The effects of fiber ply orientation, laminate layer and PLA content on mechanical properties of carbon fiber reinforced bioplastic composites

In this study, two kinds of bioplastic materials, where the first consists of 10% PLA, corn starch of 80% and CaCO3 10%, and the second consists of 45% PLA content, corn starch of 45% and CaCO3 10%, were used. The composites were also reinforced by the carbon fibers, which were prepared with one and two layers of carbon fiber and then ply orientations of [0[Formula: see text]] and [45[Formula: see text]]. The maximum tensile strength was observed for PLA 45% with a [0[Formula: see text]] ply orientation of two layers of carbon fiber. For composite with two layers of carbon fiber, the tensile strength showed higher for the [0[Formula: see text]] ply orientation than for the [45[Formula: see text]] ply orientation. The fatigue strength strongly depends on the orientation of carbon fiber, but in the long fatigue life range, the difference of fatigue strength between the fiber ply orientations reduces.

Corrosion-Induced Mass Loss Measurement under Strain Conditions through Gr/AgNW-Based, Fe-C Coated LPFG Sensors

In this study, graphene/silver nanowire (Gr/AgNW)-based, Fe-C coated long period fiber gratings (LPFG) sensors were tested up to 72 hours in 3.5 w.t% NaCl solution for corrosion-induced mass loss measurement under four strain levels: 0, 500, 1000 and 1500 µε. The crack and interfacial bonding behaviors of laminate Fe-C and Gr/AgNW layer structures were characterized using Scanning Electron Microscopy (SEM) and electrical resistance measurement. Both optical transmission spectra and electrical impedance spectroscopy (EIS) data were simultaneously measured from each sensor. Under increasing strains, transverse cracks appeared first and were followed by longitudinal cracks on the laminate layer structures. The spacing of transverse cracks and the length of longitudinal cracks were determined by the bond strength at the weak Fe-C and Gr/AgNW interface. During corrosion tests, the shift in resonant wavelength of the Fe-C coated LPFG sensors resulted from the effects of the Fe-C layer thinning and the NaCl solution penetration through cracks on the evanescent field surrounding the LPFG sensors. Compared with the zero-strained sensor, the strain-induced cracks on the laminate layer structures initially increased and then decreased the shift in resonant wavelength in two main stages of the Fe-C corrosion process. In each corrosion stage, the Fe-C mass loss was linearly related to the shift in resonant wavelength under zero strain and with the applied strain taken into account in general cases. The general correlation equation was validated at 700 and 1200 µε to a maximum error of 2.5% in comparison with 46.5% from the zero-strain correlation equation.

WLCSP Laminate Removal Using NIR Laser

Driven by the cost reduction and miniaturization, Wafer Level Chip Scale Packaging (WLCSP) has experienced significant growth mainly driven by mobile consumer products. Depending on the customers or manufacturing needs, the bare silicon backside of the WLCSP may be covered with a backside laminate layer. In the failure analysis lab, in order to perform the die level backside fault isolation technique using Photon Emission Microscope (PEM) or Laser Signal Injection Microscope (LSIM), the backside laminate layer needs to be removed. Most of the time, this is done using the mechanical polishing method. This paper outlines the backside laminate removal method of WLCSP using a near infrared (NIR) laser that produces laser energy in the 1,064 nm range. This method significantly reduces the sample preparation time and also reduces the risk of mechanical damage as there is no application of mechanical force. This is an effective method for WLCSP mounted on a PCB board.

Dominikia lithuanica and Kamienskia divaricata: new species in the Glomeromycota

New species in the genera Dominikia and Kamienskia (Glomeromycota) are characterized based on morphology and sequences of SSU–ITS–LSU nrDNA and the RPB1 gene. Both species produce glomoid spores only in clusters. Spores of Dominikia lithuanica are hyaline to pale yellow and 22–52 μm in diameter when globose. In their three-layered spore wall, layers 1 and 2 are almost equal in thickness and much thinner than the structural laminate layer 3. Spore wall layers 1 and 3 usually stain faintly in Melzer’s reagent. Spores of Kamienskia divaricata remain hyaline regardless of age, are 10–24 μm in diameter and have a spore wall with two layers of nearly the same thickness. The laminate layer 2 usually shows a faint dextrinoid reaction in Melzer’s reagent. A further conspicuous character of K. divaricata spores is a relatively wide subtending hypha at the spore base. In the field, D. lithuanica and K. divaricata have so far been found only twice and once, respectively, and only in maritime sand dunes of the Curonian Spit, Lithuania (D. lithuanica), and South Africa (K. divaricata). Sequence data available in public databases suggest that D. lithuanica has not yet been detected by other researchers, and K. divaricata also occurs in Texas, USA.

Multilayer Strip Dipole Antenna Using Stacking Technique and Its Application for Curved Surface

This paper presents the design of multilayer strip dipole antenna by stacking a flexible copper-clad laminate utilized for curved surface on the cylindrical objects. The designed antenna will reduce the effects of curving based on relative lengths that are changed in each stacking flexible copper-clad laminate layer. Curving is different from each layer of the antenna, so the resonance frequency that resulted from an extended antenna provides better frequency response stability compared to modern antenna when it is curved or attached to cylindrical objects. The frequency of multilayer antenna is designed at 920 MHz for UHF RFID applications.