Optimal Control of Large Space Structures

We present a computational spectral factorization method to solve the optimal state feedback control problem for flexible structures with the following features: (1) Mathematically rigorous (2) Wide range of applicability (3) Flexibility of design (4) Fast and Efficient (5) Mini-computer (versus Super- computer) implementation. We apply this method to the following systems: (a) A membrane (b) A string (c) An Euler- Bernoulli/Timoshenko beam models (d) A beam with structural damping and boundary contro

Spectrophotometric Determination of Omeprazole Sodium and Ranitidine Hydrochloride Using 2, 4-dinitrofluorobenzene and 4- chloro-7-nitrobenzen-2-oxa-1, 3-diazole Accompanied with a Kinetic Study

Two accurate, simple and sensitive spectrophotometric methods were developed for determination of omeprazole sodium and ranitidine hydrochloride in bulk and pharmaceutical dosage forms. The first method was based on the reaction of these drugs with 2, 4- dinitrofluorobenzene producing yellow colored products measured at λmax 470 nm and 420 nm for omeprazole sodium and ranitidine HCl, respectively. Beer’s law was obeyed in the concentration range from (5-40 µg.ml-1) for omeprazole sodium and (30-180 µg.ml-1) for ranitidine HCl with molar absorpitivity 9.202 x 103 Lmol-1cm-1 and 1.778 x 103 Lmol-1cm-1, respectively. The second method was based on the reaction of omeprazole sodium and ranitidine HCl with 4- Chloro-7-nitrobenzen-2-oxa-1, 3-diazole producing yellow colored adducts measured at λmax 481 nm and 468 nm for omeprazole sodium and ranitidine HCl, respectively. This method was accompanied with a kinetic study for ranitidine HCl. The absorbance-concentration plots were rectilinear over concentration range (2-12 µg.ml-1) and (0.025-0.15 µg.ml-1) for omeprazole sodium and ranitidine HCl with molar absorpitivity 4.062 x 104 Lmol-1cm-1 and 2.802 x 106 Lmol-1cm-1, respectively. These methods hold their accuracy and precision well when applied to the determination of omeprazole sodium and ranitidine HCl in their dosage forms

The Impacts of the COVID-19 Pandemic on Youth Violence: Insights from Professional Key Informants

Introduction The COVID-19 pandemic has had drastic effects on youth violence protective and risk factors by isolating many at risk youth. While youth violence is a growing global health problem, there are limited studies exploring youth violence during the COVID-19 pandemic. Lake County in Northwest Indiana presents an opportunity for youth violence research and prevention given its socio-demographic context and its limited youth violence data. This study explored the COVID-19 pandemic’s impacts on youth violence and its risk and protective factors from the perspectives of professional key informants in Lake County, Indiana.  Methods This study utilized a descriptive qualitative design inspired by the constructivist grounded theory. We recruited professional key informants through purposive and snowball sampling. Data collection consisted of virtual semi-structured key informant interviews that were audio-recorded and transcribed verbatim. Data analysis consisted of inductive thematic analysis with open line-by-line coding, focused coding in Dedoose, and theme identification.  Results A total of six key informants were interviewed, representing diverse youth-serving occupations. These interviews revealed five general themes portraying the impacts of the COVID-19 pandemic on youth violence: mental health impacts on youth; socialization of youth; youth as victims, perpetrators, or witnesses; shifting of learning environments; and parent-child relationships. Key informants observed an increase in less visible types of youth violence, underlying pandemic-induced or-exacerbated youth mental and behavioral health issues, strained parent-child relationships, and the educational marginalization of youth in underserved communities during online learning transitions. Conclusions This study highlighted underserved youth’s vulnerability to the COVID-19 pandemic’s adverse impacts on youth violence experiences, risk, and protective factors. Our findings support the need to prioritize youth during and after crises, to utilize innovative strategies to better reach underserved youth, and to develop ethical and integrated youth violence data systems. Future research should explore youth’s lived experiences with violence throughout the pandemic. 

