Rib Depth Research Articles

Effect of the Rib Depth to the Overall Beam Depth Ratio in the Lightweight One-Way Ribbed Slabs

The ribbed slabs provide a lighter and stiffer slab than an equivalent traditional slab with minimizing the total volume of the materials. Four one-way lightweight concrete panels, including one flat and three ribbed panels were cast and tested under two-point load as simply supported up to the failure. The main investigated variable is a ratio of the rib depth (d) to the overall beam depth (h). All the panels have the same concrete volume and the same steel reinforcement ratio. Also, the width of the rib is equal to the slab thickness as a constraint condition in all the panels. Data were recorded at the loading stages to determine the load capacity and the deflection. A nonlinear finite element analysis carried out by using ANSYS-15 software program to analyze the panels and to verify the results. Increase the (d/h) ratio improved the structural behavior by increase the carrying load capacity and reduces the deflection to a certain limit. Compatibility results have been obtained between the numerical and experimental work.

Behaviour of punching shear in normal RC slab and waffle slab

This study presents the behaviour of punching shear in waffle slabs at slab–column joints subjected to concentric loading. Although it was observed that waffle slabs are very similar to that of flat slabs, the shear capacity is relatively reduced because some of the potential surfaces are lost when it extends into waffle section. The current IS code of practice does not consider the punching shear mechanism of waffle slabs. For the different sizes of waffle slab a square column size of 100 × 100 mm is considered for the designed slab size of 1200 × 1200 mm. Waffle slabs of different sizes are created by increasing the depth of slab by 20%, width of the rib by 25% and also increasing the solid section. The experimental results were compared with theoretical values from IS code. The comparison of the test results reveals that waffle slab gives more strength than conventional slab. The comparison has been made for the waffle slab of different sizes; slab provided with more depth and thickness of ribs gives extra strength to the structure against punching shear and the stiffness of the slab is substantially improved in the case of an increase in the rib size.

Assessment of body fat composition in crossbred Angus × Nellore using biometric measurements.

This study was conducted to assess the body and empty body fat physical and chemical composition through biometric measurements (BM) as well as postmortem measurements taken in 40 F Angus × Nellore bulls and steers. The animals used were 12.5 ± 0.51 mo of age, with an average shrunk BW of 233 ± 23.5 and 238 ± 24.6 kg for bulls and steers, respectively. Animals were fed 60:40 ratio of corn silage to concentrate diets. Eight animals (4 bulls and 4 steers) were slaughtered at the beginning of the trial, and the remaining animals were randomly assigned to a 1 + 2 × 3 factorial arrangement (1 reference group, 2 sexes, and 3 slaughter weights). The remaining animals were slaughtered when the average BW of the group reached 380 ± 19.5 (6 bulls and 5 steers), 440 ± 19.2 (6 bulls and 5 steers), and 500 ± 19.5 kg (5 bulls and 5 steers). Before the slaughter, the animals were led through a squeeze chute in which BM were taken, including hook bone width (HBW), pin bone width, abdomen width (AW), body length (BL), rump height, height at the withers, pelvic girdle length (PGL), rib depth (RD), girth circumference (GC), rump depth, body diagonal length (BDL), and thorax width. Additionally, the following postmortem measurements were obtained: total body surface (TBS), body volume (BV), subcutaneous fat (SF), internal physical fat (InF), intermuscular fat, carcass physical fat (CF), empty body physically separable fat (EBF), carcass chemical fat (CFch), empty body chemical fat (EBFch), fat thickness in the 12th rib, and 9th to 11th rib section fat. The equations were developed using a stepwise procedure to select the variables that should enter into the model. The and root mean square error (RMSE) were used to account for precision and accuracy. The ranges for and RMSE were 0.852 to 0.946 and 0.0625 to 0.103 m, respectively for TBS; 0.942 to 0.998 and 0.004 to 0.022 m, respectively, for BV; 0.767 to 0.967 and 2.70 to 3.24 kg, respectively, for SF; 0.816 to 0.900 and 3.04 to 4.12 kg, respectively, for InF; 0.830 to 0.988 and 3.44 to 8.39 kg, respectively, for CF; 0.861 to 0.998 and 1.51 to 10.98 kg, respectively, for EBF; 0.825 to 0.985 and 5.96 to 8.46 kg, respectively, for CFch; and 0.862 to 0.992 and 5.54 to 12.19 kg, respectively, for EBFch. Our results indicated that BM that could accurately and precisely be used as alternatives to predict different fat depots of F Angus × Nellore bulls and steers are AW, GC, or PGL for CF estimation; HBW and RD for CFch estimation; and body lengths such as BL and BDL for InF and SF estimation, respectively.

