Mechanical

K16 motor domain. The crystal structure revealed that the length of the loop L5 was much shorter than that of conventional kinesin. Therefore, the novel conformation of the L5 of K16 may determine the unique enzymatic properties. Therefore, it is expected that photo regulation of ATPase activity of K16 by incorporation of photochromic molecules in to L5. We prepared the K16 mutants that have elongated different length L5. The result of these mutants ATPace activity suggests that the length of L5 is important for rice kinesin k16 ATPase activity. Subsequently, we have prepared the K16 mutant Q101C C214S and L5 KIF5A H101C C214S that have a single reactive cysteine reside in the L5. Photochromic molecule of azobenzene derivative PAM or spiropyran derivative MA-SP was incorporated into the cysteine residue to induce conformational change of L5 by ultraviolet and visible light irradiation. The ATPase activities of kinesin mutants modified by PAM or MA-SP showed reversible alteration by ultraviolet and visible light irradiations.

We have studied the phonon specific heat in single-layer, bilayer and twisted bilayer graphene. The calculations were performed using the Born-von Karman model of lattice dynamics for intralayer atomic interactions and spherically symmetric interatomic potential for interlayer interactions. We found that at temperature T<15 K, specific heat varies with temperature as T n , where n = 1 for graphene, n = 1.6 for bilayer graphene and n = 1.3 for the twisted bilayer graphene. The phonon specific heat reveals an intriguing dependence on the twist angle in bilayer graphene, which is particularly pronounced at low temperature. The results suggest a possibility of phonon engineering of thermal properties of layered materials by twisting the atomic planes.

We theoretically investigated phonon dispersion and specific heat in twisted bilayer graphene with various rotation angles. It was found that rotation affects the out-of-plane acoustic phonon modes the most. It was established, that the relative difference between specific heat in bilayer graphene without twisting and twisted bilayer graphene constitutes 10—15% at 1 K and 3—6% at 5 K in dependence on rotational angle. Obtained theoretical results contribute to a better understanding of the phonon processes in graphene and are important for the design of novel heat management applications.

Ben cana alam , kecelakaan lalu-lintas dan penuaan dapat menjadi penyebab tulang patah (bone fracture) dan keropos tulang . Salah satu teknik penyembuhan tulang yang rusak (bone defect) adalah dengan mengimplankan struktur tulang buatan atau skafol tulang yang dapat menginisiasi pertumbuhan jaringan tulang baru. Bone scaffold untuk aplikasi kerusakan tulang berpori (cancellous bone) yang terletak di bagian dalam struktur tulang. Dalam penelitian ini, diujikan pengaruh ukuran serbuk magnesium yang dipadukan dengan potongan titanium sebagai material penyangga (titanium pieces space holder) terhadap kualitas produk magnesium berpori untuk aplikasi skafol tulang. Titanium (Ti) pieces disiapkan dalam ukuran campur (random) dan berasal dari potongan kawat titanium murni (pure titanium wire) untuk dicampurkan dengan serbuk Magnesium (Mg) dengan ukuran 100, 200, dan 250µm. Campuran bahan tersebut kemudian dikompaksi dan dipanaskan (sintering) menggunakan alat squeeze casting untuk mendapatk...

Tapered cantilever beams, traditionally termed as leaf springs, undergo much larger deflections in comparison to a beam of constant cross-section that takes their study in the domain of geometric nonlinearity. This paper studies response of a leaf spring of parabolic shape, assumed to be made of highly elastic steel. Numerical simulation was carried out using both the small and large deflection theories to calculate the stress and the deflection of the same beam. Non-linear analysis is found to have significant effect on the beam&#39;s response under a tip load. It is seen that the actual bending stress at the fixed end, calculated by nonlinear theory, is 2.30-3.39% less in comparison to a traditional leaf spring having the same volume of material. Interestingly, the maximum stress occurs at a region far away from the fixed end of the designed parabolic leaf spring. Keywords: Parabolic leaf spring, End-shortening, Geometric nonlinearity, Equilibrium Configuration Path, Varying Cross...

This paper presents the design, development, and construction of an automated cane and bottle crusher. The primary objective is to create a portable and compact machine that can crush bottles and cans, facilitating recycling while minimizing human effort. The machine incorporates a single slider-crank mechanism, a fulcrum system, and basic automation features to achieve efficient crushing. This project also includes a comprehensive study of forces, design elements, and manufacturing processes, ensuring user ergonomics and ease of maintenance. Key components, such as pulleys, belts, an induction motor, and a speed reducer, are detailed. The paper concludes with the successful assembly and testing of the machine, demonstrating its effectiveness in recycling applications.

