Energy Conversion Ratio Research Articles

Supplementation of Microbial and Fungal Phytases to Low Protein and Energy Diets: Effects on Productive Performance, Nutrient Digestibility, and Blood Profiles of Broilers

To evaluate in possible use of phytases for improving the utilization of low protein and energy diets, 420, one-day-old chicks were distributed among 7 groups (5 replicates of 12 chicks/group). During the starter (1–35 day), grower (37–56 day), and finisher (57–64 day) periods, the control group fed diets containing 21.2% crude protein (CP)-2947 Kcal/kg metabolizable energy (ME), 19.6 CP-3023 ME and 18.0 CP-3100 ME, respectively. The three low-CP groups received diets isocaloric but with −1% CP than the control, while the three low-CPME groups fed diets with −1% CP and −100 Kcal than the control. In addition, the low-CP and low-CPME groups were supplemented with 0 (low-CP_uns and low-CPME_uns), 500 U/kg of an Aspergillus niger (low-CP_AP and low-CPME_AP) or 500 FTU/kg of an Escherichia coli phytase (low-CP_EP and low-CPME_EP), respectively. Low-CP and low-CPME diets decreased (p < 0.01) the intake of feed as well as the protein and metabolizable energy conversion ratios in comparison to the control group. In general, phytases lowered (p < 0.01) the intake of feed, protein, and energy, but bacterial phytase showed a higher (p < 0.01) effect than A. niger one. The diets with low-CP and low-CPME levels decreased (p < 0.01) the amount of the excreta nitrogen. The supplementation of phytases had similar effects on digestibility of nutrients, carcass traits, bone mineralization and blood biochemistry. The supplementation of A. niger increased abdominal fat deposition of compared low-CPME diet compared to low-CPME_uns diet. All diets showed similar production index allowing the use of low-CPME diet when phytases was supplemented.

Environmental impacts of milk production and processing in the Eastern Alps: A “cradle-to-dairy gate” LCA approach

This study aimed to evaluate the environmental footprint and feed energy conversion ratio of Alpine dairy chains in the Eastern Alps, taking into account both the milk production and dairy processing phases, and to identify farm management features useful for targeting mitigation measures in the production phase. A cradle-to-farm gate Life Cycle Assessment model that included herd and manure management, on-farm feedstuff production and purchased feedstuffs and materials (dairy farm), and production inputs and dairy outputs (dairy processing) was applied to 75 farms (10 dairies). As functional units, we used 1 kg fat- and protein-corrected milk (FPCM) and 1 m2 of agricultural land, to account for production intensity and land managed by alpine farms, respectively. Impact categories (CML-IA and CED methods, background data from Ecoinvent database) assessed were global warming (GWP), GWP plus land-use change (GWP_LUC), acidification (AP) and eutrophication (EP) potentials, cumulative energy demand (CED) and land occupation (LO). Feed energy conversion ratio (whole diet - ECR; potentially human-edible portion of the diet - HeECR) was computed as the ratio between gross energy in feeds and that in milk. Mean ECR was 6.6 ± 0.5 MJ feed/MJ milk, of which only 8% derived from potentially human-edible feedstuffs. For 1 kg of FPCM at the dairy farm, GWP averaged 1.19 kg CO2-eq, GWP_LUC 1.31 kg CO2-eq, AP 17.3 g SO2-eq and EP 6.0 g PO4-eq (coefficients of variation, CV, ranged 17–21%), whereas mean CED was 2.7 MJ and LO 2.1 m2/y (CVs: 40–46%). When dairy processing was included, the impact values for 1 kg of dairy product were from 8 to 13 times greater than those obtained for 1 kg FPCM. Based on the outcomes of a principal component analysis, the farm management features most related to impacts and feed ratios were milk yield (MY, for the impacts per unit of milk and ECR), stocking rate (SR, for the impacts per unit of area), and percentages of concentrates (C, for GWP_LUC and HeECR). Step-wise analysis evidenced that strategies aiming to decrease the environmental footprint referred to milk and managed area at the same time and to improve the feed energy conversion ratios should include MY, SR and C jointly. These issues are particularly important for the sustainability of mountain farming systems, which need to create a virtuous link with local forage resources and the territory.

