Research Article - Archives of Applied Science Research ( 2022) Volume 14, Issue 1
Received: 08-Aug-2022, Manuscript No. aasr-22-70887; Editor assigned: 10-Aug-2022, Pre QC No. aasr-22-70887 (PQ); Reviewed: 17-Aug-2022, QC No. aasr-22-70887 (Q); Revised: 22-Aug-2022, Manuscript No. aasr-22-70887 (R); Published: 31-Aug-2022 , DOI: 0
The objective of the study was to determine the possible incidence of the ROR methodology in the modelling of the total number of monthly mosquito outbreaks in Villa Clara province, Cuba. The research covered the 13 municipalities of the province, as well as the number of outbreaks reported in the different months of the period analyzed (2010-2020). A descriptive, ecological, retrospective and statistical study was carried out, for which all the information on the work cycles established for surveillance and vector control was collected. The data were organized in the Windows Excel application, by years and months. The forecast of the outbreaks was modelled employing the Objective Regressive Regression Methodology (ROR), with the use of dichotomous variables DS, DI, and NoC. Forty-five mosquito species distributed in 13 genera were identified, with the best represented and distributed species being Anopheles albimanus, Aedes aegypti, Ae. albopictus, Ae. scapularis, Culex quinquefasciatus, Cx. nigripalpus and Psorophora confines. The summary of the ROR model for the total monthly foci in Villa Clara explained 91% of the variance, with a low error for the focal point, where the analysis of variance corroborated that the model was valid and significant at 100%. The model parameters, SD, DI, and trend were significant, with a tendency to increase the number of foci per month. We conclude that it is possible to model mosquito outbreaks in a given geographical area, however large it may be, and even to predict the behaviour of the outbreaks in the short, medium, and long term.
Calcium Fluoride Nanoparticles; X-ray Diffractometry; Scanning Electron Microscopy; Ultrasonic Velocity; Ion-Dipole Interactions
Nanoparticles are routinely defined as anything with a particle size of the order of 100nm that shows properties that are not found in bulk samples of the same material. The synthesis of nanoparticles and the study of their properties are of fundamental importance in the advancement of recent research. It is found that the optical, electronic, magnetic, and catalytic properties of metal nanoparticles depend on their size, shape, and chemical surroundings [1, 2]. In nanoparticles synthesis, it is very important to control not only the particle size but also the particle shape and morphology as well. In the present investigation, the synthesis of Calcium fluoride by chemical route is discussed, which is an easy, simple, cost-effective, and convenient route for preparing nanoparticles [3, 4]. It is easy to control synthesis parameters and yield a large number of samples.
Low solubility and wide transmission make calcium fluoride extremely useful for a variety of different applications including microlithography, mirror substrates for UV laser systems, windows, lenses, and prisms for UV and IR applications. A polished calcium fluoride surface can be expected to withstand several years of exposure to normal atmospheric conditions [5]. Due to its high transmission, it is also used in spectroscopic windows, lenses, and for the design of vacuum furnaces.
T he acoustic properties of particle-fluids interaction are investigated by ultrasonic interferometer techniques. The method is also used for the investigation of structure changes under the influence of different temperatures and concentrations. Only by ultrasonic technique, weak interaction between nanoparticles suspension can be determined. The possible aggregation of nanoparticles in nano colloids plays a key role in the drug delivery system because colloidal forms of the drug are easily absorbed by the body tissues and hence are more effective. The investigations of Ultrasonic velocity and measurement of density are the basic parameters to derive many acoustical relation such as adiabatic compressibility, isothermal compressibility, free volume, free length, acoustic impedance, and relaxation time etc. All these acoustical parameters are related to the surface of nanoparticles and nanoparticle’s interaction. T he ions-dipole interaction of nanoparticles causes to increase or decrease in acoustic parameters, making us to detect possible particlebase fluids interaction with the ultrasonic technique.
Ultrasound spectroscopy is very useful in the investigation of acoustic properties of nanosuspensions and has some advantages over many existing technologies because it is non-destructive and non-invasive [6]. Only by ultrasound technique, weak interaction between nanoparticles can be determined. It can provide useful information to a higher concentration than optical methods.
