Energy Efficiency, Indoor Air Quality and Thermal Comfort Studies at the Faculty of Engineering and Built Environment, University Kebangsaan Malaysia

The study was conducted to identify indoor air quality and the level of thermal comfort in various selected locations in Faculty of Engineering and Built Environment （FKAB）, University Kebangsaan Malaysia （UKM） with built-up area of 250,936 fie. The indoor air quality and thermal comfort were measured at various selected locations by using indoor air quality equipment （Thermal Comfort SERI）. The thermal comfort assessments are based on Malaysian Code of Practice Indoor Air Quality 2005 and Moderate Thermal Environments-Determination of the PMV and PPD indices specification of the condition for thermal comfort （ISO7730：1994） From the data analysis, the FKAB building is considered inadequately vented space. The concentration of CO2 for all sampling area evaluated exceeds the recommended concentration （〉 1000 ppm）. The ventilation system used in FKAB building is designed by delivering fix amount of fresh air into building from external building without consideration on the number of occupants. This common ventilation design will increase the amount of CO2 dramatically all day long and these reflect the inefficiency of energy used. The faculty needs to be equipped with a comprehensive energy management system that can allow detailed documentation of continuous performance of all energy system and consumption in the building.

Improving energy utilization efficiency of electrical discharge milling in titanium alloys machining

Electrical discharge milling(ED-milling) can be a good choice for titanium alloys machining and it was proven that its machining efficiency can be improved to compete with mechanical cutting. In order to improve energy utilization efficiency of ED-milling process, unstable arc discharge and stable arc discharge combined with normal discharge were implemented for material removal by adjusting servo control strategy. The influence of electrode rotating speed and dielectric flushing pressure on machining performance was investigated by experiments. It was found that the rotating of electrode could move the position of discharge plasma channel, and high pressure flushing could wash melted debris out the discharge gap effectively. Both electrode rotating motion and high pressure flushing are contributed to the improvement of machining efficiency.

Dietary supplementation with xylooligosaccharides and exogenous enzyme improves milk production,energy utilization efficiency and reduces enteric methane emissions of Jersey cows

Background Sustainable strategies for enteric methane(CH_(4))mitigation of dairy cows have been extensively explored to improve production performance and alleviate environmental pressure.The present study aimed to investigate the effects of dietary xylooligosaccharides(XOS)and exogenous enzyme(EXE)supplementation on milk production,nutrient digestibility,enteric CH_(4) emissions,energy utilization efficiency of lactating Jersey dairy cows.Forty-eight lactating cows were randomly assigned to one of 4 treatments:(1)control diet(CON),(2)CON with 25 g/d XOS(XOS),(3)CON with 15 g/d EXE(EXE),and(4)CON with 25 g/d XOS and 15 g/d EXE(XOS+EXE).The 60-d experimental period consisted of a 14-d adaptation period and a 46-d sampling period.The enteric CO_(2)and CH_(4) emissions and O2 consumption were measured using two GreenFeed units,which were further used to determine the energy utilization efficiency of cows.Results Compared with CON,cows fed XOS,EXE or XOS+EXE significantly(P<0.05)increased milk yield,true protein and fat concentration,and energy-corrected milk yield(ECM)/DM intake,which could be reflected by the significant improvement(P<0.05)of dietary NDF and ADF digestibility.The results showed that dietary supplementation of XOS,EXE or XOS+EXE significantly(P<0.05)reduced CH_(4) emission,CH_(4)/milk yield,and CH_(4)/ECM.Furthermore,cows fed XOS demonstrated highest(P<0.05)metabolizable energy intake,milk energy output but lowest(P<0.05)of CH_(4) energy output and CH_(4) energy output as a proportion of gross energy intake compared with the remaining treatments.Conclusions Dietary supplementary of XOS,EXE or combination of XOS and EXE contributed to the improvement of lactation performance,nutrient digestibility,and energy utilization efficiency,as well as reduction of enteric CH_(4) emissions of lactating Jersey cows.This promising mitigation method may need further research to validate its long-term effect and mode of action for dairy cows.

