This communication presents two dual-polarized microstrip patch antenna systems based on a single radiating element with 180° ring hybrid coupler for differential feeding to achieve high interport RF ...isolation. One of the implemented single-layer patch antennas provides more than 67 dB isolation between transmit (Tx) and receive (Rx) ports at 2.4 GHz while the second fabricated antenna with slot coupled Tx port along with differential feeding for Rx operation provides more than 90 dB RF isolation at 2.41 GHz between dc isolated Tx-Rx ports. Moreover, the single-layer antenna provides better than 62 dB interport isolation for 10 dB-return loss impedance bandwidth (BW) of 50 MHz. Measured interport isolation for implemented antenna with slot coupled Tx port achieves around 70 and 79 dB port to port RF isolation for 50 and 20 MHz BWs, respectively, and these are the highest amounts of isolation for a single antenna to best of our knowledge. The antenna with slot coupled Tx port provides more interport RF isolation as compared to single-layer antenna due to low coupling between slot coupled and co-planar quarter-wave microstrip fed ports. Both antenna structures have the capability to remove in-band nonlinear self-interference (SI) components without complex SI cancellation circuits.
This letter presents a 2.4 GHz, dual-polarized microstrip patch antenna with extremely high interport isolation for a shared antenna architecture-based in-band full-duplex transceiver. The presented ...antenna configuration is based on four-ports linearly polarized single radiating element with differential feeding for both transmit <inline-formula> <tex-math notation="LaTeX">(T_{x})</tex-math></inline-formula> and receive <inline-formula><tex-math notation="LaTeX"> (R_{x})</tex-math></inline-formula> operation. The double-differential feeding using two identical 3 dB/180° ring hybrid couplers with nice amplitude and phase balance effectively suppresses the interport RF leakage to achieve very high isolation. The prototype of the proposed antenna architecture is implemented using a 1.6 mm thick general-purpose FR-4 substrate. The implemented antenna provides more than 90 and 80 dB interport RF isolation for 20 and 40 MHz bandwidths, respectively, in addition to more than 98 dB port-to-port peak isolation when measured inside an anechoic chamber. To the best of our knowledge, this is the highest amount of RF isolation reported for a single dual-polarized patch antenna.
This work presents a dual-polarized, proximity-fed bistatic antenna system with comparatively wideband self-interference cancellation (SIC) performance for 2.4 GHz single-channel full-duplex (SCFD) ...or in-band full-duplex (IBFD) wireless applications. The presented antenna system is comprised of two closely spaced (spatial separation of <inline-formula> <tex-math notation="LaTeX">\lambda _{\mathrm {o}} </tex-math></inline-formula>/4) proximity-fed patches with dual-polarized characteristics for transmit (T x ) and receive (R x ) modes. The proximity feeding offers comparatively wider impedance bandwidths (BWs) for both T x and R x ports. The T x mode is excited through a single-port proximity-fed square patch, whereas the R x mode operation is realized through a differentially driven proximity-fed dual-port patch. The compact structure for the presented antenna is realized through the vias interconnection of R x ports of patch and differential feeding circuit. The implemented antenna prototype characterizes better than 87 dB peak interport decoupling, and the experimental results demonstrate higher than 80 dB interport isolation over the entire 10 dB return-loss impedance BW of 120 MHz for the presented antenna. Furthermore, the recorded results provide better than 6 dBi gains with higher than 75% peak radiation efficiencies for both T x and R x modes. In addition, the measured cross-polarization levels are more than 30 and 42 dB below the respective T x and R x co-polarization levels. The contributions of this work are the demonstration of a compact, dual-port antenna with comparatively wider impedance and isolation BWs along with low cross-polarization characteristics for both modes without compromising the radiation performance and electrical size of the proximity-fed printed patch antenna.
Pectinases, member of the hydrolases family of enzymes, are one of the important enzymes of the biotechnological sector with 25% share in the global food and beverage enzyme market. They hold a ...leading position among the commercially produced industrial enzymes. These enzymes are sustainable and environmentally-friendly tool of nature with wide application perspective in many industrial processes, such as, retting and degumming of plant fibers, fermentation of tea and coffee, oil extraction, clarification of fruit juices and wine, valorization of industrial wastes, debasement of cellulosic biomass for biofuel production, wastewater remediation, desizing, scouring and bleaching of fabric, animal feed production, and protoplast fusion technology etc. However, like many other industrial enzymes, pectinases also face the constraint of low yield and productivity in its economized production. Therefore, pectinases have been the target of studies aiming to achieve the expression levels on a commercial scale. Among the natural sources of pectinases, microbial pectinases are employed frequently owing to its ease of production and unique physicochemical properties. This review mainly focuses on the production of pectinase enzymes along with different types of recent strategies used for their production optimization to get overexpression/production. The promise of genetic engineering approaches applied so far to get the higher production of these enzymes using simpler molecular devices and simple fermentation media is also covered in this review.
