Wave propagation in graphite/epoxy laminates due to impact

The low velocity impact response of graphite-epoxy laminates is investigated theoretically and experimentally. A nine-node isoparametric finite element in conjunction with an empirical contact law was used for the theoretical investigation. Flat laminates subjected to pendulum impact were used for the experimental investigation. Theoretical results are in good agreement with strain gage experimental data. The collective results of the investigation indicate that the theoretical procedure describes the impact response of the laminate up to about 150 in/sec. impact velocity

A second-order class-D audio amplifier

Class-D audio amplifiers are particularly efficient, and this efficiency has led to their ubiquity in a wide range of modern electronic appliances. Their output takes the form of a high-frequency square wave whose duty cycle (ratio of on-time to off-time) is modulated at low frequency according to the audio signal. A mathematical model is developed here for a second-order class-D amplifier design (i.e., containing one second-order integrator) with negative feedback. We derive exact expressions for the dominant distortion terms, corresponding to a general audio input signal, and confirm these predictions with simulations. We also show how the observed phenomenon of “pulse skipping” arises from an instability of the analytical solution upon which the distortion calculations are based, and we provide predictions of the circumstances under which pulse skipping will take place, based on a stability analysis. These predictions are confirmed by simulations

Proteomics of Cytochrome c Oxidase-Negative versus -Positive Muscle Fiber Sections in Mitochondrial Myopathy

The mosaic distribution of cytochrome c oxidase(+) (COX+) and COX - muscle fibers in mitochondrial disorders allows the sampling of fibers with compensated and decompensated mitochondrial function from the same individual. We apply laser capture microdissection to excise individual COX+ and COX- fibers from the biopsies of mitochondrial myopathy patients. Using mass spectrometry-based proteomics, we quantify >4,000 proteins per patient. While COX+ fibers show a higher expression of respiratory chain components, COX- fibers display protean adaptive responses, including upregulation of mitochondrial ribosomes, translation proteins, and chaperones. Upregulated proteins include C1QBP, required for mitoribosome formation and protein synthesis, and STOML2, which organizes cardiolipin-enriched microdomains and the assembly of respiratory supercomplexes. Factoring in fast/slow fiber type, COX (-) slow fibers show a compensatory upregulation of beta-oxidation, the AAA(+) protease AFG3L1, and the OPA1-dependent cristae remodeling program. These findings reveal compensatory mechanisms in muscle fibers struggling with energy shortage and metabolic stress

Risk Quotient of Airborne Paraquat Exposure Among Workers in Palm Oil Plantation

Paraquat is the herbicide widely used at palm oil plantations, although usage it in some countries has been banned and restricted. Paraquat spraying was not appropriate procedure could be polluted the environment and lead to health disorders workers. Paraquat could enter the body through inhalation, dermal and ingestion, one of frequent routes through inhalation during spraying weeds in plantation areas. This study aimed was to analyze potential inhalation dose and Risk Quotient to workers at palm oil plantation. This research was a descriptive study with cross sectional design and analysis of environmental health risk methods. Airborne Paraquat residue was collected from 8 workers with occupational activity as a supervisor and sprayer. Airborne Paraquat residue was measured for 25 minutes during spraying by using personal air sampler at worker's breathing zone. Airborne Paraquat residue was detected by High Performance Liquid Chromatography (HPLC) with NIOSH 5003 methods. The average of airborne Paraquat residue was 0.0125 mg/m3, it values was less than the Threshold Limit Value (0.05 mg/m3) of American Conference of Government Industrial Hygienists, but the average of potential inhalation dose was 0.001 mg/kg/day for worker's weight 55 kg, it was value higher than Acceptable Operator Exposure Limit (0.0005 mg/kg/day) and the calculation of Risk Quotient (RQ) was more than 1, it conditions was unacceptable for workers. Although, airborne Paraquat residue were safe, but potential inhalation dose and Risk Quotient (RQ) were unsafe for workers, cause it can be lead to lung function disorders. Therefore, for further studies it was necessary to assess the lung function of workers and the use of personal protective equipment must be completely and standard

Analisis Ketidakharmonisan antara PPSAK No. 13, 16, dan 19 dengan UU No. 36 Tahun 2008 dan Peraturan Menteri Keuangan No. 79/PMK 03/2008 Mengenai Revaluasi Aset Tetap, Properti Investasi, dan Aset Tak Berwujud

The purpose of this paper is to analyze disharmony between SFAS No. 13, 16, and 19 which are adopted from Internatonal Financial Reporting Standard (IFRS 2009) and Law no. 36 of 2008 and Regulation of the Minister of Finance No. 79/PMK 03/2008 about the Revaluation of Fixed Assets, Investment Property, and Intangible Assets. The Authors use descriptive analysis method in this paper. The analysis showed that (1) There are no major obstacles in implementing the revaluation model under SFAS No. 13 and 19 with the tax regulation, (2) The application of SFAS No. 16 is not in line with the Law No. 36 of 2008 and Regulation of the Minister of Finance No. 79/PMK 03/2008, (3) There are 7 dysharmony between SFAS No. 16 with the Regulation of the Minister of Finance No. 79/PMK 03/2008 with the level of problem: 3 are major, 3 are medium, and 1 is minor. Disharmony can cause companies reluctant to report their assets at fair value as required under the revaluation model. Though the information of assets which is measured by fair value is needed by investors and creditors in their economic decision-making. Therefore, the author suggesting the application of revaluation model is separated between fiscal and commercial financial reporting. Considering the purpose of SFAS and Law No. 36 of 2008 and Regulation of the Minister of Finance No.79/PMK 03/2008 basically different, the author recommendation can be considered by regulators