Clinical treatments of skeletal muscle weakness are hindered by a lack of an approach to evaluate individual muscle force. Intramuscular pressure (IMP) has shown a correlation to muscle force in vivo, but patient to patient and muscle to muscle variability results in difficulty of utilizing IMP to estimate muscle force. The goal of this work was to develop a finite element model of whole skeletal muscle that can predict IMP under passive and active conditions to further investigate the mechanisms of IMP variability. A previously validated hypervisco-poroelastic constitutive approach was modified to incorporate muscle activation through an inhomogeneous geometry. Model parameters were optimized to fit model stress to experimental data, and the resulting model fluid pressurization data were utilized for validation. Model fitting was excellent (root-mean-square error or RMSE <1.5 kPa for passive and active conditions), and IMP predictive capability was strong for both passive (RMSE 3.5 mmHg) and active (RMSE 10 mmHg at in vivo lengths) conditions. Additionally, model fluid pressure was affected by length under isometric conditions, as increases in stretch yielded decreases in fluid pressurization following a contraction, resulting from counteracting Poisson effects. Model pressure also varied spatially, with the highest gradients located near aponeuroses. These findings may explain variability of in vivo IMP measurements in the clinic, and thus help reduce this variability in future studies. Further development of this model to include isotonic contractions and muscle weakness would greatly benefit this work.

In this study a modified version of the Conditional Source Estimation (CSE) model has been developed. It is assessed on a diffusion flame (SANDIA Flame D) and a 1m diameter methane pool fire. In both cases it has been found that mean mass species concentration, temperature, scalar and velocity fields agree reasonably well with the experiments. The main goal of this paper is to prove the possibility of employing the CSE as a model of low computational cost for large fire simulations. The work also highlights the importance of soot and radiation models in large scale fires.

In combustion applications, the weighted-sum-of-grey-gases (WSGG) model is widely used because it is computationally efficient, but it often yields relatively large errors. The objective of this study is to examine the effect of radiation models on CFD predictions of flame spread. To this end, a statistical narrow band (SNB) model and the WSGG model are employed for the simulation of two upward flame spread scenarios, one being a largescale flame spread over a vertical PMMA wall while the other representing flame spread along vertical corner walls. The entire flame spread model also consists of a fourequation turbulence model, an eddy-break-up (EBU) combustion model, a discrete transfer (DT) radiation model, a simple soot model and a non-charring pyrolysis model. Quantitative comparison is made between the prediction results obtained with the SNB model and the WSGG model as well as the experimental data. Results clearly show that the SNB model yields more accurate results than the WSGG approach. However, the SNB model is about four to five times more time consuming than the WSGG model. Therefore, for simulations of complex engineering applications a compromise between accuracy and numerical efficiency should be taken into account.

The eddy dissipation concept (EDC) for turbulent combustion modeling was originally proposed by Magnussen in the Reynolds averaged Navier-Stokes (RANS) context. This study has extended it to the large eddy simulation (LES) framework. Since the fine structures in EDC are still not resolved in LES, they are modeled with SGS turbulent kinetic energy and its dissipation rate instead of the mean quantities in RANS. A new expression is proposed for the reacting fraction of the fine structures to alleviate the limitations of the original formula. Three fire cases including a 7.1 cm methane fire, a 30 cm heptane fire and a 30.5 cm methanol fire are simulated to verify the improved EDC (M-EDC), which has been implemented in the FireFOAM solver. The predictions from the M-EDC are found to be in reasonably good agreement with the measurements, while the original EDC tends to under-predict temperature and velocity.

Numerical simulations are carried out for a highly under-expanded hydrogen jet resulting from an accidental release of high-pressure hydrogen into the atmospheric environment. The predictions are made using two independent CFD codes, namely CFX and KIVA. The KIVA code has been substantially modified by the present authors to enable large eddy simulation (LES). It employs a oneequation sub-grid scale (SGS) turbulence model, which solves the SGS kinetic energy equation to allow for more relaxed equilibrium requirement and to facilitate high fidelity LES calculations with relatively coarser grids. Instead of using the widely accepted pseudo-source approach, the complex shock structures resulting from the high under-expansion is numerically resolved in a small computational domain above the jet exit. The computed results are used as initial conditions for the subsequent hydrogen jet simulation. The predictions provide insight into the shock structure and the subsequent jet development. Such knowledge is valuable for studying the ignition characteristics of high-pressure hydrogen jets in the safety context.