Effects of vertical ribs protruding from facades on the wind loads of super high-rise buildings

The auxiliary structures of a high-rise building, such as balconies, ribs, and grids, are usually much smaller than the whole building; therefore, it is difficult to simulate them on a scaled model during wind tunnel tests, and they are often ignored. However, they may have notable effects on the local or overall wind loads of the building. In the present study, a series of wind pressure wind tunnel tests and high-frequency force balance (HFFB) wind tunnel tests were conducted on rigid models of an actual super high-rise building with vertical ribs protruding from its facades. The effects of the depth and spacing of vertical ribs on the mean values, fluctuating values and the most unfavorable values of the local wind pressure coefficients were investigated by analyzing the distribution of wind pressure coefficients on the facades and the variations of the wind pressure coefficients at the cross section at 2/3 of the building height versus wind direction angle. In addition, the effects of the depth and spacing of vertical ribs on the mean values, fluctuating values and power spectra of the overall aerodynamic force coefficients were studied by analyzing the aerodynamic base moment coefficients. The results show that vertical ribs significantly decrease the most unfavorable suction coefficients in the corner recession regions and edge regions of facades and increase the mean and fluctuating along-wind overall aerodynamic forces.

Antixenosis Studies in Different Genotypes of Bitter Gourd Fruits against the Infestation of Melon Fruit Fly

In crop plants, three principle mechanism viz., non-preference (antixenosis), antibiosis and tolerance are responsible for imparting resistance to insects. Non preference denotes a group of plants character and insect response that keep away the insect from using a particular plant or variety for oviposit ion, food, shelter, or combination of both. Keeping in this view, seventy four promising genotypes of bitter gourd were screened against fruit fly infestation to identify the antixenosis traits involved in host plant selection by the melon fruit fly. On the basis of percent fruit infestation and the average number of larvae per damage fruit, the genotypes were categorized in to different groups i.e. (Highly resistant, resistant, moderately resistant, susceptible, and highly susceptible). The fruit infestation during the 2006 and 2007 summer season (Average of two years) ranged from 13.23% to 83.75%. Larval density per fruit ranged from 2.59 to 8.13 larvae per fruit. The larval density increased with the increase in percent fruit infestation and showed significant positive correlation (r = 0.98).The depth of ribs in resistant genotypes was higher as compared to susceptible genotypes. The number of seed was recorded maximum in the genotype VRBT-96 (31.8) and minimum was recorded in the genotype IC 68314(14.8). The fruit toughness had significant negative effect on fruit infestation(r = -0.52) and larval density (r = -0.57) of fruit fly. There was a strong correlation between number of ribs and fruit toughness, and these traits can be used as markers to select bitter gourd genotype resistant to melon fruit fly.

Determination of carcass traits in Pelibuey ewes using biometric measurements

The objective of this study was to evaluate de relationship between biometric measurements (BM) and carcass traits of 28 Pelibuey ewes. The BM were obtained the day before the slaughter and included height at withers (HW), rib depth (RD), body diagonal length (BDL), body length (BL), pelvic girdle length (PGL), rump depth (RuD), rump height (RH), pin bone width (PBW), hook bone width (HBW), abdomen width (AW), girth circumference (GC), and abdomen circumference (AC). Additional measurements included shrunk BW (SBW) and empty BW (EBW). Data recorded at slaughter were weights of viscera, carcass, and internal fat and offals. The carcasses was weighed, and chilled at 1°C during 24h; then, the left half of the carcass was completely dissected into subcutaneous and intermuscular fat (carcass fat), muscle, and bone and each component weighed separately. The result indicated that the equations to predict SBW and EBW involving BM had an r2 that ranged from 0.72 to 0.91. For weights of muscle, carcass fat, and bone, the r2 ranged from 0.57 to 0.93. We concluded that using BM can improve the accuracy and precision of the predictions of carcass traits of Pelibuey ewes to selection programs and to assist decision support systems to determine optimal carcass endpoint.

