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Metallogel formation by an individual ligand is well known, but simultaneous need of two ligands in selective metallogelation is relatively less common. In our present study, we have shown that disodium succinate and hexamethylenetetramine, when allowed to react simultaneously with CuCl 2 in an aqueous medium, instantaneously form a greenish metallogel. The gelation is not attainable in the absence of any of the two ligands, which ascertains the cooperativity of the ligands to successfully achieve the metallogelation. Different microanalytical studies [Fourier transform infrared (FTIR), powder X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, rheology, and so on] have been performed for complete characterizations of the gel sample. The gel shows a nanodimensional entangled network morphology. Metal−ligand coordination in association with solventmediated hydrogen bonding interactions becomes a part-and-parcel in making the nanoscale fibrillar network of the metallogel. Different related ligands and metal ions were also reviewed in lieu of the above two ligands and the Cu(II) ion, but none of the alternatives was able to result in the gel formation. Thus, both the ligands were highly specific for the said metallogelation with Cu(II) only. The effect of counter anions of the Cu(II) salt was also studied. The gel also exhibits its stimuli-responsive nature toward different interfering chemical parameters such as pH, selective anions, selective complexing agents, and so forth. Finally, the robust Cu(II) metallogel was deliberately exploited as a heterogeneous catalyst for successful oxidative conversion of 2-aminophenol (OAPH) to phenoxazinone hiring atmospheric oxygen and thereby conferring its role as a biomimetic nanozyme catalyst. The catalytic conversion has been followed spectrophotometrically. The detailed kinetics for the reaction was performed with varied reaction parameters. The Michaelis−Menten model was applied to analyze the results. Based on the experimental results (e.g., FTIR, XRD, thermogravimetric analysis, and electrospray ionization−mass spectrometry), a mechanistic approach has also been anticipated to establish the catalytic process. Finally, recyclability of the catalyst was also verified. This nanozymatic phenoxazinone synthase-like activity of a nanodimensional metallogel is hitherto unknown and thus suggests its enzyme mimicking feature.

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dimensions: length L ¼ 35.9 mm, width W ¼ 32 mm. Inserted microstrip feed line section provides 50 X input element impedance. Two-bit phase shifters are implemented on the base of switched-line concept, which uses electronically controlled switches and lines of different lengths to obtain a set of phase steps. Outputs of the antenna array elements are connected with 50 X inputs of feed line that has 50 X output impedance and combines all signals into one output. AOA measurement setup is shown in Figure 8b. Linear array mounted on turn table can change azimuth position relative to RF incoming source angle.Photograph of the fabricated array prototype is shown in Figure 8c. Designed array is fabricated on an h ¼ 1.6 mm FR-4 substrate with an element separation equal 7.5 cm which is 0.5 of the free space wave length. Switch system consists of commercially available SPDT switches RF2436 from RF Micro Devices. Array is built according to the block diagram shown in Figure 8a. Integrated amplifier ERA-6 (measured gain is about 9 dB) is used for amplification in reference channel. Power supplier and control circuits are placed on the back side of the FR-4 board.Two series of experiments were conducted with four antenna array elements: first one refers to the RF wave coming from the angle h ¼ 20 to the array normal and the other one-to h ¼ 40 . Tables 2 and 3 show power measurements results P k (h,r) (dB scale normalized to the value P k (h,0)) due to the differential phase shifts 0 (r ¼ 0), 90 (r ¼ 1), 180 (r ¼ 2), and 270 (r ¼ 3) realized by k-th element phase shifter.Using power measurement results and formulas (1)-(4) we estimated arrival angle h est : h est (h ¼ 20 ) ¼ 22 and h est (h ¼ 40 ) ¼ 34 . Simulations based on an amplifier gain equal 10 dB in reference channel show h est0 (h ¼ 20 ) ¼ 21 and h est0 (h ¼ 40 ) ¼ 36 . We see good agreement between measurements and simulation. The error 4 between simulation and original AOA for original arrival angle equal 40 can be reduced up to 1 by increasing the amplifier gain to the value 20 dB. Table 4 demonstrates the effect of instrumental errors in power measurements. We used power measurement data from Table 3, added random errors (imitating measurement errors) and performed AOA algorithm. Table 4 shows 10 AOA estimations for uniformly randomly distributed instrumental errors: column 1 corresponds to the interval 60.5 dB; column 2 -to the interval 61 dB; and column 3-to the interval 62 dB.It is seen that random errors in power measurements 62 dB or less do not effect on AOA errors more than 10 . CONCLUSIONWe investigate car angle position system proposed for automotive applications particular for determination of the car location in large parking lot. Key of the system is small phased antenna array. Array consists of small number of elements with two-bit phase shifters and one reference element with an amplifier. Computer modeling is presented for four and eight array elements. Simulation results are shown as functions of the algorithm processing errors, phase shifters e...

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show the insertion loss of 2.42 and 1.99 dB at the center frequency of 2.43 and 5.70 GHz, respectively, and the bandwidth is slightly reduced.The tapped-line geometry is imported for the second transmission zeros by alternating the coupling section and the tapped-line structure in the suggested dualband BPF using dualmode resonator, as shown in Figure 6. The position of the tapped-line can be defined by the impedance, z R2 , and the value of the inverter. The electrical lengths of y t and y t 0 are calculated as 7 and 46 , respectively. Figure 6 shows the photograph for the fabricated dualband BPF using dual-mode resonator with the coupling and tapped-line geometry for the two transmission zeros and its size is 25.81 Â 28.59 mm 2 . The simulation and measurement results of the dualband BPF using dual-mode resonator are shown in Figure 7. The dualband BPF is simulated with the insertion losses of 1.75 and 1.40 dB at 2.43 and 5.68 GHz, respectively, and measured with the insertion loss of 1.92 and 1.71 dB at the center frequency of 2.42 and 5.65 GHz, respectively. Also, each passband of the suggested dualband BPF has two transmission zeros. CONCLUSIONIn this article, the value of the J-inverter for the dual-mode k g /2 BPF is investigated as functions of the impedance and the electrical length of the open-stub for the dual-mode k g /2 microstrip resonator. As impedance of the open-stub decreases, the dualmode k g /2 BPF has a good out-of-band performance and low value of the inverter. The dualband BPF using dual-mode resonator for 2.45 and 5.8 GHz is suggested by using the second spurious of the SIR structure that has the ratio of the impedance of 0.581. To demonstrate the dualband BPF using dual-mode resonator with two transmission zeros, the coupling structure and tapped-line geometry are used for the J-inverter. By the open-stub of the dual-mode k g /2 resonator, the bandwidth and the frequency of one transmission zero are defined, and the other transmission zero is defined by the open-stub of the tapped-line geometry as a function of the J-inverter. The dualband BPF using dual-mode resonator has been implemented and measured with good performance. These BPFs can be used in wireless communication system.