A possible consequence of pressurized hydrogen release is an under-expanded jet fire. Knowledge of the flame length, radiative heat flux and fraction as well as the effects of variations in ground reflectance is important for safety assessment. The present study applies an open source CFD code FireFOAM to study the radiation characteristics of hydrogen and hydrogen/methane jet fires. For combustion, the eddy dissipation concept for multi-component fuels recently developed by the authors in the large eddy simulation (LES) framework is used. The radiative heat is computed with the finite volume discrete ordinates model in conjunction with the weighted-sum-of-gray-gases model for the absorption/emission coefficient. The pseudo-diameter approach is used in which the corresponding parameters are calculated using the correlations of Birch et al. . The predicted flame length and radiant fraction are in good agreement with the measurements of Schefer et al. Studer et al. [3] and Ekoto et al. [6]. In order to account for the effects of variation in ground surface reflectance, the emissivity of hydrogen flames was modified following Ekoto et al. . Four cases with different ground reflectance are computed. The predictions show that the ground surface reflectance only has minor effect on the surface emissive power of the hydrogen jet fire. The radiant fractions fluctuate from 0.168 to 0.176 close to the suggested value of 0.16 by Ekoto et al.[6] based on the analysis of their measurements.

The discrete ordinates and finite volume methods used in most fire simulations codes for radiative transfer calculations suffer from high computing overheads. A procedure based on two-step iterative method is suggested to simplify time-consuming spectral radiative transfer calculations in open flames containing scattering particles. At the first step of the problem solution, the P1 approximation is used to calculate the divergence of radiative flux, and it is sufficient to determine the flame parameters. The second step of solution is necessary to obtain the radiation field outside the flame, and this can be made independently using the raytracing procedure and the transport source function determined at the first step. Such a splitting of the complete problem results in much simpler algorithm than those used traditionally. It has been proved in previous papers that the combined two-step method is sufficiently accurate in diverse engineering applications, especially in the scattering media. At the same time, the computational time decreases in about two orders of magnitude as compared with direct methods. An axisymmetric pool fire suppressed by a water spray is considered as the case problem in the present paper to analyze the effect of radiation scattering by evaporating water droplets. The strong effect of scattering on radiative power field in the flame is obtained computationally for the first time.

The aim, herein, was to prove that the analysis of the stress concentration phenomenon with simulation methods provides results that fit those obtained experimentally, thus, corroborating that simulation is a powerful tool that minimizes costs and time in the construction of stress concentrator curves. The experimental curves of stress concentration factors available in the scientific literature can be recreated through simulations, achieving results with low errors. Due to this, geometries were selected with different shape ratios for study; these were developed in the DesingModeler® module of the ANSYS Workbench®, then meshed in the Mechanical® module, and three types of load were applied in their borders: axial force, flexing moment, and torsional moment; these were configured in the StaticStructural® module. After obtaining the maximum force and having calculated the nominal force, these were related by calculating the concentration factor to plot it against the geometric parameter modified during the virtual experimentation. In the end, these were compared with the experimental curves consulted. With the results obtained, it was concluded that it is possible to construct curves of stress concentration factor through simulations, with the same reliability as with conventional experimental methods, but at a lower cost.

Orthopedic implants require porosity gradients to achieve tissue integration and mechanical support. This study presents a novel design of Multidirectional Functionally Graded (MDFG) porous Ti6Al4V scaffolds, fabricated via Laser Powder Bed Fusion (LPBF) to mimic natural bone porosity for orthopedic applications. Four scaffold types were developed: Gyroid and Primitive (sheet-based TPMS) and Kelvin and Voronoi (strut-based lattices). A pore size of 1000 µm was maintained to promote tissue ingrowth, while strut thickness grading (0.3-0.7 mm) enhanced mechanical stability. Quasi-static compression tests showed Young's moduli of 9.5 GPa (Gyroid) and 9.3 GPa (Primitive), with ultimate strengths of 240 MPa and 190 MPa, respectively. Energy absorption was 47.74 MJ/m 3 for Gyroid and 46.68 MJ/m 3 for Primitive, demonstrating excellent resistance to mechanical failure. Fatigue testing revealed that the Gyroid lattice sustained 25 MPa after one million cycles, highlighting its long-term durability. Fractographic analysis showed that fatigue cracks initiated at surface defects and propagated along strut intersections, providing insights into failure mechanisms. These findings confirm that MDFG scaffolds, particularly Gyroid and Primitive lattices, enhance mechanical robustness and biological compatibility, making them strong candidates for load-bearing orthopedic implants.

An operating mechanic system can experience excessive vibrations if the forces acting in this system close to the natural frequency. Excessive vibration can cause damage, so it needs to be reduced. One of the ways to reduce excessive vibration, especially in system which vibrate with a single frequency, is adding DVA (Dynamic Vibration Absorber). In this study, there were simulations of non-DVA and T-DVA (Triple Dynamic Vibration Absorber) systems which DVA is arranged in series in the main system to get the RMS and amplitude of vibration response. This study used excitation in configuration model in the form of unbalance mass. Configuration model was derived, so, it was obtained equation variable state. From the equation, it was simulated by software. From this simulation, it could be concluded that DVA addition where cantered main mass of gravity center was able to reduce the vibration in yu rms dva distance system of 0.8182 m, 0.5628 m, and 0.2046m, yu rms dva mass system was 0.8911 m, 0.5242 m, and 0.3713m, and the respond result decreased, so, excitation frequency exceeded and known the natural frequency of the system.