Evaluation of equations to estimate body composition in beef cattle using live, linear and standing-rib cut measurements

Quick and reliable methods to estimate body and carcass composition of beef cattle are needed to predict the most profitable slaughter weight. This study evaluates body compositional equations using biometric measurements (BM), dissected fat (kg) at the 9–11th rib section and rib fat depth (cm). The present independent dataset used to evaluate the equations comprised of 48 F1 Nellore × Angus bulls (B) and steers (S); aged 12.5 ± 0.51 months with a mean shrunk BW (SBW) of 233 ± 23.5 and 238 ± 24.6 kg for B and S, respectively. Animals were fed a diet of 60% corn silage and 40% concentrate ad libitum. Eight animals were slaughtered at the beginning of the trial and the remaining animals were randomly assigned into a 2 (sex) × 3 (slaughter weights) factorial arrangement, and slaughtered when the average BW of the group reached 380 (6B and 5S), 440 (6B and 5S), 500 kg (5B and 5S). In addition, eight animals (4B and 4S) were fed at the maintenance level intake and slaughtered with the 500-kg group. Before slaughter, animals were led through a squeeze chute to collect BM, which included hook bone width, pin bone width, abdomen width, body length, rump height, height at withers, pelvic girdle length, rib depth, girth circumference, rump depth, body diagonal length, and thorax width. The following post-mortem measurements were included: total body surface, body volume (BV, m3), subcutaneous fat, internal fat, intermuscular fat, carcass physical fat (CF, kg), empty body fat (EBF, kg), carcass chemical fat (kg), empty body chemical fat (kg), fat thickness (cm) in the 12th rib, and 9–11th rib section fat. The predicted values were compared with the observed. Among all evaluated equations, only five were found to be adequate for F1 Nellore × Angus: Eqns (7): BV = 0.036 (±0.016) + 1.028 (±0.049) × BVcylinder (n = 28, RMSE = 0.016 m3, r2 = 0.942) and (8): BV = –0.011 (±0.004) + 9.8 × 10–4 (±1.84 × 10–5) × SBW (n = 27, RMSE = 0.003 m3, r2 = 0.997), to estimate BV; and Eqns (27): EBF = –16.8 (±2.68) + 0.142 (±0.008) × SBW (n = 36, RMSE = 4.17 kg, r2 = 0.897), (28): EBF = 0.011 (±0.002) × SBW + 1.22 (±0.024) × CF (n = 35, RMSE = 0.69 kg, r2 = 0.999), and (32): EBF = 1.445 (±0.010) × CF (n = 43, RMSE = 1.51 kg, r2 = 0.998), to estimate EBF. More research is needed to create a robust prediction of carcass and empty body fat using BM for animals of different breeds under diverse production conditions.

Test and Evaluation for Bonding Property Between GFRP and Concrete

Abstract Glass fiber reinforced polymer (GFRP) composite is applied widely in continuously reinforced concrete pavement (CRCP) because of its prominent advantages in properties and cost compared with conventional steel materials. This paper investigated influences of concrete strength, embedded depth, surface form, and diameter of bars on the GFRP-concrete bond performance by a series of pull-out tests. A finite element model was built to simulate the whole pull-out process. The test results showed that, within a certain range, rib depth has a positive effect on both slip control and stress improvement. Smaller rib spacing had a positive effect on controlling the slip displacement, but the diameter of bars and concrete strength had a negligible impact on both the bond strength and slip displacement. The developed finite element model (FEM) could provide similar results as the pull-out tests, and the model also demonstrated a distinct peak value in a shear stress cloud chart. Meanwhile, in order to analyze the effect of embedded depth on bond strength, a normal distribution model was utilized to fit the shear stress distribution. The analysis results retrieved from the normal distribution model, with an extreme small relative error less than 4 %, were more in line with the experimental results than the traditional average distribution model.

The Influence of the Rib Depth on the Tensile Properties of GFRP Bar

Different surface forms will have a huge impact on bond of GFRP rebar and concrete, and the ribs depth is the key factor that affects the bond with concrete, therefore, the surface forms and rib depth should be taken into account when GFRP bars are used as the structural reinforcement material. Based on two kinds of rib spacing and rib depth of GFRP reinforcement on tensile performance test, this article studies the different influence of ribs depth on the tensile properties and mechanism. Experimental results show that rib depth has distinctive impact for the GFRP tendons ultimate tensile strength, elastic modulus and ultimate elongation.

