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The highly oriented 2D perovskite templates of n = 1 have typically been created to attain controllable and oriented crystallization of 3D α‐phase formamidinium lead triiodide (α‐FAPbI3) perovskites. However, the role of methylammonium iodide (MAI), a widely used α‐FAPbI3 phase stabilizer, in regulating the growth dynamics of 2D/3D perovskites is generally ignored. Herein, Ruddlesden–Popper type n = 1 2D octylammonium lead iodide (OA2PbI4) perovskites are added into FAPbI3 precursor solution. The template of n = 2 (OA2MAPb2I7), which is spontaneously constructed by the mixture of n = 1 2D and methylammonium chloride (MACl), acts as a skeleton to template the epitaxial growth of α‐FAPbI3. However, the volatilization of MACl inevitably causes damage to the 2D structure during thermal annealing. This study reveals that small amounts of less volatile MAI additive enables the creation of stable 2D template, leading to more controlled vertical orientation crystallization. Consequently, the high‐quality mixed‐dimensional perovskite film delivers a high efficiency of 24.19% together with improved intrinsic stability. This work provides an in‐depth understanding of 2D‐assisted controlled epitaxial growth of α‐FAPbI3. [ABSTRACT FROM AUTHOR]

Abstract The highly oriented 2D perovskite templates of n = 1 have typically been created to attain controllable and oriented crystallization of 3D α‐phase formamidinium lead triiodide (α‐FAPbI3) perovskites. However, the role of methylammonium iodide (MAI), a widely used α‐FAPbI3 phase stabilizer, in regulating the growth dynamics of 2D/3D perovskites is generally ignored. Herein, Ruddlesden–Popper type n = 1 2D octylammonium lead iodide (OA2PbI4) perovskites are added into FAPbI3 precursor solution. The template of n = 2 (OA2MAPb2I7), which is spontaneously constructed by the mixture of n = 1 2D and methylammonium chloride (MACl), acts as a skeleton to template the epitaxial growth of α‐FAPbI3. However, the volatilization of MACl inevitably causes damage to the 2D structure during thermal annealing. This study reveals that small amounts of less volatile MAI additive enables the creation of stable 2D template, leading to more controlled vertical orientation crystallization. Consequently, the high‐quality mixed‐dimensional perovskite film delivers a high efficiency of 24.19% together with improved intrinsic stability. This work provides an in‐depth understanding of 2D‐assisted controlled epitaxial growth of α‐FAPbI3.

The fast-growing tree, eastern cottonwood (Populus deltoides), currently is being planted to catalyze native forest restoration on degraded agricultural sites in the southeastern United States. Many of these restoration sites are appropriate for short rotation woody crop (SRWC) culture that addresses climate mitigation objectives, but information needed to optimize climate mitigation objectives through such plantings is limited. Therefore, we established a 10-year experiment on degraded agricultural land located in the Mississippi Alluvial Valley, USA, aiming to quantify the dynamics of aboveground carbon (AGC) accumulation in a cottonwood planting of four replicated spacing levels (3.7 × 3.7 m, 2.7 × 1.8 m, 2.1 × 0.8 m, and (0.8 + 1.8) × 0.8 m) aligned with SRWC systems targeting various ecosystem services. Annual sampling revealed a substantial range in increments of AGC and year 10 carbon stocks among stands of different densities. Mean annual increments for AGC (MAIAGC) were similar for the two tightest spacing levels, peaking higher than for the other two spacings at about 7.5 Mg ha−1 y−1 in year 7. Year 10 AGC ranged between 22.3 Mg ha−1 for stands spaced 3.7 × 3.7 m and 70.1 Mg ha−1 for stands of the two tightest spacings, leading us to conclude that a spacing between 2.1 × 0.8 m and 2.7 × 1.8 m would maximize aboveground carbon stocks through year 10 on sites of similar agricultural degradation. Increments and accumulation of AGC on the degraded site trended lower than values reported from more productive sites but illustrate that quick and substantial transformation of the carbon stock status of degraded agricultural sites can be achieved with the application of SRWCs to restore forests for climate mitigation and other compatible ecosystem services. [ABSTRACT FROM AUTHOR]

