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  1. Article ; Online: Exponential stabilization of swelling porous systems with thermoelastic damping

    Tijani A. Apalara / Moruf O. Yusuf / Soh E. Mukiawa / Ohud B. Almutairi

    Journal of King Saud University: Science, Vol 35, Iss 1, Pp 102460- (2023)

    1480  

    Abstract: We study two systems of swelling porous thermoelasticity with minimum damping. Employing the standard multiplier method, we stabilize the systems exponentially without imposing restrictions on the wave velocities of the systems. This result is contrary ... ...

    Abstract We study two systems of swelling porous thermoelasticity with minimum damping. Employing the standard multiplier method, we stabilize the systems exponentially without imposing restrictions on the wave velocities of the systems. This result is contrary to those obtained for closely related systems (like Timoshenko and porous systems) with similar single damping. In such scenarios, the authors established that a single damping term is insufficient to exponentially stabilize the system unless the assumption of the equality of wave velocities is imposed.
    Keywords 93D23 ; 35B40 ; 74F05 ; Science (General) ; Q1-390
    Language English
    Publishing date 2023-01-01T00:00:00Z
    Publisher Elsevier
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article: Determinants of hypercalcemia and hypercalciuria in immobilized trauma patients.

    Yusuf, Moruf B / Akinyoola, Akinyele L / Orimolade, Ayodele E / Idowu, Ademola A / Badmus, Tajudeen A / Adeyemi, Taofeek O

    BoneKEy reports

    2015  Volume 4, Page(s) 709

    Abstract: Hypercalcemia and hypercalciuria secondary to immobilization can be occasionally severe, producing an array of symptoms. This study looked at possible determinants of hypercalcemia and hypercalciuria in immobilized trauma patients. This is a prospective ... ...

    Abstract Hypercalcemia and hypercalciuria secondary to immobilization can be occasionally severe, producing an array of symptoms. This study looked at possible determinants of hypercalcemia and hypercalciuria in immobilized trauma patients. This is a prospective observational study carried out over a period of 7 months. Fifty-five immobilized trauma patients were evaluated weekly for 4 weeks for symptoms of hypercalcemia, total serum calcium and 24-h urinary calcium. The number of limbs immobilized had a significant relationship with hypercalcemia at the end of week 1 (P<0.001) and week 4 (P=0.008) and with hypercalciuria at the end of week 1 only (P<0.001). The number of bones fractured also had a significant relationship with hypercalcemia at the end of week 1 (P=0.005) and week 4 (P=0.019), as well as with hypercalciuria at the end of week 1 (P<0.001) and week 2 (P=0.036). Weight loss was significantly associated with hypercalcemia at the end of week 4 (P=0.014) and with hypercalciuria at the end of week 3 (P<0.001) and week 4 (P<0.001), whereas polyuria and polydipsia had a significant association with hypercalciuria at the end of week 2 (P<0.001) and week 3 (P=0.030). The number of limbs immobilized and bones fractured showed an early significant relationship with the development of hypercalcemia and hypercalciuria. Weight loss showed late association with hypercalcemia and hypercalciuria, whereas polyuria and polydipsia showed early association with hypercalciuria.
    Language English
    Publishing date 2015-06-03
    Publishing country England
    Document type Journal Article
    ZDB-ID 2816308-4
    ISSN 2047-6396
    ISSN 2047-6396
    DOI 10.1038/bonekey.2015.78
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Bond Characterization in Cementitious Material Binders Using Fourier-Transform Infrared Spectroscopy

    Moruf Olalekan Yusuf

    Applied Sciences, Vol 13, Iss 3353, p

    2023  Volume 3353

    Abstract: ... elemental displacement due to changes in molar mass, activated temperature, pH, activator concentration, w/b ...

    Abstract Fourier-transform infrared (FTIR) spectroscopy is a fast and simple technique for functional group identification. This work provides a review and insight into the application and interpretation of FTIR spectroscopy for cementitious binders that comprise ordinary Portland cement, alkaline-activated binders, geopolymers, and material characterization for civil engineering material applications. This technique can be used to identify different compounds and a moiety of bond vibrations in inorganic molecules such as Si-O, -OH, H-O-H (water), C-O (carbonate or carbonation), aluminosilicate (Si-O-T, where T is Al or Si), and S-O (sulfate or gypsum) found in hydrated cement, alkaline binders, and geopolymers. The prominent bands include those representing carbonation (CO 3 2− 1390–1475 cm −1 ), calcium carbonate (871, 1792–2516 cm −1 ), hydroxylation and water molecules (1607, 3400–3650 cm −1 ), strength skeletal framework compositions or Al-Si substitutions, silicate organization (C-A-S-H, N-A-S-H, or C-S-H (950–1055 cm −1 ), and sulfate (600–680, 1080–1100 cm −1 ). Some of the factors that could affect the spectra bands include elemental displacement due to changes in molar mass, activated temperature, pH, activator concentration, w/b ratio, Ca/Si ratio, Si/Al ratio, and the silica modulus (SiO 2 /Na 2 O) of the activators used in the binder synthesis. The method could be used for destructive and non-destructive testing on paste sample by using transmission and attenuated total reflectance methods, respectively.
    Keywords Fourier-transform infrared spectroscopy ; geopolymers ; alkaline-activated binder ; material characterization ; aluminosilicate materials ; Technology ; T ; Engineering (General). Civil engineering (General) ; TA1-2040 ; Biology (General) ; QH301-705.5 ; Physics ; QC1-999 ; Chemistry ; QD1-999
    Subject code 333
    Language English
    Publishing date 2023-03-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  4. Article ; Online: Comparison of serum and urinary calcium profile of immobilized and ambulant trauma patients.