Predicting carcass and body fat composition using biometric measurements of grazing beef cattle1

This study was conducted to develop equations to predict carcass and body fat compositions using biometric measures (BM) and body postmortem measurements and to determine the relationships between BM and carcass fat and empty body fat compositions of 44 crossbred bulls under tropical grazing conditions. The bulls were serially slaughtered in 4 groups at approximately 0 d (n = 4), 84 d (n = 4), 168 d (n = 8), 235 d (n = 8), and 310 d (n = 20) of growth. The day before each slaughter, bulls were weighed, and BM were taken, including hook bone width, pin bone width, abdomen width, body length, rump height, height at withers, pelvic girdle length, rib depth, girth circumference, rump depth, body diagonal length, and thorax width. Others measurements included were total body surface (TBS), body volume (BV), subcutaneous fat (SF), internal fat (InF), intermuscular fat, carcass physical fat (CFp), empty body physical fat (EBFp), carcass chemical fat (CFch), empty body chemical fat (EBFch), fat thickness in the 12th rib (FT), and 9th- to 11th-rib section fat (HHF). The stepwise procedure was used to select the variables included in the model. The r(2) and the root-mean-square error (RMSE) were used to account for precision and variability. Our results indicated that lower rates of fat deposition can be attributed to young cattle and low concentration of dietary energy under grazing conditions. The BM improved estimates of TBS (r(2) = 0.999) and BV (r(2) = 0.997). The adequacy evaluation of the models developed to predict TBS and BV using theoretical equations indicated precision, but lower and intermediate accuracy (bias correction = 0.138 and 0.79), respectively, were observed. The data indicated that BM in association with shrunk BW (SBW) were precise in accounting for variability of SF (r(2) = 0.967 and RMSE = 0.94 kg), InF (r(2) = 0.984 and RMSE = 1.26 kg), CFp (r(2) = 0.981 and RMSE = 2.98 kg), EBFp (r(2) = 0.985 and RMSE = 3.99 kg), CFch (r(2) = 0.940 and RMSE = 2.34 kg), and EBFch (r(2) = 0.934 and RMSE = 3.91 kg). Results also suggested that approximately 70% of body fat was deposited as CFp and 30% as InF. Furthermore, the development of an equation using HHF as a predictor, in combination with SBW, was a better predictor of CFp and EBFp than using HHF by itself. We concluded that the prediction of physical and chemical CF and EBF composition of grazing cattle can be improved using BM as a predictor.

Laboratory Test and Numerical Simulation of Bond Performance between Basalt Fiber Reinforced Polymer Rebar and Concrete

Abstract Because of its high strength and durability, basalt fiber reinforced polymer (BFRP) rebar is a promising alternative to the steel counterpart in reinforced concrete. Using BFRP rebar in continuously reinforced concrete pavement (CRCP) allows one to avoid the rusting of traditional steel bars caused by water that infiltrates through cracks. A sufficient bond between BFRP rebar and concrete is critical in order to apply BFRP rebar in CRCP. This paper investigates the effects of different ribs and anchorage lengths on the bond performance of BFRP rebar and concrete through a series of pull-out tests. The finite element method (FEM) is utilized to simulate the bond between BFRP rebar and concrete. The pull-out test results indicate that the bond strength changes with rib depth and rib spacing. The highest bond strength can be achieved when the rib depth is 10 % of the diameter of the BFRP rebar and the rib spacing is 80 % of the diameter. The bond strength of BFRP rebar with an anchorage length of 10 times the diameter is greater than that of BFRP rebar with an anchorage length of 5 times the diameter. The developed FEM models could provide the same bond-sliding relationship as the results of pull-out tests.

Optimum design of FRP rib core bridge deck

In this paper, an optimum design methodology is presented for Fiber Reinforced Polymer (FRP) bridge decks having one way rib core cross section. The ribs are considered to be oriented in the transverse direction only. The behavior of a typical representative bridge panel of dimension 2m×1m is studied in the present investigation. The panel is simply supported in two opposite edges while the other edges are taken as free. The panel is subjected to self weight and imposed live load as per IRC 70R loading for the tracked vehicle. The thicknesses of the top and bottom face plates; thickness, depth and number of ribs in the core are considered as the basic design parameters for the structural optimization. The material properties adopted for different components are treated as invariable. The optimization has been performed by following different criteria based on deflection limit, buckling and failure load. Graphical User Interface (GUI) of ABAQUS CAE has been utilized for the parametric modeling in which the PYTHON scripts are modified. The design parameters are varied to obtain different trial solutions. The optimum dimensions are finalized based on the solutions corresponding to the minimum volume of the FRP materials.

