A New Hybrid Synchronous Reluctance Machine Capable of Ultra-High Output Power

A new hybrid synchronous reluctance machine capable of ultra-high Xd/Xq ratio output power has been studied. A d-q model (voltage and flux linkage) of the hybrid synchronous reluctance machine has been idealized and developed. Also the impedance and current loci from steady state analysis of the machine was obtained. The effect of capacitor loading in the auxiliary winding was investigated. The power factor and torque developed in the hybrid synchronous reluctance machine was compared with the conventional synchronous reluctance machine. The hybridized synchronous reluctance machine improved the major constraints of conventional reluctance machine – low power output and poor power factor due to low ratio of direct to quadrature axis reactance (Xd/Xq). To achieve this two elemental synchronous machines was conceived. Both were internally wound with identical winding in the stator. The rotor of one of the synchronous reluctance machine component is round while the other has a salient pole. Both machine halves were mechanically coupled together. One set of the winding of both machines were connected in series and fed from the main while the other set was also connected in series (but transposed between the two section of the of the machine) and then connected to a balanced three phased variable capacitance load. It was the capacitance loading of the auxiliary winding makes the overall Xd/Xqratio of the hybrid machine to be variable that can theoretically attain values between zero and infinity. This translates to ultra-high output and unity power factor

A New Hybrid Synchronous Reluctance Machine Capable of Ultra-High Output Power

A new hybrid synchronous reluctance machine capable of ultra-high Xd/Xq ratio output power has been studied. A d-q model (voltage and flux linkage) of the hybrid synchronous reluctance machine has been idealized and developed. Also the impedance and current loci from steady state analysis of the machine was obtained. The effect of capacitor loading in the auxiliary winding was investigated. The power factor and torque developed in the hybrid synchronous reluctance machine was compared with the conventional synchronous reluctance machine. The hybridized synchronous reluctance machine improved the major constraints of conventional reluctance machine – low power output and poor power factor due to low ratio of direct to quadrature axis reactance (Xd/Xq). To achieve this two elemental synchronous machines was conceived. Both were internally wound with identical winding in the stator. The rotor of one of the synchronous reluctance machine component is round while the other has a salient pole. Both machine halves were mechanically coupled together. One set of the winding of both machines were connected in series and fed from the main while the other set was also connected in series (but transposed between the two section of the of the machine) and then connected to a balanced three phased variable capacitance load. It was the capacitance loading of the auxiliary winding makes the overall Xd/Xqratio of the hybrid machine to be variable that can theoretically attain values between zero and infinity. This translates to ultra-high output and unity power factor

Design and Construction of Rice De-Stoning Machine

A rice de-stoning machine was designed, fabricated and evaluated for performance. The de-stoning machine will utilize vibrating motion to further separate the rice grains from the impurities. The vibration causes the rice grains to move in a specific direction, while the heavier impurities remain stationary. Mild steel was used in the construction of the machine. The machine is driven by a 2Hp electric motor with 1103W required power. Standard equations were used to determine the dimension of the pass and optimization of machine parameters such as air flow rate and vibration frequency. The effectiveness of the de-stoning machine will be evaluated by testing its performance with different masses of rice samples and impurities. The machine has a capacity of 436.16Kg/hr and an efficiency of 90.03%

Design and Construction of Rice De-Stoning Machine

A rice de-stoning machine was designed, fabricated and evaluated for performance. The de-stoning machine will utilize vibrating motion to further separate the rice grains from the impurities. The vibration causes the rice grains to move in a specific direction, while the heavier impurities remain stationary. Mild steel was used in the construction of the machine. The machine is driven by a 2Hp electric motor with 1103W required power. Standard equations were used to determine the dimension of the pass and optimization of machine parameters such as air flow rate and vibration frequency. The effectiveness of the de-stoning machine will be evaluated by testing its performance with different masses of rice samples and impurities. The machine has a capacity of 436.16Kg/hr and an efficiency of 90.03%

Design of a Universal Sieving Machine

The design of a universal sieving machine was explored to meet the diverse needs of sieving applications across various industries. The machine incorporates various mechanisms to enable it to handle different types of materials (e.g., cassava flakes, Sand, Flour, etc.) and sieve them to desired particle sizes. Careful component selection and procurement were undertaken to ensure compatibility, quality, and availability. The machine's performance was evaluated by conducting various tests, including the sieving of different materials (sand and granulated cassava) with varying particle sizes. The results showed that the Universal Sieving machine achieved excellent sieving accuracy and efficiency of 98%, indicating its potential for use in industrial and research settings. This project offers a cost-effective solution to the challenges of sieving a diverse range of materials and has significant implications in the fields of food processing, mining, and pharmaceuticals