Urban green–blue space (UGBS) plays a crucial role in Chinese cities, occupying more than half of the built-up areas. Understanding the spatiotemporal dynamics and driving factors of UGBS in central Nanjing during rapid urbanization is important for studying UGBS evolution in high-density urban-area environments, providing a fundamental basis for related research and policy formulation. This study utilized remote sensing images to estimate the extent of UGBS from 2000 to 2020 and analyzed the evolution using the intensity of area change, a land transfer matrix, the multi-order adjacency index, and a boosted regression tree model. This study revealed the spatiotemporal dynamics and driving factors of UGBSs in central Nanjing from 2000 to 2020: (1) between 2000 and 2020, there was a 4.0% net increase in the total area of UGBSs in central Nanjing. (2) UGBS primarily showed marginal-type expansion, accompanied by proximity-type expansion. Spatially, new green–blue patches tended to cluster around large pre-existing natural green–blue patches. Furthermore, the expansion of UGBS shifted from the urban periphery to the urban interior. (3) Natural factors exerted a greater influence (88.3%) than socioeconomic factors (11.7%) on the expansion of UGBS. Average annual radiation (43.4%), elevation (16.5%), slope (15%), aspect (13.4%), and population density (2.8%) were the primary driving factors. Our results contribute to understanding changes in UGBS and the driving factors behind these changes, thereby providing support for the future planning, protection, and sustainable development of UGBS.

Interferometric Synthetic Aperture Radar (InSAR) remote sensing generally lacks deformation sensitivity in the along-track direction. In this proposed approach, across-track observations from conventional InSAR, using both ascending and descending passes, were superimposed with the along-track movement derived from multi-aperture InSAR (MAI) to determine the full three-dimensional (3-D) velocity of the Siachen Glacier in the Karakoram range of the Himalayas. The along-track velocity signal is essential for estimating the movement component in the north/south direction, which is needed for a complete delineation of 3-D deformation. The velocity observed was improved using the MAI technique in comparison to the conventional ascending/descending 3-D velocity estimation approach, and substantial differences were noticed between these two methods, particularly in the lower part of the glacier, which is moving almost in an along-track (north/south) direction. Glacier velocity varied from 0.3 md−1 in the accumulation zone to 0.60 md−1 in the terminus zone of the Siachen Glacier using this newly proposed approach. This study presents a 3-D velocity estimation without any preconceived assumptions regarding the flow conditions of glaciers and without any azimuth ambiguity. [ABSTRACT FROM AUTHOR]

In this paper, the performance efficiency of the free‐space optical (FSO) communication link has been enhanced using a new hybrid prime code (NHPC) and M‐ary digital pulse position modulation (M‐ary DPPM) technique. The passive optical network (PON) optical code division multiple access (OCDMA) technique based on the FSO link is proposed. The analysis and optimization of the bit error rate (BER) performance of the Gaussian approximation techniques are investigated in the existence of both an atmospheric turbulence (AT) channels and multiple access interference (MAI). Additionally, 76 NHPC orthogonal sequences have been transmitted at a data rate of 10 Gbps over a turbulent FSO channel. In the proposed design, the NHPC M‐ary DPPM modulation is used to provide extra bits of information to enhance the system performance. Also, the adaptive optics technique to mitigate the AT effect and improve the modulation efficiency is offered in this design. Further, the impact of the turbulence effect on the proposed system performance based on NHPC-M ary-DPPM modulation as a function of M‐ary DPPM parameters and other atmospheric parameters is investigated. The NHPC M‐ary DPPM provides an optical signal‐to‐noise ratio (OSNR) of about 2–4 dB for the strong turbulence at a target BER of 10−9. Additionally, the proposed system performance is compared with another system that uses the on–off keying-DPPM (OOK-M ary- DPPM). The numerical results indicate that the proposed design can be enhanced with the NHPC M-ary DPPM for FSO-OCDMA systems and the OSNR can be increased 14–18 dB at a BER of 10−9 in comparison to other approaches. The simulation results show that the proposed modulation technique can be used in the FSO-OCDMA systems, having a significant increase in their efficiency. Finally, the use of the NHPC M‐ary DPPM modulation schemes is a new technique that is used to reduce the AT, interchannel crosstalk and the MAI noise for the FSO-OCDMA systems. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to determine the level of development of metacognitive skills of undergraduate students in Colombia and to establish whether there are differences by institution of origin, or by gender or by semester. Method: A quantitative study and a non-probabilistic sampling was conducted. A total of 1.199 students from three universities participated, one public and distance modality; and the other two private and face-to-face modality. The Metacognitive Awareness Inventory (MAI) was used to determine metacognitive skills. Results: At a general level, Colombian university students present a high level of development of their metacognitive skills with an average of 3,86 on a 5-point scale. When analyzing the abilities of the students according to the university of origin, the Kruskal-Wallis test shows that there are significant differences (p<0,05) in favor of the students in the distance modality. The Mann-Whitney U test allowed us to conclude that there are no significant differences by gender, although women have higher means (M = 3,88) than men (M = 3,83). It was possible to establish through the Spearman correlation that there are significant and negative differences in the level of metacognitive skills according to the semester of the students, as their skills decrease as they progress. Conclusions: Although students have a good level of development of their metacognitive skills it is required to strengthen especially evaluation processes. Students trained in virtual distance learning methodology showed a higher degree of development of metacognitive skills than those in face-to-face mode, which could be explained by a greater development of self-regulation as an indicator of maturity for learning. [ABSTRACT FROM AUTHOR]

