoPs' employees in different branches in Gaza strip, and interview with the HR manager of BoP and a focus group with BoP's HR team. The results of this study concluded that there is a correlation between HRM practices and innovation culture. The HRM practices, which include staffing process, compensation, employee and labor relations, training and development, safety and health and communication, and participation, should be implemented in a holistic system and not in isolation in order to best stimulate innovation culture. The study recommended the pre-evaluation tests should be changed to better measure employees' creativity, flexibility and ability to take risks which all lead to a better innovation culture
Development of Acid-Soil Tolerant Corn (Zea Mays L.) with High-Quality Protein
Corn is an important food crop in Indonesia. Plant expansion has been hampered by soilacidity problem and the protein content of many corn varieties was low. This research initiates development of soil-acid-tolerant corn with highquality- protein content. Research was done on 12 factorial treatments and 3 replications as blocks in RCBD. The first factor was corn populations: Toray-1(G1), Toray-2(G2), GS- 5(G3) and GS-10(G4). The second factor was fertilizations: P1(69 kg N+36 kg P2O5+15 kg K2O per ha)); P2(115 kg N+54 kg P2O5+30 kg K2O per ha); and P3(161 kg N+72 kg P2O5+45 kg K2O per ha). The observed variables consisted of several agronomic traits, including the protein content. Results indicated that the corn populations, in general, showed good agronomic traits. The differences were mostly between populations, not between fertilizations, and no interaction was observed. The yield potential ranged from 4.25 to 6.47 ton dry seeds per ha. The protein content of seed resulted from cross ranged from 9.84% to 11.30%, as compared to the parents of 9.11% and 12.62%. This research concludes that genetic factors play an important role as confirmed by heritability estimate (h2)=0.75
Analysis of Microwave Heating Process for Demulsification of Water-in-Crude Oil Emulsions
In this investigation, the process of microwave heating technology was evaluated to measure the effect of some important parameters such as dielectric properties (έ and ɛʺ), rate of temperature increase (dT/dt), volume rate of heat generation (Qmw), wavelength (λ) and penetration depth (Dp) during the microwave irradiation on crude oil emulsions. Two types of Malaysian crude oil mixed together at a volume ratio of 50-50% and applied for further investigations. In order to ensure the efficiency of the process, the improvement of existing techniques and the development of new technology different ratios of water and oil were utilized to prepare the emulsions of water-in-crude oil (W/O). The emulsion samples were heated under 360 watt and 540 watt for 3 to 5 minutes. The findings of the microwave heating demulsification showed that higher microwave power (540 watt) along with the radiation time (5 min) were not much effective for water separation. This is because of the over boiling of the samples. Consequently, for microwave heating demulsification the best water separation efficiency was achieved at 3 (minutes), 360 (watt). Based on the result of microwave parameter’s calculations, it was found that parameters such as; dT/dt, Qmw, έ and ɛʺ, were inversely proportional to the radiation time. However, parameters such as λ and Dp were directly proportional to the time of the radiation
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