ASSESSMENT OF EFFECTIVE ENERGY RETROFIT STRATEGIES AND RELATED IMPACT ON INDOOR ENVIRONMENTAL QUALITY A case study of an elementary school in the State of Maryland

1.0.INTRODUCTION In the United States,K-12 school buildings spend more than$8 billion each year on energy-more than they spend on computers and textbooks combined[1].Most occupied older buildings demonstrate poor operational performance-for instance,more than 30 percent of schools were built before 1960,and 53 percent of public schools need to spend money on repairs,renovations,and modernization to ensure that the schools’onsite buildings are in good overall condition.And among public schools with permanent buildings,the environmental factors in the permanent buildings have been rated as unsatisfactory or very unsatisfactory in 5 to 17 percent of them[2].Indoor environment quality(IEQ)is one of the core issues addressed in the majority of sustainable building certification and design guidelines.Children spend a significant amount of time indoors in a school environment.And poor IEA can lead to sickness and absenteeism from school and eventually cause a decrease in student performance[3].Different building types and their IEQ characteristics can be partly attributed to building age and construction materials.[4]Improving the energy performance of school buildings could result in the direct benefit of reduced utility costs and improving the indoor quality could improve the students’learning environment.Research also suggests that aging school facilities and inefficient equipment have a detrimental effect on academic performance that can be reversed when schools are upgraded.[5]Several studies have linked better lighting,thermal comfort,and air quality to higher test scores.[6,7,8]Another benefit of improving the energy efficiency of education buildings is the potential increase in market value through recognition of green building practice and labeling,such as that of a LEED or net zero energy building.In addition,because of their educational function,high-performance or energy-efficient buildings are particularly valuable for institution clients and local government.More and more high-performance buildings,net zero energy buildings,and positive energy buildings serve as living laboratories for educational purposes.Currently,educational/institutional buildings represent the largest portion of NZE(net zero energy)projects.Educational buildings comprise 36 percent of net zero buildings according to a 2014 National New Building Institute report.Of the 58 net zero energy educational buildings,32 are used for kindergarten through grade 12(K-12),21 for higher education,and 5 for general education.[9]Finally,because educational buildings account for the third largest amount of building floor space in the United States,super energy-efficient educational buildings could provide other societal and economic benefits beyond the direct energy cost savings for three reasons:1)educational buildings offer high visibility that can influence community members and the next generation of citizens,2)success stories of the use of public funds that returns lower operating costs and healthier student learning environments provide documentation that can be used by others,and 3)this sector offers national and regional forums and associations to facilitate the transfer of best design and operational practices.

Effect of Rural Sewage Irrigation Regime on Water-Nitrogen Utilization and Crop Growth of Paddy Rice in Southern China

Reclaimed water irrigation has become an effective mean to alleviate the contradiction between water availability and its consumption worldwide.In this study,three types of irrigation water sources(rural sewage’s primary treated water R1 and secondary treated water R2,and river water R3)meeting the requirements of water quality for farmland irrigation were selected,and three types of irrigation water levels(low water levelW1 of 0–80 mm,medium water level W2 of 0–100 mm,and high water level W3 of 0–150 mm)were adopted to carry out research on the influence mechanismS of different irrigation water sources and water levels on water and nitrogen use and crop growth in paddy field.The water quantity indicators(irrigation times and irrigation volume),soil ammonium nitrogen(NH4+-N)and nitrate nitrogen(NO3−-N),rice yield indicators(thousand-grain weight,the number of grains per spike,and the number of effective spikes),and quality indicators(the amount of protein,amylose,vitamin C,nitrate and nitrite content)of rice were measured.The results showed that,the average irrigation volume under W3 was 2.4 and 1.9 times of that under W1 and W2,respectively.Compared with R3,the peak consumption of rice was lagged behind under R1 and R2,and the nitrogen form in 0–40 cm soil layers under rural sewage irrigation was mainly NH4+-N.The changes of NO3−-N and NH4+-N in the 0–40 cm soil layer showed the trend of declining and then increasing.The water level control only had a significant effect on the change of NO3−-N in the 60–80 cm soil layer.Both irrigation water use efficiency and crop water use efficiency were gradually reduced with the increase of field water level control.The nitrogen utilization efficiency under rural sewage irrigation was significantly higher than that under R3.Compared with the R3,rural sewage irrigation could significantly increase the yield of rice,and as the field water level rose,the effect of yield promotion was more obvious.It was noteworthy that the grain of rice under R1 monitored the low nitrate and nitrite content,but no nitrate and nitrite was discovered under R2 and R3.Therefore,reasonable rural sewage irrigation(R2)and medium water level(W2)were beneficial to improve nitrogen utilization efficiency,crop yield and crop quality promotion.