Copyright of RumeliDE Journal of Language & Literature Research / RumeliDE Dil ve Edebiyat Araştırmaları Dergisi is the property of RumeliDE Uluslararasi Hakemli Dil & Edebiyat Arastirmalari Dergisi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Mariculture is an important part of aquaculture, and it is important to address global food security and nutrition issues. However, seawater environmental conditions are complex and variable, which causes large uncertainties in the remote sensing spectral features. At the same time, mariculture types are distinct because of the different types of aquaculture (cage aquaculture and raft aquaculture). These factors bring great challenges for mariculture extraction and mapping using remote sensing. In order to solve these problems, an optical remote sensing aquaculture index named the marine aquaculture index (MAI) is proposed. Based on this spectral index, using time series Sentinel-1 and Sentinel-2 satellite data, a random forest classification scheme is proposed for mapping mariculture by combining spectral, textural, geometric, and synthetic aperture radar (SAR) backscattering. The results revealed that (1) MAI can emphasize the difference between mariculture and seawater; (2) the overall accuracy of mariculture in the Bohai Rim is 94.10%, and the kappa coefficient is 0.91; and (3) the area of cage aquaculture and raft aquaculture in the Bohai Rim is 16.89 km2 and 1206.71 km2, respectively. This study details an effective method for carrying out mariculture monitoring and ensuring the sustainable development of aquaculture. [ABSTRACT FROM AUTHOR]

The fast-growing tree, eastern cottonwood (Populus deltoides), currently is being planted to catalyze native forest restoration on degraded agricultural sites in the southeastern United States. Many of these restoration sites are appropriate for short rotation woody crop (SRWC) culture that addresses climate mitigation objectives, but information needed to optimize climate mitigation objectives through such plantings is limited. Therefore, we established a 10-year experiment on degraded agricultural land located in the Mississippi Alluvial Valley, USA, aiming to quantify the dynamics of aboveground carbon (AGC) accumulation in a cottonwood planting of four replicated spacing levels (3.7 × 3.7 m, 2.7 × 1.8 m, 2.1 × 0.8 m, and (0.8 + 1.8) × 0.8 m) aligned with SRWC systems targeting various ecosystem services. Annual sampling revealed a substantial range in increments of AGC and year 10 carbon stocks among stands of different densities. Mean annual increments for AGC (MAIAGC) were similar for the two tightest spacing levels, peaking higher than for the other two spacings at about 7.5 Mg ha−1 y−1 in year 7. Year 10 AGC ranged between 22.3 Mg ha−1 for stands spaced 3.7 × 3.7 m and 70.1 Mg ha−1 for stands of the two tightest spacings, leading us to conclude that a spacing between 2.1 × 0.8 m and 2.7 × 1.8 m would maximize aboveground carbon stocks through year 10 on sites of similar agricultural degradation. Increments and accumulation of AGC on the degraded site trended lower than values reported from more productive sites but illustrate that quick and substantial transformation of the carbon stock status of degraded agricultural sites can be achieved with the application of SRWCs to restore forests for climate mitigation and other compatible ecosystem services.

The characterization of prospective plants is one of the critical issues in the efficiency and success of the phytoremediation process. Due to adaption and tolerance to different environmental stresses, native plant species have priority in this method. This study examined fifty plants of five species, namely Launaea acanthodes, Artemisia sp., Cousinia congesta, Peganum harmala, and Stipa sp., growing near a smelter and refinery in Iran to identify potential species for phytoextraction and phytostabilization. Therefore, Pb, Ni, Mn, Mo, S, and Cu concentrations in sampled plants and soils were analyzed. Three different pollution indices, namely metal accumulation index (MAI), translocation factor (TF), and bioconcentration factor (BCF) were used for evaluating the metal concentrations in roots and shoots of each plant species. The results indicated that Artemisia sp., with values of 3.21, 1.09, and 1.14 for MAI, BCF, and TF, respectively, is appropriate for phytoextraction in the study area. Plants such as Launaea acanthodes and Cousinia congesta with high BCF and low TF values showed the potential for phytostabilization. Investigating the indices for different elements demonstrated that Launaea acanthodes had a BCF value greater than 1 and a TF value less than 1; therefore, this plant could be used in the phytoremediation of arsenic through the phytostabilization technique. Furthermore, copper has very low bioavailability in these plant species. In addition, these native plant species were highly capable of accumulating sulfur from the soil because the BCF and TF indices for all inspected species were higher than 1; for Launaea acanthodes, the relevant TF value was about 10. The proposed native plant could be applied in practical applications of phytoremediation for soil remediation of contaminated sites around the metal factories and mines in southeastern Iran. [ABSTRACT FROM AUTHOR]