The wastewater utilization for irrigation purposes is common practice in peri-urban areas located in vicinity of developed cities. This water contains elements like chromium (Cr), nickel (Ni), ...cadmium (Cd) and nitrate (NO3-N) that poses health risk when exposed to human. In this study effect of wastewater irrigation from Chakara wastewater plant, Faisalabad on growth of wheat and health risks was assessed. Pot experiment was conducted at Institute of Soil and Environmental, University of Agriculture, Faisalabad using different concentration of wastewater as treatment 100% tap water, 25% wastewater + 75% tap water, 50% wastewater + 50% tap water, 75% wastewater + 25% tap water, 100% wastewater. The results indicated that the wastewater irrigation negatively effects the plant growth and physiological parameters. The minimum plant height, grain weight, spike length, osmotic potential and SPAD values were recorded 50.33 cm, 1.47 g plant−1, 7.00 cm, 423 and 38.91 respectively in 100% wastewater irrigation. The risk quotient (RQ TEs) for each toxic element and cumulative risk index (RI TEs) values were calculated. The cadmium risk quotient (Cd RQ) for adults was on margin and value was >1 for in 75% wastewater + 25% tap water and 100% wastewater irrigation, while the RQ for Ni and Cr was <1. Maximum RI TEs values calculated in 100% wastewater irrigation 0.424 and 0.294 for children and adults respectively. Hence it was concluded that wastewater irrigation significantly increased the accumulation rate of metals and nitrate in wheat and cause potential health risks for children and adults.
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•Impacts of wastewater irrigation on wheat growth and grain yield.•Sustainable utilization of wastewater for crop growing using dilution technique.•Accumulation of Cd, Cr, Ni, NO3-N significantly elevated by increasing concentration of wastewater.•Health risks evaluated due to the consumption of wastewater contaminated wheat.•Risk quotient value of Cd for children calculated was >1 when wastewater concentration was >50% in irrigation water.
In view of promising adsorption efficiency of biocomposites, the removal of imidacloprid was studied using biocomposites of polypyrole (PPY), polyaniline (PAN) and sodium alginate (Na-Alginate) with ...peanut husk (PH). The affecting variables such as pH, insecticide concentration, composite dose, contact time, temperature were optimized for efficient removal of imidacloprid. The biocomposites showed promising efficiency for the removal of imidacloprid. Among all composites polypyrole composite exhibited maximum efficiency at pH 3, 0.05 g adsorbent dose, 90 min contact time, 25 mg/L initial concentration at 35 °C. Langmuir, Freundlich, Harkins-Jura and Temkin isotherms models were applied on the experimental data. The best fitted were Langmuir and Freundlich isotherms with R2 value > 0.904 and >0.97, respectively. Insecticide adsorption followed the pseudo first order kinetics model. Thermodynamics (free energy, enthalpy and entropy) study revealed that the insecticide adsorption process on to biocomposites was spontaneous and exothermic in nature. This study revealed that the polypyrole, polyaniline and sodium alginate composites with peanut husk have promising adsorption potential and this class of adsorbent could be used for the remediation of wastewater contains imidacloprid insecticide.
The effect of solvent polarity on extraction yield and antioxidant properties of phytochemical compounds in bean seeds was studied. Seed flour of three varieties of bean was extracted in a series of ...organic solvents with increasing polarity (n-hexane, petroleum ether, chloroform, ethyl acetate, ethanol, acetone and water). Preliminary screening of phytochemicals showed the presence of tannins, flavonoids, cardiac glycosides, anthocyanins, terpenoids, carotenoids, ascorbic acid and reducing compounds in all extracts. One way analysis of variance (ANOVA) of results showed that extraction yield, phytochemical content and antioxidant properties were significantly influenced (p<0.05) by the polarity of extracting solvents. The regression analysis of data showed polarity-dependent second order polynomial variations in the extraction yield, phytochemical contents, antioxidant activity, reducing properties and free radical scavenging activity of each variety. Extraction in highly polar solvents resulted in high extract yield but low phenolic and flavonoid content as compared to non-polar ones. The polarity-dependent increase in total antioxidant activity and reducing properties indicates the extraction of strong antioxidant compounds in polar solvents. The study suggests the use of a combination of polar and nonpolar solvents to increase the extraction efficiency of phytochemicals with good antioxidant quality from the bean and other legume seeds.
