Approximation error model (AEM) approach with hybrid methods in the forward-inverse analysis of the transesterification reaction in 3D-microreactors

This work advances the approximation error model approach for the inverse analysis of the biodiesel synthesis using soybean oil and methanol in 3D-microreactors. Two hybrid numerical-analytical approaches of reduced computational cost are considered to offer an approximate forward problem solution for a three-dimensional nonlinear coupled diffusive-convective-reactive model. First, the Generalized Integral Transform Technique (GITT) is applied using approximate non-converged solutions of the 3D model, by adopting low truncation orders in the eigenfunction expansions. Second, the Coupled Integral Equations Approach (CIEA) provides a reduced mathematical model for the average concentrations, which leads to inherently approximate solutions. The AEM approach through the Bayesian framework is illustrated in the simultaneous estimation of kinetic and diffusion coefficients of the transesterification reaction. For this purpose, the fully converged GITT results with higher truncation orders for the 3D partial differential model are employed as reference results to define the approximations errors. The results highlight that either the non-converged solutions via GITT or the reduced model solution obtained via CIEA, when taking into account the model error, are robust and cost-effective alternatives for the inverse analysis of nonlinear convection–diffusion-reaction problems

PENGARUH PENGGUNAAN CATUDAYA PWM (PULSE WIDTH MODULATION) PADA LAMPU LED (LIGHT EMITTING DIODE)

Penelitian ini mengenai pengaruh penggunaan catudaya pwm (pulse width modulation) terhadap lampu led (light emitting diode). Tujuan penelitian ini untuk menganalisis konsumsi daya lampu led dan intensitas cahaya yang dihasilkan lampu led dengan pengaruh catudaya pwm dengan variasi frekuensi dan dutycycle pwm. Pwm digunakan untuk mengatur kerja transistor sebagai saklar otomatis untuk mengatur tegangan dan arus yang masuk ke lampu led berdasarkan frekuensi dan dutycycle yang divariasikan menggunakan mikrokontroler sebagai pembangkit pwm. Pengukuran tegangan dan arus dilakukan menggunakan multimeter dan pengukuran intensitas cahaya menggunakan luxmeter yang dilakukan pada suatu ruangan kedap cahaya. Hasil penelitian ini menunjukkan dengan frekuensi pwm yang tinggi menyebabkan adanya pengurangan daya konsumsi untuk menghasilkan intensitas cahaya yang sama dengan intensitas cahaya yang dihasilkan pada kondisi normal tanpa catudaya pw

Superpulsed low-level laser therapy protects skeletal muscle of mdx mice against damage, inflammation and morphological changes delaying dystrophy progression.

Aim: To evaluate the effects of preventive treatment with low-level laser therapy (LLLT) on progression of dystrophy in mdx mice. Methods: Ten animals were randomly divided into 2 experimental groups treated with superpulsed LLLT (904 nm, 15 mW, 700 Hz, 1 J) or placebo-LLLT at one point overlying the tibialis anterior muscle (bilaterally) 5 times per week for 14 weeks (from 6th to 20th week of age). Morphological changes, creatine kinase (CK) activity and mRNA gene expression were assessed in animals at 20th week of age. Results: Animals treated with LLLT showed very few morphological changes in skeletal muscle, with less atrophy and fibrosis than animals treated with placebo-LLLT. CK was significantly lower (p = 0.0203) in animals treated with LLLT (864.70 U.l−1, SEM 226.10) than placebo (1708.00 U.l−1, SEM 184.60). mRNA gene expression of inflammatory markers was significantly decreased by treatment with LLLT (p<0.05): TNF-α (placebo-control = 0.51 µg/µl [SEM 0.12], - LLLT = 0.048 µg/µl [SEM 0.01]), IL-1β (placebo-control = 2.292 µg/µl [SEM 0.74], - LLLT = 0.12 µg/µl [SEM 0.03]), IL-6 (placebo-control = 3.946 µg/µl [SEM 0.98], - LLLT = 0.854 µg/µl [SEM 0.33]), IL-10 (placebo-control = 1.116 µg/µl [SEM 0.22], - LLLT = 0.352 µg/µl [SEM 0.15]), and COX-2 (placebo-control = 4.984 µg/µl [SEM 1.18], LLLT = 1.470 µg/µl [SEM 0.73]). Conclusion: Irradiation of superpulsed LLLT on successive days five times per week for 14 weeks decreased morphological changes, skeletal muscle damage and inflammation in mdx mice. This indicates that LLLT has potential to decrease progression of Duchenne muscular dystrophy

Innovative Metallic Microfluidic Device for Intensified Biodiesel Production

We present a strategy for intensified biodiesel production in a novel metallic microdevice. Additive manufacturing using Selective Laser Melting (SLM) was employed to build the metallic device consisting of multiple micro reactors monolithically integrated with multiple micro heat exchangers. This device allows high conversion rate of biodiesel production with concomitant use of the rejected heat from external source to enhance the reaction temperature and, thereby, its output. The biodiesel production was carried out using soybean oil, ethanol and NaOH as the catalyst. The influences of the reaction temperature and the residence time in the biodiesel production was examined. Biodiesel yield increased with the reaction temperature and a rate of conversion of 99.6% was achieved with a reactor residence time of less than 35 seconds. The work opens up a pathway to exploit waste heat to intensify biodiesel production and contribute significantly to global sustainability

Efficacy of diadynamic currents as an adjunct to exercise to manage symptoms of knee osteoarthritis in adults: A randomized controlled clinical trial