Interferometric Synthetic Aperture Radar (InSAR) remote sensing generally lacks deformation sensitivity in the along-track direction. In this proposed approach, across-track observations from conventional InSAR, using both ascending and descending passes, were superimposed with the along-track movement derived from multi-aperture InSAR (MAI) to determine the full three-dimensional (3-D) velocity of the Siachen Glacier in the Karakoram range of the Himalayas. The along-track velocity signal is essential for estimating the movement component in the north/south direction, which is needed for a complete delineation of 3-D deformation. The velocity observed was improved using the MAI technique in comparison to the conventional ascending/descending 3-D velocity estimation approach, and substantial differences were noticed between these two methods, particularly in the lower part of the glacier, which is moving almost in an along-track (north/south) direction. Glacier velocity varied from 0.3 md−1 in the accumulation zone to 0.60 md−1 in the terminus zone of the Siachen Glacier using this newly proposed approach. This study presents a 3-D velocity estimation without any preconceived assumptions regarding the flow conditions of glaciers and without any azimuth ambiguity.

This paper presents a technique to mitigate multiple access interference (MAI) in multicarrier code division multiple access (MC-CDMA) wireless communications systems. Although under normal circumstances the MC-CDMA system can achieve high spectral efficiency and resistance towards inter symbol interference (ISI) however when exposed to substantial nonlinear distortion the issue of MAI manifests. Such distortion results when the power amplifiers are driven into saturation or when the transmit signal experiences extreme adverse channel conditions. The proposed technique uses a modified iterative block decision feedback equalizer (IB-DFE) that uses a minimal mean square error (MMSE) receiver in the feed-forward path to nullify the residual interference from the IB-DFE receiver. The received signal is re-filtered in an iterative process to significantly improve the MC-CDMA system’s performance. The effectiveness of the proposed modified IB-DFE technique in MC-CDMA systems has been analysed under various harsh nonlinear conditions, and the results of this analysis presented here confirm the effectiveness of the proposed technique to outperform conventional methodologies in terms of the bit error rate (BER) and lesser computational complexity.

The key technologies of 4G/LTE are OFDM and CDMA. Predefined precoding codebook defined by 3GPP for LTE is a promising technique with limited feedback from the receiver. Multipath problem and interference at the UE and eNB are the major problems of cellular communication. WHT, Kasami and gold sequences are CDMA code sets used to mitigate MAI and multipath problems. This paper combines mode 2Precoding transmission mode of LTE with CDMA code sets in frequency domain. WHT lowers interference in uplink transmission whereas Kasami and Gold sequences give good results in downlink transmission. In this paper BER of WHT, Kasami and Gold sequences with precoding are compared and graphs are plotted. [ABSTRACT FROM AUTHOR]

In wireless communication, obtaining high SNR at the transceiver is challenging work. The uplink and downlink transmission of cellular communication technologies are affected by self-interference (SI), Multiple Access interference and Inter Carrier Interference (ICI). Good Auto and cross correlation function make spread sequences of CDMA, suitable for reducing interference at eNB(Base station) and UE(User Equipment). In this paper, Kasami sequence is combined at the transmitter with TM2 transmission mode of LTE in frequency domain to mitigate MAI in Uplink transmission. BER and SNR plots for with and without Kasami sequence for TM2 mode and results are compared. Kasami sequence precoding is found to be good for reducing interference in Uplink transmission of MIMO-LTE. [ABSTRACT FROM AUTHOR]

The highly oriented 2D perovskite templates of n = 1 have typically been created to attain controllable and oriented crystallization of 3D α-phase formamidinium lead triiodide (α-FAPbI 3 ) perovskites. However, the role of methylammonium iodide (MAI), a widely used α-FAPbI 3 phase stabilizer, in regulating the growth dynamics of 2D/3D perovskites is generally ignored. Herein, Ruddlesden-Popper type n = 1 2D octylammonium lead iodide (OA 2 PbI 4 ) perovskites are added into FAPbI 3 precursor solution. The template of n = 2 (OA 2 MAPb 2 I 7 ), which is spontaneously constructed by the mixture of n = 1 2D and methylammonium chloride (MACl), acts as a skeleton to template the epitaxial growth of α-FAPbI 3 . However, the volatilization of MACl inevitably causes damage to the 2D structure during thermal annealing. This study reveals that small amounts of less volatile MAI additive enables the creation of stable 2D template, leading to more controlled vertical orientation crystallization. Consequently, the high-quality mixed-dimensional perovskite film delivers a high efficiency of 24.19% together with improved intrinsic stability. This work provides an in-depth understanding of 2D-assisted controlled epitaxial growth of α-FAPbI 3 ., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