Cyclic stretch is an important inducer of vascular smooth muscle cell (VSMC) proliferation, which is crucial in vascular remodeling during hypertension. However, the molecular mechanism remains unclear. We studied the effects of emerin and lamin A/C, two important nuclear envelope proteins, on VSMC proliferation in hypertension and the underlying mechano-mechanisms. In common carotid artery of hypertensive rats in vivo and in cultured cells subjected to high (15%) cyclic stretch in vitro, VSMC proliferation was increased significantly, and the expression of emerin and lamin A/C was repressed compared with normotensive or normal (5%) cyclic stretch controls. Using targeted siRNA to mimic the repressed expression of emerin or lamin A/C induced by 15% stretch, we found that VSMC proliferation was enhanced under static and 5%-stretch conditions. Overexpression of emerin or lamin A/C reversed VSMC proliferation induced by 15% stretch. Hence, emerin and lamin A/C play critical roles in su...

Ti-Si-C-ON films were deposited by DC reactive magnetron sputtering using different partial pressure of oxygen (p O2 ) and nitrogen (p N2 ) ratio. Compositional analysis revealed the existence of two different growth zones for the films; one zone deposited under low p O2 /p N2 and another zone deposited under high p O2 /p N2 . The films produced under low p O2 /p N2 were deposited at a lower rate and presented a fcc structure, as well as, dense and featureless morphologies. The films deposited with high p O2 /p N2, consequently higher oxygen content, were deposited at a higher rate and developed an amorphous structure. The structural changes are consistent with the hardness and Young's modulus evolution, as seen by the significant reduction of the hardness and influence on the Young's modulus by increasing p O2 /p N2.

Pengawetan makanan merupakan salah satu hal penting dalam menanggulangi kelangkaan pangan. Hal ini disebabkan karena teknologi pengawetan makanan dapat memberikan dampak besar terhadap penyimpanan makanan. Salah satu produk yang paling banyak diminati saat ini adalah asap cair. Asap cair sendiri merupakan hasil kondensasi asap dari bahan dengan kandungan selulosa dan hemiselulosa, hingga menjadi asap cair yang dengan senyawa yang terkandung dapat mengawetkan makanan seperti daging dan ikan. Pada penelitian ini, dilakukan analisis karakter dari produk asap cair yang dibuat dengan variasi bahan baku, yaitu cangkang kemiri dan sekam padi (V1=100% cangkang kemiri, V2=70% cangkang kemiri dan 30% sekam padi, V3=50% cangkang kemiri dan 50% sekam padi. Hasil yang didapatkan dianalisis karakteristiknya berdasarkan rendemen, nilai pH, bobot jenis, dan kandungan asam asetat. Hasil yang didapatkan adalah rendemen terbaik adalah pada V3 yaitu 2,32. Nilai pH terendah adalah pada V1 yaitu 3,62. Bo...

Nyamplung (Calophyllum inophyllum) adalah tanaman hutan yang mempunyai potensi besar sebagai bioenergi. Biji nyamplung diolah menjadi minyak (biofuel). Pengolahan ini, menghasilkan limbah berupa bungkil nyamplung (press cake). Serat kasar dan protein tinggi yang terkandung pada limbah nyamplung belum dimanfaatkan secara maksimal. Penelitian ini bertujuan untuk meningkatkan kualitas bahan bakar padat dari limbah nyamplung (Calophyllum inophyllum) menggunakan konversi biomassa dengan teknologi hydrothermal. Penelitian ini menggunakan metode eksperimen dengan perlakuan hydrothermal, dilakukan pada variasi suhu 160°C, 190°C dan 220°C; holding time 30 menit dan 60 menit; dan variasi rasio antara limbah nyamplung dan air, yaitu 1:4 dan 1:5 pada suhu 190°C. Pengujian nilai kalor dan analisis proksimat juga dilakukan untuk mengetahui kualitas bahan bakar padat dari limbah nyamplung. Hasil pengujian menunjukkan nilai kalor tertinggi terdapat pada variasi suhu 220°C, holding time 60 menit yaitu 4148,8471 cal/gr. Sedangkan nilai kalor pada variasi rasio 1:5, holding time 60 menit yaitu 3883,8458 cal/gr. Nilai tersebut memenuhi standar kualitas batubara American Standard Testing and Mineral (ASTM), yaitu jenis batubara lignit (3500-4611 cal/gr). Analisis proksimat menunjukkan penurunan kadar air (1,8669%), kadar abu (12,3541%), kadar volatil (54,0331%), dan peningkatan kadar karbon (31,7459%), seiring dengan peningkatan variasi suhu dan holding time. Sedangkan, seiring peningkatan variasi rasio kompoisi air dan holding time, menunjukkan penurunan kadar air (1,6532%), kadar abu (11,2971%), dan peningkatan kadar volatil (61,7284%), serta kadar karbon (26,9536%). Hasil ini membuktikan adanya peningkatan kualitas bahan bakar padat limbah nyamplung secara signifikan. Oleh karena itu, hydrothermal adalah solusi tepat teknologi konversi biomassa yang mampu meningkatkan kualitas bahan bakar padat ramah lingkungan.

