Dispersion behavior of torsional guided waves in a small diameter steel gas pipe

Condition monitoring of gas pipes has been an important issue for gas companies. Failure to accurately identify condition of gas pipes result in numerous problems. Also, producing a condition monitoring system for buried pipelines is challenging. Small pipes (with diameters less than 50 mm) are considered here as most of the literature focuses on larger pipes. Guided wave theory will be introduced alongside a numerical simulation of the relevant dispersion curves of the system. This paper investigates the feasibility of using torsional guided waves for inspecting defects in buried pipes with small diameters. The pipes are assumed to be lossless and hence the effect of attenuation is ignored in the calculations. Upon finding the theoretical guided wave characteristics, experiments were conducted to see if the aim could be achieved in a realistic scenario. A steel pipe with a diameter of 34 mm and wall thickness of 5.5 mm is considered. High reverberation levels at high frequency propagations due to mode conversion are studied. Having only a limited number of transducers could be a reason for high reverberation at high frequencies

Effects of progesterone injection on performance, plasma hormones and ovarian morphology of ad libitum and restricted fed broiler breeder hens

An experiment was conducted to evaluate responses of feed-satiated and feed- restricted breeder hens to daily injection of progesterone (P4). A total of 64 Cobb 500 hens were fed either restricted or ad libitum from 27 to 38 wk of age. Fourteen laying hens from each group were selected to conduct P4 injection assay. Half of birds in each group (n = 7) were injected daily by 2.5 mg P4/kg BW and remaining birds were used as control. The P4 was injected subcutaneously, at the base of the neck daily(at 0900 h) for 21 d. Settable and abnormal eggs were recorded daily. Blood samples were taken just before initiation of injections, 10-d and 20-d after initiation of injection. Plasma samples were analyzedfor glucose, cholesterol, triacylglycerol (TAG), P4, estradiol (E2), testosterone, T3 and T4 concentration. Settable egg production declined following P4 injection, whereas total egg production (including softshell egg) remain at high levels in injected birds during the first week after initiation of P4 injection. Progesterone injection in feed-satiated and feed-restricted birds resulted in ovary regression; the ovaryof these birds had no hierarchical follicle. Progesterone injection increased incidence of holding hardshelled eggs in the uterus. Plasma E2 concentrations were affected both by feeding pattern and P4 injection. Progesterone injection depressed plasma E2 concentration in both ad libitum and restricted fed hens. Hens with free access to feed had significantly lower plasma E2 levels compared to restricted fed hens. Our results revealed that whereas injection of P4 induced frequent ovulation early in the injection period in both feed- satiated and feed-restricted breeder hens; however this higher ovulation rate did not result in more settable egg production

Impact of dietary glutamine on amino acid digestibility values and intestinal morphometric parameters in neonate chicks

Two experiments were conducted to investigate the effects of fortification of the pre-starter diet with glutamine in post-hatch broiler chicks. In the first experiment, male chicks were used to study the impact of glutamine supplementation at three levels (0%, 1% and 2%) on performance, apparent faecal digestibility (AFD) and ileal digestibility (AID) of amino acids (AAs), as well as intestinal morphometric parameters from 0 to 14 days old. The best performance was obtained at 1% supplementation. Average daily feed intake and feed conversion ratio (FCR) were affected by treatments. Supplementing diets with glutamine resulted in increase of digestibility values for arginine (Arg), lysine (Lys), isoleucine (Ile) and valine (Val). Glutamine-supplemented diets led to higher villus height (VH) and shallower crypt depth (CD) in the jejunum and ileum. A second experiment was performed to investigate whether the form of glutamine could affect performance and morphometric parameters in newly hatched chickens. A control diet was prepared, based on casein as the sole source of protein-bound AAs. Three diets based on synthetic AAs were used to obtain nutrient values of the control diet, which were supplemented with a synthetic form of glutamine, glutamic acid and a 50 : 50 ratio of glutamine : glutamic acid. Chickens fed the control diet presented higher average daily weight gain and better FCR. None of the AID coefficients of amino acids were influenced by the dietary treatments, except glutamic acid and aspartic acid, which were decreased in chicks fed synthetic AAs. In conclusion, 1% glutamine supplementation improved performance, morphometric parameters and AID and AFD values of cationic AAs. The form in which dietary glutamine was provided could affect performance.Keywords: Amino acid, broiler, digestibility, intestinal morpholog

