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Number of results: 4
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Abstract

Fifth generation (5G) applications like Internet of Things (IoT), Enhanced Mobile Broadband (eMBB), Cognitive Radios (CR), Vehicle to Vehicle (V2V) and Machine to Machine (M2M) communication put new demands on the network in terms of low latency, ultra-reliable communication and efficiency when transmitting very small bursts. One new contender that makes its appearance recently is the Universal Filtered Multi- Carrier (UFMC). UFMC is a potential candidate to meet the requirements of 5G upcoming applications. This related waveform encounters the peak-to-average power ratio (PAPR) issue arising from the usage of multi-carrier transmission. In this investigation, two PAPR reduction techniques, called Per Subband Tone Reservation (PSTR) scheme to alleviate PAPR in UFMC systems are suggested. The first one is a pre-filtering PSTR scheme that uses the least squares approximation (LSA) algorithm to calculate the optimization factor(μ) and the second one is a post-filtering method. The concept of this proposal lies on the use of peaks reductions Tone to carry the correctional signal that reduces the high peaks of each sub-band individually. To shed light on UFMC as a potential waveform for 5G upcoming application, a comparison with OFDM modulation is done.
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Authors and Affiliations

Laabidi Mounira
1
Bouallegue Ridha
1

  1. Sup’Com, University of Carthage, Tunisia
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Abstract

Exogenous fibrolytic enzymes (EFE) and yeast are feed supplements that improve forage digestion in rumen, but their influences on physical reticulorumen parameters are not well studied. This study was designed to evaluate the effect of the EFE:endo-β-xylanase (37x104 U/cow/day), endocellulase (45x104 U/cow/day), endo-β-glucanase (12x104U/cow/day), and active yeast – Saccharomyces cerevisiae CNCM-1077 (10x109CFU/cow/day) supplements on reticulorumen pH (RpH) and temperature (RT) in dairy cows. Nine Lithuanian Red cows were allocated into three groups (3 cows/group): control group (C) – farm diet without supplementa- tion, enzyme group (E) – farm diet supplemented with EFE, enzyme and active yeast group (EY) – farm diet supplemented with EFE and active yeast. The feeding trial lasted for 60 d. All cows were equipped with reticuloruminal telemetric pH and temperature sensor device. Data provided by the device were used to calculate the mean RpH (RpH/24h), the mean minimal RpH ( RpH/24h min.) and mean of the time that RpH was below the threshold value of 6.0 (RpH<6.0/24h, min.). The highest RpH/24h (6.37±0.22) was observed in group EY and it was by 1.62% (p<0.05) and 1.27% (p<0.001) higher as compared with groups E and C, respectively. Also min RpH/24h (6.24±0.24) was highest in group EY and values were by 0.63% (p<0.001) and 0.65% (p<0.001) higher as compared with groups C and E, respectively.

The shortest duration of RpH<6.0/24h, was recorded in group EY, and it was by 57.76% (p<0.05) and 47.87% shorter as compared with groups C and E, respectively. In conclusion, feed supple- mentation with EFE and Saccharomyces cerevisiae CNCM-1077 had beneficial effect on RpH.

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Authors and Affiliations

I. Šilinskas
I. Monkevičienė
I. Tapio
K. Musayeva
R. Japertienė
S. Kerzienė
G. Dovydaitienė
A. Sederevičius
R. Želvytė
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Abstract

Day-to-day life advanced composite materials usage is increasing continuously and replacing the existing monolithic materials. These composite materials are designed and fabricated for human needs with specific applications and also meet the standard requirements. In present study, the agro and industrial wastes derived ceramic reinforcements based Aluminium metal matrix composites, i.e. AA7075/welding slag and AA7075/Rice husk ash are fabricated through liquid metal stir casting route with varying the reinforcement contents from 2 to 12 (wt.%) in the matrix. Mechanical and microstructural characterization of the AA 7075 metal matrix composite were measured and compared to the base material. The results show an improved mechanical strength and high hardness in composites. Impact energy has also significantly improved at higher concentrations of reinforcement particles. Impact energy of the composites increases to 3 J for 9% and 12%, the maximum tensile strength obtained is 173 MPa for 12% Weld Slag MMC. The highest hardness achieved is 98 BHN for 12% Weld Slag MMC. Furthermore, the microstructural results reflect significant grain refinement with stir casting process with good interface characteristics in the matrix and uniform dispersion of agro reinforcement’s particles.
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Authors and Affiliations

M. Kolli
1
S. Naresh Dasari
2
S. Kosaraju
3
ORCID: ORCID

  1. Lakireddy Bali Reddy College of Engineering, Mylavaram, Andhra Pradesh, India
  2. R&D Mechatronics, Design and Engineering, VEM Technologies PVT Ltd , Hyderabad, Telangana, India
  3. Gokaraju Rangaraju Institute of Engineering and Technology, Mechanical Engineering, Hyderabad – 500090, Telangana State, India
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Abstract

The photoacoustic cell is the heart of the nondestructive photoacoustic method. This article presents a new simple lumped-components CRLC model of the Helmholtz type photoacoustic cell. This model has been compared with the well known literature models describing the Helmholtz type cells for photoacoustic spectroscopy. Experimental amplitude and phase frequency data obtained for the two photoacoustic cells have been presented and interpreted in a series of models. Results of the fitting of theoretical curves, obtained in these models, to the experimental data have been shown and discussed.

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Authors and Affiliations

Łukasz Bartłomiej Chrobak
Mirosław Andrzej Maliński

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