This paper presents a novel low-complexity full-duplex radio design, which only uses a single patch antenna without any duplexer or circulator for passive suppression of self-interference, and a ...computationally efficient technique for linear digital cancellation. The proposed full-duplex design is tested for IEEE 802.11g Wireless Standard on the WARP (v3) software-defined radio implementation platform. It is shown that this design provides a total suppression of 88 dB, which is sufficient for low-power or short-range full-duplex communication. The dual polarized slot coupled patch antenna used in our design provides an interport isolation as high as 60 dB in 2.4 GHz band. Additionally, the digital domain cancellation utilizes a frequency domain-based estimation and reconstruction approach, which not only offers up to <inline-formula><tex-math notation="LaTeX">61\%</tex-math></inline-formula> reduction in the computational complexity but also provides a <inline-formula><tex-math notation="LaTeX">5-7 </tex-math></inline-formula> dB better digital cancellation performance in highly selective channel conditions, as compared to the time-domain-based techniques. The proposed full-duplex implementation can be easily applied in OFDM-based wireless systems, such as IEEE 802.11, which is the considered air interface in this paper.
Lipase-mediated polymer degradation is a robust alternative approach to conventional methods due to biocompatibility and mild conditions. In the present study, response surface methodology was ...applied to improve the production of lipase from
Penicillium fellutanum
by optimization of various process parameters. Under the optimized bioprocess conditions of pH 5.0, incubation time 24 h, temperature 35 °C, and lactose as an additional carbon source in 40 experimental runs, the maximum lipase titer of 1038.86 U/gds was achieved, 2.05-fold higher than the lipase yield in basal medium. All the linear and interactive coefficients (except linear carbon source) were found significant by analysis of variance. The as-synthesized cell-free lipase extract was partially purified by ammonium sulfate fractionation and dialysis (2.06-folds, 272.37 U/mg proteins) and applied to the degradation of polyester vylon 200. The biocatalytic action of the enzyme results in an 81% weight loss of PV-200 after 7 days of incubation at pH 7.5 and 35 °C. Different characterization techniques, i.e., SEM, FT-IR, and DSC corroborated the lipase-catalyzed degradation of PV-200. The untreated polyester film had a smooth surface, while after enzymatic treatment, deformities and various micron-sized holes and cracks appeared on the film surface. In conclusion, the outcomes of study display a high potential of lipase as green and ecofriendly biocatalyst for efficient degradation and depolymerization of polyester for environmental safety.
Graphic Abstract
•Surface-enhanced Raman spectroscopy (SERS) employed to characterize the serum samples of oral cancer patients.•SERS spectral features associated with oral cancer employed for diagnostic purpose as ...biomarkers.•The differences of biochemical components between eight subsites of oral cavity cancer are analyzed.•Principal components analysis is helpful for the differentiation between oral cancer and healthy samples.•Partial least square discriminant analysis shows differenetiaiton between cancer and healthy samples with 95% accuracy.
Background The prognosis for oral cancer patients is still very poor worldwide. Early detection and treatment therapy remain the key issue to be addressed for improved patient survival. The characteristic Raman spectral features associated with the biochemical changes in the blood serum samples can be used for the diagnosis of diseases, particularly for oral cancer. Surface-enhanced Raman spectroscopy (SERS) is a promising technique for non-invasive and early detection of oral cancer by analyzing molecular changes in body fluids.
Objectives To detect oral cavity anatomical subsites (buccal mucosa, cheek, hard palate, lips, mandible, maxilla, tongue and tonsillar region) cancers by using blood serum samples, SERS with principal component analysis is used.
Material and Method SERS is employed with silver nanoparticles for the analysis and detection of oral cancer serum samples by comparing with healthy serum samples. SERS spectra are recorded by Raman instrument and preprocessed using the statistical tool. Principal component analysis (PCA) and Partial least square discriminant analysis (PLS-DA) are used to discriminate between oral cancer serum samples and control serum samples.
Results Some major SERS peaks are observed at 1136 cm−1 (Phospholipids) and 1006 cm−1 (Phenylalanine) remain higher in intensities for oral cancer spectra as compared to healthy spectra. The peak at 1241 cm−1 (amide III) is observed only in oral cancer serum samples while absent in healthy serum samples. Higher protein and DNA contents were detected in SERS mean spectra of oral cancer. Moreover, PCA is used to identify the biochemical differences in the form of SERS features which is used to differentiate between oral cancer and healthy blood serum samples, while PLS-DA is used to build differentiation model of oral cancer serum samples and healthy control serum samples. PLS-DA provides successful differentiation with 94% specificity and 95.5% sensitivity.
Conclusions SERS can be used for the diagnosis of oral cancer and to identify metabolic changes that occur during disease development.
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