Sample Preparation
All chemicals used were of analytical grade. Aniline, ammonium persulphate, and ammonium hydroxide from SD Fine Chemical, India. Stannic chloride and hydrochloric acid from Merk were used as received without further purification. Double distilled water was used throughout this work.
n the preparation of CaF2 , we used Calcium Chloride Dehydrate (CaCl2 .2H2 O, Merk-99.9%), Nitric Acid (conc. HNO3 , Merk99.99%), Ammonium Fluoride (NH4 F, Merk-99.50%), Bismuth Nitrate (Bi (NO3 )3 .5H2 O, Merk-99.50%), and Ethanol as raw materials. T he CaF2 was prepared in the following method. Dehydrated calcium chloride was mixed into alcohol to form a transparent solution and then ammonium fluoride was added in excess to the calcium chloride solution. A whitish solution was obtained, which was then stirred for 10–12 h, after that calcium chloride was mixed completely with ammonium fluoride solution. Then ethanol was added to the solution and kept on a high-speed centrifuge at 3000 rpm for 3 h at 22-25°C, finally paste was formed in white color. This paste was dried at 60°C for 12 h to get white powder. The mean crystallite size of the sample is calculated using Scherer’s formula [7],
Where ‘λ’ is the wavelength of X-ray (0.1541nm), ’W’ is FWHM (full width at half maximum), ’θ’ is the diffraction angle and ‘D’ is particle diameter (size). The average particle size of CaF2 is found to be around 48 nm (Figure 1).
Figure 1. X-ray Diffraction pattern of CaF2
Measurement
The X-ray diffraction of the nano-sized calcium fluoride is obtained by using a Philips Holland, PW-1710 x-ray diffractometer having Cu kα x-ray radiation of wavelength λ=1.5405 A0 and a continuous scan of 20/ min at 35 kV and at 20mA as shown in figure 1. Ultrasonic velocity measurements were carried out using multifrequency interferometer (Mittle F-83 model) techniques at the frequency of piezoelectric transducers 1MHz. A Thermostat (Lab Slab) controls the temperature of the liquid to an accuracy of ± 0.1°C. Density measurement was carried out using specific gravity bottles and digital mono pan-balance with an accuracy of 0.001mg. The SEM photographs of prepared CaF2 powders as shown in Figure 2.
Figure 2. SEM images of synthesized CaF2
T he SEM results reveal that the powder was porous and agglomerated with polycrystalline nanoparticles. The larger particles exhibited numerous spherical perturbances on the surface, suggesting that they were formed during the precipitation process through fusion of the much smaller particles. The synthesized CaF2 nanoparticles nanoparticles are spherical in shape while were smaller size of around 48 nm and less agglomerated (Table 1-8) [8].
Table 1.Measured Value of Ultrasonic Velocity, Density, Adiabatic compressibility, and Isothermal compressibility at 25°C
| Concentration wt% X |
Ultrasonic Velocity [ m/sec] |
Density [Kg/m3] |
Adiabatic compressibility [Kg-1ms2] |
Isothermal compressibility [Kg-1ms2] |
|---|---|---|---|---|
| 0 | 1101.5 | 780 | 1.05666 Χ 10-9 | 1.58499 Χ 10-9 |
| 0.002 | 1141.654 | 759.576 | 1.01009 Χ 10-9 | 1.48 Χ 10-9 |
| 0.004 | 1119.679 | 763.3415 | 1.04495 Χ 10-9 | 1.55 Χ 10-9 |
| 0.006 | 1100 | 765.412 | 1.12336 Χ 10-9 | 1.65 Χ 10-9 |
| 0.008 | 1120.556 | 766.0151 | 1.0268 Χ 10-9 | 1.5402 Χ 10-9 |
| 0.01 | 1093.111 | 767.9913 | 1.08972 Χ 10-9 | 1.63458 Χ 10-9 |