The synthesis of natural silica-based mesoporous silica is continuously being carried out, especially to obtain silica with high crystallinity and larger pores from high water absorption. In this study, the synthesis of mesoporous silica using the sol-gel method by adding hexane and varying the mass addition of Pluronic 104 surfactant (2 g, 4 g, 6 g). The synthesized silica was characterized using XRD, and the absorption capacity analysis was manual. The results of measurements using XRD showed that the diffraction pattern appeared as the relevant peak for the three products with standard mesopore silica diffraction patterns, namely wide and low peaks at 2ϴ 22.7; 21.8; 22.1 for the products SM02, SM04 and SM06 respectively. Meanwhile, the highest intensity / crystallinity given by the SM06 sample.

We investigated the effects of operator-applied force on diffuse optical spectroscopy (DOS) by integrating a force transducer into the handheld probe. Over the typical range of contact forces measured in the breasts of eight patients, absorption and reduced scattering coefficients (650 to 1000 nm) variance was 3.1 ± 1.0% and 1.0 ± 0.4%. For trained operators, we observed <5% variation in hemoglobin and <2% variation in water and lipids. Contact force is not a significant source of variation, most likely because of a relatively wide probe surface area and the stability of the DOS method for calculating tissue optical properties.

The primary objective of the study is to analyse the aerodynamic loads exerted on the cooling tower through wind
analysis. This examination aims to comprehend the impact of aerodynamic forces on the structural integrity and
stability of the cooling tower. Furthermore, the study encompasses thermal and fluid dynamic analyses to evaluate
the heat dissipating rate from the cooling tower. The research considers the variables of heat exchanger
temperature and air mass flow rate to comprehensively understand the heat dissipation process. By varying these
parameters, the researchers aim to assess their influence on the efficiency of heat dissipation and optimize the
cooling tower's performance. overall, this study contributes to advancing understanding in the field of thermal
power generation by providing insights into the aerodynamic behaviour and thermal performance of cooling
towers. The findings derived from this research could potentially inform the design and operation of cooling
systems in thermal power stations, thereby enhancing their efficiency and sustainability.

Force measurement results from this study have revealed that the degree of performance enhancement possible for an airfoil with tubercles is not significantly influenced by three-dimensional effects at Reynolds number, Re = 120,000. Therefore, based on the present results and the available literature, it is postulated that the effectiveness of tubercles as a passive flow control mechanism is more dependent on the Reynolds number than on three-dimensional effects.

The end-product of the electrospinning process is typically a randomly aligned fiber mesh or membrane. This is a result of the electric field generated between the drop of polymer solution at the needle and the collector. The developed electric field causes the stretching of the fibers and their random deposition. By judicious selection of the collector architecture, it is thus possible to develop other morphologies on the nanofiber meshes. The aim of this work is to prepare fiber meshes using various patterned collectors with specific dimensions and designs and to evaluate how those patterns can affect the properties of the meshes relevant to biomedical applications. This study aims at verifying whether it is possible to control the architecture of the fiber meshes by tailoring the geometry of the collector. Three different metallic collector topographies are used to test this hypothesis. Electrospun nonwoven patterned meshes of polyethylene oxide (PEO) and poly( -caprolactone) (PC...

Foremost, I would like to express my sincere gratitude to my advisor Dr. Syed Sohail Akhtar for the continuous support of my MSc study and research, for his patience, motivation, enthusiasm, and immense knowledge. His guidance helped me in all the time of research and writing of this thesis. I could not have imagined having a better advisor and mentor for my MSc study. Besides my advisor, I would like to thank the rest of my thesis committee: Prof. Abul Fazal M. Arif, and Dr. Khalid Al-Athel, for their encouragement, insightful comments, and hard questions. I would also like to extend my sincere gratitude to my graduate coordinator, Dr. Esmail M. A. Mokheimer, and the mechanical engineering chairman, Dr. Zuhair M. Gasem, for giving me all the required support at KFUPM. I thank my fellow labmates in Stress Analysis Lab.: Khalid Naseem, Osama Siddiqui, and Aliyu Arisekola, for the stimulating discussions, and for the sleepless nights we spent together. Also I thank all my friends in KFUPM.