Evaluation of Radon Indoor Pollution Risk in High Efficiency Energy Buildings

The target of achieving high energy efficiency standard in order to comply with the EU Directives is leading to remarkable efforts to improve the performance of the building envelope. Excellent thermal insulation and airtight sealing of leakages are of the utmost importance to fulfil the expected targets. Unfortunately, airtightness produces the negative effect of increasing the indoor concentration of air pollutants like radon. Despite the seriousness of the problem is generally misconceived, long-term exposition to radon is acknowledged to be the second cause of lung cancer after smoke. The paper outlines the implications for the building sector and focuses on design and preventive criteria as well as on mitigation and remedial techniques.

Labor Quality, Labor Utilization Efficiency and Economic Development： Regional Discrepancies and Solutions＊

This paper presents the results of our experiments to assess average labor quality and labor force utilization in different regions of China using slack-based inefficiency measurement （SBI）. We found that there is a discrepancy between different regions＇ labor resources and their stages＇ of economic development. In central and western regions, the average quality of labor is significantly higher than in eastern regions, but labor force utilization is less efficient. Slow in economic growth and laggard in industrial upgrading, central and western regions have failed to provide their high-quality labor forces with adequate and suitable job opportunities, leading to the discrepancy between labor resource quality and economic development. Resolving this discrepancy might help coordinate economic development across different regions in China.

Comparison of two schemes for district cooling system utilizing cold energy of liquefied natural gas

Two schemes（scheme Ⅰ and scheme Ⅱ）for designing a district cooling system（DCS）utilizing cold energy of liquefied natural gas（LNG）are presented.In scheme Ⅰ,LNG cold energy is used to produce ice,and then ice is transported to the central cooling plant of the DCS.In scheme Ⅱ,return water from the DCS is directly chilled by LNG cold energy,and the chilled water is then sent back to the central plant.The heat transportation loss is the main negative impact in the DCS and is emphatically analyzed when evaluating the efficiency of each scheme.The results show that the DCS utilizing LNG cold energy is feasible and valuable.The cooling supply distance of scheme Ⅱ is limited within 13 km while scheme Ⅰ has no distance limit.When the distance is between 6 and 13 km,scheme Ⅱ is more practical and effective.Contrarily,scheme Ⅰ has a better economic performance when the distance is shorter than 6 km or longer than 13 km.

