Synthesis, characterization and optimization of magnetic nanostructures by sol-gel technique and application in water purification

Tailored maghemite nanoparticles with improved thermo-physical properties have attracted vast interest in current years. The design and synthesis of these particles have generated innovative magnetic, optical and other physical properties that arise from quantum size effect and enhanced surface to volume ratio with huge application significance. Tailored magnetic nanoparticles are prepared either by wet chemical methods such as colloidal chemistry or by dry processes such as vapor deposition techniques. This PhD project, aimed to develop novel vanadium doped maghemite (Fe2−xVxO3) particles with novel properties of ~ 5 nm and nanohybrids of maghemite size ranges from 13-15 nm decorated multiwalled carbon nanotubes (MWCNTs) by wet methods. Tailored maghemite – MWCNTs nanohybrid was later, applied in efficient Lead removal application from aqueous solutions. The synthesis involved a facile Sol-gel route, with control over the size, morphology and the magnetic properties. Tailored maghemite particles were synthesized from a metal precursors and MWCNTs in a single pot reactor assembly, with forced nucleation in slight basic medium at pH ~ 9, yields crystalline, pure phase and thermally stable particles and nanohybrids. The synthesized particles and nanohybrids were characterized for different physical properties; crystallinity, phase purity and transformations, morphology, hydrodynamic particle size, polydispersity, magnetic properties, surface area studies, elemental and oxidation states of iron and vanadium, thermal stability, colloidal stability, zeta potential values and elemental ratios of iron, oxygen and carbon in tailored maghemite – MWCNT nanohybrids. The comparative changes in structural, magnetic, surface area and colloidal properties of the nanoparticles were found significant for future applications in nano devices, magnetic coatings, magnetic separations and other applications. Tailored maghemite – MWCNT nanohybrids were applied for efficient removal of Lead from aqueous solutions in batches magnetically. Lead adsorption mechanism was studied with Kinetics rate, adsorption isotherms. The effects of pH, contact time, adsorbent dosage, and agitation speed on the Pb (II) removal were scrutinized. Repeated adsorption–desorption cycles were studied to investigate the prolonged use of nanohybrids. The maximum removal achieved was ~ 94 % in less than 2 h in a pH range of 6–7, which is very good yield with respect to previous studies. A mathematical model (Minitab version 15) was studied to validate the experimental method for the removal of Lea

Querying ontology using keywords and quantitative restriction phrases

Many approaches for converting keyword queries to formal query languages are presented for natural language interfaces to ontologies. Some approaches present fixed formal query templates, so they lack in providing support with increasing number of words in the user query. Other approaches work on constructing and manipulating subgraphs from RDF graphs so their processing is complex with respect to time and space. Techniques are presented to perform operations by obtaining a reduced RDF graph but they limit the input to some type of resources so their complete complexity with all type of input resources is unknown. For formal query generation, we present a variable query template whose computation is facilitated by less complex and distributed RDF property and relation graphs. A prototype QuriOnto is developed to evaluate our design. The user can query QuriOnto with any number of words and resource types. Also, to the best of our knowledge, it is the first system that can handle quantitative restrictions with keyword queries. As QuriOnto has no support for semantic similarity at this time except for rdfs labels so its recall is low but high precision shows that the approach is promising for the generation of corresponding formal queries

Answering user queries from hotel ontology for decision making

Semantic web comes out with the vision of making human readable information to be machine processable. Ontology, the core of semantic web, with concept instantiations serves as a domain knowledge base while semantic web query language provides retrieval of that information. In this paper, we presented a system that populates hotel related information in the ontology and a natural language querying platform to retrieve the information from a common interface for decision making. A simple user experiment shows that the system is time effective and helpful in making decisions with minimum queries as compared to browsing even with selected sites

