Fresh Feed Research Articles

Real-Time Simulation and Control of a SAG Mill

Abstract: Real-time simulation plays an important role not only in the design and commissioning of new control strategies, but also in training the operators before the actual system is installed. There are in the market several simulation environments for carrying out these tasks. However, there is still a need of having more flexible environments that can be easily integrated with other systems and tools such as real-time optimization and advanced data analysis. In this work, several standard tools such as Simulink®/Simulink®, OPC toolbox, RSLogix 5000, and FactoryTalk® are integrated to simulate a control strategy for a SAG mill designed to keep the mill operating in the stable region by manipulating the fresh ore feed. The implementation of this strategy is based on standard control blocks available in the ControlLogix Programmable Logic Controllers (PLCs). Experimental results show the effectiveness of the proposed approach to integrate standard tools, and open new possibilities for further developments in the design of advanced monitoring and control strategies for industrial processes.

A Review of Broodstock Improvement to Brachyuran Crab: Reproductive Performance

An improvement in adult brachyuran crabs performance is vital in order to produce better captive broodstock of commercially seed productions. Many factors can control the broodstock performance in brachyuran crabs but of particular importance in aquaculture will be the enhancement of female broodstock that indirectly improve the reproductive performance because of high quality berried females can be used to increase hatchery seed production. This review gives a recent overview on methods to enhance the female’s broodstock performance and many of the most important factors affecting female’s reproduction, including environmental conditions, nutritional requirements, genetic management, physiological effects and etc. and advise on the future research directions. Eyestalk ablation was the basic procedure to enhance the reproductive performance in most brachyuran crabs. Environmental factors such as temperature, salinity and oxygen affect most brachyuran crab’s reproduction such as carapace width, ovarian development and spawning success. For maximal berried female production of brachyuran crabs, a fine balance must be maintained between two distinct nutrient classes (macronutrient and micronutrient) and fresh feed items. The identification of functional gene such as molt-inhibiting hormone, extracellular signal-regulated kinase 2, cyclin B or vasa gene in controlling of gonadal development is a preliminary attempt to boost the broodstock performance of brachyuran crabs. On the other hand, most chemical used in the acceleration of ovarian maturation are from hormone supplementation or direct injection such as thyroxine hormone, androgenic hormone, steroid hormone and serotonin hormones and was used to exert their effects on target tissue in crabs.

Off-cut Recycle for Batch and Batch Extractive Distillation Separation of a Multicomponent Azeotropic Mixture

The influence of recycling off-cuts for the batch and batch extractive distillation separation of a four component (methanol- THF- water- toluene) waste solvent mixture of a pharmaceutical plant is studied by rigorous dynamic simulation. The evolution of the charge composition, of the amount of fresh feed and that of methanol product are determined for six consecutive productions of batch rectification. As an alternative of the traditional batch distillation, batch extractive distillation by using water as entrainer is also studied. Water feeding is applied during the heating-up phase, in order to decrease the methanol concentration in the column top, in this way reducing methanol loss with the fore-cuts. The profit of the productions is calculated on the basis of the operational and incineration costs and the price of the methanol. The influence of the volume of the first fore-cut, which is later incinerated, on the profit of the whole production process is also investigated and its optimal amount is determined for both separation methods. For the extractive process the profit of the regeneration is higher, the optimal volume of the first fore-cut is lower, which means a reduction in the air pollution caused by the incineration.

