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  • 1
    Online Resource
    Online Resource
    Design and Development of Copper Trimesic Acid Anchored sPEEK/Polyimide Composite Membranes for Fuel Cell Applications
    Wiley ; 2023
    In:  ChemistrySelect Vol. 8, No. 14 ( 2023-04-13)
    Details
    In: ChemistrySelect, Wiley, Vol. 8, No. 14 ( 2023-04-13)
    Abstract: Electrolyte membranes play a critical role as their properties directly influences the performance of fuel cell. A copper‐based metal organic framework (MOF) anchored polymeric blend membrane was developed for fuel cell application. Cu‐MOF serves as an excellent filler material due to its small size, high degree of crystallinity and surface area. Through XRD analysis well defined crystallite sites was evidenced and the average crystallite size measured ∼ 0.3 Å. The acidic functional group in MOF interacts with sulfonic acid (−SO 3 H) group in sulfonated polyetheretherketone (sPEEK) matrix which further improves proton conduction via . hydrogen bonding interaction. With the as‐prepared sPEEK as the matrix; polyimide (PI) was blended to improve its processibility and thermal stability. Cu‐MOF loaded composite membranes (X wt.% Cu‐MOF‐sPEEK/PI) were prepared and characterized. To assess the suitability of the developed membranes for proton exchange membrane fuel cell (PEMFC) applications, ion exchange capacity (IEC), water uptake and proton conductivity was measured. 3 wt.% Cu‐MOF‐2‐sPEEK/PI membrane displayed an IEC value of 2.35 meq g −1 with a water uptake of 38.18 % and proton conductivity of 0.0711 S cm −1 . Overall, the experimental results of the prepared membranes revealed that they act as an efficient proton exchange membrane (PEM) for PEMFCs.
    Type of Medium: Online Resource
    ISSN: 2365-6549 , 2365-6549
    URL: Issue
    URL: Article
    DOI: 10.1002/slct.v8.14
    DOI: 10.1002/slct.202204584
    Language: English
    Publisher: Wiley
    Publication Date: 2023
    detail.hit.zdb_id: 2844262-3
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  • 2
    Online Resource
    Online Resource
    Dual-Domain Image Encryption in Unsecure Medium—A Secure Communication Perspective
    MDPI AG ; 2023
    In:  Mathematics Vol. 11, No. 2 ( 2023-01-15), p. 457-
    Details
    In: Mathematics, MDPI AG, Vol. 11, No. 2 ( 2023-01-15), p. 457-
    Abstract: With the growing demand for digitalization, multimedia data transmission through wireless networks has become more prominent. These multimedia data include text, images, audio, and video. Therefore, a secure method is needed to modify them so that such images, even if intercepted, will not be interpreted accurately. Such encryption is proposed with a two-layer image encryption scheme involving bit-level encryption in the time-frequency domain. The top layer consists of a bit of plane slicing the image, and each plane is then scrambled using a chaotic map and encrypted with a key generated from the same chaotic map. Next, image segmentation, followed by a Lifting Wavelet Transform, is used to scramble and encrypt each segment’s low-frequency components. Then, a chaotic hybrid map is used to scramble and encrypt the final layer. Multiple analyses were performed on the algorithm, and this proposed work achieved a maximum entropy of 7.99 and near zero correlation, evidencing the resistance towards statistical attacks. Further, the keyspace of the cryptosystem is greater than 2128, which can effectively resist a brute force attack. In addition, this algorithm requires only 2.1743 s to perform the encryption of a 256 × 256 sized 8-bit image on a host system with a Windows 10 operating system of 64-bit Intel(R) Core(TM) i5-7200U CPU at 2.5 GHz with 8 GB RAM.
    Type of Medium: Online Resource
    ISSN: 2227-7390
    URL: Article
    DOI: 10.3390/math11020457
    Language: English
    Publisher: MDPI AG
    Publication Date: 2023
    detail.hit.zdb_id: 2704244-3
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  • 3
    Online Resource
    Online Resource
    Neural Attractor-Based Adaptive Key Generator with DNA-Coded Security and Privacy Framework for Multimedia Data in Cloud Environments
    MDPI AG ; 2023
    In:  Mathematics Vol. 11, No. 8 ( 2023-04-07), p. 1769-
    Details
    In: Mathematics, MDPI AG, Vol. 11, No. 8 ( 2023-04-07), p. 1769-
    Abstract: Cloud services offer doctors and data scientists access to medical data from multiple locations using different devices (laptops, desktops, tablets, smartphones, etc.). Therefore, cyber threats to medical data at rest, in transit and when used by applications need to be pinpointed and prevented preemptively through a host of proven cryptographical solutions. The presented work integrates adaptive key generation, neural-based confusion and non-XOR, namely DNA diffusion, which offers a more extensive and unique key, adaptive confusion and unpredictable diffusion algorithm. Only authenticated users can store this encrypted image in cloud storage. The proposed security framework uses logistics, tent maps and adaptive key generation modules. The adaptive key is generated using a multilayer and nonlinear neural network from every input plain image. The Hopfield neural network (HNN) is a recurrent temporal network that updates learning with every plain image. We have taken Amazon Web Services (AWS) and Simple Storage Service (S3) to store encrypted images. Using benchmark evolution metrics, the ability of image encryption is validated against brute force and statistical attacks, and encryption quality analysis is also made. Thus, it is proved that the proposed scheme is well suited for hosting cloud storage for secure images.