    Yusuf, Moruf B / Ikem, Innocent C / Oginni, Lawrence M / Akinyoola, Akinyele L / Badmus, Tajudeen A / Idowu, Ademola A / Orimolade, Ayodele E

    Bone

    2013  Volume 57, Issue 2, Page(s) 361–366

    Abstract: Background: Hypercalcemia occurs more frequently than is recognized in patients who are immobilized, but most of these patients are asymptomatic. This study is to determine serum and urinary calcium levels, incidence of hypercalcemia and hypercalciuria ... ...

    Abstract Background: Hypercalcemia occurs more frequently than is recognized in patients who are immobilized, but most of these patients are asymptomatic. This study is to determine serum and urinary calcium levels, incidence of hypercalcemia and hypercalciuria in immobilized and ambulant trauma patients.
    Methods: A prospective comparative study was carried out over a period of seven months. Total serum calcium level and 24-hour urinary calcium output were measured weekly over 4weeks in 55 immobilized trauma patients as study group and 51 ambulant trauma patients as control group.
    Results: Mean total serum calcium of immobilized patients increased progressively (on admission: 2.315±0.056mmol/l and week 4: 2.552±0.231mmol/l, p<.001) while that of ambulant patients did not change significantly (on admission: 2.306±0.041mmol/l, and week 4: 2.300±0.028mmol/l, p=.348). There is a significant difference in overall mean total serum calcium between immobilized and ambulant patients (p<.001). In immobilized and ambulant patients, mean 24-hour urinary calcium increased progressively from baseline (3.044±0.480mmol/day and 3.056±0.540mmol/day respectively), till the end of the study (8.543±2.142mmol/day and 6.783±1.372mmol/day respectively). Overall mean 24-hour urinary calcium is significantly different between immobilized and ambulant patients {multivariate Pillai F (5,100)=883.124, p<.001}. Incidence of hypercalcemia increased progressively in immobilized patients (end of week 1=7.27% and end of week 4=29.09%) while none of the ambulant patients had hypercalcemia. Incidence of hypercalciuria also increased progressively in immobilized patients (end of week 1=7.27% and end of week 4=63.64%) while ambulant patients only had hypercalciuria at the end of week 3 (9.8%) and week 4 (21.57%).
    Conclusion: Mean total serum calcium increased with increased duration of immobilization in trauma patients. Both immobilized and ambulant trauma patients developed hypercalciuria but it is worse and earlier in the immobilized trauma patients.
    MeSH term(s) Adolescent ; Adult ; Ambulatory Care ; Calcium/blood ; Calcium/urine ; Child ; Disabled Persons ; Female ; Humans ; Hypercalcemia/blood ; Hypercalcemia/urine ; Immobilization ; Male ; Middle Aged ; Phosphates/blood ; Phosphates/urine ; Wounds and Injuries/blood ; Wounds and Injuries/urine ; Young Adult
    Chemical Substances Phosphates ; Calcium (SY7Q814VUP)
    Language English
    Publishing date 2013-12
    Publishing country United States
    Document type Comparative Study ; Journal Article
    ZDB-ID 632515-4
    ISSN 1873-2763 ; 8756-3282
    ISSN (online) 1873-2763
    ISSN 8756-3282
    DOI 10.1016/j.bone.2013.09.001
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Microstructural Characteristics, Modeling of Mechanical Strength and Thermal Performance of Industrial Waste Glass Blended Concrete

    Moruf Olalekan Yusuf / Khaled A. Alawi Al-Sodani / Adeshina A. Adewumi / Ali H. Alateah / Mohammed M. H. Al-Tholaia / Sami M. Ibn Shamsah / Umair Yaqub Qazi / Ghazi Dibas S. Alanazi

    Applied Sciences, Vol 12, Iss 8600, p

    2022  Volume 8600

    Abstract: ... is denoted as C x G 10−x , where x is 0–20 wt.% at an interval of 5 wt.% in mortar (w/b = 0.4) and 0 ... 10, 20 and 30 in concrete (w/b = 0.42). The study investigates the effects of glass on the setting ...

    Abstract The need to get rid of solid waste in the environment necessitates the incorporation of waste glass powder (WGP) in mortar and concrete. The blending of WGP (G) with ordinary Portland cement (OPC) is a valorization technique that is not only cost efficient but also environmentally friendly. The replacement level is denoted as C x G 10−x , where x is 0–20 wt.% at an interval of 5 wt.% in mortar (w/b = 0.4) and 0, 10, 20 and 30 in concrete (w/b = 0.42). The study investigates the effects of glass on the setting, workability, thermal resistance, microstructure, mineral phases and bond characteristics of silicon and hydroxyl-based compounds and C-O vibrations. It also provides the model equations for strength characteristics in terms of OPC, G and ages in mortar and concrete on one hand and investigates the residual strength and density of glass blended concrete at elevated temperature (550 °C) on the other. It is found that glass enhances the workability, reduces the setting time and density and enhances the residual strength and density of concrete. The presence of glass leads to the formation of coesite and microstructural distortion and decreases the Ca/Si ratio. Besides, the bond characteristics of the binder are significantly affected, while the thermal residual strength capacity in glass blended concrete (C 80 G 20 ) is 40.4% and 75.14% lower than that in OPC concrete (C 100 G 0 ) because of the low thermal conduction of glass particles. The optimum glass content in mortar and concrete to produce 33 MPa (28 days) and 47 MPa (90 days) is found to be 10 wt.% and 20 wt.%, respectively.
    Keywords glass waste powder ; cement ; density ; microstructure ; consistency ; compressive strength ; Technology ; T ; Engineering (General). Civil engineering (General) ; TA1-2040 ; Biology (General) ; QH301-705.5 ; Physics ; QC1-999 ; Chemistry ; QD1-999
    Subject code 690
    Language English
    Publishing date 2022-08-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
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