Table 2. Measured Value of Free volume, Free length, Acoustic Impedance and Relaxation time at 25°C
| Concentration wt% X |
Free volume [cm3/mol] |
Free length [A°] |
Acoustic Impedance [Kg.m-2s-1] | Relaxation Time [sec] |
|---|---|---|---|---|
| 0 | 5.85127 Χ 10-8 | 6.48502 Χ 10-11 | 859170 | 7.71 Χ 10-12 |
| 0.002 | 3.91897 Χ 10-5 | 6.34049 Χ 10-11 | 867172.9787 | 1.00049 Χ 10-11 |
| 0.004 | 3.73774 Χ 10-5 | 6.44896 Χ 10-11 | 854697.4436 | 1.05065 Χ 10-11 |
| 0.006 | 3.64053 Χ 10-5 | 6.68655 Χ 10-11 | 809261.9348 | 1.13253 Χ 10-11 |
| 0.008 | 4.14689 Χ 10-5 | 6.39273 Χ 10-11 | 863724.9551 | 1.03401 Χ 10-11 |
| 0.01 | 4.27783 Χ 10-5 | 6.58568 Χ 10-11 | 839499.7298 | 9.86002 Χ 10-11 |
Table 3.Measured Value of Ultrasonic Velocity, Density, Adiabatic compressibility, and Isothermal compressibility at 30°C
| Concentration wt% X |
Ultrasonic Velocity [ m/sec] | Density [Kg/m3] | Adiabatic compressibility [Kg-1ms2] | Isothermal compressibility [Kg-1ms2] |
|---|---|---|---|---|
| 0 | 1085.8 | 774 | 1.09587 Χ 10-9 | 1.64381 Χ 10-9 |
| 0.002 | 1137.667 | 754 | 1.0247 Χ 10-9 | 1.53706 Χ 10-9 |
| 0.004 | 1113.111 | 760.3369 | 1.06149 Χ 10-9 | 1.59224 Χ 10-9 |
| 0.006 | 1090.693 | 761 | 1.14438 Χ 10-9 | 1.71657 Χ 10-9 |
| 0.008 | 1114 | 762.892 | 1.05625 Χ 10-9 | 1.58437 Χ 10-9 |
| 0.01 | 1080.556 | 763.5114 | 1.12173 Χ 10-9 | 1.6826 Χ 10-9 |
Table 4. Measured Value of Free volume, Free length, Acoustic Impedance and Relaxation time at 30°C
| Concentration wt% X |
Free volume [cm3/mol] | Free length [A°] | Acoustic Impedance [Kg.m-2s-1] |
Relaxation Time [sec] |
|---|---|---|---|---|
| 0 | 6.18185 Χ 10-8 | 6.60424 Χ 10-11 | 840409.2 | 7.60 Χ 10-12 |
| 0.002 | 5.00972 Χ 10-5 | 6.38619 Χ 10-11 | 857800.918 | 8.95521 Χ 10-12 |
| 0.004 | 4.30002 Χ 10-5 | 6.49982 Χ 10-11 | 846339.3646 | 9.66386 Χ 10-12 |
| 0.006 | 4.06899 Χ 10-5 | 6.74882 Χ 10-11 | 801175.7105 | 1.06217 Χ 10-11 |
| 0.008 | 4.51594 Χ 10-5 | 6.48375 Χ 10-11 | 849861.6896 | 9.36776 Χ 10-12 |
| 0.01 | 5.08142 Χ 10-5 | 6.68171 Χ 10-11 | 825016.8464 | 8.9453 Χ 10-12 |
Table 5.Measured Value of Ultrasonic Velocity, Density, Adiabatic compressibility and Isothermal compressibility at 35°C
| Concentration wt% X |
Ultrasonic Velocity [ m/sec] |
Density [Kg/m3] |
Adiabatic compressibility [Kg-1ms2] |
Isothermal compressibility [Kg-1ms2] |
|---|---|---|---|---|
| 0 | 1070.1 | 770 | 1.13412 Χ 10-9 | 1.70119 Χ 10-9 |
| 0.002 | 1122.333 | 750 | 1.05851 Χ 10-9 | 1.58777 Χ 10-9 |
| 0.004 | 1102.632 | 755.6488 | 1.08848 Χ 10-9 | 1.63271 Χ 10-9 |
| 0.006 | 1074.444 | 756 | 1.18091 Χ 10-9 | 1.77137 Χ 10-9 |
| 0.008 | 1105 | 757.6592 | 1.08094 Χ 10-9 | 1.62141 Χ 10-9 |
| 0.01 | 1071.778 | 758.3551 | 1.14794 Χ 10-9 | 1.7219 Χ 10-9 |
Table 6.Measured Value of Free volume, Free length, Acoustic Impedance and Relaxation time at 35°C
| Concentration wt% X |
Free volume [cm3/mol] | Free length [A°] |
Acoustic Impedance [Kg.m-2s-1] | Relaxation Time [sec] |
|---|---|---|---|---|
| 0 | 6.71477 Χ 10-8 | 6.71851 Χ 10-11 | 823977 | 7.33 Χ 10-12 |
| 0.002 | 5.37138 Χ 10-5 | 6.49069 Χ 10-11 | 841749.75 | 8.3911 Χ 10-12 |
| 0.004 | 4.98967 Χ 10-5 | 6.58192 Χ 10-11 | 833202.5199 | 8.88949 Χ 10-12 |
| 0.006 | 4.75045 Χ 10-5 | 6.8557 Χ 10-11 | 788130.1247 | 9.73852 Χ 10-12 |
| 0.008 | 5.19951 Χ 10-5 | 6.55909 Χ 10-11 | 837213.4146 | 8.65641 Χ 10-12 |
| 0.01 | 5.89141 Χ 10-5 | 6.7593 Χ 10-11 | 812788.3282 | 8.2273 Χ 10-12 |