Energy, exergy, and economic analysis of an integrated solar combined cycle power plant

AbstractIntegrated Solar Combined Cycle (ISCC) power plants based on Parabolic Trough Concentrators (PTCs) are the most efficient way for solar into electrical energy conversion. However, due to operation in several climate conditions, they need more efforts in their adaptation. This paper presents a techno‐economic assessment of an ISCC ‐ PTC system operating at Hassi R'mel site (Algerian Sahara) for which a new thermal storage system is incorporated. The obtained results reveal noticeable enhancements in the solar energy conversion and the overall power plant performance, hence offering better stability to the grid. As shown, the net solar thermal energy conversion ratio may reach up to 14%. Energy and exergy efficiencies are respectively equal to 56.06% and 53.29%, and about 46% of exergy received by the system is destructed. Moreover, the obtained Levelized Cost of Energy (LCOE) is around 9.75 ¢/kWh which is very promising, but still higher compared with a simple Combined Cycle (CC). At this geographical site, the modified ISCC ‐ PTC power plant will allow saving about 30 million $ in natural gas consumption and 13 million $ in emission taxes.

Numerical simulation and parametric study of various operational factors affecting a PV-battery-air conditioner system under prevailing European weather conditions

The building sector currently accounts for approximately 40 % of final energy consumption. In the near future, renewable energy driven heat pump systems will play an important role in the thermal management of buildings. The work described here deals with the effect of weather conditions as well as operational characteristics on the energy and economic performances of a solar PV powered air conditioning unit (ACU) with a battery system (PBAS) based on numerical and experimental investigations. The experiments were carried out to test the developed TRNSYS model. In the assessment, various performance indicators were used while a novel performance indicator, the so-called annual grid independence ratio, was also proposed. The simulated studies revealed that annual energy performance indicators (self-consumption, self-sufficiency, grid independence and energy conversion ratios) are greatly affected by climatic conditions and operational characteristics. Besides, the economic analysis has shown that the net present value and the energy consumption profiles or diverging values for state of charges are directly proportional for the hottest (Seville) climate. However, they are inversely proportional for the coldest (Stockholm) climate for the considered PBAS configuration (PV-2.5 kWp, ACU-2.52 kW cooling and 2.84 kW heating, batteries-9.6 kW h) under the selected economic status of the sites.

Biocrude Oil from Algal Bloom Microalgae: A Novel Integration of Biological and Thermochemical Techniques.

Algal bloom microalgae are abundant in polluted water systems, but their biocrude oil production potential via hydrothermal liquefaction (HTL) is limited. This study proposed a novel process that combined biological (dark fermentation) and thermochemical (HTL) techniques aimed at changing the feedstock characteristics to be more suitable for thermochemical conversion, herein named integrated dark fermentation-hydrothermal liquefaction (DF-HTL). DF-HTL conversion of algae significantly enhanced the biocrude oil yield (wt %), carbon content (mol), energy content (MJ), and energy conversion ratios by 9.8, 29.7, 40.0, and 61.0%, respectively, in comparison to the control. Furthermore, DF-HTL processing significantly decreased the aqueous byproduct yield (wt %), carbon content (mol), nitrogen content (mol), and ammonia content (mol) by 19.0, 38.4, 25.0, and 13.2%, respectively, in comparison to the control. Therefore, DF-HTL reduced the environmental impact associated with disposing of the wastewater byproduct. However, DF-HTL also augmented the nitrogen content (mol) of the biocrude oil by 42.2% in comparison to the control. The benefits of DF-HTL were attributed to the increased acid content, the incorporation of H2 as a processing gas, and the enhancement of the Maillard reaction, which shifted the distribution of reaction products from the aqueous phase to the biocrude oil phase. This article provides insights into the efficacy of a novel integrated biological-thermochemical processing method with distinct environmental and energetic advantages over conventional HTL that heightens the biocrude oil yield for feedstocks with a high carbohydrate and a high protein content.