Mariculture is an important part of aquaculture, and it is important to address global food security and nutrition issues. However, seawater environmental conditions are complex and variable, which causes large uncertainties in the remote sensing spectral features. At the same time, mariculture types are distinct because of the different types of aquaculture (cage aquaculture and raft aquaculture). These factors bring great challenges for mariculture extraction and mapping using remote sensing. In order to solve these problems, an optical remote sensing aquaculture index named the marine aquaculture index (MAI) is proposed. Based on this spectral index, using time series Sentinel-1 and Sentinel-2 satellite data, a random forest classification scheme is proposed for mapping mariculture by combining spectral, textural, geometric, and synthetic aperture radar (SAR) backscattering. The results revealed that (1) MAI can emphasize the difference between mariculture and seawater; (2) the overall accuracy of mariculture in the Bohai Rim is 94.10%, and the kappa coefficient is 0.91; and (3) the area of cage aquaculture and raft aquaculture in the Bohai Rim is 16.89 km2 and 1206.71 km2, respectively. This study details an effective method for carrying out mariculture monitoring and ensuring the sustainable development of aquaculture.

This study explores the influence of molar ratio of the synthetic solution of methylammonium iodide (MAI) and PbI2 on perovskite solar cells. The complete perovskite crystals must be produced in a low-humidity environment. The substrate is spin-coated in the adjusted MAPbI3 synthesis solution and annealed by using a nitrogen furnace tube to form perovskite crystals. During the crystallization of MAPbI3, some of the PbI2 remains, which improves the efficiency of the perovskite solar cell. Therefore, we adjust the molar concentration of MAI to find the appropriate amount of the PbI2 residual. We fix the MAI molar concentration at 1 M and adjust the PbI2 molar concentration from 0.8 M to 1.4 M. The molar ratios of MAI and PbI2 are, then, 1:0.8, 1:1, 1:1.2, and 1:1.4, respectively. Then, we use UV–vis, FE-SEM, and photoelectric conversion efficiency (PCE) measurements for comparing the growth of perovskite crystals and their photoelectric characteristics. The results show that 1.2 M of PbI2 is the most appropriate concentration for perovskite solar cells among the adjusted concentrations. [ABSTRACT FROM AUTHOR]

This is a Unicode proposal for one character, KAITHI NUMBER SIGN ABOVE. The character was published in Unicode 11.0 in 2018. Kaithi is an historical script of northern India, used from the 16c until the 20th century.

This is a proposal to add one Kaithi characters to the international character encoding standard Unicode. The character was published in Unicode Standard version 11.0 in June 2018.

The field of optics is flourishing day by day due to the wide usage of the Internet and its associated technologies. Free Space Optics (FSO) is a data transmission technique that employs light propagation to send data. This technology is effective in circumstances where fiber optic cables cannot be deployed. This paper provides a model and simulation of the Fiber Bragg Grating (FBG) based FSO network under different conditions, such as modulation types and data rates. The paper also investigates the impact of Multiple Access Interference (MAI) on FSO under design parameters. The designed system performance is analyzed under the multiuser optical wireless network by changing data rates and modulation types. The proposed model's security is achieved through the use of the FBG encoder/decoder and the FSO channel for transmission. It has been inferred that the CRZ modulation type provides the best BER and Q factor compared to other formats. A data rate as high as 1Gbps can be achieved using the CRZ modulation format. It has been noticed that as the number of users grows, the BER value begins to deteriorate. [ABSTRACT FROM AUTHOR]

This study presents the design analysis and correlation properties of a new spreading code for the incoherent synchronous pulse position modulation‐optical code division multiple access (PPM‐OCDMA) networks. The proposed code called optimised modified prime code (OMPC), which refers to the modified prime codes (MPCs) family. Additionally, this new code designed at a higher code length, optimised code weight and good correlation characteristics to enhance communication security and improve the bit error rate (BER) performance. In this study, the proposed code is used as source code for different kinds of multimedia services such as data, voice, and video. Furthermore, the characteristics and correlation properties of the OMPC in comparison with the other MPCs families that utilised in the PPM‐OCDMA networks are presented. Moreover, for the PPM‐OCDMA networks, the effect of OMPC auto‐ and cross‐correlation properties on the multiple access interference (MAI) was investigated. Consequently, the MAI is considered in the BER analysis and calculations. Finally, the results show that the proposed OMPC is better than the other existing codes with respect to the channel capacity and system performance. [ABSTRACT FROM AUTHOR]

X-linked inhibitor of apoptosis (XIAP) deficiency is a rare primary immunodeficiency with a broad spectrum of clinical manifestations, including susceptibility to hemophagocytic lymphohistiocytosis (HLH), inflammatory bowel disease (IBD), hypogammaglobulinemia, and severe infections. We present a case of a 39-year-old male with a past medical history of XIAP deficiency complicated by HLH, Crohn's disease, and hypogammaglobulinemia, who developed acute respiratory distress syndrome (ARDS) due to Pneumocystis jiroveci pneumonia (PJP) and concurrent multiorgan failure due to disseminated Mycobacterium avium intracellulare (MAI) infection. This case highlights the challenges in managing XIAP deficiency, emphasizing the importance of early recognition, and the need for further research to improve outcomes in this population., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2024, Kim et al.)

