Chinese and North American Culture: a New Perspective in Linguistics Studies

We explored the two cultures in the two countries. There has been discussed on Chinese culture and North American culture. Chinese language, ceramics, architecture, music, dance, literature, martial arts, cuisine, visual arts, philosophy, business etiquette, religion, politics, and history have global influence, while its traditions and festivals are also celebrated, instilled, and practiced by people around the world. The culture of North America refers to the arts and other manifestations of human activities and achievements from the continent of North America. The American way of life or simply the American way is the unique lifestyle of the people of the United States of America. It refers to a nationalist ethos that adheres to the principle of life, liberty and the pursuit of happiness

Optimization on fresh outdoor air ratio of air conditioning system with stratum ventilation for both targeted indoor air quality and maximal energy saving

Stratum ventilation can energy efficiently provide good inhaled indoor air quality with a proper operation (e.g., fresh outdoor air ratio). However, the non-uniform CO2 distribution in a stratum-ventilated room challenges the provision of targeted indoor air quality. This study proposes an optimization on the fresh outdoor air ratio of stratum ventilation for both the targeted indoor air quality and maximal energy saving. A model of CO2 concentration in the breathing zone is developed by coupling CO2 removal efficiency in the breathing zone and mass conservation laws. With the developed model, the ventilation parameters corresponding to different fresh outdoor air ratios are quantified to achieve the targeted indoor air quality (i.e., targeted CO2 concentration in the breathing zone). Using the fresh outdoor air ratios and corresponding ventilation parameters as inputs, energy performance evaluations of the air conditioning system are conducted by building energy simulations. The fresh outdoor air ratio with the minimal energy consumption is determined as the optimal one. Experiments show that the mean absolute error of the developed model of CO2 concentration in the breathing zone is 1.9%. The effectiveness of the proposed optimization is demonstrated using TRNSYS that the energy consumption of the air conditioning system with stratum ventilation is reduced by 6.4% while achieving the targeted indoor air quality. The proposed optimization is also promising for other ventilation modes for targeted indoor air quality and improved energy efficiency

Heat removal efficiency of stratum ventilation for air-side modulation

Stratum ventilation has significant thermal non-uniformity between the occupied and upper zones. Although the non-uniformity benefits indoor air quality and energy efficiency, it increases complexities and difficulties in the air-side modulation. In this study, a heat removal efficiency (HRE) model is first established and validated, and then used for the air-side modulation. The HRE model proposed is a function of supply air temperature, supply airflow rate and cooling load. The HRE model proposed has been proven to be applicable to stratum ventilation and displacement ventilation for different room geometries and air terminal configurations, with errors generally within ±5% and a mean absolute error less than 4% for thirty-three experimental cases and five simulated cases. Investigations into the air-side modulation with the proposed HRE model reveal that for both the typical stratum-ventilated classroom and office, the variable-air-volume system can serve a wider range of cooling load than the constant-air-volume system. The assumption of a constant HRE used in the conventional method could lead to errors in the room temperature prediction up to ±1.3 °C, thus the proposed HRE model is important to the air-side modulation for thermal comfort. An air-side modulation method is proposed based on the HRE model to maximize the HRE for improving energy efficiency while maintaining thermal comfort. Results show that the HRE model based air-side modulation can improve the energy efficiency of stratum ventilation up to 67.3%. The HRE model based air-side modulation is also promising for displacement ventilation

Thermal process and novel control methods for spin-casting

Published ArticleThe quality of spin casting products and mould life are critically dependent on thermal conditions they undergo. In order to improve the performance of production and to optimise the spin-casting process, characteristics of the thermal process was firstly identified by means of the measurement and simulation. Furthermore the investigation of the developed control methods, including the thermal property substitute method and mixture method of the metal powder, was kept on the effect of air-cooling induced automatically from the spinning of the mould on the thermal process. The air cooling system was developed to optimise the thermal process during casting, utilising a theoretical analysis of the air-flow characteristics in a cooling tube submerged in a silicon mould and the characteristics of convection heat transfer associated with the mould and cast part. A numerical simulation of the casting process was also adopted in the analysis. The effect of the developed system on the thermal process was determined experimentally and it was found that a system of aircooling, automatically induced from the spinning of the mould, is feasible in optimisation of the thermal process. The developed control methods can be applied to the practice of spin casting individually or collectively according to the specific situations and requirements

CASSAVA FLOUR SUBSTITUTION AND MOISTURE CONTENT VARIATION ON SOME QUALITY CHARACTERISTICS OF HEAT PUMP DRIED EXTRUDED FISH FEED

This study examined the effect of substitution of maize with cassava flour at varying moisture contents on heat pump drying and some quality attributes including strength properties, durability index, micro-structure and floatability. The samples identified as S1- S6, were prepared from various levels of cassava flour before being extruded at steady state at 3 moisture contents (30, 35, and 40% db) in a single screw cooking extruder. Drying was done with an open loop heat pump dryer while a scanning electron microscope (FEG-SEM) was used to study the microstructure of the fish feeds. Results showed that drying rates and pellet durability were proportional to the source and concentration of starch in the samples. Some of the samples floated in water.   The Coefficient of performance (COP) of the heat pump used for the drying decreased with increase in ambient temperature; the average COP being 4.77. The thermal efficiency of the heat pump dryer was 92.45%. The scanning electron microscopy indicated that cassava substituted samples lack some elements required of fish feed. Also, extrusion cooking resulted in changes in mineral composition of fish feed blends.     &nbsp

EFFECT OF EXTRUSION PROCESSING CONDITIONS OF A LOCALLY DEVELOPED EXTRUDER ON THE PRODUCT TEMPERATURE OF SELECTED STARCH CROPS

Product temperature is a very important system parameter as well as an indicator of extrusion process. In this study, the product temperature response of a single screw extruder developed locally was investigated for the extrusion process of the flour and starch of maize and cassava which are grown in Nigeria in large quantity but with high post-harvest losses. These were compared with wheat flour which is commonly used for the production of alimentary pastes. A factorial experiment in completely randomized design was employed to study the effect of extrusion variables: feed moisture (30, 40, 50 %), extruder temperature (40, 70, 100oC) built up by varying the duration of sampling and screw speed (100, 150, 200 rpm) on Product temperature.   A maximum temperature of 150oC was attained in 30 minutes through viscous dissipation and up to a moisture loss of 55% w.b. Also, product temperature is strongly related to the starch type and the extrusion process parameters under study. Product temperature decreased with increasing moisture content. The highest values of product temperature were demonstrated by maize starch and cassava flour extrudates while the lowest values were observed on maize flour and wheat flour extrudates. Generally, it was easier for cassava to cook/gelatinize under the heat provided by the extruder. Maize starch requires more shear/cooking to form than cassava starch. This extruder is by far more cost efficient for cassava than other products i.e. Maize and wheat. Process Parameters were expected to have effects on the product temperature of the final extrudates. Thus, model-fitting using response surface methodology was performed to examine their effect on product temperature. Quadratic coefficients fit the extrusion data very well, better than linear models. Furthermore, additional research could optimize product temperature for a specific product application. The equations relating the various dependent and independent variables were established to predict the performance of the machine.     &nbsp