IMPACT OF PELLET BINDER ON BROILER PERFORMANCE AND FEED PROCESSING ECONOMICS

Total number of 216 one-day-old, unsexed Hubbard broiler chicks were used to study effects of pellet binder level together with pelleting diameter on growth performance, carcass measurements, and economic efficiency. Experimental birds were distributed over 6 groups, each group comprised of 36 chicks in 6 replicates of 6 chicks each. The experimental dietary treatments were as follows: control (T1) basal diet (BD) that is pelleted in standard diameter (SD) with addition of calcium lignosulfonate (CL) 2 Kg/ Ton; (T2) BD pelleted in SD with CL 4 Kg/ Ton; (T3) BD pelleted in SD with CL 8 Kg/ Ton; (T4) BD pelleted in a diameter thicker that SD by 1.0 mm (SD+1) with CL 2 Kg/ Ton; (T5) BD pelleted in SD+1 with CL 4 Kg/ Ton; and (T6) BD pelleted in SD+1 with CL 8 Kg/ Ton. Obtained results showed that all parameters of growth performance; live body weight (LBW), daily weight gain (DWG), daily feed consumption (DFC), and feed conversion ratio (FCR) were not significantly affected (P>0.05) by dietary treatments. Also, values of growth efficiency; relative growth rate (RGR),performance index (PI), production efficiency factor (PEF), protein conversion ratio (PCR), and energy conversion ratio (ECR) indicated no significant differences (P>0.05) within all tested groups. Moreover, data of carcass traits; dressed carcass, abdominal fat, giblets, total edible parts appeared significantly similar (P>0.05) among all treatments. Additionally, data of economic evaluation showed better economic efficiency with T2, T5, or T6 groups when compared to other groups. It could be concluded that using CL as a pellet binder in SD conditions, could be more beneficial with inclusion level of 4 Kg/Ton. Moreover, it might be advised to include CL at 8 Kg/ Ton in diets only when pelleting feedatSD+1 as these conditions positively maintained performance and carcass of birds.

Net Energy Prediction Equations Used in Chinese Yellow Chickens for Energy Evaluation

This study assessed whether the net energy (NE) system is beneficial for determining the efficiency of feed utilization in Chinese Yellow Chickens. A total of 5,600 male Chinese Yellow Chickens were assigned to eight dietary treatments (ten replicate pens per treatment and 70 chickens per pen) of differing apparent metabolizable energy (AME) and NE values. A highly significant linear correlation between dietary energy and feed conversion ratios (FCR) was observed (p<0.01). The linear regression equation between metabolizable energy (ME) and FCR was: AME=−1435.5×F/G+6278.2, where R²=0.8272. The linear regression equation between NE and FCR was NE=−1350.1×F/G+5340.9, and R²=0.9551. The R² of FCR (0.9551) for diets formulated using NE values was higher than the R² of FCR (0.8272) for diets prepared on the basis of the ME system. We conclude that the NE system is more accurate than the AME system for determining the energy requirements of Chinese Yellow Chickens.

Research on the Impact of Different Force Directions on the Mechanical Properties and Damage Evolution Law of Sandstone with Different Hole Diameters

In this research, a uniaxial acoustic emission experiment was conducted on rock samples with different positions and diameters of the hole, and an analysis was made on the impact of different hole positions and diameters on the mechanical properties, failure, energy conversion, and acoustic emission‐caused damage characteristics and laws of the rock samples. The results reveal as follows: first, due to the existence of holes in rocks, the stress‐strain curve changes at each stage, accompanied by multiple stress drops. And the peak strength gradually reduces with the increase in hole diameter. At different hole positions, the duration that the rock sample passes through at each stage of the stress‐strain curve varies, and the peak strength of the rock with the vertical hole is greater than that of the rock with the horizontal hole. This indicates that the bearing capacity and stability of the rock sample with the vertical hole are greater than those of the rock sample with the horizontal hole of the same diameter. Second, by making a comparison on the failure characteristics of rock samples, it is found that the intact rock shows brittle failure. For the rock sample with the horizontal hole, symmetrical tensile cracks initially appear in the upper and lower parts of the hole and finally form shear failure. As for the rock sample with the vertical hole, Y‐shape failure originally presents and eventually forms N‐shape failure with the increase in hole diameter. Over a comparison with the failure pattern of an intact rock sample, it is demonstrated that the final failure pattern and crack expansion trend on the rock sample vary with the change in the hole position and diameter. Third, as obtained by comparing and analyzing the energy conversion of the rock with different diameters of the hole, the energy conversion in the rock is changed due to the existence of holes, and the increase in hole diameter causes a gradual decrease in the elastic energy stored in the rock and gradual increase in the dissipated energy. And by comparing the energy conversion of the rock with different positions of the hole, it is acquired that the elastic energy conversion ratio of the rock with the vertical hole is higher than that of the rock with the horizontal hole. Furthermore, an explanation was made on the difference in the failure processes of the two types of rocks from the perspective of energy conversion.

