scholarly journals Study on Rigidity Coefficient of Silicon Beams of Micromechanical Resonance Accelerometers

2017 ◽  
Vol 22 (3) ◽  
pp. 276-284
Author(s):  
Thura Aung Thura ◽  
◽  
B.M. Simonov ◽  
S.P. Timoshenkov ◽  
◽  
...  
Keyword(s):  
Rigidity Coefficient ◽  
Silicon Beams

MORPHOLOGICAL PROPERTIES OF HURA CREPITANS L. (EUPHORBIACEAE) AS PROSPECTIVE RESOURCE FOR PULP AND PAPERMAKING

2021 ◽  
Vol 5 (1) ◽  
pp. 186-192
Author(s):  
E. T. Tembe ◽  
David Oriabure Ekhuemelo ◽  
R. Astuwe
Keyword(s):  
Slenderness Ratio ◽  
Fibre Diameter ◽  
Pulp And Paper ◽  
Morphological Properties ◽  
Randomized Design ◽  
Short Fibres ◽  
Hura Crepitans ◽  
Rigidity Coefficient ◽  
High Flexibility ◽  
Fibre Characteristics

Hura crepitans L. (Euphorbiaceae) is a tropic tree species that was investigated for pulp and paper characteristics in this study. The diameters of five (5) different stands of Hura crepitans trees were first determined using diameter tape. Wood slivers were obtained from sapwood of the trees parallel to grain and at three (3) different positions along the axis, at the base (5%), middle (50%) and top (90%). The wood slivers were macerated in a mixture of equal volumes of glacial acetic acid and hydrogen peroxide at between 80 -100 degrees Celsius for 2 hours. Macerated fibres were washed and used to prepare microscopic slides where 15 fibres were measured per slide. Data recorded was subjected to One-way Analysis of Variance (ANOVA) based on Completely Randomized Design (CRD). Results show that both the primary fibre characteristics and derived characteristics were significantly different at p<0.05? The mean fibre characteristics ranged as follows, Fibre lengths (0.87-1.16 mm), Fibre diameter (18.84 - 24.44 µm), Lumen width (9.92-16.89 µm) and Cell wall thickness (3.93-4.60 µm). The derived mean fibre characteristics ranged as follows; Runkel ratio (0.36-0.78), Elasticity coefficient (44.20-67.91%), Rigidity coefficient (15.98-27.82 %) and Slenderness ratio (0.44-0.80). This result implies that Hura crepitans has short fibres with high flexibility, which can collapse easily and form a fully bonded paper and is therefore recommended for pulp and paper production

scholarly journals Design and fabrication of a microelectromechanical system resonator based on two orthogonal silicon beams with integrated mirror for monitoring in-plane magnetic field

2019 ◽  
Vol 11 (7) ◽  
pp. 168781401985368 ◽  
Author(s):  
Jesús Acevedo-Mijangos ◽  
Antonio Ramírez-Treviño ◽  
Daniel A May-Arrioja ◽  
Patrick LiKamWa ◽  
Héctor Vázquez-Leal ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Finite Element Method ◽  
Finite Element ◽  
Resonant Frequency ◽  
Microelectromechanical Systems ◽  
Analytical Models ◽  
Complex Signal ◽  
Bending Vibration ◽  
Element Method ◽  
Silicon Beams

We present a resonant magnetic field sensor based on microelectromechanical systems technology with optical detection. The sensor has single resonator composed of two orthogonal silicon beams (600 µm × 26 µm × 2 µm) with an integrated mirror (50 µm × 34 µm × 0.11 µm) and gold tracks (16 µm × 0.11 µm). The resonator is fabricated using silicon-on-insulator wafer in a simple bulk micromachining process. The sensor has easy performance that allows its oscillation in the first bending vibration mode through the Lorentz force for monitoring in-plane magnetic field. Analytical models are developed to predict first bending resonant frequency, quality factor, and displacements of the resonator. In addition, finite element method models are obtained to estimate the resonator performance. The results of the proposed analytical models agree well with those of the finite element method models. For alternating electrical current of 30 mA, the sensor has a theoretical linear response, a first bending resonant frequency of 43.8 kHz, a sensitivity of 46.1 µm T−1, and a power consumption close to 54 mW. The experimental resonant frequency of the sensor is 53 kHz. The proposed sensor could be used for monitoring in-plane magnetic field without a complex signal conditioning system.

Load-bearing capacity and characteristic forms of destruction of furniture joints made with rastex 15 and P-10 clamex fasteners

2019 ◽  
Vol 106 ◽  
pp. 38-48
Author(s):  
Maciej Sydor ◽  
PIOTR POHL
Keyword(s):  
Bearing Capacity ◽  
Load Capacity ◽  
Bending Moment ◽  
Shear Forces ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Angular Deflection ◽  
Maximal Load ◽  
Rigidity Coefficient ◽  
The Relationship

Load-bearing capacity and characteristic forms of destruction of furniture joints made with rastex 15 and P-10 clamex fasteners. The study tested the relationship between the load and angular deflection in furniture joints. The tests were carried out for two types of fasteners and five types of materials: chipboard, MDF, hardwood plywood, glued pine boards and glued oak boards. The furniture joint samples contained two fasteners preloaded only with a bending moment (without application of shear forces). The results were converted per single fastener specifying: its maximal load capacity, 50 mrad (2.9°) limit deflection and rigidity coefficient. It was found that rigidity is a better structural property of the tested joint types than their load capacity. As far as rigidity is concerned, the most durable is the combination of oak glued board – rastex 15 fastener (13.2 Nm bending moment per fastener), while the least durable combination is chipboard – clamex P-10 fastener (4.8 Nm bending moment per fastener). Photographic documentation of damaged furniture joint samples was prepared and analysed. In case of chipboard and MDF combinations (where the load is determined by the combined material), the combined boards suffer a disastrous damage, while in combinations of plywood boards and pine or oak glued boards, (where the capacity is determined by the fastener), both clamex P10 and rastex 15 fasteners are damaged.

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