Impact of timing of feed delivery on the behavior and productivity of dairy cows

The objective of this work was to assess the effect of timing of feed delivery on the behavior and productivity of cows milked 3 times per day. Twelve lactating Holstein dairy cows (4 primiparous and 8 multiparous), milked 3 times per day (at 1400, 2100, and 0700 h), were individually assigned and exposed to each of 2 treatments (over 21-d periods) in a replicated crossover design. Treatments were the manipulation of timing of TMR delivery, 2 times per day, in relation to milking time: (1) feeding at milking time (at 1400 and 0700 h), and (2) feeding halfway between milking times (at 1730 and 1030 h). Milk production, feeding, sorting, and rumination behavior were monitored for each animal for the last 7d of each treatment period. Milk samples were collected for 2 of the last 4d of each period for milk component analysis. With a feed delivery delay, dry matter intake (DMI) tended to be lower (26.5 vs. 27.2kg/d). Although no difference was found in feeding time (224.2min/d), cows fed with a delay consumed their feed more slowly (0.12 vs. 0.13kg of dry matter/min) in more frequent meals (10.0 vs. 9.1 meals/d), which were smaller in size (2.8 vs. 3.1kg/meal) and tended to be shorter in duration (26.7 vs. 30.1min/meal). Cows fed at milking sorted for long particles (102.3%), whereas cows fed with a delay did not sort for or against those particles. Cows sorted for medium particles to a similar extent (102.5%) on each treatment. Cows did not sort for or against short particles on either treatment. Sorting against fine particles was observed, to a similar extent (97.1%), on both treatments. Rumination time (8.9 h/d) and lying time (9.5 h/d) were similar between treatments. Cows without fresh feed at the 1400h milking tended to stand for less time following that milking (71.0 vs. 94.0min), whereas cows without fresh feed at the 0700h milking stood for less time following that milking (66.3 vs. 87.8min). No difference in this latency to lie down was seen at the 2100h milking. Milk yield (48.0kg/d), milk fat content (3.64%), and milk protein content (2.86%) were similar between treatments. Given the tendency for a difference in DMI and no change in yield, efficiency of production was improved with a feed delay (1.93 vs. 1.80kg of milk/kg of DMI). These data suggest that moving the timing of feed delivery resulted in cows consuming their feed more slowly in smaller, more frequent meals, contributing to an improvement in efficiency of production.

Evaluation of enzyme supplementation of palm kernel meal-based diets on the performance of broilers

An experiment was conducted to determine the effect of partially replacing maize with palm kernel meal with and without enzyme supplementation on the performance and gut morphology of broilers. One hundred and fifty (150) 7 day-old broiler chicks were randomly allotted to 5 dietary treatment groups of 3 replicates each. Each replicate had10 birds. The experimental design was Completely Randomized Design (CRD). The diets were as follows: diet 1- control diet; diet 2- 10% PKM with Hemicell; diet 3- 10% PKM without Hemicell; diet 4- 20% PKM with Hemicell and diet 5- 20% PKM without Hemicell. The active ingredient in Hemicell is ß-mannanase. Palm kernel meal replaced 10% and 20% of maize in the test diet. The control diet had no palm kernel meal and Hemicell was added to diets 2 and 4 at the rate of 500g/tonne of feed. Routine management and vaccination procedures were followed while fresh feed and water were supplied ad libitum. The experiment lasted 42days. Significant differences were observed in the final body weight and weight gain of the birds with birds on diet 5 having the highest values. No significant differences were observed in the gut morphology (villus height) of the birds on the different diets. The feed cost and cost incurred per kilogramme weight gain were lowest for birds on diet 5.The results of this study showed that broilers can tolerate 20% inclusion rate of palm kernel meal in their rations without enzyme supplementation and partially replacing maize with palm kernel meal at that level of inclusion can reduce the cost of production of broilers.Key words: Broilers, enzyme, hemicell, morphology, palm kernel meal, villus.

Improving the nutritional value of rapeseed cake and wheat dried distillers grains with solubles by addition of enzymes during liquid fermentation

