Numerical Simulation of Solid and Porous Fins’ Impact on Heat Transfer Performance in a Differentially Heated Chamber

The development of different industrial fields, including mechanical and power engineering and electronics, demands the augmentation of heat transfer in engineering devices. Such enhancement can be achieved by adding extended heat transfer surfaces to the heated walls or heat-generating elements. This investigation is devoted to the numerical analysis of natural convective energy transport in a differentially heated chamber with isothermal vertical walls and a fin system mounted on the heated wall. The developed in-house computational code has been comprehensively validated. The Forchheimer–Brinkman extended Darcy model has been employed for the numerical simulation of transport phenomena in a porous material. The partial differential equations written, employing non-primitive variables, have been worked out by the finite difference technique. Analysis has been performed for solid and porous fins with various fin materials, amounts and heights. It has been revealed that porous fins provide a very good technique for the intensification of energy removal from heated surfaces.

Timbre in the Musical Performance as a Result of Audio-Mental Operations

The aim of this paper is to reveal the relationship between the timbre, i.e. sound quality, obtained by an instrumentalist when playing a music piece, and the role of the hearing, listening, and other musical specific mental operations that take place in the brain of the instrumentalist during the performance, with the focus on the classical music, which depends in the most cases on the score. The timbre is a characteristic of every instrument or voice that makes their tone unique. It is given by the different sound components (partials) with different frequencies and amplitudes. The number and the amplitude of the partials are different from instrument to instrument; they depend on the construction of the instrument and on the art of playing, the last being the point in this article. It is known that timbre has an emotional impact on the perception. Its semantic features are represented through descriptors as: dark, bright, round, dull, dry, harsh, etc. that have to be created by the performers, in order to affect the auditory. Thus, they have to possess a good technique, able to get different timbres. Although, the technique has to be subordinated to the capacity of hearing in advance the sound with all its features: pitch, duration, intensity and timbre.

Anastomotic Technique—How to Optimize Success and Minimize Leak Rates

Determining when to perform a bowel anastomosis and whether to divert can be difficult, as an anastomosis made in a high-risk patient or setting has potential for disastrous consequences. While the surgeon has limited control over patient-specific characteristics, the surgeon can control the technique used for creating anastomoses. Protecting and ensuring a vigorous blood supply is fundamental, as is mobilizing bowel completely, and employing adjunctive techniques to attain reach without tension. There are numerous ways to create anastomoses, with variations on the segment and configuration of bowel used, as well as the materials used and surgical approach. Despite numerous studies on the optimal techniques for anastomoses, no one method has prevailed. Without clear evidence on the best anastomotic technique, surgeons should focus on adhering to good technique and being comfortable with several configurations for a variety of conditions.

MR imaging characteristics of uveal melanoma with histopathological validation

Purpose To evaluate the magnetic resonance imaging (MRI) characteristics of uveal melanoma (UM), to compare them with fundoscopy and ultrasound (US), and to validate them with histopathology. Methods MR images from 42 UM were compared with US and fundoscopy, and on 14 enucleated cases with histopathology. Results A significant relationship between the signal intensity on T1 and pigmentation on histopathology was found (p=0.024). T1 hyperintense UM were always moderately or strongly pigmented on histopathology, while T1-hypointense UM were either pigmented or non-pigmented. Mean apparent diffusion coefficient (ADC) of the UM was 1.16 ± 0.26 × 10−3 mm2/s. Two-thirds of the UM had a wash-out and the remaining a plateau perfusion time-intensity curve (TIC). MRI was limited in evaluating the basal diameter of flat tumors. US tends to show larger tumor prominence (0.5mm larger, p=0.008) and largest basal diameter (1.4mm larger, p<0.001). MRI was good in diagnosing ciliary body involvement, extrascleral extension, and optic nerve invasion, but limited on identifying scleral invasion. An increase of tumor prominence was associated with lower ADC values (p=0.030) and favored a wash-out TIC (p=0.028). An increase of tumor ADC correlated with a plateau TIC (p=0.011). Conclusions The anatomical and functional MRI characteristics of UM were comprehensively assessed. Knowing the MRI characteristics of UM is important in order to confirm the diagnosis and to differentiate UM from other intra-ocular lesions and because it has implications for treatment planning. MRI is a good technique to evaluate UM, being only limited in case of flat tumors or on identifying scleral invasion.

