Intermittent Audio Failure Analysis of a Remote Speaker-Microphone for a Two-Way Radio

This paper presents a case study of an intermittent audio failure analysis of a remote speaker-microphone module for a two-way radio. A root cause analysis was undertaken to identify probable causes of the intermittent failure, followed by a series of experiments to determine the strength and the intermittent audio failure load of cable components and the fully assembled cable. The combined experimental and finite element results demonstrated that the main contributor of the intermittent audio failure was the micro surface cracks on the copper conductor strands. In addition, the combination of the component materials and design of the cable have also contributed to the non-uniform state of residual stress induced in the copper conductors which have reduced the ability of the copper conductors to withstand the normal handling load under the influence of micro surface cracks.     

Detection of trivalent-iron based on low-dimensional semiconductor metal oxide nanostructures for environmental remediation by ICP-OES technique

A large-scale synthesis of undoped low-dimensional semiconductor metal oxide nanostructures (ZnO nanoparticles, NPs) by simple wet-chemical method was performed using reducing agents at low temperature. The NPs were characterized in terms of their morphological, structural, and optical properties, and efficiently applied for the metal ions uptake. The detailed structural, compositional, and optical characterizations of the NPs were evaluated by powder X-ray diffraction pattern (XRD), Fourier-transform infra-red spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Electron dispersion spectroscopy (EDS), and UV–vis. spectroscopy, respectively which confirmed that the obtained NPs are well-crystalline undoped ZnO and possessed good optical properties. The ZnO NSs morphology was investigated by FESEM, which confirmed that the calcined materials were spherical shape in nano-level and growth in huge-quantity. The analytical efficiency of newly synthesized ZnO NPs was also investigated for a selective separation of trivalent iron [Fe(III)] prior to its determination by inductively coupled plasma-optical emission spectrometry (ICP-OES). The selectivity of ZnO NPs towards different metal ions, including Cd(II), Co(II), Cr(III), Cu(II), Fe(III), Ni(II), Zn(II), and Zr(IV), was studied. Data obtained from the selectivity study suggested that that ZnO NPs phase was the most selective towards Fe(III). The static uptake capacity of Fe(III) was found to be ~79.80 mg g⁻¹. Moreover, adsorption isotherm data also provided that the adsorption process was mainly monolayer on a homogeneous adsorbent surface.     

Effects of garlic on platelet biochemistry and physiology

Increased platelet aggregation plays a significant role in the aetiology of cardiovascular disease, and is complex involving multiple mechanisms. On platelet activation, there is a transient increase in free cytoplasmic calcium (Ca(2+)), thromboxane A2 generation, and the activation of the fibrinogen receptor GPIIb/IIIa. Other modulators are also involved in platelet aggregation and include lipoxygenase metabolites, protein kinase C, cyclic adenosine monophosphate (cAMP), cyclic guanine monophosphate (cGMP) and nitric oxide (NO). Garlic is reported to prevent cardiovascular disease by multiple effects, one of which is the inhibition of platelet aggregation and its ability to do this has been extensively investigated in vitro, however, in vivo studies are limited. In vitro studies indicate that garlic prevents inhibition of platelet aggregation by inhibiting cyclooxygenase activity and thus thromboxane A2 formation, by suppressing mobilization of intraplatelet Ca2+, and by increasing levels of cAMP and cGMP. Garlic also displays strong antioxidant properties and activates nitric oxide synthase (NOS), leading to an increase in platelet-derived NO. It can also interact directly with the GPIIb/IIIa receptors, thus reducing the ability of platelets to bind to fibrinogen. It is concluded that garlic inhibits platelet aggregation by multiple mechanisms and may have a role in preventing cardiovascular disease.     

State Diagram of Freeze-dried Garlic Powder by Differential Scanning Calorimetry and Cooling Curve Methods

ABSTRACT: The state diagram of freeze-dried garlic powder was developed using freezing curve, glass transition line, and maximal-freeze-concentration condition. Freezing points of garlic powder were measured by differential scanning calorimetry (DSC) and the cooling curve method, whereas glass transitions were measured by DSC. The freezing curve and glass transition line were modeled using the Clausius-Clapeyron equation, adjusted with unfreezable water, and the Gordon-Taylor model, respectively. Maximal-freeze-concentrated condition was found as X '_s (characteristic water content) = 0.82 [ X '_g (characteristic solids content) = 0.18] with the characteristic temperature of glass formation being T '_m (characteristic glass transition) =−38.6°C and T '_m (characteristic end point of freezing) =−26.0°C. Other characteristic glass transitions T "_g and T ‴_g equal to −29.3°C and −48.6°C, respectively.