Table 7.Measured Value of Ultrasonic Velocity, Density, Adiabatic compressibility and Isothermal compressibility at 40°C
| Concentration wt% X |
Ultrasonic Velocity [ m/sec] |
Density [Kg/m3] |
Adiabatic compressibility [Kg-1ms2] |
Isothermal compressibility [Kg-1ms2] |
|---|---|---|---|---|
| 0 | 1054.4 | 764 | 1.17732 Χ 10-9 | 1.76599 Χ 10-9 |
| 0.002 | 1080.667 | 747.6 | 1.14537 Χ 10-9 | 1.71806 Χ 10-9 |
| 0.004 | 1060.276 | 752 | 1.18289 Χ 10-9 | 1.77433 Χ 10-9 |
| 0.006 | 1058.22 | 753.5506 | 1.21872 Χ 10-9 | 1.82809 Χ 10-9 |
| 0.008 | 1076 | 752.9708 | 1.14709 Χ 10-9 | 1.72063 Χ 10-9 |
| 0.01 | 1067.719 | 753.8598 | 1.16358 Χ 10-9 | 1.74537 Χ 10-9 |
Table 8.Measured Value of Free volume, Free length, Acoustic Impedance and Relaxation time at 40 C
| Concentration wt% X |
Free volume [cm3/mol] | Free length [A°] |
Acoustic Impedance [Kg.m-2s-1] |
Relaxation Time [sec] |
|---|---|---|---|---|
| 0 | 7.19695 Χ 10-8 | 6.84527 Χ 10-11 | 805561.6 | 7.16 Χ 10-12 |
| 0.002 | 5.90989 Χ 10-5 | 6.75175 Χ 10-11 | 807906.6494 | 8.1911 Χ 10-12 |
| 0.004 | 5.17611 Χ 10-5 | 6.86144 Χ 10-11 | 797327.5521 | 8.65036 Χ 10-12 |
| 0.006 | 5.34596 Χ 10-5 | 6.96459 Χ 10-11 | 775386.8738 | 9.1491 Χ 10-12 |
| 0.008 | 5.53573 Χ 10-5 | 6.75681 Χ 10-11 | 810196.5772 | 8.48401 Χ 10-12 |
| 0.01 | 6.47293 Χ 10-5 | 6.8052 Χ 10-11 | 804910.4616 | 7.80248 Χ 10-12 |
The ultrasound wave velocity is a significant source of information on the physical and chemical properties of fluids and suspensions. The results of temperature/concentration dependence of the ultrasonic velocity in the nano CaF2 suspension are presented in figure 3. It shows the variations of ultrasonic velocity with an increase in the concentration of calcium fluoride nanoparticles in methanol at a temperature varied from 25°C to 40°C.
Figure 3: Variation of ultrasonic velocity with a concentration of CaF2 in methanol
The variation in ultrasonic propagation shows analogous behavior with an increase in the concentration of calcium fluoride nanoparticles in methanol. The variation in ultrasonic velocity initially increases, exhibiting a pick at a molar concentration of 0.002 and 0.008 indicates a strong interaction between the constituents, and a dip at 0.006 molar concentrations shows the weak interactions between the constituents in methanol-based CaF2 nanosuspension. Also with an increase in temperature, ultrasonic velocity decreases, this ultrasonic absorption is due to nanoparticles and thermo-elastic loss arises due to the Brownian motion of nanoparticles at the nanoscale level is a key mechanism governing the thermal behavior of nanoparticles colloidal-fluid suspension (nanofluids) [9]. As CaF2 is ionic bonded compound, when ionic bonded calcium fluoride nanoparticles is dispersed in methanol, Ca++ ions interact with the polar methanol through ion-dipole interaction and the strength of ion-dipole interaction is more as compared to dipole-induced dipole interaction. Also with increase in temperature, thermo-elastic loss arises due thermal agitation and hence ultrasonic velocity decreases Figure 4 shows the variation of density with a molar concentration of CaF2 nanoparticles in methanol. The density of nano CaF2 suspension increases with an increase in molar concentration of CaF2 nanoparticles in methanol. This indicates the close packing between the constituents in the nanomaterial suspension.