Background: Lung protective mechanical ventilation (MV) is the corner stone of therapy for ARDS. However, its use may be limited by respiratory acidosis. This study explored feasibility of, effectiveness and safety of low flow extracorporeal CO 2 removal (ECCO 2 R). Methods: This was a prospective pilot study, using the Abylcap® (Bellco) ECCO 2 R, with crossover off-on-off design (2-h blocks) under stable MV settings, and follow up till end of ECCO 2 R. Primary endpoint for effectiveness was a 20% reduction of PaCO 2 after the first 2-h. Adverse events (AE) were recorded prospectively. We included 10 ARDS patients on MV, with PaO 2 /FiO 2 < 150 mmHg, tidal volume ≤ 8 mL/kg with positive end-expiratory pressure ≥ 5 cmH 2 O, FiO 2 titrated to SaO 2 88-95%, plateau pressure ≥ 28 cmH 2 O, and respiratory acidosis (pH <7.25). Results: After 2-h of ECCO 2 R, 6 patients had a ≥ 20% decrease in PaCO 2 (60%); PaCO 2 decreased 28.4% (from 58.4 to 48. 7 mmHg, p = 0.005), and pH increased (1.59%, p = 0.005). ECCO 2 R was hemodynamically well tolerated. During the whole period of ECCO 2 R, 6 patients had an AE (60%); bleeding occurred in 5 patients (50%) and circuit thrombosis in 3 patients (30%), these were judged not to be life threatening. In ARDS patients, low flow ECCO 2 R significantly reduced PaCO 2 after 2 h, Follow up during the entire ECCO 2 R period revealed a high incidence of bleeding and circuit thrombosis. Trial registration: identifier: NCT01911533, registered 23 July 2013.

Peat can be fourth energy resources in Indonesia, after oil coal and natural gas. With 27 million hectares, Indonesia peat resources area is the third largest in the world, after Canada and Russia. In the current years, peat utilization as energy is very limited. The development of peat energy resources is expected to support the objective of the National Energy Management Blueprint 2006-2025. However, the environmental aspect of this matter should be emphasized Torrefaction is a thermal process appiled to organic materials operated at medium temperature, in absence of oxygen and at relatively long residence times, typically 10 to 60 minutes. The properties, such as heating value, fix char content, are improved through limited devolatilisation that occurs under these conditions. Batch torrefaction experiment showed that the heating value of the torrefied peat was at the level of subbitminuous C to bituminuous high volatile C of ASTM D 388 coal classification. A development of a labo...

The use of wind energy for energy generation is one of the oldest methods for harnessing renewable energy. Use of renewable energy is an essential ingredient of socio-economic development and economic growth. Renewable energy sources such as wind energy, tidal energy etc. is abundant and can help in reducing the dependency on fossil fuels. With increased concern for environment now days led to the research for more environment friendly sources of energy and with this considerations wind energy can be considered as a viable option in this regard. Different configurations of wind turbines such as horizontal axis wind turbine and vertical axis wind turbines are mainly used for energy extraction. Horizontal axis mainly used in large scale applications and thus its implementation is generally a concern due to huge installment setup and initial cost; whereas vertical axis wind turbines offer promising solution for smaller ruler areas or medium sized residential spaces. Energy generation f...

An experimental study was conducted to characterize the heat affected zone produced when laser heating a Ti6Al4V alloy plate workpiece. The emissivity and absorptivity of the Ti6Al4V alloy were determined experimentally. A 3D transient finite element method for a moving Gaussian laser heat source was developed to predict the depth and width of the heat affected zone on the Ti6Al4V alloy workpiece. There was a close correlation between the experimental data and the simulation results. It was found that the depth and width of the heat affected zone were strongly dependent on the laser parameters (laser power, laser scan speed, the angle of incidence and the diameter of the laser spot) and material properties (thermal conductivity, specific heat and density). Parametric studies showed that the depth and width of the heat affected zone increased with an increase in the laser power and decreased with an increase of the laser spot size and the laser scan speed. The thermal model can be used to determine the laser parameters for a given cut geometry that will yield no residual heat affected zone in the material after cutting. This provides the basis to optimize and improve laser assisted machining technique.