Fault Growth and Propagation During Incipient Continental Rifting: Insights from a Combined Aeromagnetic and Shuttle Radar Topography Mission Digital Elevation Model Investigation of the Okavango Rift Zone, Northwest Botswana

Digital Elevation Models (DEM) extracted from the Shuttle Radar Topography Mission (SRTM) data and high-resolution aeromagnetic data are used to characterize the growth and propagation of faults associated with the early stages of continental extension in the Okavango Rift Zone (ORZ), northwest Botswana. Significant differences in the height of fault scarps and the throws across the faults in the basement indicate extended fault histories accompanied by sediment accumulation within the rift graben. Faults in the center of the rift either lack topographic expressions or are interpreted to have become inactive, or have large throws and small scarp heights indicating waning activity. Faults on the outer margins of the rift exhibit either (1) large throws or significant scarp heights and are considered older and active or (2) throws and scarp heights that are in closer agreement and are considered young and active. Fault linkages between major fault systems through a process of fault piracy have combined to establish an immature border fault for the ORZ. Thus, in addition to growing in length (by along-axis linkage of segments), the rift is also growing in width (by transferring motion to younger faults along the outer margins while abandoning older faults in the middle). Finally, utilization of preexisting zones of weakness allowed the development of very long faults (\u3e100 km) at a very early stage of continental rifting, explaining the apparent paradox between the fault length versus throw for this young rift. This study clearly demonstrates that the integration of the SRTM DEM and aeromagnetic data provides a 3-D view of the faults and fault systems, providing new insight into fault growth and propagation during the nascent stages of continental rifting

The Use of Information Systems to Improve Academic Supervision in Colleges

A supervisory service known as academic advice aims to familiarize the student with the university and its scientific departments, the domains in which graduates work, the facets of care, and the services the university offers to its students. The academic advising service assists students in adjusting to the university environment and taking advantage of the opportunities available to them by equipping them with fundamental knowledge and skills that raise their educational attainment. Academic advising is an important link in guiding students to achieve the best performance during the teaching and learning processes, to obtain the best educational outcomes and the best possible academic achievement. Exam anxiety, academic pressures, low achievement, a lack of study time, weak motivation to learn, low self-concept, social and economic pressures, and other issues are common during the university stage and prevent students from adjusting to the university environment. As a result, it becomes urgently necessary to have an advanced academic advising system to address all of these issues and ensure its capacity to achieve psychological harmony. By considering the factors of the student's academic level and university specialty, this study seeks to shed light on the reality of the Faculty of Management Academic Guidance Unit from the perspectives of students and faculty members. The statistical analysis results from the use of various statistical approaches demonstrate that students are generally satisfied with the many dimensions of the questionnaire on the caliber of academic extension services offered by the institution

Synthesis of a novel Ce(iii)/melamine coordination polymer and its application for corrosion protection of AA2024 in NaCl solution

ABSTRACT: We present the synthesis of a new cerium(III)–melamine coordination polymer (CMCP) by a mixedsolvothermal method and its characterization. Characterization techniques included Raman, Fourier Transformation Infra-Red (FTIR), X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM), in which the change in the electronic environment and the crystallinity were tracked. The characterization results confirm the coordination of cerium(III) with melamine through –NH₂ groups, instead of the N atoms of the triazine ring, for which we propose a mechanism of interaction. In addition, Biovia Materials Studio package was applied to determine and investigate the molecular structure of the CMCP. All simulations were done using COMPASS force-field theory and atom-based method for summation of electrostatic and van de Waals forces. The application of the CMCP for the corrosion inhibition of AA2024 in 3.5% NaCl solution was tested using the potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The results point out that the presence of cerium as cerium(III) in the CMCP structure plays the fundamental role of inhibition, whereby the inhibition mechanism occurs by cathodic oxidation of Ce(III) to Ce(IV) and cyclic reduction of Ce(IV) to Ce(III) by melamine part of CMCP

DEVELOPMENT OF CERAMIC MICROFILTRATION SUPPORT FROM MOROCCAN SAHARA CLAY

The new ceramic microfiltration support prepared from Moroccan clay (Laayoune region, South of Morocco) is reported in this paper. To optimize the support elaboration conditions, the powder clay is mixed with organic additives and water. The formed paste is shaped by using an extrusion processing and then sintered at 950 °C. The ceramic supports present a porosity and mechanical strength of 44 % and 12MPa respectively. The layer filtration deposition has been carried out by the slip casting method, in order to test its operation in textile effluents treatment

DEVELOPMENT OF CERAMIC MICROFILTRATION SUPPORT FROM MOROCCAN SAHARA CLAY

The new ceramic microfiltration support prepared from Moroccan clay (Laayoune region, South of Morocco) is reported in this paper. To optimize the support elaboration conditions, the powder clay is mixed with organic additives and water. The formed paste is shaped by using an extrusion processing and then sintered at 950 °C. The ceramic supports present a porosity and mechanical strength of 44 % and 12MPa respectively. The layer filtration deposition has been carried out by the slip casting method, in order to test its operation in textile effluents treatment