Effects of chemical acidification and microbial fermentation on the rheological properties of meat products

The gelation patterns of meat batters acidified with lactic acid bacteria (LAB) fermentation, liquid lactic acid, encapsulated lactic, citric and gluconic acids were studied. LAB provided slow (overnight) acidification that resulted in a significantly higher pre-cooking modulus of rigidity (G') value compared to all treatments, including a non-acidified control. The LAB heat-gelation pattern was also different from all other treatments. Liquid lactic acid caused an immediate pH reduction (from 5.6 to 4.6), crumbly texture, moisture release, and an initial higher G' value compared to the control, but lower than the LAB. The hydrogenated oil encapsulated acids, designed to release acid at 51-55°C, did not produce crumbly texture or moisture release. Encapsulated lactic acid showed an increase in the initial G', probably because of limited pre-cooking acid release. However, citric and gluconic acids showed no such effect. During cooling, LAB treatment showed the lowest G' value curve, followed by the control, liquid lactic acid, and the encapsulated acids.     

Noninvasive detection of fibrillation potentials in skeletal muscle

The presence of spontaneous muscle activity was determined by analysis of the power spectra of computer-model-generated sequences of spontaneous activity and additive noise. The modeling results identified the frequency band of 100-300 Hz as the band of peak signal-to-noise ratio for the detection of fibrillation potentials. Animal experiments were conducted in which the left sciatic nerves of three rats were transected. Measurements were taken 14 days following surgery with Ag/AgCl gel electrodes on the skin surface. Data was recorded from the gastrocnemius muscle on both the normal and denervated side for all three rats. The normal data and the denervated data yielded no discernible difference in the time-domain. Spectral analysis, however, demonstrated a clear and quantifiable difference between denervated and normal muscle signals. The average difference between the denervated and normal power spectral densities for the frequency band from 100 Hz to 300 Hz was 3.43, 1.90, and 3.02 dB for the three rats. The additional energy observed in the signals recorded from denervated muscles suggests that the single fiber spontaneous muscle activity that occurs in denervated muscle can be noninvasively detected. The potential diagnostic utility of noninvasive fibrillation potential detection is discussed and suggestions for future experiments are made.     

A variation on the min cut linear arrangement problem

The Min Cut Linear Arrangement problem asks, for a given graphG and a positive integerk, if there exists a linear arrangement ofG's vertices so that any line separating consecutive vertices in the layout cuts at mostk of the edges. A variation of this problem insists that the arrangement be made on a (fixed-degree) tree instead of a line. We show that (1) this problem isNP-complete even whenG is planar; (2) it is easily solved whenG is a tree; and (3) there is a simple characterization for all graphs with cost 2 or less. Our main result is a linear-time algorithm to embed an outerplanar graphG into a spanning tree with cost at most maxdegree(G) + 1. This result is important because it extends to an approximation algorithm for the standard Min Cut Linear Arrangement Problem on outerplanar graphs.Supported in part by NSF Grant CCR-8710730.     

Support vector tracking

Support Vector Tracking (SVT) integrates the Support Vector Machine (SVM) classifier into an optic-flow-based tracker. Instead of minimizing an intensity difference function between successive frames, SVT maximizes the SVM classification score. To account for large motions between successive frames, we build pyramids from the support vectors and use a coarse-to-fine approach in the classification stage. We show results of using SVT for vehicle tracking in image sequences.     

Biodegradation of 2,4,6-tribromophenol during transport in fractured chalk

The effect of physicochemical conditions (residence time, oxygen concentrations, and chalk characteristics) on the biodegradation of 2,4,6-tribromophenol (TBP) during transport was investigated in low-permeability fractured-chalk cores. Long-term (approximately 600 d) biodegradation experiments were conducted in two cores (approximately 21 cm diameter, 31 and 44 cm long, respectively), intersected by a natural fracture. TBP was used as a model contaminant and as the sole carbon source for aerobic microbial activity. Bacterial isolates were recovered and identified by both Biolog identification kit and 16S rDNA sequences from batch enrichment cultures. One of the strains, with 98% similarity (based on the 16S rDNA data) to Achromobacter xylosoxidans, was shown to have the ability to degrade TBP in the presence of chalk. The decrease in TBP concentration along the fracture due to biodegradation was not affected by reducing the residence time from 49 to 8 min. In contrast, adding oxygen to the water at the inlet and increasing the flow rates improved TBP removal. Although the matrix pore-size distribution limits microbial activity to the fracture void, the chalk appears to provide an excellent environment for biodegradation activity. Approximately 90% of TBP removal occurred within 10 cm of the TBP source, indicating that in-situ bioremediation can be used to remove organic contaminants in low-permeability fractured rocks if nutrient-delivery pathways within the aquifer are secured.     