Influence of light on biomass and lipid production in microalgae cultivation

Microalgae have a diverse application in food, pharmaceutical, beauty, animal feed and bioenergy industry. The demand for high-quality pure microalgae biomass has steered the large-scale production of microalgae in the photobioreactor. The usage of light-emitting diodes (LEDs) as a light source is gaining attention as to conventional fluorescent lamps due to the higher energy conversion ratio, lower heat dissipation and its flexible application in photobioreactors. Besides, the narrow spectrum of LEDs could efficiently promote specific compounds in microalgae. This article reviews the influence of using various LED spectra on the biomass and lipid composition of microalgae. In addition, suggestions on the use of different LEDs cultivating common microalgae species in aquaculture are provided.

Promoted plasma generation for laser-driven flyer by MgAl hydride films

MgAl hydride films with different hydrogen contents were fabricated in Ar and H2 mixed atmosphere using magnetron sputtering. Neutron reflectometry was performed to measure hydrogen contents, which indicated that up to 11atom% hydrogen was absorbed into MgAl. The MgAl hydride films were irradiated using pulsed lasers and the electron temperature and density of the generated plasma was measured. Results showed the electron temperature and density at delay time of 1μs were 7330 K, 7.9 × 1015 cm−3 and 8044 K, 9.0 × 1015 cm−3 for MgAl hydride films with 5atom% and 11atom% hydrogen, respectively. For comparison, the electron temperature and density for pure MgAl film were 5634 K and 6.9 × 1015 cm−3. Obviously, the electron temperature and density increases with the hydrogen content. Subsequently, the conversion ratio of the shock wave energy to the incident pulse energy were analyzed by investigating plasma induced shock wave evolution. The conversion ratio for MgAl hydride films with 5atom% and 11atom% hydrogen was 19.2% and 28.6%, which was 1.2 and 1.8 times of that for the MgAl film. Therefore, the MgAl hydride film promised to be a new class of material capable of promoting the plasma generation of the laser-driven flyers.

Highly stable ethanol-based Cu2ZnSnS4 (CZTS) low-cost thin film absorber: Effect of solution aging

Aging is an important factor that can affect the grain size, surface morphology and optical band gap of the thin films. Especially, it is thought that these important parameters will have a strong impact on the solar cell energy conversion ratio in Cu2ZnSnS4 (CZTS) absorber based photovoltaic devices. With this aim the presented study reports the effect of the aging time on the structural, morphological and optical characteristics of p-type quaternary CZTS absorber materials, produced by using a solution assisted dip-coating process on the glass substrate and annealed at 515 °C without using any dangerous environment (such as sulphurization or selenization). The kesterite crystal structure was determined by X-ray diffraction (XRD) analyses for all the CZTS samples. To support the observed kesterite crystal structure of the CZTS, the main vibration modes and chemical composition of the samples were investigated by Raman and XPS tools. Besides, the comprehensive surface analyses were conducted to better understanding of the morphology variation within the CZTS thin films depending on the aging time of the CZTS precursor solution by using SEM and AFM tools. Generally, large grain size and solution stability of absorber material have important impacts on the solar cell energy conversion solar cells. Furthermore, the band gap of the CZTS thin film shifts toward the optimal energy value (from 1.82 eV to 1.56 eV), observed from the optical studies. This last result is highly attractive for the CZTS based solar cell applications.

