This paper was written in honor of Prof. Viktor Olimpanovich Kononenko from Ukraine and takes into account reports of recent progress about non-ideal vibrating systems (NIS) published in the period ...from 2004 to 2017. New and old studies of NIS, with limited power supply (small DC motors or electrodynamical shakers), are usually used in laboratory tests, and therefore, the investigation of mutual interactions of driven and driving sub-system is very important. In this paper, main properties of NIS have been reviewed, such as the Sommerfeld effect, i.e., jump phenomena and the increase in power supply that is required by an excitation source operating near resonance; the possibility of saturation phenomenon occurrence, i.e., the transference of energy from higher frequency and lower amplitude to lower frequency and higher amplitude mode; and the existence of regular (periodic motion) and irregular (chaotic motion) behaviors, depending on the value of control parameters (voltage of a DC motor). This paper is divided into two goals: on the one hand will be treated about NIS and on the other hand will be provided an overview of the main engineering applications, analyzing their physical phenomena involved and the adequate methodologies to deal with them.
In the present study we reported for the first time the feasibility of pecan nutshell (PNS,
Carya illinoensis) as an alternative biosorbent to remove Cu(II), Mn(II) and Pb(II) metallic ions from ...aqueous solutions. The ability of PNS to remove the metallic ions was investigated by using batch biosorption procedure. The effects such as, pH, biosorbent dosage on the adsorption capacities of PNS were studied. Four kinetic models were tested, being the adsorption kinetics better fitted to fractionary-order kinetic model. Besides that, the kinetic data were also fitted to intra-particle diffusion model, presenting three linear regions, indicating that the kinetics of adsorption should follow multiple sorption rates. The equilibrium data were fitted to Langmuir, Freundlich, Sips and Redlich–Peterson isotherm models. Taking into account a statistical error function, the data were best fitted to Sips isotherm model. The maximum biosorption capacities of PNS were 1.35, 1.78 and 0.946
mmol
g
−1 for Cu(II), Mn(II) and Pb(II), respectively.
Background: Although dysarthria and respiratory failure are widely described in literature as part of the natural history of Amyotrophic lateral sclerosis (ALS), the specific interaction between them ...has been little explored.
Aim: To investigate the relationship between chronic respiratory failure and the speech of ALS patients.
Materials and methods: In this cross-sectional retrospective study we reviewed the medical records of all patients diagnosed with ALS that were accompanied by a tertiary referral center. In order to determine the presence and degree of speech impairment, the Amyotrophic Lateral Sclerosis Functional Rating Scale-revised (ALSFRS-R) speech sub-scale was used. Respiratory function was assessed through spirometry and through venous blood gasometry obtained from a morning peripheral venous sample. To determine whether differences among groups classified by speech function were significant, maximum and mean spirometry values of participants were compared using multivariate analysis of variance (MANOVA) with Tukey's post hoc test.
Results: Seventy-five cases were selected, of which 73.3% presented speech impairment and 70.7% respiratory impairment. Respiratory and speech functions were moderately correlated (seated FVC r = 0.64; supine FVC r = 0.60; seated FEV1 r = 0.59 and supine FEV1 r = 0.54, p < .001). Multivariable logistic regression revealed that the following variables were significantly associated with the presence of speech impairment after adjusting for other risk factors: seated FVC (odds ratio OR = 0.862) and seated FEV1 (OR = 1.106). The final model was 81.1% predictive of speech impairment. The presence of daytime hypercapnia was not correlated to increasing speech impairment.
Conclusion: The restrictive pattern developed by ALS patients negatively influences speech function. Speech is a complex and multifactorial process, and lung volume presents a pivotal role in its function. Thus, we were able to find that lung volumes presented a significant correlation to speech function, especially in those with bulbar onset and respiratory impairment. Neurobiological and physiological aspects of this relationship should be explored in further studies with the ALS population.
An analytical and numerical investigation into the dynamic interaction between a cantilever beam with nonlinear damping and stiffness behavior, modeled by the Duffing-Rayleigh equation, and a ...non-ideal motor that is connected to the end of the beam, is presented. Non-stationary and steady-state responses in the resonance region as well as the passage through resonance behavior when the frequency of the excitation is varied are analyzed. The influences of nonlinear stiffness, nonlinear damping and the extent of the unbalance in the motor are examined. It is found that in this situation so-called Sommerfeld effects may be observed; the increase required by a source operating near the resonance results in a small change in the frequency, but there is a large increase in the amplitude of the resultant vibration and the jump phenomenon occurs.
To study the impact of surgery on pain, disability, quality of life, and patient satisfaction in a sample of patients with Degenerative Lumbar Disease (DLD).
Retrospective analysis of prospectively ...collected data. Comparison between pre and postoperative (6 - 12 months) ODI and SF-36, plus postoperative Patient Satisfaction Index.
From a total of 216 patients included, improvement was observed in average scores of pain (201.2%), disability (39.7%), physical quality of life (42%), and mental quality of life (37.8%). Among these patients, 57.7% reached or surpassed the minimal clinically important difference (MCID) for ODI, 57.7% for the SF-36 pain component, 59.7% for the SF-36 physical component summary, and 50.5% achieved or surpassed the MCID for the SF-36 mental component summary.
Surgery produced a significantly positive impact on pain, disability, and quality of life of patients. Overall, 82.5% of the patients were satisfied.