Effects of Nitrogen on N Uptake,Grain Yield and Quality of Medium-Gluten Wheat Yangmai 10

The effects of the basal and top-dressing nitrogen (N) on N uptake and translocation, N utilization efficiency, grain yieldand quality of medium-gluten winter wheat Yangmai 10 were studied from 2000 to 2002. The main results were as follows.Nitrogen content and nitrogen accumulation in plant at maturity increased with the amount of N application. Grain proteincontent and wet gluten content were significantly correlated with applied N. There was a significantly positive correlationbetween nitrogen accumulation before anthesis (NBA) and basal N fertilizer, and between nitrogen accumulation afteranthesis (NAA) and top-dressing N. N accumulated in grains was significantly correlated to NBA, NAA and N translocationfrom vegetative organs after anthesis (NTVA). NBA was significantly correlated with N application, but NAA and NTVAhad a quadratic curve correlation with applied N. N fertilizer use efficiency (NUE) had a quadratic curve correlation withapplied N, and the NUE was high when basal and top-dressing N was equally applied. For the medium-gluten wheatYangmai 10 under the same N application ratio, there was a N-regulating effect when the N application was less than266.55 kg ha-1, a stagnation of yield and quality when N application ranged from 266.55 to 309.08 kg ha-1, and an excessiveN application when the N application rate was greater than 309.08 kg ha-1. Under the conditions of this experiment, theprecise N application is 220-270 kg ha-1 with basal and top-dressing N equally used when a grain yield of more than 6 750kg ha-1, protein content higher than 12%, wet gluten content more than 30% and NUE greater than 40% could be obtained.

A Clustering-tree Topology Control Based on the Energy Forecast for Heterogeneous Wireless Sensor Networks

How to design an energy-efficient algorithm to maximize the network lifetime in complicated scenarios is a critical problem for heterogeneous wireless sensor networks (HWSN). In this paper, a clustering-tree topology control algorithm based on the energy forecast (CTEF) is proposed for saving energy and ensuring network load balancing, while considering the link quality, packet loss rate, etc. In CTEF, the average energy of the network is accurately predicted per round (the lifetime of the network is denoted by rounds) in terms of the difference between the ideal and actual average residual energy using central limit theorem and normal distribution mechanism, simultaneously. On this basis, cluster heads are selected by cost function (including the energy, link quality and packet loss rate) and their distance. The non-cluster heads are determined to join the cluster through the energy, distance and link quality. Furthermore, several non-cluster heads in each cluster are chosen as the relay nodes for transmitting data through multi-hop communication to decrease the load of each cluster-head and prolong the lifetime of the network. The simulation results show the efficiency of CTEF. Compared with low-energy adaptive clustering hierarchy (LEACH), energy dissipation forecast and clustering management (EDFCM) and efficient and dynamic clustering scheme (EDCS) protocols, CTEF has longer network lifetime and receives more data packets at base station. © 2014 Chinese Association of Automation.

Research on Storage Capacity of Compressed Air Pumped Hydro Energy Storage Equipment

Compressed air pumped hydro energy storage equipment combines compressed air energy storage technology and pumped storage technology. The water is pumped to a vessel to compress air for energy storage, and the compressed air expanses pushing water to drive the hydro turbine for power generation. The novel storage equipment saves natural gas resources, reduces carbon emission, and improves the controllability and reliability. The principle of compressed air pumped hydro energy storage is introduced and its mathematical model is built. The storage and generation process of the novel equipment is analyzed using the model. The calculation formula of the storage power is deduced in theory in different situations of isothermal and adiabatic compression. The optimal storage scheme is given when the capacity and withstand pressure of the vessel is definitive, and the max available capacity and the equipment utilization efficiency evaluation of the scheme is given.

Energy Efficiency Maximization Strategy for Sink Node in SWIPT-Enabled Sensor-Cloud Based on Optimal Stopping Rules

Leveraging energy harvesting abilities in wireless network devices has emerged as an effective way to prolong the lifetime of energy constrained systems.The system gains are usually optimized by designing resource allocation algorithm appropriately.However,few works focus on the interaction that channel’s time-vary characters make the energy transfer inefficiently.To address this,we propose a novel system operation sequence for sensor-cloud system where the Sinks provide SWIPT for sensor nodes opportunistically during downlink phase and collect the data transmitted from sensor nodes in uplink phase.Then,the energy-efficiency maximization problem of the Sinks is presented by considering the time costs and energy consumption of channel detection.It is proved that the formulated problem is an optimal stopping process with optimal stopping rules.An optimal energy-efficiency(OEE)algorithm is designed to obtain the optimal stopping rules for SWIPT.Finally,the simulations are performed based on the OEE algorithm compared with the other two strategies to verify the effectiveness and gains in improving the system efficiency.