Experimental Study on Influence of Borehole Arrangement on Energy Conversion and Acoustic Characteristics of Coal-Like Material Sample

This paper examines the effects of borehole arrangement on the failure process of coal-like materials based on its energy conversion and acoustic characteristics from the perspectives of energy, AE energy, AE spectrum, and frequency band. Findings from the study revealed that the presence of borehole can significantly reduce the conversion ratio and growth rate of elastic energy during the loading of coal-like material sample and delay the release of internal energy of the sample. Also, it can reduce the frequency band energy of the main frequency of acoustic emission signal but has little effect on the size and richness of the peak frequency of acoustic emission signal. The practice that makes drilling diameter and depth increase stepwise can minimize the elastic energy conversion ratio, the growth rate, and the main frequency band energy of acoustic emission signal of coal-like material sample and postpone the internal energy release of the sample to the greatest extent, so as to enrich the richness of the secondary frequency of acoustic emission signal. The results of this study have certain guiding significance for the layout of pressure relief boreholes in the production process of coal mines.

Maximum Power Point Tracking Menggunakan Algoritma Artificial Neural Network Berbasis Arus Hubung Singkat Panel Surya

The conversion of solar energy into electrical can be utilized by using the solar panel, but the energy conversion ratio is still low. Maximum Power Point Tracking (MPPT) is a method used to increase energy production in the process of converting electrical to the solar panel. Artificial Neural Network (ANN) is one of the soft-computing methods that can be applied as MPPT with the advantage of having a learning process, very stable, fast, doesn’t require complicated mathematical modeling, and has good performance. ANN is proposed with input from the short circuit current of the solar panel and is used as a reference for the ANN to reach the maximum power. The process of detecting a short circuit current is indicated by a momentary decrease of the power by the solar panel. The results show the proposed algorithm can reach the maximum power operating point of the solar panel despite the change of radiation. When at maximum power operating point, ANN can hold the value, so the resulting value doesn’t change and doesn’t generate ripple. At radiation of 1000 W/m 2 and using 100 WP, ANN can produce a maximum power of 99.97 Watts with a time of 0.063 seconds.

Feed and production efficiency of young crossbred beef cattle stratified on a terminal total merit index.

Few studies have attempted to quantify the association between a terminal total merit index with phenotypic feed and production efficiency in beef cattle, particularly when feed efficiency is itself explicitly absent as a goal trait in the index. The objective of the present study was to quantify the differences in phenotypic performance for feed intake, feed efficiency, and carcass traits of crossbred bulls, steers, and heifers differing in a terminal total merit index. A validation population of 614 bulls, steers, and heifers that were evaluated for feed intake and efficiency in the same feedlot and subsequently slaughtered at the end of their test period was constructed. The Irish national genetic evaluations for a terminal index of calving performance, docility, feed intake, and carcass traits were undertaken with the phenotypic records of animals present in the validation population masked. The validation population animals were subsequently stratified into four groups, within sex, according to their terminal index value. Mixed models were used to quantify the association between terminal genetic merit and phenotypic performance; whether the associations differed by sex were also investigated. The regression coefficient of phenotypic feed intake, carcass weight, carcass conformation, or carcass fat on its respective estimated breeding values was 0.86 kg dry matter 0.91 kg, 1.01 units, and 1.29 units, respectively, which are close to the expectation of one. On average, cattle in the very high terminal index stratum had a 0.63 kg DM/d lower feed intake, a 25.05 kg heavier carcass, a 1.82 unit better carcass conformation (scale 1 to 15), and a 1.24 unit less carcass fat score (scale 1 to 15), relative to cattle in the very low terminal index stratum. Cattle of superior total genetic merit were also more feed efficient (i.e., had a lower energy conversion ratio, lower residual feed intake, and greater residual gain), had a greater proportion of their live-weight as carcass weight (i.e., better dressing percentage) and were slaughtered at a younger age relative to their inferior total genetic merit counterparts. This study provides validation of an all-encompassing total merit index and demonstrates the benefits of selection on a total merit index for feed and production efficiency, which should impart confidence among stakeholders in the contribution of genetic selection to simultaneous improvements in individual animal performance and efficiency.