浅议防汛抗洪工作的全民性

防汛抗洪工作已引起全社会的广泛关注。以《中华人民共和国防洪法》为依据，从防汛责任制、行政首长负责制、防洪规划、防洪调度、建设和保护好防洪设施以及应用非工程措施等方面阐述了防汛抗洪工作的社会性和全民参与的必要性。     

Low bit-rate image coding using adaptive geometric piecewise polynomial approximation.

We present a new image coding algorithm, the geometric piecewise polynomials (GPP) method, that draws on recent developments in the theory of adaptive multivariate piecewise polynomials approximation. The algorithm relies on a segmentation stage whose goal is to minimize a functional that is conceptually similar to the Mumford-Shah functional except that it measures the smoothness of the segmentation instead of the length. The initial segmentation is "pruned" and the remaining curve portions are lossy encoded. The image is then further partitioned and approximated by low order polynomials on the subdomains. We show examples where our algorithm outperforms state-of-the-art wavelet coding in the low bit-rate range. The GPP algorithm significantly outperforms wavelet based coding methods on graphic and cartoon images. Also, at the bit rate 0.05 bits per pixel, the GPP algorithm achieves on the test image Cameraman, which has a geometric structure, a PSNR of 21.5 dB, while the JPEG2000 Kakadu software obtains PSNR of 20 dB. For the test image Lena, the GPP algorithm obtains the same PSNR as JPEG2000, but with better visual quality at 0.03 bpp.     

Subsurface damage and microstructure development in precision microground hard ceramics using magnetorheological finishing spots

We demonstrate the use of spots taken with magnetorheological finishing (MRF) for estimating subsurface damage (SSD) depth from deterministic microgrinding for three hard ceramics: aluminum oxynitride (Al(23)O(27)N(5)/ALON), polycrystalline alumina (Al(2)O(3)/PCA), and chemical vapor deposited (CVD) silicon carbide (Si(4)C/SiC). Using various microscopy techniques to characterize the surfaces, we find that the evolution of surface microroughness with the amount of material removed shows two stages. In the first, the damaged layer and SSD induced by microgrinding are removed, and the surface microroughness reaches a low value. Peak-to-valley (p-v) surface microroughness induced from grinding gives a measure of the SSD depth in the first stage. With the removal of additional material, a second stage develops, wherein the interaction of MRF and the material's microstructure is revealed. We study the development of this texture for these hard ceramics with the use of power spectral density to characterize surface features.     

Improvements in optical generation of high-frequency ultrasound

The thermoelastic effect in a black polydimethylsiloxane (PDMS) film is used to produce high-frequency, high-intensity ultrasound for applications in water and soft tissue. We show that the optoacoustic transduction efficiency is improved by about 10 dB by decreasing the thickness of the black PDMS film from 25 microm to 11 microm. The center frequency of the generated ultrasound is 60 MHz, with a -6 dB bandwidth of 80%. When a 5 ns laser pulse with energy of 50 microJ is delivered to a spot size of 25 microm, the acoustic pressure 10 mm away from the film surface is about 800 kPa. Furthermore, we demonstrate that the center frequency and bandwidth of the generated ultrasound is mainly determined by the temporal profile of the input optical pulse, and it has the potential to be easily improved to above 100 MHz.     

Methodology to Replace Sensitivity BER and Transmit Power Production Tests in Bluetooth Devices with BiSTs

Production testing of Bluetooth (BT) devices is challenging due to the complex nature of the RF tests that have to be performed to verify functionality. In this paper we detail Built-in Self Tests (BiSTs) that can be used to replace these complex and expensive functional tests. We also present the data from our analysis of over 1 million production units. With sufficient margin to specification, we can eliminate functional tests and implement BiSTs that are faster, cheaper and provide better coverage while guaranteeing acceptable Defective Parts Per Million (DPPM) numbers. These BiSTs along with traditional digital tests can completely replace traditional Bluetooth RF tests like Bit Error Rate (BER) and Transmitted (TX) Power.