Theory and Application of Multi-robot Service-oriented Architecture

In order to solve the problem of heterogeneity in multi-robot cooperation, a new service-oriented architecture is proposed for multi-robot cooperation. Service provision and energy consumption are the basic cooperative behaviors. A set of basic concepts of robot service are proposed. A layered multi-robot service-oriented architecture is designed. Finally, the experiments illustrate the superiority of the proposed architecture which makes robot's underlying functional components be transparently encapsulated and the services in upper layer be transparently invoked, which will effectively avoid the impact of heterogeneous characteristics in multi-robot cooperation and facilitate the system construction, expansion, restructuring and maintenance. © 2014 Chinese Association of Automation.

RISK FRAMEWORK FOR ENERGY PERFORMANCE CONTRACTING BUILDING RETROFITS

Energy performance contracting(EPC)has emerged as a useful project financ-ing and delivery tool for building retrofits,particularly among building owner-ships which have experienced reduced funding for capital projects.Through EPC,a contractor(called the EPC contractor or the energy service company)guaran-tees minimum energy savings performance and enables the building owner to finance the project using utility savings over the length of the project(which is typically 12-15 years,or longer).Despite its growing use,there is a dearth of lit-erature regarding a contractor’s risks related to the delivery and execution of EPC building retrofits.This is particularly important as the performance guarantee effec-tively transfers project performance risk from the owner to the EPC contractor.This research proposes a project factors-based risk framework for EPC building retrofits,initially developed through a comprehensive review of relevant literature and project documents and refined through the elicited expertise of 19 highly expe-rienced EPC contracting professionals.A Delphi technique-based expertise elici-tation strategy was used to confirm the findings of the a priori(literature-based)framework and provide additional analysis related to risk causes and control mea-sures as well as relative risk importance.This information was used to construct a refined risk framework which provides insight into the lengthy project performance period during the earliest phases of the project’s life cycle.This has the advantage of providing rapid screening of the project factors that can potentially lead to the greatest project performance risks.

Effects of Energy Production and Consumption on Air Pollution and Global Warming

In this study, different fuel combinations that can be adopted to reduce the level of air pollution and GHG emissions associated with the energy generation are assessed;and the air pollution and global warming effects of the Jamaican electricity generation fuel mix are determined. Based on the energy production and consumption patterns, and global warming potentials;the authors conclude that: Increase in energy consumption and generation yields increase in emissions of major air pollutants and GHGs;Choice of the fuel mix determines the success of GHG emissions reductions;and there is no single fuel that is not associated with GHG or other air pollution or environmental degradation implications.

Priority-Based Hybrid MAC for Energy Efficiency in Wireless Sensor Networks

This paper introduces I-MAC, a new medium access control protocol for wireless sensor networks. I-MAC targets at improving both channel utilization and energy efficiency while taking into account traffic load for each sensor node according to its role in the network. I-MAC reaches its objectives through prioritized and adaptive access to the channel. I-MAC performances obtained through simulations for different network topologies, scenarios and traffic loads show significant improvements in energy efficiency, channel utilization, loss ratio and delay compared to existing protocols.

Energetic and Environmental Optimization of the Biomass Using

Biomass energy conversion can be done in several ways-combustion, gasification, pyrolysis or anaerobic fermentation （biogas production）. Each of these technologies has certain advantages and disadvantages from the point of view of energy generation for final consumption. In parallel, each of them has certain environmental impact in terms of emissions. The proposed EU directive prefers utilization of primary energy sources by application of highly efficient co-generation. Such change in assessment of energy effectiveness also means a completely new approach in assessment of current technologies. This report presents a guide for optimization of biomass energy conversion technologies assuming application of this new condition and minimal environmental impact. Specific values of emissions from particular technologies are used for the evaluation.