Objective To investigate the effect of diadynamic currents administered prior to exercises on pain and disability in patients with osteoarthritis of the knee. Design A randomized-controlled trial. Setting Special Rehabilitation Services in Taboão da Serra. Participants Patients with bilateral knee osteoarthritis. Intervention Participants were randomly allocated to Group I (diadynamic currents and exercises; n = 30, 60 knees) or Group II (exercises alone; n = 30, 60 knees) and were treated three times a week for 8 weeks. Main outcome measures The primary outcome measures were change in knee pain evaluated by visual analog scale and disability Index Score (Lequesne). Secondary outcomes included change in mobility (Timed Up and Go test), range of motion (goniometer), muscle strength (dynamometer), a composite score for pain and disability (Western Ontario and McMaster Universities Osteoarthritis questionnaire), and a drug diary to measure consumption of rescue pain medication (paracetamol). All measurements were collected at baseline, 8 weeks, and 6 months from baseline (follow-up). Results There were 60 participants with a mean (SD) age of 63.40 (8.20) years. Between-group differences in the follow-up (8 weeks and 6 months) were observed for pain at rest, pain during activities of daily living and disability. There was improvement in Group I that was maintained for the three variables 6 months after treatment. Mean difference for pain at rest was −3.08 points (95% confidence interval −4.13; −2.02), p < 0.01 with an effect size of 1.4; mean difference for pain during activities of daily living was −2.40 points (95% confidence interval −3.34; −1.45), p < 0.01 with an effect size of 1.24; and mean difference for disability was −4.08 points (95% confidence interval −5.89; −2.26), p < 0.01 with an effect size of 1.04. Conclusion Patients with symptomatic knee osteoarthritis receiving 8 weeks of treatment with diadynamic currents as an adjunct to a program of exercises had significantly greater improvements in pain and disability than those receiving exercises alone. Beneficial effects were sustained for 6 months

Red (660 nm) and infrared (830 nm) low-level laser therapy in skeletal muscle fatigue in humans: what is better?

In animal and clinical trials low-level laser therapy (LLLT) using red, infrared and mixed wavelengths has been shown to delay the development of skeletal muscle fatigue. However, the parameters employed in these studies do not allow a conclusion as to which wavelength range is better in delaying the development of skeletal muscle fatigue. With this perspective in mind, we compared the effects of red and infrared LLLT on skeletal muscle fatigue. A randomized double-blind placebo-controlled crossover trial was performed in ten healthy male volunteers. They were treated with active red LLLT, active infrared LLLT (660 or 830 nm, 50 mW, 17.85 W/cm2, 100 s irradiation per point, 5 J, 1,785 J/cm2 at each point irradiated, total 20 J irradiated per muscle) or an identical placebo LLLT at four points of the biceps brachii muscle for 3 min before exercise (voluntary isometric elbow flexion for 60 s). The mean peak force was significantly greater (p < 0.05) following red (12.14%) and infrared LLLT (14.49%) than following placebo LLLT, and the mean average force was also significantly greater (p < 0.05) following red (13.09%) and infrared LLLT (13.24%) than following placebo LLLT. There were no significant differences in mean average force or mean peak force between red and infrared LLLT. We conclude that both red than infrared LLLT are effective in delaying the development skeletal muscle fatigue and in enhancement of skeletal muscle performance. Further studies are needed to identify the specific mechanisms through which each wavelength acts

Efficacy of prolonged application of low-level laser therapy combined with exercise in knee osteoarthritis: A randomized controlled double-blind study.

OBJECTIVES: To investigate the effect of prolonged low-level laser therapy application combined with exercise on pain and disability in patients with osteoarthritis of the knee. DESIGN: A randomized controlled trial. SETTING: Special rehabilitation services. SUBJECTS: Forty-three participants with knee osteoarthritis. INTERVENTION: Following initial assessment, participants were randomly allocated to the Laser group (n = 22, 44 knees) and received low-level laser therapy while the Placebo group (n = 21, 42 knees) received placebo therapy three times a week for 3 weeks. Both groups then received low-level laser therapy combined with exercise three times a week for the following 8 weeks. MAIN OUTCOME MEASURES: The primary outcome was change in knee pain and disability (Lequesne). Secondary outcomes included change in mobility (Timed Up and Go test), range of motion (goniometer), muscular strength (dynamometer), activity (Western Ontario and McMaster Universities Osteoarthritis questionnaire), and medication intake and relief. RESULTS: Mean (SD) age of participants was 63.02 (9.9) years. Pain scores at baseline, 3 weeks, 11 weeks, and 6 months follow-up were 9.1 (1.3), 2.6 (2.3), 0.2 (0.9), and 0.2 (0.8) for the Laser group and 9.5 (8.0), 7.7 (5.3), 5.6 (2.4), and 7.4 (5.0) for the Placebo group, respectively. Disability scores at baseline, 3 weeks, 11 weeks, and 6 months follow-up were 14.9 (4.7), 7.6 (4.8), 3.9 (4.2), and 3.5 (4.1) for the Laser group and 17.8 (14.7), 15.2 (11.5), 11.6 (6.4), and 15.8 (11.9) for the Placebo Group, respectively. CONCLUSION: In participants with osteoarthritis of the knee, the isolated application of low-level laser therapy in the initial 3 weeks and combined with exercises in the final 8 weeks reduced pain, disability, and intake of medication over a 6-month period