Improvement of the Plantation Success in a Crib Wall in a Mediterranean Hydro-Meteorological Risks Scenario—Practical Results

Due to the clime change scenario, severe hydro-meteorological phenomena are having a high impact on the ecosystems of the earth. Some strategies based on the use of natural communities associated with geomorphological changes that restore the natural landscape are gaining success due the resistance and resilience against damages. All of these strategies are known as nature-based solutions (NBS). Soil and water bioengineering techniques are one of the most appreciated tools to reach effectiveness for slope stabilization. They are based on the capacity of some plants to consolidate the soil with his rooting system in special conditions (high slope, flooding impact). Slope stabilization solutions with soil and water bioengineering techniques need to be adapted to this new scenario. Crib wall is one of the most complete soil and water bioengineering technique for structural slope stabilization. It is based on a wooden box full of live plants that in the future will grow and gain stability at the same time that wood decays. The crib wall box is full of soil, and the front area is traditionally stabilized with some branches of fascines to let plants grow, maintaining the structure. Fascines are made of branches of riparian species with the capacity for vegetative propagation. Their diameter can change due to the humidity variation, so the stiffness of the system is at risk against severe hydro-meteorological phenomena. This study aims to assess that the introduction of HDCL in crib walls improves planting success and makes them more resistant to adverse weather events in Mediterranean areas. Four experiments were performed in controlled and natural conditions with this proposal. The results show that the use of natural fibers instead of branch fascine helps to maintain the humidity conditions and increase the resistance capacity. High-density coir logs (HDCL) are not affected by volume changes for humidity conditions. HDCL maintains the plant’s humidity conditions longer and makes plants grow faster, bigger and increase their survival. This method of Crib wall construction increases the associated biodiversity. The most important results are that the use of HDCL in crib walls has an effect on the growth of planted shrub, the development of roots, the colonization of native vegetation and ultimately, the resistance of the structure to the floods. The results also show that crib walls are a good technique for the stabilization of slopes with considerable gradients and high hydraulic impacts. HDCL can reduce the water stress of plantations, and they can be a good system to retain runoff and provide it to the plants. Finally, the HDCL allows the revegetation of a crib wall 30% faster than with branch fascine.

FBMC OQAM: novel variant of OFDM

Orthogonal frequency division multiplexing (OFDM) revolutionizes the transmission technologies, including, optical as well as wireless communication. In OFDM the orthogonal nature of carriers makes it very good technique for data transfer. Still the out-of-band (OOB) radiation in OFDM leads to inter symbol interference (ISI) and bit error rate (BER) goes down. Moreover amplitude variations of the subcarriers lead to power variations and peak-to-average power ratio (PAPR) problem. To overcome these issues a novel filter bank multicarrier (FBMC) scheme is proposed, where each carrier is allowed to pass through to a separate filter and orthogonality among subcarriers is relaxed. Thus FBMC has better OOB and PAPR performance. In this work, we also have evaluated the PAPR performance by the simulation results. For the improvement of PAPR nonlinear companding scheme along with clipping is presented. The hybrid technique (clipping + companding) parameters are set in such a way that PAPR is reduced while signal power remains constant. Results are also compared with recent methods and it has been found that the proposed technique preforms better than other chosen techniques.

Economic analysis of the inclusion of thermoelectric ash in asphalt mixtures

The replacement of conventional materials used in hot asphalt mixtures with others of good technique and lower cost and environmental impact has motivated research in this area of knowledge in recent decades. The researches should be expanded in the scope of engineering, given that it contributes considerably to the transformation of spaces and raw material. In this context, thermoelectric ashes, which are residues from the production of electric energy, appear as an alternative to replace the stone powder input which contributes negatively to the environment considering that it comes from the blasting of rocks. This work aims to compare the cost of producing traditional asphalt concrete (reference) to asphalt compositions containing 5,15% of alternative material characterized by stone dust. There was a saving of R$ 0.21 per ton of AC machining, consisting of thermoelectric ash as a partial substitute (5.15%) for stone powder, which represents significant savings in a practical context.

PEGylated DPPC/Anti-SNAP25 Antibody Targeted Liposomes: From Langmuir Monolayer Study to Formulations