Potential probiotic of Lactobacillus johnsonii LT171 for chicken nutrition

The objective of this research was to investigate the potential probiotic of Lactobacillus johnsonii LT171. It had aggregation (60 min) and antibacterial effects against Salmonella Enteritidis, Salmonella Typhimurium and Escherichia coli O78:K80. It showed amylase and protease activity and high clear zone in culture medium containing calcium phytate; cell surface hydrophobicity, 85.21 ± 7.27%; resistance to acidic condition (pH 3 for 90 min) and bile salts (in culture medium containing 0.075% ox gall). Also it had resistance to nalidixic acid and neomycine. This research showed appropriate probiotic properties of L. johnsonii LT171 for chicken nutrition. Hence this strain can complement the characteristics of other strains in multistrain probiotics because of its high clear zone in culture medium containing calcium phytate

Effects of feeding strategy, fiber source of the diet, and crude protein content on productive performance of broiler breeder hens

A 12-wk experiment was conducted to investigate the effect of feeding program, dietary fiber, and CP content of the diet on productive performance of Ross broiler breeder hens (41 wk of age). There were 12 treatments arranged factorially with 2 levels of CP (14.5 vs. 17.4%), 3 fiber sources (0 vs. 3% inulin vs. 3% cellulose), and 2 levels of feed intake (160 vs. 208 g/d) that corresponded to restricted (R) or ad libitum (AL) feeding systems. The experimental diets contained 2,800 kcal ME with either 0.65 (14.5% CP) or 0.78% Lys (17.4% CP)

Efectos de la inclusión de trigo y suplementación con xilanasas del pienso sobre la actividad enzimática intestinal, la retención de los nutrientes y la productividad en gallinas de 25 a 33 semanas de edad

El trigo es un cereal rico en xilanos lo que reduce su potencial en piensos para aves de puesta por su efecto perjudicial sobre la digestibilidad y el porcentaje de huevos sucios (Lázaro et al., 2003). La utilización de xilanasas podría resolver esta problemática y mejorar la productividad de las aves. Diversos autores (Gracia et al., 2003) han estudiado los efectos de la inclusión de xilanasas en el pienso sobre la digestibilidad de los nutrientes y la productividad (Gutiérrez-Álamo et al., 2008). Sin embargo, sus efectos sobre la producción de enzimas endógenas y el pH de los diversos segmentos del tracto gastrointestinal (TGI) han sido poco estudiados. El objetivo de este ensayo fue estudiar la inclusión de una variedad de trigo de alto contenido en xilanos sobre diversas variables digestivas y la productividad en aves de puesta blancas

Effect of wheat inclusion and xylanase supplementation of the diet on intestinal enzyme activity, nutrient retention and performance in laying hen from 25 to 47 wks of age

A trial was conducted to examine the effects of increasing levels of wheat in the diet and xylanase (ES) supplementation on nitrogen and ether extract retention, pH of the GIT, productive performance from 25 to 47 wks of age, and enzyme activity at the small intestine level. The basal diets (from 25 to 33 wks and from 33 to 47 wks) consisted of soybean meal and corn, and the wheat was introduced in the experimental diets at expenses of corn, primarily

Energy harvesting: an overview of techniques for use within the transport industry

This article introduces the various energy harvesting mechanisms that can be used to energize sensing systems and associated wireless communication channels. It outlines energy scavenging techniques, along with an assessment of useful materials for each mode of harvesting

Towards in-flight temperature monitoring for nozzle guide vanes using ultrasonic guided waves

The temperature monitoring of nozzle guide vanes is a challenging task due to the extreme temperatures, gas pressures, and cramped conditions of aero-engines. Ultrasonic guided waves are an attractive method of temperature monitoring as the sensors can be placed outside of the gas path without influencing component operation. In this paper the suitability of using ultrasonic guided waves in the form of the S0 Lamb wave mode is investigated by comparing experimentally measured wave velocity change with temperature against theoretical wave velocity extracted from dispersion curves. Waves are transmitted through an aluminium plate using a pitch-catch wedge transducer configuration, and wave velocity is measured using across-correlation function. Temperature is controlled with a hot plate from room temperature to 100°C, and monitored using thermocouples. Results show that this transducer configuration is capable of monitoring a change in temperature based on a change in wave velocity, showing a good agreement with theoretical predictions, within 4.89+/-2.27 m/s on average. The temperature sensitivity of the system is 1.26–1.78 m/s/°C over the range 24°C–94°C. This shows the potential for a guided wave based temperature monitoring system, assuming a suitable transducer configuration can be found that is able to operate at higher temperatures. Further investigation will study the possibility of using Piezoelectric Wafer Active Sensors (PWAS) or waveguides for this application