The characterization of prospective plants is one of the critical issues in the efficiency and success of the phytoremediation process. Due to adaption and tolerance to different environmental stresses, native plant species have priority in this method. This study examined fifty plants of five species, namely Launaea acanthodes, Artemisia sp., Cousinia congesta, Peganum harmala, and Stipa sp., growing near a smelter and refinery in Iran to identify potential species for phytoextraction and phytostabilization. Therefore, Pb, Ni, Mn, Mo, S, and Cu concentrations in sampled plants and soils were analyzed. Three different pollution indices, namely metal accumulation index (MAI), translocation factor (TF), and bioconcentration factor (BCF) were used for evaluating the metal concentrations in roots and shoots of each plant species. The results indicated that Artemisia sp., with values of 3.21, 1.09, and 1.14 for MAI, BCF, and TF, respectively, is appropriate for phytoextraction in the study area. Plants such as Launaea acanthodes and Cousinia congesta with high BCF and low TF values showed the potential for phytostabilization. Investigating the indices for different elements demonstrated that Launaea acanthodes had a BCF value greater than 1 and a TF value less than 1; therefore, this plant could be used in the phytoremediation of arsenic through the phytostabilization technique. Furthermore, copper has very low bioavailability in these plant species. In addition, these native plant species were highly capable of accumulating sulfur from the soil because the BCF and TF indices for all inspected species were higher than 1; for Launaea acanthodes, the relevant TF value was about 10. The proposed native plant could be applied in practical applications of phytoremediation for soil remediation of contaminated sites around the metal factories and mines in southeastern Iran.

A new architecture for Spectral Amplitude Coding Optical Code Division Multiple Access (SAC-OCDMA) system based on two Dimensional Multi Diagonal (2D-MD) codes named 2D-MD SAC-OCDMA and utilizing a laser optical source is proposed for Long-Reach Passive Optical Network (LR-PON). In this work, a computer simulator tool is used, for the first time, as a SAC-OCDMA simulation set-up utilizing the unique combination of a coherent laser array and 2D-MD codes. In addition, the system performance is addressed numerically by taking into account Multiple Access Interference (MAI), optical coherent source noise, first, second and third order fiber dispersion, nonlinear effects and photo-detector noise. Simulation results indicate that for a single user (i.e., without considering MAI), the system can operate at a maximum bit rate of 55 Gb/s over 250 km of Single Mode Fiber (SMF), with a Bit Error Rate (BER) below 10−9 (Q-limit = 15.5 dB), when only first order fiber dispersion is considered. However, including the effects of second and third order fiber dispersion as frequency domain parameters, results in a reduction of the maximum bit rate to 40 Gb/s, while maintaining a Q-factor above the Q-limit under the same transmission distance. Furthermore, we demonstrate that the proposed architecture extends the SMF transmission reach up to 600 km and 480 km, when considering linear and nonlinear effects, respectively. Finally, we show that our proposed 2D-MD SAC-OCDMA system outperforms existing solutions presented in the literature for LR-PON configuration, in terms of both aggregate bit rate and transmission reach. [ABSTRACT FROM AUTHOR]

In this paper, a comprehensive analysis is presented to investigate the performance of two dimensional wavelength hopping/time spreading optical code division multiple access (2D WH/TS OCDMA) system through atmospheric turbulence channel. The 2D prime code approach is used for both WH and TS as user address sequence. A wavelength of 1.55 μm is assumed as the operating central wavelength to determine the bit error rate (BER) performance of the 2D WH/TS OCDMA system in terms of different system parameters. The interferences such as multiple access interference, optical beating interference, and the different receiver noises are considered to interpret the system BER performance. In presence of atmospheric turbulence, the required optical power for the system is determined at a standard value of BER of 10–6. However, the proposed system performance is found to be highly affected in atmospheric turbulence regimes, especially when the turbulence level becomes strong. [ABSTRACT FROM AUTHOR]