Figure 4: Variation of density with a concentration of CaF2 in methanol
The adiabatic compressibility of a liquid is a thermodynamic parameter of fundamental significance. It enables direct access to the liquid structure in terms of the particle packing density and the inter-particle forces. According to the well-known Newton–Laplace equation β=(1/[pv]^2 ). T. The adiabatic compressibility of a fluid is related to its density ρ and sound velocity v. Hence, ultrasound velocity measurements offer a favorable method to determine the compressibility.
T he adiabatic compressibility shows the reverse trends as that of ultrasonic velocity which is theoretically accepted as shown in figure 5. It is observed that as the molar concentration of calcium fluoride nanopowder in methanol increases, adiabatic compressibility decreases initially and it shows a dip at molar concentrations 0.002 and 0.008. This indicates the strong particle-fluids interaction between the constituents of nanosuspension. It is termed as association in the constituents of nanosuspension. There is a peak at a molar concentration of 0.006; this indicates the weak partile-fluids interaction. It is termed as dissociation in the constituents of nanosuspension as shown in Figure 6.
Figure 5: Variation of adiabatic compressibility with a concentration of CaF2 in methanol
Figure 6: Variation of isothermal compressibility with concentration of CaF2 in methanol
Figure 7 shows the variation of free volume with a molar concentration of CaF2 nanoparticles in methanol. It indicates the closed packing of constituents of the CaF2 nanoparticle suspension. An increase in free volume shows the increase in the magnitude of interaction. Figure 8 shows the variation of free length with a molar concentration of CaF2 nanoparticles in methanol. As the molar concentration of CaF2 in methanol increases, free length decreases and it shows deep at a molar concentration of 0.002 and 0.008. This indicates association and strong interaction between solute and solvent. At a molar concentration of 0.006, it shows the peak. This indicates molecular dissociation and weak interaction between solute and solvent.
Figure 7: Variation of free volume with concentration of CaF2 in methanol
Figure 8: Variation of free length with concentration of CaF2 in methanol
Figure 9 shows the variation of acoustic impedance with an increase in CaF2 nanoparticles in methanol. It shows similar trends as that of ultrasonic velocity. It is in good agreement with the theoretical requirements. An increase in acoustic impedance shows the association of nanoparticles and a decrease in acoustic impedance shows the dissociation of nanoparticles in nanosuspension.
Figure 9: Variation of acoustic impedance with concentration of CaF2 in methanol
Figure 10 shows the variation of relaxation time with molar concentration. An increase in relaxation time with an increase in molar concentration of CaF2 nanoparticles in methanol indicates the stability of CaF2 nanoparticles in methanol.
Figure 10: Variation of relaxation time with concentration of CaF2 in methanol
In this study methanol-based, nanosuspension with CaF2 nanoparticles is prepared by chemical route. The particle size, ultrasonic velocity, density, adiabatic compressibility, isothermal compressibility, free volume, free length, acoustic impedance, and relaxation time of methanol-based nano suspension are measured. The ultrasonic velocity increases with an increase in the concentration of nanoparticles and the enhancement are observed to be 1141.654 m/s and 1100 m/s for the concentration of 0.002 wt/vol% and 0.008 wt/ vol% of CaF2 methanol-based nano suspension respectively. It is due to the association of CaF2 nanoparticles in methanol-based nano suspension indicating a strong interaction between the constituents. It is observed that ultrasonic velocity decreases with an increase in temperature, this is due to the Brownian motion of nanoparticles in methanol-based nanosuspension and thermal agitation.
The author are grateful to Professor O. P. Chimankar, Head, Acoustical Researh Lab, RTM Nagpur University, Nagpur and Dr. S. A. Shah, Head, Department of Chemistry, Anand Niketan College for valuable help and fruitful discussions.
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