    Type of Medium: Online Resource
    ISSN: 2227-7390
    URL: Article
    DOI: 10.3390/math11081769
    Language: English
    Publisher: MDPI AG
    Publication Date: 2023
    detail.hit.zdb_id: 2704244-3
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  • 4
    Online Resource
    Online Resource
    An integrated design for improving spectral efficiency of FSO communication system in 6G applications
    Wiley ; 2024
    In:  International Journal of Communication Systems
    Details
    In: International Journal of Communication Systems, Wiley
    Abstract: In the case of future access networks, such as 6G‐based applications, the free‐space optical communication (FSO) technology is an efficient solution. FSO in 6G is extremely popular because of its unique properties, which include ease of installation, high bandwidth, high security, license‐free long range, and interference resistance. However, environmental disturbances have a negative impact on the FSO system's functioning. Because of these atmospheric turbulences, the optical information gets restricted, which in turn reduces the link reliability, power density, and distance. This paper proposes a hybrid FSO strategy for improving system efficiency to address these problems. Signal creation is fundamental to every successful communication system. The FSO system consists of three components: the transmitter, the channel medium, and the receiver. The transmitter section includes a continuous wave laser, a Mach–Zehnder modulator, a nonreturn to zero transpose Walsh code generator, and a nonreturn to zero pulse generator. Wavelength division multiplexing‐optical code division multiple access‐spectrum slicing (WDM‐OCDMA‐SS) is used to facilitate efficient data transfer after signals have been generated by alternate mark inversion (AMI). In order to boost a weak signal, fused Raman erbium amplifiers (Fuse‐RE) are used. Q factor and log bit error rate (BER) are used to assess the performance of the suggested approach. The proposed model has obtained a log BER of −15.3291 for clear air and a Q factor of 8.2922, whereas the performances are implemented using Python. The proposed approach achieves better performance when compared to the existing methodologies.
    Type of Medium: Online Resource
    ISSN: 1074-5351 , 1099-1131
    URL: Article
    DOI: 10.1002/dac.5776
    Language: English
    Publisher: Wiley
    Publication Date: 2024
    detail.hit.zdb_id: 2024893-3
    SSG: 24,1
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  • 5
    Online Resource
    Online Resource
    Synthesis and fabrication of BST/SPVdF-co-HFP composites for proton exchange membrane fuel cell applications
    Springer Science and Business Media LLC ; 2022
    In:  Journal of Polymer Research Vol. 29, No. 12 ( 2022-12)
    Details
    In: Journal of Polymer Research, Springer Science and Business Media LLC, Vol. 29, No. 12 ( 2022-12)
    Type of Medium: Online Resource
    ISSN: 1022-9760 , 1572-8935
    URL: Article
    DOI: 10.1007/s10965-022-03358-y
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2022
    detail.hit.zdb_id: 2065616-6
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  • 6
    Online Resource
    Online Resource
    A Histidine Aspartate Ionic Lock Gates the Iron Passage in Miniferritins from Mycobacterium smegmatis
    Elsevier BV ; 2014
    In:  Journal of Biological Chemistry Vol. 289, No. 16 ( 2014-04), p. 11042-11058
    Details
    In: Journal of Biological Chemistry, Elsevier BV, Vol. 289, No. 16 ( 2014-04), p. 11042-11058
    Type of Medium: Online Resource
    ISSN: 0021-9258
    URL: Article
    DOI: 10.1074/jbc.M113.524421
    Language: English
    Publisher: Elsevier BV
    Publication Date: 2014
    detail.hit.zdb_id: 2141744-1
    detail.hit.zdb_id: 1474604-9
    SSG: 12
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  • 7
    Online Resource
    Online Resource
    A comparison of Sentinel-1 and Sentinel-2 in assessing flooded area and built-up land use: A case study of selected coastal districts in Andra Pradesh, India
    LLC Kartfond ; 2020
    In:  InterCarto. InterGIS Vol. 26, No. 2 ( 2020), p. 421-435
    Details
    In: InterCarto. InterGIS, LLC Kartfond, Vol. 26, No. 2 ( 2020), p. 421-435
    Abstract: In tropical climatic conditions, floods occur during heavy rainfall. Floods during this thick cloud cover partially stops the optical imagery to pass through the atmosphere and record the surface reflectance. Another kind of satellite imagery that is available is microwave remote sensing data that can pass through the clouds. However, the exploration of this microwave remote sensing began recently for earth observation applications. So, the algorithms and methods available for exploiting advantages from microwave data is still under research. The current part of the work is to explore the methods available to differentiate between the microwave data (Sentinel-1) and Optical imagery (Sentinel-2) in flooded and built-up area estimation. The ultimate aim is to conclude with most suitable datasets and fast computing methods in estimating the built-up area and flooded area during the emergency disaster time. Two case studies taken up for the study are August 2019 East Godavari floods and October 2019 Titli cyclone. So, the adopted method to estimate the flooded areas and built-up areas from the Sentinel-1A and Sentinel-2B was RGB clustering (Red, Green and Blue clustering) using the derived RGB colour combinations in snap 7.0 software. The datasets were classified into built-up, flooded area and vegetation areas using Random Forest supervised classification, a machine learning technique Validation of estimated built-up and flooded areas estimated from Sentinel-1A and Sentinel-2B was done using the random pixel distribution technique. Since the de-centralisation of estimated flooded areas and built-up area helps in fast distribution of the response forces to the affected area, estimation of built-up and flooded area was also taken up for the sub-districts of East Godavari district, India. Finally, the study estimates the damaged built-up and vegetation due to August 2019 East Godavari floods from Sentinel-1A and Sentinel-2B. Flooded area due to ‘Titli’ cyclone 2018 was estimated in East Godavari, Visakhapatnam and Vijianagaram districts of Andhra Pradesh state.