Prediction of retail beef yield, trim fat and proportion of high-valued cuts in Nellore cattle using ultrasound live measurements

The objective of this study was to develop equations to predict retail product and fat trim (weights and percentages) for Nellore (Bos indicus) cattle. Live ultrasound measurements of the longissimus muscle area, backfat thickness at the 12th rib and rump fat depth and shrunk body weight were obtained from 218 Nellore steers to predict weights and percentages of carcass retail product, pistola retail product and fat trimmings. After slaughter, carcasses were deboned and weighed and percentages of retail cuts were obtained directly. Measurements taken directly in the carcasses explained 97% and 36% of variation in carcass retail product weight and percentage, and 94% and 36% of variation in pistola retail weight and percentage, respectively. Live measurements explained 93% of carcass retail product weight and 39% of carcass retail product percentage. Lower accuracies were observed for pistola retail product weight (R2=0.87) and percentage (R2=0.33). Accuracies for fat trimmings weight and percentage were 79% and 55%, respectively. Ultrasound rump fat thickness showed greater correlations with retail product and fat trimmings (weights and percentages) when compared with ultrasound backfat thickness. The weight and percentage of retail products and of trimmable fat can be estimated in Nellore steers from live animal measurements, with similar accuracy to equations developed based on carcass measurements obtained at slaughter.

Experimental Evaluation of the Shear Resistance of Corrugated Perfobond Rib Shear Connections

Push-out tests were carried out to examine the shear strength of corrugated perfobond rib shear connections. The corrugated perfobond rib shear connection, formed by folding the straight perfobond rib steel panel, can be expected to increase the shear capacity and ductility of a shear connector due to the shear resistance and deformation of the inclined rib panel. To examine the shear behaviour of the corrugated perfobond rib connection and compare it with that of the perfobond rib, the push-out specimens were fabricated to suit the shear corrugated rib resistance parameters of depth of rib, height of rib, holes in the corrugated rib and whether transverse rebar is placed in the corrugated rib holes. Results of the push-outs show that the failure of corrugated perfobond rib shear connection is determined by concrete bearing and small deformations of inclined perfobond rib panel. Specifically, the corrugated rib specimens showed different relative slips at each side of the composite interface owing to the stress flow along the inclined rib developed by inclined direction of the welded corrugated perfobond rib. The transverse rebar in the rib hole reduced the difference in relative slips. The shear strength of the corrugated connection is increased by about 198∼512% compared with the standard perfobond rib specimen connection with transverse rebars and without transverse rebars respectively. However, the contribution of other shear resistance parameters is found to be relatively small compared with the contribution provided by transverse rebars in the rib holes. In terms of the ductility of the shear connector, the relative slip of the corrugated rib connections increased after ultimate load, so it is evaluated to have a sufficient ductility.

The effect of forage species on performance and gastrointestinal nematode infection in lambs

An experiment was designed to determine the effect of forage species on growth rate and gastrointestinal nematode infection in lambs. Southdown lambs ( n = 20; 26 ± 4.28 kg initial BW) stratified by weight, sex and FAMACHA© score were assigned to graze either bermudagrass [BG; Cynodon dactylon (L.) Pers.] or chicory [CH; Cichorium intybus L.]. Lambs grazed for 80 d from July 7, 2009 to September 25, 2009. Lambs were weighed and FAMACHA© scored every 14 d. Fecal samples were taken on d 14, 42, 56, and 69 for modified McMaster fecal egg counts. Ultrasound measures of subcutaneous fat thickness (FT) over the 12th and 13th rib and longissimus dorsi muscle depth (MD) were taken on d 80. Lambs grazing CH had lower ( P < 0.01) FAMACHA© scores by d 69 than lambs grazing BG (2.4 ± 0.43 and 3.1 ± 0.59, respectively). By d 80 FAMACHA© scores were 2.0 ± 0.22 and 3.9 ± 0.64 ( P < 0.01) for CH and BG, respectively and fewer ( P < 0.01) CH lambs than BG lambs required anthelmintic treatment (0/10 and 7/10, respectively). CH lambs also exhibited lower ( P < 0.01) FEC than BG lambs. Average daily gain was greater ( P < 0.01) in lambs grazing CH than those grazing BG (0.28 ± 0.04 and 0.08 ± 0.02 kg/d, respectively). At the end of 80 d, weights were 49.2 ± 3.53 and 33.1 ± 3.82 kg ( P < 0.01) for CH and BG, respectively. On d 80, FT and MD were greater in CH lambs than those grazing BG ( P < 0.01). Lambs grazing CH had increased performance and reduced GIN infection compared to those grazing BG.