INDOOR AIR QUALITY(IAQ)IMPROVEMENTS USING BIOFILTRATION IN A HIGHLY EFFICIENT RESIDENTIAL HOME

INTRODUCTION Americans spend the majority of their time indoors where levels of pollutants may run two to five times-and occasionally more than 100 times-higher than outdoor levels[1].Many of these pollutants can cause adverse health reactions in building occupants,which can contribute to lower worker productivity and increased sick leave.Traditional methods of indoor pollutant control in sealed buildings involve the use of outdoor ventilation.Outdoor ventilation requires the intake of outdoor air,which must be heated or cooled to meet indoor temperature and humidity requirements.This represents between 10-20%of the total energy consumption of a building[2].

Function, transport, and regulation of amino acids: What is missing in rice?

Amino acids are essential plant compounds serving as the building blocks of proteins,the predominant forms of nitrogen(N)distribution,and signaling molecules.Plant amino acids derive from root acquisition,nitrate reduction,and ammonium assimilation.Many amino acid transporters(AATs)mediating transfer processes of amino acids have been functionally characterized in Arabidopsis,whereas the function and regulation of the vast majority of AATs in rice(Oryza sativa L.)and other crops remain unknown.In this review,we summarize the current understanding of amino acids in the rhizosphere and in metabolism.We describe their function as signal molecules and in regulating plant architecture,flowering time,and defense against abiotic stress and pathogen attack.AATs not only function in root acquisition and translocation of amino acids from source to sink organs,regulating N uptake and use efficiency,but also as transporters of non-amino acid substrates or as amino acid sensors.Several AAT genes show natural variations in their promoter and coding regions that are associated with altered uptake rate of amino acids,grain N content,and tiller number.Development of an amino acid transfer model in plants will advance the manipulation of AATs for improving rice architecture,grain yield and quality,and N-use efficiency.

Indirect calorimetry to estimate energy requirements for growing and finishing Nellore bulls

Determination of nutritional requirements is the basis for diet formulation. The objectives of this study were to determine the net energy requirements for maintenance （NEro） and weight gain （NEg） in Nellore bulls during the growing and finishing phases, and to estimate efficiency of metabolizable energy （ME） utilization for maintenance and gain （km, kg）. Five Nellore bulls were housed in individual pens at the Universidade Federal de Minas Gerais （Belo Horizonte, Brazil） and evaluated over four experimental periods at 210, 315,378 and 454 kg shrunk body weight （SBW）, approximately. During each period, heat production （HP） was quantified by open circuit indirect calorimetry for three feeding levels： ad libitum, restricted and fasting. The NEm requirement was determined by linear regression between the Log of HP andthe ME intake （MEI） for the ad libitum and restricted levels. This requirement was also determined by quantifying fasting heat production （FHP）. The NEQ requirement was calculated by the difference between MEI and HP during ad libitum feeding. The k and kg were calculated by the relationship between net energy （NE） and ME requirements for maintenance and weight gain （MEm, MEp）, respectively. The NEm requirements per kg of metabolic empty body weight （EBW0.75） fluctuated between 348 and 517 kJ d-1, showing a decreasing trend with age, and were higher than the values reported in the literature. The NEg requirements ranged between 48.3 and 164 kJ kg-1 EBW0.75 d-1, and varied according to age and weight gain. The k values varied between 58.6 and 69.7%, while kg varied between 23.4 and 40.2%. We concluded that NEm and NEg requirements were influenced by age and possibly by the level of stress, nervousness and activity of animals into the respirometry chamber. Further studies should quantify HP with records of positional changes （time spent standing vs. lying down）. Additionally, HP quantification should be repeatedly performed in the same experimental period to obtain a representative value of NEg requirements.