MiSuRe is all you need to explain your image segmentation

The last decade of computer vision has been dominated by Deep Learning architectures, thanks to their unparalleled success. Their performance, however, often comes at the cost of explainability owing to their highly non-linear nature. Consequently, a parallel field of eXplainable Artificial Intelligence (XAI) has developed with the aim of generating insights regarding the decision making process of deep learning models. An important problem in XAI is that of the generation of saliency maps. These are regions in an input image which contributed most towards the model's final decision. Most work in this regard, however, has been focused on image classification, and image segmentation - despite being a ubiquitous task - has not received the same attention. In the present work, we propose MiSuRe (Minimally Sufficient Region) as an algorithm to generate saliency maps for image segmentation. The goal of the saliency maps generated by MiSuRe is to get rid of irrelevant regions, and only highlight those regions in the input image which are crucial to the image segmentation decision. We perform our analysis on 3 datasets: Triangle (artificially constructed), COCO-2017 (natural images), and the Synapse multi-organ (medical images). Additionally, we identify a potential usecase of these post-hoc saliency maps in order to perform post-hoc reliability of the segmentation model

TINGKAT PENGETAHUAN CALON HAJI SEBELUM DAN SESUDAH MENGIKUTI PELATIHAN MANASIK HAJI

Pendahuluan: Haji adalah rukun Islam yang ke 5, yang wajib dilaksanakan bagi orang-orang Islam yang mampu. Allah menggunakan lafadj “fa Adzin” dimaksudkan agar Haji dilaksanakan dengan iman, ilmu dan amal. Ibadah haji hanya akan mendatangkan kepuasan pribadi Ketika haji dilaksanakan sebatas pemenuhan seremonial pelaksanaan rukun islam yang ke5. Pendidikan merupakan cara untuk merubah pola fikir maupun merubah tingkah laku kearah yang lebih baik. Melalui bimbingan ibadah haji , calon haji dilatih  dengan materi manasik baik teori maupun praktek.Sesuai dengan misi Muhammadiyah “Da’wah amar ma’ruf nahi Mungkar” maka  Kelompok Bimbingan Ibadah Haji (KBIH) Pimpinan Daerah Muhammadiyah Semarang berkempentingan memberikan bimbingan manasik dengan harapan dapat mengantarkn  calon jama’ah haji menjadi jama’ah yang mandiri, mengetahui syarat, rukun dan wajib haji dan dilaksanakan sesuai tuntunan Rasulullah saw. Methode: Metode yang digunakan dalam penelitian ini adalah diskriptif. Hasil: Dari hasil penelitian diketahui Jumlah sampel 140 orang yang terdiri dari laki-laki 60 orang dan perempuan 80 orang . Umur rata-rata calon jama’ah haji 46 th, adapun umur termuda 29 th dan tertua 76 tahun. Tingkat pengetahuan calon jama’ah haji sebelum mengikuti pelatihan  mayoritas  dengan skor tingkat pengetahuan rendah sebanyak 116 orang (82,9 %) dan tidak ditemukan calon jama’ah haji dengan skor tingkat pengetahuan baik.Setelah dilakukan pelatihan manasik, diketahui bahwa mayoritas tingkat pengetahuan calon jama’ah haji adalah 101 orang (71,2 %), adapun jumlah yang memperoleh skor tingkat pengetahuan rendah 7 orang (5 %). Kesimpulan:Tingkat pengetahuan calon jama’ah haji sebelum mengikuti pelatihan dengan skor tingkat pengetahuan  rendah menduduki   jumlah mayoritas sebanyak 116 orang (82,9 %). Tingkat pengetahuan calon jama’ah haji setelah mengikuti pelatihan dengan skor tingkat pengetahuan  cukup menduduki  jumlah mayoritas sebanyak 101 orang (71,2 %

Effectiveness of Connections Type on Vibration Response of Steel Beam

In a steel structure, choosing the connections type are one of the most important parameters in design consideration. How a connection type affects the vibration of steel beams has been investigated in this paper. The most effective connection type in reducing beam vibration has been highlighted. The study was conducted using different finite element models to simulate each connection type. Firstly, the model was validated by comparing its results with the results obtained by the analytical approach. In the numerical model, a linear frequency analysis was performed to determine beam natural frequency, then it has been compared with the corresponding value obtained by the Euler-Bernoulli approximations for simply supported beams. After that, two analysis procedures have been executed, steady-state analysis and transient analysis. In the steady-state analysis, a harmonic load with different frequencies was applied to the beam mid-span, while an impulsive load has been applied in the transient analysis. The results indicate that the deflection could be reduced by 72%, furthermore steady vibration of the beam can be reduced by 81% with using one of the moment connections instead of the traditional shear connection