Influence of adding different levels of local dried Tarragon (Artemisia dracunculus) as a feed additive on production performance of broiler chicks.

A total of 240 (one-day-old) unsexed broiler chicks (Ross 308) were used. The experiment included four treatment groups, with four replications per treatment with 15 birds each. The experiment persisted 42 days, the chickens were provided with feed and water ad libitum. Experimental treatments were given basal diet only (T0), basal diet with adding 200 g dried local tarragon (T1), basal diet with adding 400 g dried local tarragon (T2) and basal diet with adding 600 g dried local tarragon (T3). The tarragon additive positively affects the values of daily feed intake, in overall period(1-42 day of age),333.88g/bird/day was the best feed intake which was belonged to T3 treatment. Also, the tarragon additive affects positively protein and energy intake. No significant effects were obtained in body weight gain between the different treatments and within several age periods. Significant effects were recorded for the results of feed conversion ratio and both protein and energy conversion ratio in the age period (29-42 day) and in overall period (1-42 day) but did not affect body weight gain during the trial periods.

Laser-induced rotary micromotor with high energy conversion efficiency

Light is a precious resource that nature has given to human beings. Converting green, recyclable light energy into the mechanical energy of a micromotor is undoubtedly an exciting challenge. However, the performance of current light-induced micromotor devices is unsatisfactory, as the light-to-work conversion efficiency is only 10 − 15 – 10 − 12 . In this paper, we propose and demonstrate a laser-induced rotary micromotor operated by Δ α -type photopheresis in pure liquid glycerol, whose energy conversion ratio reaches as high as 10 − 9 , which is 3–6 orders of magnitude higher than that of previous light-induced micromotor devices. In addition, we operate the micromotor neither with a light field carrying angular momentum nor with a rotor with a special rotating symmetrical shape. We just employ an annular-core fiber to configure a conical-shaped light field and select a piece of graphite sheet (with an irregular shape) as the micro-rotor. The Δ α -type photophoretic force introduced by the conical-shaped light field drives the rotation of the graphite sheet. We achieve a rotation rate up to 818.2 r/min, which can be controlled by tuning the incident laser power. This optical rotary micromotor is available for twisting macromolecules or generating vortex and shear force in a medium at the nanoscale.

A prototype for light-electric harvester based on light sensitive liquid crystal elastomer cantilever

In this paper, a prototype of a light-electric mini-generator based on light sensitive liquid crystal elastomer cantilever is proposed. Firstly, the mechanism of this light-electric mini-generator is introduced. Then the governing equation of motion of the cantilever is established considering the light induced inhomogeneous strain distribution. By means of superposition method and Duhamel integral, the closed-form expressions for the vibration deflection, induced electromotive force and energy conversion efficiency are obtained. Numerical results show that the induced electromotive force and energy conversion ratio can be tuned by adjusting the light parameters and cantilever dimensions. The maximum voltage and conversion efficiency are in proportion to the light intensity, the contraction coefficient, the second power of thermal relaxation time and light decay distance ratio, but inversely proportional to the third power of damping factor. Based on the present material parameters, a maximum voltage up to 75.8 mV with a preferable energy conversion efficiency of 9.50 × 10−3% per magnetic induction intensity and circuit resistance can be achieved, which obviously could be greatly improved with the subtler design of cantilever and circuit materials.

Environmental impact and efficiency of use of resources of different mountain dairy farming systems