An increased production of biofuel during the last decade with a subsequent increased amount of co-products has led to an interest in utilizing these co-products as inexpensive alternatives to traditional ingredients for pig feed. Biofuel co-products are considered valuable sources of protein but the high amount of fibre resuts in low digestibility in pigs. An in vitro study was conducted to screen several enzyme mixtures, primarily carbohydrases, for their ability to solubilise non-starch polysaccharides (NSP) and protein in rapeseed cake (RSC) and wheat dried distillers grains with solubles (wDDGS) during fermentation. During the first 48h of the experiment, denoted the initial phase, the mixture was fermented and samples were collected at 0, 24 and 48h. Then, backslopping was performed every 24h, where 50% of the mixture was replaced with fresh feed, water and enzyme, until a steady state cycle was reached. Samples were collected at 0, 6, 12 and 24h after the last backslopping. Results on RSC showed a decrease during the initial phase of fermentation in the amount of total NSP (−31%, P<0.001) and insoluble NSP (−42%, P<0.001) in fermented RSC treated with the enzyme mixture composed by β-glucanase+xylanase+pectinase (GluXylPec). Carbohydrates released from the GluXylPec sample of RSC were fermented by the microorganisms present in the mixture, resulting in elevated amounts of lactic acid during the steady state phase (P≤0.05) and acetic acid from 24h of incubation to the end of the study (P<0.01), and reduced pH levels from 24h to the end of the study (P≤0.01) compared to the Control were measured. Protein solubility in RSC increased in samples fermented with GluXylPec (+14% during the initial 48h, P<0.05). Samples fermented with phytase (Phy) showed a higher protein solubility, too (+18% during the initial 48h, P<0.01); and addition of phytase clearly reduced the level of phytate-P in RSC. Although all the enzymatic treatments showed a small reduction of total NSP content in wDDGS in the initial phase (P≤0.01), and three enzymes [GluXylPec (6), CelXyl (9), and Xylmix (7)] reduced the level of soluble NSP in the initial phase (P≤0.05), no increase in protein solubility or organic acid concentration was detected as a result of enzyme addition. For both fermented products, the biggest effect of enzyme addition was observed in the initial phase of fermentation. In conclusion, addition of β-glucanase, xylanase and pectinase during especially the first 48h of liquid fermentation can be a strategy to disrupt NSP and increase protein solubility in RSC. The overall impact of enzymes on wDDGS was more ambiguous, though reduction of total NSP was observed for all enzymes. Addition of phytase resulted in an almost complete reduction of phytate-P in RSC during fermentation.

Effect of ensiling pumpkin (Cucurbita maxima D.) with dried sugar beet pulp on the content of bioactive compounds in silage and its antioxidant potential

Increased carotenoid and dry matter content in new varieties of pumpkin (Cucurbita maxima D.) make it a valuable fresh feed and a good material for ensiling. The study used the ambar variety of pumpkin (C. maxima D.), which was ensiled with dried sugar beet pulp at a 80:20 ratio of fresh matter. Silages were prepared with or without a commercial bacterial-enzyme inoculant. Silages were made in 20-L mini-silos, 10 for each treatment. The effect of ensiling and the addition of inoculants on fatty acid composition, carotenoids content (β-carotene, α-carotene, violaxanthin, zeaxanthin), α-tocopherol content, total polyphenol content and antioxidant potential of the silages (TAS, FRAP) was studied.Compared to fresh material, silages had a significantly higher proportion of SFA and a significantly lower proportion of PUFA. Inoculant-treated silages were characterized by higher proportions of SFA and a lower proportion of MUFA compared to untreated silages. As a result of ensiling, the content of carotenoids (β-carotene, α-carotene, violaxanthin, zeaxanthin) and α-tocopherol decreased significantly in silages in comparison with fresh material. Comparison of the silages showed that untreated silage had a significantly lower content of β-carotene, α-carotene and α-tocopherol. In comparison with the pre-ensiled material, silages had a higher content of total polyphenols (TPC). The antioxidant potential of the silages (TAS, FRAP) was similar to that of the fresh material and there were no significant differences between silage treatments.

Biohydrogen and Bioethanol Production from Biodiesel-Based Glycerol by Enterobacter aerogenes in a Continuous Stir Tank Reactor.