    Type of Medium: Online Resource
    ISSN: 2414-9209 , 2414-9179
    URL: Issue
    URL: Journal
    URL: Article
    DOI: 10.35595/2414-9179-2020-2-26
    DOI: 10.35595/2414-9179
    DOI: 10.35595/2414-9179-2020-2-26-421-435
    Language: English
    Publisher: LLC Kartfond
    Publication Date: 2020
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  • 8
    Online Resource
    Online Resource
    Vortex phase deterioration common-path interferometry
    IOP Publishing ; 2023
    In:  Journal of Optics Vol. 25, No. 8 ( 2023-08-01), p. 085601-
    Details
    In: Journal of Optics, IOP Publishing, Vol. 25, No. 8 ( 2023-08-01), p. 085601-
    Abstract: Common-path interferometers (CPIs) are significant due to their compactness and vibration resistance. The usual challenge with CPIs arises due to a very small separation between reference and sample beams, where sending a reference beam through a sample is considered to be a limitation. However, this limitation also makes it difficult to probe the interaction of beams with materials as a function of their phase structure. This study paves the way for a new kind of interferometry that can provide unique phase signatures to study the sample. This paper proposes and demonstrates a novel approach based on thermo-optic refraction, to send both beams through the sample and probe the phase deterioration due to the relative interaction of beams in the material medium. Here, thermo-optic refraction interferometry allows the superposition of a higher-order vortex beam with a non-vortex beam through the phenomenon of thermal lensing. The non-vortex beam is made to expand in a controlled fashion by another laser. The relative interaction between the expanding non-vortex beam and the vortex beam within the sample, results in the output interferogram. The phase deterioration analysis of the output interferogram elucidates medium-driven phase changes. This technique is demonstrated using milk samples by recording the root-mean-square azimuthal phase deterioration of the orbital angular momentum beam.
    Type of Medium: Online Resource
    ISSN: 2040-8978 , 2040-8986
    URL: Article
    DOI: 10.1088/2040-8986/ace11f
    Language: Unknown
    Publisher: IOP Publishing
    Publication Date: 2023
    detail.hit.zdb_id: 2532144-4
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  • 9
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    Online Resource
    Non-Identical Inverter Rings as an Entropy Source: NIST-90B-Verified TRNG Architecture on FPGAs for IoT Device Integrity
    MDPI AG ; 2023
    In:  Mathematics Vol. 11, No. 4 ( 2023-02-19), p. 1049-
    Details
    In: Mathematics, MDPI AG, Vol. 11, No. 4 ( 2023-02-19), p. 1049-
    Abstract: True random key generator (TRNG) architectures play a notable role in strengthening information security infrastructure. The development of new entropy sources based on reconfigurable hardware is always in demand, especially for the integrity of devices in IoT applications. TRNGs can be adopted for generating unique device IDs that form the data network in the IoT. A ring oscillator (RO) is an efficient entropy source which can be implemented on FPGAs or realised as ASIC hardware. This work proposes a non-identical RO array as an entropy source. The TRNG architecture, based on an increasing odd number of inverters per ring, was extensively studied. The various statistical and hardware analyses provided encouraging results for this reliable entropy unit. The suggested device-independent non-identical RO structure was implemented on five different types of FPGA hardware belonging to the Xilinx and Intel families, consuming 13 registers and nearly 15 combinational functions. This TRNG achieved a throughput of 3.5 Mbps. While the emergence of the Gaussian response evaluated true randomness, the NIST 800-90B and NIST 800-22 tests yielded good results in terms of the justification of randomness evolving from the proposed TRNG architecture.
    Type of Medium: Online Resource
    ISSN: 2227-7390
    URL: Article
    DOI: 10.3390/math11041049
    Language: English
    Publisher: MDPI AG
    Publication Date: 2023
    detail.hit.zdb_id: 2704244-3
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