Dispersion characteristics of nanometer-scaled silicon rib waveguides

We investigate the dispersion properties of nanometer-scaled silicon waveguides with channel and rib cross section around the optical fiber communication wavelength and systematically study their relationship with the key structural parameters of the waveguide. The simulation results show that the introduction of an extra degree of freedom in the rib depth enables the rib waveguide more flexible in engineering the group velocity dispersion (GVD) compared with the channel waveguide. Besides, we get the structural parameters of the waveguides that can realize zero-GVD at 1550 nm.

Determination of carcass and body fat compositions of grazing crossbred bulls using body measurements1

The objectives of this study were to analyze body measurements of 40 crossbred bulls grazing low quality forage with different supplementation strategies, to estimate interrelationships among those measurements and carcass and body compositions, and to develop systems of equations to predict body fat using body and carcass measurements. Eight animals were slaughtered at the beginning of the experiment, and the remaining animals were slaughtered at 90 or 220 d. The biometric measures (BM) were obtained the day before the slaughter and included hook width, pin width, pelvic girdle length, rump depth, rump height, abdomen width, body length, height at withers, rib depth, girth, and body diagonal length. Other measurements included full, shrunk, and empty BW; internal physical and chemical fats; body volume; body area; carcass weight; 9th- to 11th-rib section weight and composition; fat thickness; subcutaneous fat; intermuscular fat; carcass chemical fat; and empty body physical and chemical fats. The relationships between BM and body components were evaluated, and equations to predict body area, body volume, subcutaneous fat, and carcass and body physical and chemical fat were developed. Biological interpretations of the parameter estimates of equations were similar to those found in the literature such as a ratio of 1 kg of subcutaneous fat to 1.6 kg of intermuscular fat and a deposit of 72 to 76% of body fat in the carcass. The first system used to predict carcass and empty body physical and chemical fat was devised using in vivo information, whereas the second system used BW and the 9th- to 11th-rib fat weight. Our results indicated the combination of BW, carcass traits, and BM was precise and accurate in estimating carcass and body fat composition of backgrounding bulls. The second system had better adequacy statistics [r(2) > 0.92, concordance correlation coefficient (CCC) > 0.957, and root mean square error (RMSE) < 14.4% of the average observed value] compared with the first system. The first system had acceptable adequacy statistics (r(2) > 0.767, CCC > 0.866, and RMSE varying from 15.8 to 22.3% of the average observed value). For both systems, the simultaneous F-test of the linear regression of observed on model-predicted values indicated intercepts were equal to zero, and slopes were equal to 1 (P > 0.246). We concluded that BM can improve the accuracy and precision of the predictions of body composition of grazing animals.

Effects of Lower Dietary Lysine and Energy Content on Carcass Characteristics and Meat Quality in Growing-finishing Pigs