[Display omitted] • From 2000 to 2020, green space increased more than did blue space in central Nanjing. • Fringe-type expansion of urban green–blue space (UGBS) was most common in central Nanjing. • Average annual solar radiation, DEM, slope, and aspect are natural factors influencing the evolution of UGBSs. • Population density is a socio-economic factor affecting the evolution of UGBSs. Urban green–blue space (UGBS) plays a crucial role in Chinese cities, occupying more than half of the built-up areas. Understanding the spatiotemporal dynamics and driving factors of UGBS in central Nanjing during rapid urbanization is important for studying UGBS evolution in high-density urban-area environments, providing a fundamental basis for related research and policy formulation. This study utilized remote sensing images to estimate the extent of UGBS from 2000 to 2020 and analyzed the evolution using the intensity of area change, a land transfer matrix, the multi-order adjacency index, and a boosted regression tree model. This study revealed the spatiotemporal dynamics and driving factors of UGBSs in central Nanjing from 2000 to 2020: (1) between 2000 and 2020, there was a 4.0% net increase in the total area of UGBSs in central Nanjing. (2) UGBS primarily showed marginal-type expansion, accompanied by proximity-type expansion. Spatially, new green–blue patches tended to cluster around large pre-existing natural green–blue patches. Furthermore, the expansion of UGBS shifted from the urban periphery to the urban interior. (3) Natural factors exerted a greater influence (88.3%) than socioeconomic factors (11.7%) on the expansion of UGBS. Average annual radiation (43.4%), elevation (16.5%), slope (15%), aspect (13.4%), and population density (2.8%) were the primary driving factors. Our results contribute to understanding changes in UGBS and the driving factors behind these changes, thereby providing support for the future planning, protection, and sustainable development of UGBS. [ABSTRACT FROM AUTHOR]

Summary: In this paper, a hybrid bio‐inspired algorithm is proposed to enhance the performance of channel estimation of the orthogonal frequency‐division multiplexing–interleave division multiple access (OFDM–IDMA) system. This algorithm is a fusion of the lion algorithm and group search optimization algorithm named as SU‐LA, scrounger updated lion algorithm. It works on the optimal selection of pilot tone positions that ensure the attainment of the least value of mean square error. Polar code is used for error detection and correction along with Quadrature Amplitude Modulation (QAM) and 16 QAM techniques. Carrier frequency offset (CFO), user, and Eb/No factors are selected to analyze their impact on the BER performance in the presence of Rayleigh channel. It is observed that the proposed SU‐LA‐based system with the QAM technique achieves 91.23% enhancement in BER at zero CFO as compared to harmony search‐based system for Eb/No of 12 dB. Further, in the presence of 0.1 CFO, the proposed system retains BER performance. The experimentation is also carried with 16 QAM over various CFOs and the number of users. The BER performance of the proposed system is also superior to the particle swarm optimization (PSO) and genetic algorithm (GA)‐based system. The effect of peak‐to‐average power ratio (PAPR) and symbol time offsets is not considered. [ABSTRACT FROM AUTHOR]

In this paper, artificial neural network-based adaptive optimal threshold estimation for a two-dimensional optical code division multiple access conventional correlation receiver is proposed. A multilayer perceptron neural network with back-propagation learning algorithm is considered. This estimator uses the weight (w) and the length (F) of the code word, the number of active users (Ν) and the signal to noise ratio as inputs to estimate the required optimal threshold. We have evaluated the proposed approach on a data set of 46,200 samples. We have found that it gives accurate results: 0.029 for the root mean square error, 0.37% for the relative root mean square error and 99.984% for the correlation coefficient (R), which reflects the efficiency of the proposed optimal threshold estimator. [ABSTRACT FROM AUTHOR]

This study presents the design analysis and correlation properties of a new spreading code for the incoherent synchronous pulse position modulation‐optical code division multiple access (PPM‐OCDMA) networks. The proposed code called optimised modified prime code (OMPC), which refers to the modified prime codes (MPCs) family. Additionally, this new code designed at a higher code length, optimised code weight and good correlation characteristics to enhance communication security and improve the bit error rate (BER) performance. In this study, the proposed code is used as source code for different kinds of multimedia services such as data, voice, and video. Furthermore, the characteristics and correlation properties of the OMPC in comparison with the other MPCs families that utilised in the PPM‐OCDMA networks are presented. Moreover, for the PPM‐OCDMA networks, the effect of OMPC auto‐ and cross‐correlation properties on the multiple access interference (MAI) was investigated. Consequently, the MAI is considered in the BER analysis and calculations. Finally, the results show that the proposed OMPC is better than the other existing codes with respect to the channel capacity and system performance. [ABSTRACT FROM AUTHOR]