Noonan syndrome (NS) and Noonan-like syndromes (NLS) are autosomal dominant disorders caused by heterozygous mutations in genes of the RAS/MAPK pathway. The aim of the study was to construct specific ...growth charts for patients with NS and NLS. Anthropometric measurements (mean of 4.3 measurements per patient) were obtained in a mixed cross-sectional and longitudinal mode from 127 NS and 10 NLS patients with mutations identified in PTPN11 (n = 90), SOS1 (n = 14), RAF1 (n = 10), KRAS (n = 8), BRAF (n = 11), and SHOC2 (n = 4) genes. Height, weight, and body mass index (BMI) references were constructed using the lambda, mu, sigma (LMS) method. Patients had birth weight and length within normal ranges for gestational age although a higher preterm frequency (16%) was observed. Mean final heights were 157.4 cm -2.4 standard deviation score (SDS) and 148.4 cm (-2.2 SDS) for adult males and females, respectively. BMI SDS was lower when compared to Brazilian standards (BMI SDS of -0.9 and -0.5 SDS for males and females, respectively). Patients harboring mutations in RAF1 and SHOC2 gene were shorter than other genotypes, whereas patients with SOS1 and BRAF mutations had more preserved postnatal growth. In addition, patients with RAF1 and BRAF had the highest BMI whereas patients with SHOC2 and KRAS mutations had the lowest BMI. The present study established the first height, weight, and BMI reference curves for NS and NLS patients, based only on patients with a proven molecular cause. These charts can be useful for the clinical follow-up of patients with NS and NLS.
The association of RASopathies Noonan syndrome (NS) and Noonan-related syndromes and autoimmune disorders has been reported sporadically. However, a concomitant evaluation of autoimmune diseases and ...an assessment of multiple autoantibodies in a large population of patients with molecularly confirmed RASopathy have not been performed. The clinical and laboratory features were analyzed in 42 RASopathy patients, the majority of whom had NS and five individuals had Noonan-related disorders. The following autoantibodies were measured: Anti-nuclear antibodies, anti-double stranded DNA, anti-SS-A/Ro, anti-SS-B/La, anti-Sm, anti-RNP, anti-Scl-70, anti-Jo-1, anti-ribosomal P, IgG and IgM anticardiolipin (aCL), thyroid, anti-smooth muscle, anti-endomysial (AE), anti-liver cytosolic protein type 1 (LC1), anti-parietal cell (APC), anti-mitochondrial (AM) antibodies, anti-liver-kidney microsome type 1 antibodies (LKM-1), and lupus anticoagulant. Six patients (14%) fulfilled the clinical criteria for autoimmune diseases systemic lupus erythematous, polyendocrinopathy (autoimmune thyroiditis and celiac disease), primary antiphospholipid syndrome (PAPS), autoimmune hepatitis, vitiligo, and autoimmune thyroiditis. Autoimmune antibodies were observed in 52% of the patients. Remarkably, three (7%) of the patients had specific gastrointestinal and liver autoantibodies without clinical findings. Autoimmune diseases and autoantibodies were frequently present in patients with RASopathies. Until a final conclusion of the real incidence of autoimmunity in Rasopathy is drawn, the physicians should be alerted to the possibility of this association and the need for a fast diagnosis, proper referral to a specialist and ultimately, adequate treatment.
In the present study we reported the feasibility of the Brazilian-pine fruit coat, named piñon wastes (PW;
Araucaria angustifolia) as biosorbent to remove Cr(VI) from aqueous solutions.
The PW ...biosorbent was characterized by N
2 adsorption–desorption isotherms, FTIR spectroscopy, scanning electron microscopy, elemental analysis, mineral composition determination, and functional groups detection.
The ability of PW to adsorb Cr(VI) was investigated by using batch adsorption procedure. The effects such as pH, contact time and biosorbent dosages on the adsorption capacity were studied. The adsorption kinetics followed the Elovich chemisorption kinetic model, obtaining the following the initial adsorption rate, 284.9, 396.9 and 461.5
mg
g
−1
h
−1 using a 500.0, 700.0 and 1000.0
mg
L
−1 initial concentration of Cr(VI), respectively. The maximum adsorption capacity of PW was 240.0
mg
g
−1 for Cr(VI), using Sips isotherm model. This high adsorption capacity of PW places this biosorbent as one of the best adsorbents for removal of Cr(VI) from aqueous effluents.
A practical problem of synchronization of a non-ideal (i.e. when the excitation is influenced by the response of the system) and non-linear vibrating system was posed and investigated by means of ...numerical simulations. Two rotating unbalanced motors compose the mathematical model considered here with limited power supply mounted on the horizontal beam of a simple portal frame. As a starting point, the problem is reduced to a four-degrees-of-freedom model and its equations of motion, derived elsewhere via a Lagrangian approach, are presented. The numerical results show the expected phenomena associated with the passage through resonance with limited power. Further, for a two-to-one relationship between the frequencies associated with the first symmetric mode and the sway mode, by using the variation of torque constants, the control of the self-synchronization and synchronization (in the system) are observed at certain levels of excitations.
In this paper, self-synchronization of four non-ideal exciters is examined via numerical simulation. The mathematical model consists of four unbalanced direct current motors with limited power supply ...mounted on a flexible structural frame support.
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