Crude glycerol from the biodiesel manufacturing process is being produced in increasing quantities due to the expanding number of biodiesel plants. It has been previously shown that, in batch mode, semi-anaerobic fermentation of crude glycerol by Enterobacter aerogenes can produce biohydrogen and bioethanol simultaneously. The present study demonstrated the possible scaling-up of this process from small batches performed in small bottles to a 3.6-L continuous stir tank reactor (CSTR). Fresh feed rate, liquid recycling, pH, mixing speed, glycerol concentration, and waste recycling were optimized for biohydrogen and bioethanol production. Results confirmed that E. aerogenes uses small amounts of oxygen under semi-anaerobic conditions for growth before using oxygen from decomposable salts, mainly NH4NO3, under anaerobic condition to produce hydrogen and ethanol. The optimal conditions were determined to be 500 rpm, pH 6.4, 18.5 g/L crude glycerol (15 g/L glycerol) and 33% liquid recycling for a fresh feed rate of 0.44 mL/min. Using these optimized conditions, the process ran at a lower media cost than previous studies, was stable after 7 days without further inoculation and resulted in yields of 0.86 mol H2/mol glycerol and 0.75 mol ethanol/mole glycerol.

CCD Series No-15: simple design batch SWRO-CCD units of high recovery and low energy without ERD for wide range flux operation of high cost-effectiveness

Closed-circuit desalination (CCD) is a batch process of low energy without need for an energy recovery device (ERD), high recovery irrespective of the number of elements per module, and wide range flux independent of cross-flow and/or recovery, which can be made continuous by the engagement of a side conduit for brine replacement with fresh feed. Batch units for seawater desalination (SWRO-CCD) of the general NMEn (n = 1–3) design, where N stands for the number of modules and n for the number of elements per module, are low-cost systems since avoid the need for ERD and the valves means for the making such a process continuous. Such SWRO-CCD batch units, which pose for recharge between desalination steps, can supply 10 → 1,200 m3/d low-cost seawater permeates sufficient for communities of 100 → 12,000 resident on the basis of 100 L/d/person and for much larger communities if supplied permeates used primarily for drinking and cooking applications. Batch SWRO-CCD units are ideal for small seashore communities with access to shallow beach wells in light of their low-energy consumption and great operational flexibility such as of low flux energy saving mode during night time of low demand with increased production as function of demand at higher flux and greater energy expense during daytime. The wide range flux performance capability of the referred batch units make them ideal for integration with renewable energy sources through solar panels and/or small wind turbines. The energy consumption and permeates quality (parenthesis) as function of flux for the referred units with ME3 (E = SWC6-MAX) modules’ designs for ocean seawater (35,000 ppm) operation of 50% recovery using pressurizing means of 85% efficiency are as follows: 1.79 kWh/m3 (595 ppm) at 13 Lmh; 1.97 kWh/m3 (388 ppm) at 20 Lmh; 2.12 kWh/m3 (309 ppm) at 25 Lmh; and 2.25 kWh/m3 (259 ppm) at 30 Lmh. The experimentally confirmed cited energy figures, even at high flux, manifest high-energy conversion efficiency unattainable by conventional SWRO techniques.

CCD series no-13: illustrating low-energy SWRO-CCD of 60% recovery and BWRO-CCD of 92% recovery with single element modules without energy recovery means—a theoretical extreme case study

In contrast with the conventional SWRO and BWRO plug flow desalination (PFD) techniques where recovery depends on the number of lined membrane elements and energy consumption on the efficiency of energy recovery device (ERD), the newly conceived closed-circuit desalination (CCD) technologies enable the attainment of high recovery, irrespective of the number of elements per module with low energy consumption without need for ERD. The present theoretical model analysis describes the extreme performance prospects of CCD illustrated by a single-element SWRO–CCD unit performing up to 60% recovery with near absolute energy efficiency without need for ERD (e.g. 50% recovery; 13 lmh; 1.573 kWh/m3 for 32,000 ppm NaCl feed equivalent to ocean seawater of 35,000 ppm) as well as by a single-element BWRO–CCD unit performing up to 92% recovery with low energy (e.g. 90% recovery; 25 lmh; 0.472 kWh/m3 for 1,500 ppm NaCl feed equivalent to common brackish water sources of 1,700–2,000 ppm). Another illustration pertains to the performance of a single-element BWRO–CCD–PFD unit, wherein replacement of brine by fresh feed takes place at the end of each CCD sequence by a brief PFD step with results showing only a minor increase in energy consumption compared with that of BWRO–CCD (e.g. 90% recovery; 25 lmh; 0.488 kWh/m3 for 1,500 ppm NaCl feed). The illustrated theoretical model’s results show good agreement with experimental data and manifest the conceptual differences between CCD and conventional RO techniques at their extreme.