Influence of Blanching on the Drying Characteristics of Convective Hot Air Dried Aerial Yam

A research on the drying characteristics of aerial yam using convectional hot air was done. The raw unblanched and blanched samples were dried using convectional hot air. Fan speed, temperature and slice thickness were varied to determine the change in moisture content. The Fourier transform infrared (FTIR) and scanning electron microscopy (SEM) were done to determine the functional groups and surface morphology respectively for each sample. FTIR results revealed the presence of some important functional groups such as esters, ethers and nitro-compounds, and shows that drying at this temperatures (40-70oC) does not alter the nutrient components of this variety of yam. The SEM results showed that important cells were not destroyed at the drying temperature. Batch studies on the drying process also showed that increase in temperature and air speed increased the drying process, but decreases with increase in slice thickness. Effect of drying rate on the sample showed that drying rate increase with increase in temperature and air speed but decrease with increase in slice thickness. After 90 minutes of drying, the drying rate of the 2 mm slice thickness was 0.353 g/g.min for drying of aerial yam while for 4 mm and 6 mm slice thickness, the drying rate were 0.261 and 0.169 g/g.min respectively, for effect of drying rate on sample thickness. It showed also that blanched aerial yam sampleshad a higher drying rate than the unblanched aerial yam sample at the same conditions. Therefore, the economic advantages of this yam species can be optimized by blanching

Quaternion-Octonion Unitary Symmetries and Analogous Casimir Operators

An attempt has been made to investigate the global SU(2) and SU(3) unitary flavor symmetries systematically in terms of quaternion and octonion respectively. It is shown that these symmetries are suitably handled with quaternions and octonions in order to obtain their generators, commutation rules and symmetry properties. Accordingly, Casimir operators for SU(2)and SU(3) flavor symmetries are also constructed for the proper testing of these symmetries in terms of quaternions and octonions

Spatial insurance against a heatwave differs between trophic levels in experimental aquatic communities

Climate change-related heatwaves are major threats to biodiversity and ecosystem functioning. However, our current understanding of the mechanisms governing community resistance to and recovery from extreme temperature events is still rudimentary. The spatial insurance hypothesis postulates that diverse regional species pools can buffer ecosystem functioning against local disturbances through the immigration of better-adapted taxa. Yet, experimental evidence for such predictions from multi-trophic communities and pulse-type disturbances, like heatwaves, is largely missing. We performed an experimental mesocosm study to test whether species dispersal from natural lakes prior to a simulated heatwave could increase the resistance and recovery of plankton communities. As the buffering effect of dispersal may differ among trophic groups, we independently manipulated the dispersal of organisms from lower (phytoplankton) and higher (zooplankton) trophic levels. The experimental heatwave suppressed total community biomass by having a strong negative effect on zooplankton biomass, probably due to a heat-induced increase in metabolic costs, resulting in weaker top-down control on phytoplankton. While zooplankton dispersal did not alleviate the negative heatwave effects on zooplankton biomass, phytoplankton dispersal enhanced biomass recovery at the level of primary producers, providing partial evidence for spatial insurance. The differential responses to dispersal may be linked to the much larger regional species pool of phytoplankton than of zooplankton. Our results suggest high recovery capacity of community biomass independent of dispersal. However, community composition and trophic structure remained altered due to the heatwave, implying longer-lasting changes in ecosystem functioning

How length of light exposure shapes the development of riverine algal biomass in temperate rivers?

The impact of cumulative daily solar radiation (CDSR) on the biomass of river phytoplankton (Chl-a) in the growing season was studied using a large dataset of rivers in the Carpathian Basin. The amount of solar radiation was cumulated over the range of 1–60 days. The CDSR–Chl-a relationship could be described by linear regression and appeared to be significant for almost all watercourses with the exception of rivers with short water residence time. To determine the most relevant time period of CDSR impacting phytoplankton biomass, the slopes of regressions were plotted against the accumulating number of days of light exposure (1–60). Two characteristic shapes were obtained: unimodal for rhithral rivers with hard substrate and steady increase for lowland potamal rivers with fine substrate. In both cases, there is an increasing tendency in the slope values with water residence time (WRT). It was demonstrated that CDSR has a pronounced impact on river phytoplankton biomass even in cases when WRT was shorter than the cumulated solar radiation period. These results indicate that development of phytoplankton within the river channel is a complex process in which meroplankton dynamics may have significant impacts. Our results have two implications: First, CDSR cannot be neglected in predictive modelling of riverine phytoplankton biomass. Second, climate models forecast increased drought with subsequently increased CDSR in several regions globally, which may trigger a rise in phytoplankton biomass in light-limited rivers with high nutrient concentrations