Peningkatan jumlah kendaraan bermotor saat ini mengakibatkan pemakaian bahan bakar minyak bumi semakin meningkat. Peningkatan pemakaian bahan bakar minyak bumi maka akan menyebabkan krisis energi. Krisis energi ini menyebabkan manusia beralih pola pikir untuk lebih mengintensifkan penelitian dan penggunaan dari energi yang tidak dapat diperbarui ke energi yang dapat diperbarui. Salah satu sumber energi yang dapat diperbarui tersebut adalah berasal dari biomass yang diproses menjadi bioethanol. Campuran bioethanol dan premium belum cukup untuk menaikkan angka oktan karena di era saat ini tuntutan kebutuhan bahan bakar dengan nilai angka oktan tinggi untuk meningkatkan unjuk kerja mesin semakin meningkat. Salah satu cara untuk memenuhi kebutuhan tersebut, maka perlu penambahan octane booster untuk meningkatkan nilai oktan. Variasi yang digunakan pada penelitian ini adalah variasi biopremium 0, E 5 , E 10 , E 15 , dan E 20 dan variasi penambahan 0.05% dan 0.08% octane bosster. Dalam penelitian ini menggunakan bioethanol dari tetes tebu dan octane booster merk Preston octane booster. Data yang diperoleh dari hasil eksperimen dimasukkan ke dalam tabel dan ditampilkan dalam bentuk grafik yang kemudian akan dianalisa dan ditarik kesimpulannya, sehingga dapat diketahui persentase perubahan performa mesin pada Honda Vario CBS 2011 yang menggunakan biopremium 0.05% dan 0.08% octane booster. Berdasarkan hasil penelitian dapat disimpulkan bahwa penggunaan bahan bakar 0 5 , E 5 , E 10 , E 15 , dan E 20 0.05% octane booster pada motor Honda Vario CBS tahun 2011 dapat meningkatkan torsi (torque), daya (power), tekanan efektif rata-rata dan menurunkan konsumsi bahan bakar karena pada biopremium tersebut mengalami peningkatan pada torsi, peningkatan daya, penurunan konsumsi bahan bakar dan peningkatan tekanan efektif rata-rata. Torsi meningkat pada putaran 2000 rpm sebesar 0.52%. Daya meningkat pada putaran 3000 rpm sebesar 0.95%. Konsumsi bahan bakar menurun pada putaran 3500 rpm sebesar 24.8%. Tekanan efektif rata-rata meningkat pada putaran 5000 rpm sebesar 3.62%.

Sample handling in miniaturized bioanalytical instruments typically depends on pressure or electrokinetic effects. This is particularly true of post-separation detection processes where a sample is moved past a single point detector. In contrast to such methods, the present study investigates a separation system that takes advantage of a steady-state, stationary separation technique known on the macroscale as capillary isoelectric focusing (cIEF). Due to the stationary nature of the final separation, sample analysis is conducted entirely without mobilization. This work explores the merits and limitations associated with miniaturizing this technique. Analyses were conducted on fluorescent peptide and protein samples in miniaturized separation columns (capillaries and glass micromachined channels between 8 and 14 mm long). In the interest of developing overall system portability, blue light emitting diodes (LED’s) were used for sample excitation. Detection was accomplished using a cha...

El tema de dignidad se encuentra comprendido dentro de la extensa gama de los derechos humanos, inclusive se puede señalar podría ser el más importante de los derechos fundamentales, y es por este motivo que cuando a una persona se le violenta su fundamental derecho humano, se ha llegado a tipificar como un delito de naturaleza internacional. suFraGio 32 artículos La dignidad como derecho fundamental del hombre

In this paper, forced convective heat transfer in a water based nanofluid has experimentally beencompared to that of pure water in an automobile radiator. Five different concentrations of nanofluids inthe range of 0.1-1 vol.% have been prepared by the addition of TiO2 nanoparticles into the water. Thetest liquid flows through the radiator consisted of 34 vertical tubes with elliptical cross section and airmakes a cross flow inside the tube bank with constant speed. Liquid flow rate has been changed in therange of 90-120 l/min to have the fully turbulent regime. Results demonstrate that increasing the fluid circulating rate canimprove the heat transfer performance. Meanwhile, application of nanofluid with low concentrations can enhance heat transfer efficiency up to45% in comparison with pure water. Keywords— Nanofluid, Heat transfer coefficient, TiO2, Radiator, Cooling performance, Experimental

Unsteady natural convection due to differentially heating of the sinusoidal corrugated side walls of a modified square enclosure has been numerically investigated. The fluid inside the enclosure is air, initially as quiescent. The flat top and bottom surfaces are considered as adiabatic. The numerical scheme is based on the finite element method adapted to triangular non-uniform mesh element by a non-linear parametric solution algorithm. The results are obtained for the Rayleigh number, Ra ranging from 1e+ 05 to 1e+ 08 for ...