Control System Architecture for a Cement Mill Based on Fuzzy Logic

This paper describes a control system architecture for cement milling that uses a control strategy that controls the feed flow based on Fuzzy Logic for adjusting the fresh feed. Control system architecture (CSA) consists of: a fuzzy controller, Programmable Logic Controllers (PLCs) and an OPC (Object Linking Embedded for Process Control) server. The paper presents how a fuzzy controller for a cement mill is designed by defining its structure using Fuzzy Inference System Editor [1]. Also, the paper illustrates the structure of the implemented control system together with the developed PLC program and its simulation. Finally, the dynamic behavior of the cement mill is simulated using a MATLAB-Simulink scheme and some simulation results are presented.

Star-shaped cyclopolymers: A new category of star polymer with rigid cyclized arms prepared by controlled cationic cyclopolymerization and subsequent microgel formation of divinyl ethers

The combination of living/controlled cationic cyclopolymerization and crosslinking polymerization of bifunctional vinyl ethers (divinyl ethers) was applied to the synthesis of core-crosslinked star-shaped polymers with rigid cyclized arms. Cyclopolymerization of 4,4-bis(vinyloxymethyl)cyclohexene (1), a divinyl ether with a cyclohexene group, was investigated with the hydrogen chloride/zinc chloride (HCl/ZnCl2) initiating system in toluene at 0 °C. The reaction proceeded quantitatively to give soluble poly(1)s in organic solvents. The content of the unreacted vinyl groups in the produced polymers was less than ∼3 mol%, and therefore, the degree of cyclization of the polymers was determined to be ∼97%. The number-average molecular weight (Mn) of the polymers increased in direct proportion to monomer conversion and further increased on addition of a fresh monomer feed to the almost completely polymerized reaction mixture, indicating that living cyclopolymerization of 1 occurred. The chain linking reactions among the formed living cyclopolymers with 1,4-bis(vinyloxy)cyclohexane (3) as a crosslinker in toluene at 0 °C produced core-crosslinked star-shaped cyclopoly(1)s [star-poly(1)s] in high yield (100%). Dihydroxylation of the cyclohexene double bonds of star-poly(1) gave hydrophilic water-soluble star-shaped polymers with rigid arm structure [star-poly(1)-OH] with thermo-responsive function in water. Tgs of star-poly(1) and star-poly(1)-OH were 135 °C and 216 °C, respectively; these values are very high as vinyl ether-based star-shaped polymers. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 1094–1102

Short communication: Feed sorting of dairy heifers is influenced by method of dietary transition