Sustained release of CIP from TiO₂‐PVDF/starch nanocomposite mats with potential application in wound dressing

AbstractElectrospinning is an economical and alluring method to fabricate wound dressing mats from a variety of natural and synthetic materials. In this study, polyvinylidene fluoride (PVDF) and starch composite mats containing ciprofloxacin (CIP) loaded on titanium dioxide nanoparticles (TiO₂) were prepared. Fourier Transform Infrared spectra of CIP, synthesized TiO₂ NPs, TiO₂/CIP, and PVDF/starch composite mats are analyzed. Scanning electron microscopy images revealed that the fiber diameter of PVDF nanofibers thickens by increasing starch, which varies between 180 nm and 550 nm. Strain at break of PVDF, starch, PVDF/starch (2:1 w:w; P2S1), PVDF/starch (1:1 w:w; P1S1), PVDF/starch (1:2 w:w; P1S2), and nanofibers were 103 ± 11, 3 ± 0.6, 27 ± 4, 52 ± 5.2, 7.7 ± 1%, respectively. Based on strain at break and young modulus, P2S1 was selected as a suitable candidate for wound dressing to which load TiO₂/CIP as a bioactive agent. The release rate of CIP showed that about 40% of the drug is released in the first 2 days. Furthermore, the antibacterial activity of dressings was investigated using Escherichia coli and Staphylococcus aureus microorganisms and zones of clearance were obvious around the specimen on the agar plate. Abstract Electrospinning is an economical and alluring method to fabricate wound dressing mats from a variety of natural and synthetic materials. In this study, polyvinylidene fluoride (PVDF) and starch composite mats containing ciprofloxacin (CIP) loaded on titanium dioxide nanoparticles (TiO₂) were prepared. Fourier Transform Infrared spectra of CIP, synthesized TiO₂ NPs, TiO₂/CIP, and PVDF/starch composite mats are analyzed. Scanning electron microscopy images revealed that the fiber diameter of PVDF nanofibers thickens by increasing starch, which varies between 180 nm and 550 nm. Strain at break of PVDF, starch, PVDF/starch (2:1 w:w; P2S1), PVDF/starch (1:1 w:w; P1S1), PVDF/starch (1:2 w:w; P1S2), and nanofibers were 103 ± 11, 3 ± 0.6, 27 ± 4, 52 ± 5.2, 7.7 ± 1%, respectively. Based on strain at break and young modulus, P2S1 was selected as a suitable candidate for wound dressing to which load TiO₂/CIP as a bioactive agent. The release rate of CIP showed that about 40% of the drug is released in the first 2 days. Furthermore, the antibacterial activity of dressings was investigated using Escherichia coli and Staphylococcus aureus microorganisms and zones of clearance were obvious around the specimen on the agar plate

Phase change materials incorporation into 3D printed geopolymer cement:A sustainable approach to enhance the comfort and energy efficiency of buildings

The advent of 3D printing has revolutionized conventional construction, offering cost-effective and fast construction of complex structures. Nevertheless, there remain challenges to be addressed regarding the effective integration of functional additives into 3D printing construction materials. Herein, we present a straightforward and environmentally friendly approach to promote sustainable buildings while reducing energy consumption. This is achieved by integrating Macroencapsulated Phase Change Materials (MEPCM) into a 3D printable geopolymer paste (GPP) derived from fly ashes. The research followed a systematic methodology, encompassing the assessment of fresh and hardened properties of geopolymer pastes with varying amounts of MEPCM, analyzing their thermal properties, and investigating the thermal performance by printing miniature houses without and with 20 vol% MEPCM. Notably, MEPCM demonstrated its dual functionality as a thermal energy management component and a viscosity modifier for 3D printable geopolymer paste. Overall, this study paves an innovative path toward sustainable construction, highlighting the significance of energy efficiency and waste reduction.</p