In the European Alps traditional, low-input dairy farming systems still coexist with modern high-input intensive systems. This study aimed at evaluating the effect of different Alpine farming systems on the environmental footprint, production efficiency (gross energy conversion ratio, ECR) and competition between feed and food (potentially human-edible gross energy conversion ratio, HeECR). Data originated from 37 dairy farms located in the Trento province (eastern Italian Alps), from which four dairy systems were derived by performing non-hierarchical cluster analysis based on farm facilities and management features (traditional, either with tie or loose stalls, and intensive, either with or without use of silages, systems). Environmental footprint was computed using a cradle-to-farm gate Life Cycle Assessment model. One kg fat- and protein-corrected Milk (FPCM) and 1 m2 of agricultural land were used as functional units. Global warming (GWP), acidification (AP) and eutrophication (EP) potentials, cumulative energy demand (CED) and land occupation (LO) were included as impact categories. System boundaries included herd and manure management, on-farm feedstuffs production and purchased feedstuffs and materials. Mean impact values per 1 kg FPCM were 1.0 ± 0.3 kg CO2-eq (GWP), 21.1 ± 4.3 g SO2-eq. (AP), 6.3 ± 1.2 g PO4-eq. (EP), 5.0 ± 2.0 MJ (CED), 1.4 ± 0.5 m2/y (LO), whereas per 1 m2 were 0.8 ± 0.3 kg CO2-eq (GWP), 16.3 ± 4.2 g SO2-eq. (AP), 4.9 ± 1.3 g PO4-eq. (EP), 3.8 ± 1.8 MJ (CED). Mean ECR was 5.17 ± 0.89 MJ/MJ, with 88% of gross energy provided by non-human edible feedstuffs. A large variability was found both between and within dairy systems, in terms of environmental footprint and production efficiency. Impact values were slightly greater per unit of product and lower per unit of area in traditional than in intensive farms, although generally without significant differences. Production efficiency of traditional farms was 17% lower in terms of ECR but 59% greater in terms of HeECR, due to a lower proportion of purchased concentrates in animal rations, with a positive contribution to food balance and diet self-sufficiency. These results indicate that the transition from traditional towards intensive systems improved only slightly the environmental footprint of dairy farming, but increased markedly its dependence on external concentrate feeds and the feed-food competition. In perspective, different aspects of mountain dairy systems, such as the conversion into food of human non edible feeds, the low impacts at the local scale, the ability to conserve grasslands under a land-sharing perspective, and in general the associated ecosystem services, should be considered when aiming to improve their environmental sustainability.

Influence of Different Vegetable Oils on In Vitro Ruminal Fermentability and Nutrient Digestibility in Ettawah Crossbred Goat

This research was aimed to determine the effect of supplementation of vegetable oil (corn oil, palm oil and kapok seed oil) on in vitro ruminal fermentability and nutrient digestibility. Experiment design used was Randomized Block Design with four treatments and four replication based on rumen fluid sampling time. The four treatments namely R0 = feed without oil supplementation; R1 = R0 + 5% corn oil; R2 = R0 + 5% palm oil; and R3 = R0 + 5% kapok seed oil. The result showed that supplementation of 5% vegetable oil did not affect (P&gt;0,05) the rumen pH, A/P ratio, and efficiency of energy conversion. The total VFA, acetate, propionate, butyrate, methane and NH3 was higher (P&lt;0,05) in supplementation of 5% vegetable oil than he control. The population of protozoa, microbial protein, in vitro dry matter digestibility (IVDMD), organic matter digestibility (IVOMD), and crude fiber digestibility (IVCFD) was lower (P&lt;0,05) in supplementation of 5% compared to the control. Population of protozoa decreased until 58,76% for R1; 66,89% for R2; and 43,33% for R3. It can be concluded that supplementation of 5% vegetable oil decreased the population of protozoa, increased the production of VFA and NH3. Supplementation of 5% kapok seed oil resulting the highest of total VFA, acetate, propionate, butyrate and NH3 among other treatments.

A Novel Average Torque Control of Switched Reluctance Motor Based on Flux–Current Locus Control

This article develops a novel average torque control (ATC) scheme for switched reluctance (SR) motor on the basis of a brand-new microstep flux-current locus controller. The proposed ATC is based on the calculation of the average torque from the converted mechanical energy that can be illustrated as an enclosed area in a flux-current plane. It has the superior advantage that it is able to control the average torque over any arbitrary small-angle intervals, whereas the conventional ATC can control only the average torque for a whole stroke. In order to realize the proposed ATC, a flux-current locus controller, which consists of a hybrid flux controller and current controller as well as involve the microstep process, is introduced in this article. The flux-current locus of the energy conversion loop is controlled for the first time in the literature. With the locus controller, it is possible to achieve a better energy conversion ratio and the ATC. In order to verify both the proposed locus control method and the ATC for SR motor, detailed simulation results and discussion are provided.