This study investigated the effect of exposing heifers to individual feed components on the extent and pattern of feed sorting upon transition to a novel ration. Holstein heifers (394±62d old, weighing 409.8±37.3kg; mean ± SD), consuming a familiar mixed silage-based ration [55% corn silage and 45% haylage, dry matter (DM) basis], were transitioned to a novel total mixed ration [TMR; 41.6% haylage, 36.5% corn silage, 14.6% high-moisture corn, and 7.3% protein supplement, DM basis] by 1 of 2 treatments: direct transition to novel TMR (DIR; n=5) or exposure to novel TMR components individually before receiving novel TMR (COM; n=6). During the baseline period (d 1 to 4), all heifers were offered the familiar silage-based ration. During transition (d 5 to 12), DIR heifers received the novel TMR, whereas COM heifers received the novel TMR components offered separately, in amounts according to TMR composition (target 15% orts). After transition (d 13 to 20), all heifers received the novel TMR. Feed intake and feeding time were determined daily and fresh feed and individual orts were sampled every 2d for particle size analysis and neutral detergent fiber content. The particle size separator consisted of 3 screens (18, 9, and 1.18mm) and a bottom pan, resulting in 4 fractions (long, medium, short, and fine). Sorting activity for each fraction was calculated as actual intake expressed as a percentage of predicted intake. We detected no effect of treatment on dry matter intake or feeding time. After transition to the novel TMR, COM heifers sorted to a greater extent than did DIR heifers, sorting against long particles (95.4 vs. 98.9%) and for short particles (101.7 vs. 100.6%). Differences in sorting patterns resulted in COM heifers tending to have lower neutral detergent fiber intake as a percentage of predicted intake (98.9 vs. 100.5%). The results of this study suggest that the degree of feed sorting may be influenced by method of transition to a novel ration.

DESIGN AND PERFORMANCE EVALUATION OF A PLANT FOR GLYCEROL CONVERSION TO ACROLEIN

The development of biodiesel industry in the recent past brought into discussion the valorization of glycerol as the byproduct of this technology. Dehydration of glycerol leads to acrolein, mainly used as a raw material in the production of acrylic acid and its esters. Several research efforts dealing with the synthesis of acrolein from glycerol are reported in the literature. However, they are limited to catalyst testing on laboratory scale, no attention being paid to the process feasibility at an industrial scale. The goal of this paper is to fill this gap by presenting an integrated design study of the glycerol dehydration process. A simplified kinetic model was developed based on published data, this one being able to predict with sufficient accuracy the rate of the main reaction and the formation of relevant by-products (carbonyl compounds, hydrocarbons, carbon monoxide and coke). A reaction system was designed, similar to the reactor-regenerator unit usually used in hydrocarbon catalytic cracking (FCC). Moreover, the operating conditions were determined in such a way to maximize the selectivity and ensure the autothermal operation. The reactor effluent is sent to a separation section consisting mainly in distillation units. Due to formation of a low-boiling azeotrope, extractive distillation is employed for separating the acrolein-water mixture, using a part of the fresh glycerol feed as solvent. For a set of typical operating conditions, the separation section was designed in Aspen Plus environment. An economic evaluation study was performed using Aspen Economic Evaluation module, following which an acrolein price of 1.13 EUR/kg was determined. By comparing this value with the market one of 3.3 EUR/kg, the feasibility of the proposed process from the economical point of view will be emphasized.

THE USE OF SEAWORM MEAL IN MATURATION DIET AS PARTIAL SUBSTITUTION OF FRESH DIET FOR POND REARED TIGER SHRIMP BROODSTOCK

The purpose of this experiment was to evaluate the effects of using seaworm meal in artificial diet as partial substitution of freshfeed for maturation of tiger shrimp. This experiment started by growing-out tiger shrimp with initial weight around 60 g for four months until reaching maturation phase where shrimp weight were over 90 g for female. Tiger shrimp was selected and stocked into 10 ton concrete tank with stocking density of 50 shrimps with ratio of female : male of 1:1. Dietary treatments were different levels of seaworm meal at 0% (SW0), 10% (SW10) and 20% (SW20). SW0 was positive control without seaworm meal but breeder was fed with frozen seaworm. Test diets were fed as a combination of 60% test pellet and 40% fresh feed. Artificial insemination was carried out for all females before ablation to obtain fertile eggs. Results showed that after ablation, number of female matured was highest in group fed SW10 (13 breeders) and the lowest in female fed control group (7 breeders). Number of female spawned was also highest in female fed SW10 and the lowest was in positive control. Fecundity was very low in all treatments ranged from 12,000-79,700 eggs/spawn. Even though female bearing spermatophore through insemination, number of spawning hatched was very low, only three spawned in each of SW0 and SW10 and two spawned in SW20. Based on number of breeders matured and spawning rate, breeder fed with SW10 gave better performance than other two diets. Technique of artificial insemination needs to be improved to increase the number of fertile eggs.