Background: Molecule compatibility is an important factor to be considered before preparing antibody-targeted liposomes, stealth-liposomes, and stealth antibody-targeted liposomes. Objective: To determine the intermolecular interaction of 1,2-dioleoyl-sn-glycero-3-phosphoethanolamide-N-[methoxy(polyethyleneglycol)-2000] (ammonium salt), DOPE PEG2000 and Anti-SNAP25 (AS25) in 1,2-dipalmitoyl-sn-glycero-3-phosphorylcholine (DPPC) monolayer, and their liposomes. Methods: In this study, DPPC was used to create a monolayer mimicking the half membrane of liposomes to investigate its interactions with a polyclonal antibody, AS25, and DOPE PEG2000, respectively based on Langmuir-Blodgett (LB) techniques. The surface morphology of DPPC— AS25 and DPPC— DOPE PEG2000— AS25 bilayers were also imaged and analyzed by using atomic force microscopy (AFM) to support the LB findings. The LB findings were then utilized as a reference to prepare DPPC liposomes in this work. Results: The best mole ratio of DPPCDOPE PEG2000, determined to be 50 to 1, was used to study the interaction with the polyclonal antibody AS25. The free energy of mixing (〖Δ G〗_mix) of DPPC— DOPE PEG2000—AS25 was more negative than DPPC— AS25 in the entire investigated ranges, indicating that the ternary mixture of DPPC— DOPE PEG2000— AS25 was more compatible than the binary mixture of DPPC— AS25. The presence of DOPE PEG2000 in DPPC— AS25 increased the fluidity of the membrane, which resulted in a greater interaction of AS25 with DPPC. Conclusion: The constant values of particle size and zeta potential measurements of DPPC— DOPE PEG2000— AS25 liposomes showed agreement with the LB findings, indicating that LB is a good technique to predict precise liposomal formulations.

ANALISIS POWER OTOT LENGAN, KELENTUKAN DAN KOORDINASI MATA-TANGAN TERHADAP PUKULAN LOB PERMAINAN BULUTANGKIS

This article aims to determine the components of arm muscle power and eye-hand coordination on lob shots in badminton. The method used in analyzing it is in the form of library research. Collecting data on this article through an article indexing engine, namely Google Scholar with the keywords arm muscle power, hand eye coordination, lob strokes in badminton with publication limits from 2016 to 2020. The results obtained from 30 journals reviewed showed that the component of the lob stroke badminton is, speed, accuracy, agility and power. The contribution of each component varies greatly to produce a good technique for a badminton athlete. Conclusions from 30 that have been reviewed show that the needs for the lob component of badminton players are speed, accuracy, agility and maximum power. Each component must function optimally to support an athlete in official and unofficial competitions.

Stimulation of Phenolic Compounds Accumulation and Antioxidant Activity in In Vitro Culture of Salvia Tebesana Bunge in Response to Nano-TiO2 and Methyl Jasmonate Elicitors

In the present study, we first attempted to achieve an efficient procedure for optimizing callogenesis from apical meristem and leaf explants of S. tebesana on MS media containing different concentrations of BAP alone and in combination with 2,4-D. Then, the inducing effect of nano-TiO2 (10, 60, and 120 mg L− 1) and methyl jasmonate (50, 100, and 200 µM), as abiotic elicitors were studied on the enhancement of phenolic compounds, rosmarinic acid, and some individual flavonoids as well as antioxidant capacity of callus extracts. According to the results, the highest callogenesis rate (100 and 93.33, respectively) and DW (0.55 ± 0.03 and 0.36 ± 0.02 g, respectively) per responsive explant were achieved from apical meristem on MS media containing "BAP 1 + 2,4-D 1" mg L− 1 and from leaf explant on the medium supplemented with "BAP 0.5 + 2,4-D 1" mg L− 1. The elicitation with 10 and 60 mg L− 1 nano-TiO2 (respectively for apical meristem and leaf), and 50µM MeJa could significantly promote the production of predominant phenolic derivatives in S. tebesana calli, where the highest content of total phenolics, O-diphenols, phenolic acid, flavonoid, flavone and flavonol, proanthocyanidin was recorded. Additionally, in increasing the amount of rosmarinic acid of callus, nano-TiO2 treatment was more effective than the elicitation with MeJa. Also, the highest content of Apigenin (0.33 ± 0.02 µg g− 1 DW) was detected after MeJa-elicitation (50µM), while the maximum level of Quercetin (2.61 ± 0.09 µg g− 1 DW) and Rutin (13.79 ± 08 µg g− 1 DW) were obtained after exposure to 60 mg L− 1 nano-TiO2, both from leaf-derived calli. While a significant positive correlation was recorded between antioxidant assays (DPPH and FRAP) and phenolic derivatives of treated calli; a very strong correlation occurred between the content of rosmarinic acid of apical meristem-derived calli and DPPH and FRAP values (r2 = -0.921 and r2 = -0.913, P < 0.01 respectively). Our results showed that the combination of in vitro culture and elicitation would be a good technique to successfully produce and enhance the content of pharmacologically valuable metabolites in S. tebesana.