Fifty-four PIC barrows were used to evaluate the effects of lower dietary lysine content and energy level on carcass characteristics and meat quality in slaughter pigs. Pigs were allotted to one of three treatments by body weight with six replicate pens in each treatment. The dietary treatments for body weights of 20-50 kg, 50-80 kg and 80-90 kg were as follows, respectively: control diet (digestible energy 14.22 MJ/kg, lysine/DE 0.67 g/MJ, 0.53 g/MJ and 0.42 g/MJ); a low lysine group (digestible energy 14.22 MJ/kg, lysine/DE 0.49, 0.38 and 0.30 g/MJ); and a low lysine-low energy group or low nutrient group (digestible energy 13.11 MJ/kg, lysine/DE 0.49, 0.38 and 0.30 g/MJ). The daily weight gain, daily feed intake and feed efficiency were calculated in the overall growth period (nearly 12 weeks). Meanwhile, carcass characteristics and meat quality were evaluated at 60 and 90 kg body weight respectively. During the overall growth trial, lowering dietary lysine and nutrient level both decreased weight gain (p<0.05) and feed efficiency (p<0.01). At 60 kg body weight, decreasing dietary lysine and nutrient level noticeably decreased dressing percentage (p<0.01) and back fat depth at last rib of PIC pigs (p<0.01), but enhanced marbling scores (p<0.10), intramuscular fat content (p<0.10) and water loss rate (p<0.01) of the longissimus dorsi muscle. At 90 kg body weight, lean percentage (p<0.01) was evidently reduced by both lowering lysine content and nutrient level in the diet. However, the shoulder back fat depth (p<0.05) and marbling scores of the loin eye muscle (p<0.05) were increased; Lowering dietary nutrient level could improve back fat depth of 10th rib (p<0.01) and last rib (p<0.01), intramuscular fat content (p<0.10), redness (p<0.01) and water loss rate of the loin eye muscle (p<0.05), but decrease loin area (p<0.05). Finally, when comparing the 60 kg and 90 kg slaughter weights, it was found that the shoulder back fat depth (p<0.01, p<0.10), 6th-7th rib (p<0.01, p<0.01), 10th-rib (p<0.01, p<0.01) and last rib back fat depth (p<0.01, p<0.01) of the low lysine and low nutrient group were all obviously increased comparing with the control group. Taken together, the results showed that decreasing dietary lysine content and nutrient level increased intramuscular fat content and water loss rate of longissimus dorsi muscle; On the other hand, both lowering dietary lysine and nutrient level markedly compensated to increase back fat deposition in the later finishing period (body weight from 60

STRUCTURAL ANALYSIS OF RIBBED SLAB

The traditional analysis methods recommended by design codes such as ACI 318-95 (Building 1995), BS 8110 (structural 1997) and ECP 203 ‘Egyptian code (2007)’ allow the ribbed slab to be analyzed in accordance with the rules for solid slab or as the plain flat slab. The traditional method doesn’t take into consideration a lot of factors in the analysis such as thickness of slab and depth of the ribs. The ribbed slabs were analyzed in this study using the finite element method through SAP 2000 program. The structure was analyzed as oneunit in two dimensions x and y. This study included one way and two way slabs. This study illustrated the difference in the produced internal forces in the ribs between traditional method and the finite element method. Moreover, this study included the investigation of the factors which aren’t taken into account in the traditional method. These factors were the connection between the rib and the supported beam, the effect of solid part on the behavior of rib, the effect of the edge beams on the distribution loads on ribs, the effect of cross ribs, the effect of slab thickness, the effect of the depth of rib, the effect of slab width and the effect of the location of rib.

Measuring changes in physical size and predicting weight of sows during gestation

Changes in physical body size during gestation were monitored using 529 sets of sow measurements. All sows were from the same herd and production system with a range in parity from 1 to 8. Sows were individually weighed, P2 backfat thickness was determined by ultrasound and morphometric measurements of body size were taken five times during gestation: day 0 (at service), day 25, day 50, day 80 and day 110. The morphometric measurements included sow height (from floor to last rib at the midline, from floor to ventral surface and from floor to hip), heart girth, depth of last rib, length (from snout to tail and from anterior scapula to tail) and width (at ham, at last rib and at shoulder). Regression analyses were used to model the relationship between day of gestation or parity number and morphometric measurements of body size. Regression equations were also developed to estimate sow weight from physical measurements, day of gestation and parity. As expected, sow dimensions, in general, increased as pregnancy progressed and also with increasing parity number. The relationships between day of gestation and body dimensions were described by linear and quadratic regression models, which had a range of adjusted R2 values up to 0.99. Similar relationships to parity number had a range of R2 values between 0.51 and 0.96. Sow depth, which can be used as an estimate of the width of the sow when lying, equalled the maximum width of the gestation stall (650 mm) at day 103 of gestation. However, by day 40 of gestation, predicted mean sow depth (570 mm) equalled the width at the rear of the crate. The implication of this is that after day 40 of gestation, the average sow was too wide for the rear of the crate when lying in a recumbent position. On day 110 of gestation, 95% of the mean sow body depths would be accommodated in stalls that were 674 mm wide; however, the range in body sizes with increasing parity number suggests the use of more than one stall width would be appropriate. Sow weight could be estimated with an adjusted R2 value of 0.81 and with a residual standard deviation (r.s.d.) of 16.5 kg using heart girth alone, or more accurately using a model with parity, day of gestation, P2 backfat depth and heart girth as the parameters (R2 = 0.89, r.s.d. 12.4 kg).