Prevalence and quantification of pathogenic Vibrio parahaemolyticus during shrimp culture in Thailand.

Vibrio parahaemolyticus is a major cause of seafood-borne gastroenteritis. The human pathogenic strains possess tdh or trh or both genes. In Thai shrimp farming, the level of pathogenic V. parahaemolyticus contamination has not been completely characterized, although it has been identified as a risk for people who consume undercooked shrimp. In this study, the prevalence and concentration of V. parahaemolyticus (total Vp) and pathogenic V. parahaemolyticus (tdh+ Vp and trh+ Vp) were investigated during shrimp culture cycles using the most probable number (MPN) method and were confirmed by PCR and the loop-mediated isothermal amplification (LAMP) techniques. The prevalence and concentration of total Vp were high in broodstock and egg samples at the start of the hatchery cycle, but the organism decreased in the subsequent larval and postlarval stages. In contrast, total Vp was low at the beginning of the pond cycle and dramatically increased during the later stages of culture. Broodstock and fresh feed were important sources of V. parahaemolyticus. Numbers of tdh+ Vp and trh+ Vp detected by the LAMP technique were much greater than those detected by the PCR technique, especially in the late stages of the pond cycle. A direct correlation between total Vp and pathogenic Vp was demonstrated only during the harvest stage. This study will be useful as a guideline to establish levels of V. parahaemolyticus presence which can be considered as safe during shrimp culture. In addition, it could be used to identify the source of V. parahaemolyticus, which has recently been reported to be one of the etiologic agents of acute hepatopancreatic necrosis disease.

Artificial Intelligent Modeling and Optimizing of an Industrial Hydrocracker Plant

The main objective of this study is the modelling and optimization of an industrial Hydrocracker Unit (HU) by means of Adaptive Neuro Fuzzy Inference System (ANFIS) model. In this case, some data were collected from an industrial hydrocracker plant. Inputs of an ANFIS include flow rate of fresh feed and recycle hydrogen, temperature of reactors, mole percentage of H2 and H2S, feed flow rate and temperature of debutanizer, pressure of debutanizer receiver, top and bottom temperature and pressure of fractionator column. The network was employed to calculate the flow rate of gas oil, kerosene, Light Naphtha (LN), and Heavy Naphtha (HN).Unseen data points were used to check generalization capability of the best network. There were good adjustment between network estimations and unseen data. Finally optimization was performed to maximize the production volume percent of gas oil, kerosene, HN and LN and to identify the sets of optimum operating parameters in order to maximize yields of mentioned product. Optimum conditions were found as feed flow rate of 90.9 m3/h, reactor temperature of 378.4 °C, hydrogen flow rate of 54.31 MSCM/h and LN (feed vol.%) of 9.34.

Effect of stocking density on social, feeding, and lying behavior of prepartum dairy animals