The purpose of this article is to propose a new configuration based on OCDMA and Fast-OFDM techniques for access network applications. A hybrid intensity modulation with direct detection, fast orthogonal frequency-division multiplexing–code division multiplexing access (IM/DD Fast-OFDM-CDMA) system is analytically and numerically evaluated for an amplifier-free access network. Therefore, system performance is analytically investigated in terms of bit error rate/Q-factor as a function of simultaneous users, fiber length and launched optical power. Firstly, the proposed analytical model includes the overlapping effect among OFDM subcarriers, the peak-to-average power ratio (PAPR), and multiple access interference (MAI). Secondly, a simulation setup is performed, allowing four simultaneous users operating at 40 Gb/s in a passive optical network (PON) context. Furthermore, a power budget analysis is made between IM/DD Fast-OFDM-CDMA, all-optical IM/DD OFDM-CDMA (IM/DD AO-OFDM-CDMA) and OCDMA wavelength division multiplexing (OCDMA-WDM) configurations. It is shown that at 40 Gb/s and by using 2D-hybrid coding (2D-HC), the maximum achievable transmission-reach of IM/DD Fast-OFDM-CDMA is 142 km, which is 34 km and 60 km higher than those provided by the IM/DD AO-OFDM-OCDMA and OCDMA-WDM PON configurations, respectively. [ABSTRACT FROM AUTHOR]

Vertical deformation estimation can be a significant tool in preventing geological hazards and managing environment impacts of underground mining. Common ground surface vertical deformation calculations are challenged by difficult data collection and dependence on prior knowledge. SVD (singular value decomposition) method was applied to estimate ground surface vertical deformation from single pair SAR (synthetic aperture radar) data in a mining region. During the study, LOS (line of sight) and azimuth displacement was obtained using two pass D-InSAR (differential interferometry synthetic aperture radar) and MAI (multi-aperture radar interferometry) technology, respectively. Two adjustment equations were composed using the imaging geometry of D-InSAR and MAI. The singular value decomposition theorem was used to acquire M-P (Moore-Penrose) generalized inverse of the rank deficiency coefficient matrix. From this, the optimal approximation solution of unknown parameters was calculated using weighted least squares. A working panel in the Datong mining area, Shanxi province, China, was selected to verify the SVD approach using the two ascending Sentinel-1A data. The accuracy of vertical deformation estimated by SVD approach is reliable. The RMSE (root mean square error) of vertical deformation is 2.64 mm (along upright profile) and 4.95 mm (along horizontal profile). These results suggest that the SVD approach will complement widely used vertical ground surface deformation calculations. Further study is needed to validate the method from other deformation scenarios from landslides, groundwater loss, earthquakes, underground mining, and glacier movement.

This is a proposal to encode the Tirhuta script in the international character encoding standard Unicode. This script was published in Unicode Standard version 7.0 in June 2014. Tirhuta was the main writing system for the Maithili language, which is spoken in India and Nepal. The script continued in use until the late 20c, when Devanagari replaced it.

Focusing on inbound uplink signal acquisition of the short message communication service in BeiDou system, a differential weighted accumulation algorithm using variable sliding window (DWAVSW) is proposed for the fast acquisition of short burst signal in low carrier-power to noise-density ratio (C/N0), large Doppler dynamic, and multiuser environment. In the new algorithm, the correlation results are processed by differential multiplication, and then, the output is multiplied by a weight coefficient and added to the accumulated value. The value of weight coefficient becomes larger as the accumulation time increases, and the detection and decision can be carried out after each accumulation operation. The acquisition performance of the DWAVSW algorithm is derived theoretically and verified by Monte Carlo simulations and is better than that of non-coherent differential detector. More specifically, the DWAVSW algorithm can achieve a detection rate of 0.9 and a false alarm rate of 10-4 at C/N0 = 28 dBHz. In terms of the multiple access interference (MAI) in multiuser acquisition, the DWAVSW algorithm is combined with subspace projection to solve the problem, since the sliding window width can be adjusted adaptively according to C/N0. The simulation results demonstrate that the improved algorithm can efficiently eliminate the MAI and achieve acquisition in a multiuser system by taking no extra time consumption.

In orthogonal frequency-division multiple access (OFDMA), carrier frequency offset (CFO) destroys the orthogonality between subcarriers due to Doppler effect of the channel and also causes inter-carrier interference (ICI) as well as multiple access interference (MAI). In this paper, CFO tracking algorithm for OFDMA system is presented to overcome the effect of ICI as well as MAI. The proposed algorithm employs normalized least-mean-square (NLMS) algorithm which tracks the residual carrier frequency offset in OFDMA system. The proposed NLMS-based tracking algorithm uses average of all residual carrier frequency offset (RCFO) for improving the mean square error (MSE) performance. The proposed NLMS-based frequency tracking along with frequency offset compensator improves the error performance by reducing the effect of ICI and MAI. Simulation results indicate that the proposed algorithm achieves better tracking performance in the presence of frequency offset. From the results, it is observed that the MSE of the proposed estimator is improved about 3.8 dB at SNR = 20 dB with the frequency offset. [ABSTRACT FROM AUTHOR]