1 Research student Department of Mechanical Engineering, P.V.P.I.T, Budhgaon, Sangli, Maharashtra, India 2 Associate Professor, Department of Mechanical Engineering, P.V.P.I.T, Budhgaon, Sangli, Maharashtra, India ---------------------------------------------------------------------***---------------------------------------------------------------Abstract—The Parabolic Dish Solar Collector technology is very useful as it is used for approximately all solar energy applications such as steam and power generation, water heating, air heating etc. In this paper work the performance analysis of parabolic solar dish collector is done with the use of different reflecting materials. In this work a Parabolic Dish Solar Collector system is fabricated for hot water production. Water is used as a working fluid and is recirculates from the storage tank to the absorber tank with the help of a pump. The main aim in the work is to increase the temperature of water in the storage tank to a maximum va...

This paper investigated, using experimental method, the suitability of acoustic emission (AE) technique for the condition monitoring of diesel engine valve faults. The clearance fault was adjusted experimentally in an exhaust valve and successfully detected and diagnosed in a Ford FSD 425 four-cylinder, four-stroke, in-line OHV, direct injection diesel engine. The effect of faulty exhaust valve clearance on engine performance was monitored and the difference between the healthy and faulty engine was observed from the recorded AE signals. The measured results from this technique show that using only time domain and frequency domain analysis of acoustic emission signals can give a superior measure of engine condition. This concludes that acoustic emission is a powerful and reliable method of detection and diagnosis of the faults in diesel engines and this is considered to be a unique approach to condition monitoring of valve performance.

Fiber-reinforced composite core banana stems with additional filler of husk powder is another way to obtain the expected mechanical behavior of the composite. The aim of this study was to analyze the effect of fiber volume fraction content to density, bending strength and tensile strength of sandwich composite.   Preparation of composite was done by hand lay-up method. Composite material used by banana ketip  fiber and addition of husk powder with variation of fiber volume fraction were 7, 10, and 13 % where husk was constant at 5% with random fiber direction. Tests were conducted by referring to the density est standard (ASTM C 271), bending est (ASTM C 393) and tensile test (ASTM D3039).  The result showed that the greater volume fraction of banana fiber, the lower the density value and the lower the bending strength. Whereas the tensile strength tended to increase as the volume fraction was higher.

This project deal with design, development and fabrication of "Development of multipurpose machine". This machine is designed for the purpose of multi-operations i.e. drilling, cutting and grinding. This machine perform multipurpose operation at same lime with required speed & this machine is automatic which is controlled or operated which is run with the help of current. This machine is based on the mechanism of scotch yoke. The project aims at designing and developing a multipurpose machine tool which is capable of performing multiple tasks simultaneously. The machine is operated by giving drive to the main shaft to which worm gear mechanism is directly attached; worm gear mechanism is used for sawing operation. On the main shaft bevel gear mechanism was used for transmitting power. These bevel gears are used to transmit motion in the radial direction and drives drilling centre. The Grinding wheel is directly connected to the motor shaft. This model facilitates to complete three operations simultaneously with a single power source. This model of the multi operational machine is may be used in industries and domestic operation which can perform mechanical operation like drilling, cutting & shaping of a thin by motor metallic as well as wooden model or body.

Penanganan ikan yang tepat dan benar dapat meningkatkan kualitas ikan di kapal penangkap ikan. Untuk itu diperlukan sistem pendinginan yang efektif dan efisien untuk kapal ikan terutama pada kapal ukuran 30 GT. Penelitian ini bertujuan untuk mendapatkan prototipe mesin pendingin yang hemat energi dan efektif dalam meningkatkan kualitas hasil tangkapan di KM. Inka Mina 210. Metode yang digunakan adalah pembuatan eksperimen mesin pendingin dengan menggunakan evaporator yang memiliki celah (gap) sebesar 1 mm yang disebut narrow gap evaporator dan kompresor dc mikro. Percobaan dilakukan dengan menggunakan 3 variasi beban pendinginan. Hasil yang diperoleh adalah variasi beban pada sistem refrigerasi kompak dapat meningkatkan nilai COP pada kerja refrigerasi sebesar 1.86 % hingga 21,9 % dari variasi tanpa beban. Kenaikan ∆T saturasi pada proses pendidihan meningkatkan nilai fluks kalor (heat fluks). Selain itu, semakin besar fluks kalor yang dihasilkan maka koefisien perpindahan kalor pad...

The author has granted a nonexclusive license allowing Library and Archives Canada to reproduce, publish, archive, preserve, conserve, communicate to the public by telecommunication or on the Internet, loan, distrbute and sell theses worldwide, for commercial or noncommercial purposes, in microform, paper, electronic and/or any other formats.