The objectives of this study were to determine the effects of prepartum stocking density on social, lying, and feeding behavior of dairy animals and to investigate the relationship between social rank and stocking density. In total, 756 Jersey animals were enrolled in the study approximately 4 wk before expected calving date. This study used 8 experimental units (4 replicates × 2 pens/treatment per replicate), and at each replicate, one pen each of nulliparous and parous (primiparous and multiparous) animals per treatment was enrolled. The 2 treatments were 80% stocking density (80D, 38 animals per pen; each pen with 48 headlocks and 44 stalls) and 100% stocking density (100D, 48 animals per pen). Parous animals were housed separately from nulliparous animals. Animals at 254±3d of gestation were balanced for parity (parous vs. nulliparous) and projected 305-d mature-equivalent milk yield (only parous animals) and randomly assigned to either 80D or 100D. Displacements from the feed bunk were measured for 3h after fresh feed delivery on d 2, 5, and 7 of each week. Feeding behavior was measured for 24-h periods (using 10-min video scan sampling) on d 2, 5, and 7 on wk 1 of every replicate and d 2 and 5 for the following 4 wk. A displacement index (proportion of successful displacements from the feed bunk relative to all displacements the animal was involved in) was calculated for each animal and used to categorize animals into ranking categories of high, middle, and low. Seventy nulliparous and 64 parous focal animals in the 80D treatment and 89 nulliparous and 74 parous focal animals in the 100D were used to describe lying behavior (measured with data loggers). Animals housed at 80D had fewer daily displacements from the feed bunk than those housed at 100D (15.2±1.0 vs. 21.3±1.0 per day). Daily feeding times differed between nulliparous and parous animals at the 2 stocking densities. Nulliparous 80D animals spent 12.4±5.0 fewer minutes per day feeding than nulliparous 100D animals, whereas 100D parous animals tended to spend 7.6±4.5 fewer minutes per day feeding than 80D parous animals. The 2 treatments were not different in the number of lying bouts or lying-bout duration; lying time was longer for 100D on d −33, −29, and −26 and shorter on d −7, −5, and 0 than 80D. The interaction between treatment, parity, and social rank was associated with lying and feeding times. In summary, animals in the 80D treatment had a lower number of displacements from the feed bunk and spent more time lying down near parturition than 100D animals, and 80D nulliparous animals had reduced daily feeding time compared with 100D nulliparous animals. Although these results showed some potential behavior benefits of a prepartum stocking density of 80% compared with 100%, observed changes were small. However, greater stocking density cannot be recommended; more research is needed to evaluate the effects of stocking densities greater than 100% and with other breeds of cattle besides Jersey.

Direct, rapid and sustainable vermicomposting of the leaf litter of neem (Azadirachta indica).

The recently developed concept of high rate vermicomposting was successfully used to enable direct vermicomoposting of neem leaves-without any pre-composting or cow dung supplementation as previously reported processes had necessitated. All the three epigeic species of earthworms that were explored, Eudrilus eugeniae, Eisenia fetida and Perionyx excavatus, provided efficient vermicast production with no mortality, persistent gain in body mass and good fecundity over the 16 months long period of reactor operation. In this period, all reactors were pulse-fed at the solid retention time of 20 days and were operated in the pseudo discretized continuous operation protocol developed earlier by the authors. With this, it was possible to almost completely dampen the influence of natural biodegradation of the feed or grazing by the earthworm born in the vermireactors. The findings, thus, conclusively prove that, all-through, the brisk vermicomposting was caused almost entirely by the action of the 'parent' earthworms on fresh feed.

Effect of operational parameters and recycling load on the high pressure grinding rolls (HPGR) performance

High-pressure comminution is regarded as an important technology in grinding circuits primarily because it offers considerable energy savings. HPGRs can only be operated energy efficient under choke feeding condition in which a material bed is formed between the rollers that improve the interparticle breakage. The slow load application to the particles causes the structural collapse of the grains which minimize energy losses such as heat and noise. To increase the amount of fines in the product (cake) of HPGR, the recycling load can be used up to some extent and a higher pressure gradient along the roller width is obtained. This application may result in compact flakes containing more fines. An extensive testwork was performed with an industrial HPGR unit in a cement plant in Turkey to elucidate the effects of recycling load together with the operational parameters on HPGR's performance. For this purpose the recycling load of the circuit was changed as in different ratios to the fresh feed flow rate during the testwork. Six different tests were performed and for each test, samples were collected from HPGR total feed and discharge in the steady state condition. After sampling campaigns, the particle size distributions of all samples were determined and mass balancing around the circuit was performed. Capacity, pressure and gap relationships were investigated. According to the data acquired, it was shown that the reduction ratio of the HPGR is getting higher with the recycling load for the same specific motor output power. The flake thickness indicates the same situation, as well. More compacted flakes were produced for higher recycling load ratios.