Experimental characterization of the removal efficiency and energy effectiveness of central air cleaners

This study assessed six commercially available in-duct air cleaning devices which are designed to be mounted in the central ventilation system of offices or commercial buildings.The selected devices use different air cleaning technologies:mechanical filtration,electrostatic precipitation,gas filtration,ionization/cold plasma,photocatalytic oxidation(PCO)and catalysis under UV light.They were tested against particles,a mixture of volatile organic compounds containing acetone,acetaldehyde,toluene,heptane and formaldehyde,and two bio-contaminants:Aspergillus brasiliensis(fungus)and Staphylococcus epidermidis(bacteria).Two different test rigs were used.The single pass efficiency of each device was determined for three airflow rates,corresponding to face velocities ranging from 0.9 to 2.7 m/s,and two sets of temperature and humidity that are representative of indoor air conditions in wintertime and summertime.The concentration of the chal-lenge volatile organic compounds was also varied in the 30 to 100μg/m^(3)range as a way to characterize their influence on efficiency at realistic concentration levels for non-industrial buildings.Measurements of ozone and formaldehyde concentration downstream of the air cleaners were carried out to determine the emission rate of by-products into the air stream.Finally,the energy issue was addressed by measuring the electric power drawn and pressure loss of the devices.The results showed that two devices,namely a radiant catalytic ionizer and a plasma ionizer,had a very low single pass efficiency against all the challenge pollutants.The association of the plasma ionizer and the electrostatic precipitator did not produce a synergetic effect between the two technologies either,contrary to what their manufacturer claims.Finally,three of the six devices tested were effective in terms of pollutant removal,but only two had an acceptable energy effectiveness in view of their use in low or zero energy buildings.Their energy effectiveness ranged from a few thousand m^(3)/kWh for VOCs at the highest airflow rate(3600 m^(3)/h),to more than 60000 m^(3)/kWh for particles and bio-contaminants at 1200 or 1600 m^(3)/h.These results are at least one order of magnitude higher than the majority of stand-alone air cleaners.Moreover,they suggest that optimal IAQ and energy conditions can be achieved if variable air volume control methods are used to maintain indoor temperature and humidity.

Critical Success Factors Influencing the Implementation of Sustainable Energy System in Uganda: A Case of Inter-University Council of East Africa Energy Project at the Head Quarters in Kampala, Uganda

The widespread usage of clean and sustainable energy sources is leading to a significant transformation of the world’s energy systems. Over-reliance on only the national grid energy system has made institutions fail to sustain energy systems. The council is only connected to the national grid electricity supply system, with diesel generators as the only alternative, which is unhealthy and unsafe. Surprisingly, even with such alternatives, power shortages have persisted despite government efforts to provide a solution to the shortages by installing numerous off-grid systems. Due to such a situation, the council would construct a sustainable energy system as a remedy. Thus, the purpose of this study was to establish critical success factors influencing the implementation of a sustainable energy system at the Inter-University Council of East Africa (IUCEA) Head Quarters, Kampala-Uganda. A cross-sectional survey design was used;a sample size of 84 participants was selected. Questionnaire survey and interview methods were utilized. The study found that the most significant (p < 0.05) critical factors in the implementation of sustainable energy in institutions are;the use of innovative technologies and infrastructure, the use of efficient zero emissions for heating and cooling, integration of renewable energy use in the existing buildings, building and renovating in an energy-efficient way, integrating regional energy systems, improving energy efficiency in the buildings, enhanced zero emission power technologies, energy efficient equipment in place and stakeholder empowerment in energy management. This study concludes that institutions like;the Inter-University Council of East Africa (IUCEA) need to clearly state policies and actions of energy management. The roles and responsibilities of each member have to be clearly stated while capturing the activities involved in energy conservation, energy security and energy efficiency.

Influence of Tilted Angle on Effective Linear Energy Transfer in Single Event Effect Tests for Integrated Circuits at 130 nm Technology Node

A heavy-ion irradiation experiment is studied in digital storage cells with different design approaches in 130 nm CMOS bulk Si and silicon-on-insulator(SOI) technologies. The effectiveness of linear energy transfer(LET) with a tilted ion beam at the 130 nm technology node is obtained. Tests of tilted angles θ=0°,30°and 60°with respect to the normal direction are performed under heav.y-ion Kr with certain power whose LET is about 40 MeVcm^2/mg at normal incidence. Error numbers in D flip-flop chains are used to determine their upset sensitivity at different incidence angles. It is indicated that the effective LETs for SOI and bulk Si are not exactly in inverse proportion to cosθ, furthermore the effective LET for SOI is more closely in inverse proportion to cos θ compared to bulk Si, which are also the well known behavior. It is interesting that, if we design the sample in the dual interlocked storage cell approach, the effective LET in bulk Si will look like inversely proportional to cos 0 very well, which is also specifically explained.

Electrically Tunable Energy Bandgap in Dual-Gated Ultra-Thin Black Phosphorus Field Effect Transistors

The energy bandgap is an intrinsic character of semiconductors, which largely determines their properties. The ability to continuously and reversibly tune the bandgap of a single device during real time operation is of great importance not only to device physics but also to technological applications. Here we demonstrate a widely tunable bandgap of few-layer black phosphorus(BP) by the application of vertical electric field in dual-gated BP field-effect transistors. A total bandgap reduction of 124 meV is observed when the electrical displacement field is increased from 0.10 V/nm to 0.83 V/nm. Our results suggest appealing potential for few-layer BP as a tunable bandgap material in infrared optoelectronics, thermoelectric power generation and thermal imaging.

Effect of Elastic Energy due to Atomic Size Factor on Ordering and Decomposition Behaviour of Binary Solid Solutions

A theory recently developed by the present authors is applied to the study of the effect of elastic energy due to atomic size factor on the transformation behaviour of binary solid solutions. lt is found that elastic interaction energy (EIE), which is a part of the total elastic energy plays a key role in both ordering elastic interaction ordering (EIO) and spinodal decomposition. The present study gives a reasonable explanation to the historical dilemmas, "elastic energy paradox" and "atomic size factor paradox . By solving these confusing problems, the coexistence of ordering (EIO) and decomposition, which has been regarded as impossible by conventional theories. can be well understood. The mechanism is as follows: lowering of elastic energy demands EIO, and such an ordering provides a driving force for spinodal decomposition. Therefore, in alloys with large atomic size factor, spinodal decomposition is preceded and induced by ordering. Ordering and spinodal decomposition are thus closely related processes to each

Energy pharmacological effects of chemical drugs

Background:To study the energy pharmacological effects of chemical drugs.Methods:The energy pharmacological effects of chemical drugs were studied using a literature induction method.Results:Chemical drugs have energy properties,which can be expressed in terms of cold,hot,warm,and cool.The energy properties of chemical drugs have energy pharmacological effects,which are related to the bond energy release and absorption of intermolecular chemical bonds,where the release of energy from chemical bonds indicates a warm-hot energy pharmacological effect and the absorption of energy indicates a cold energy pharmacological effect.The mechanisms of chemical drug energy may be related to the presence of temperature-sensitive ion channels in the body.Conclusion:Chemical drugs exhibit energy pharmacological effects.

Low-energy atomic displacement model of SRIM simulations

Radiation-induced atomic displacement damage is a pressing issue for materials.The present work investigates the number of atomic displacements using the Primary Knock-on Atom (PKA) energy E_(PKA)and threshold displacement energy E_(d)as two major parameters via lowenergy SRIM Binary Collision Approximation (BCA) full cascade simulations.It is found that the number of atomic displacements cannot be uniquely determined by E_(PKA)/E_(d )or E_(D) /E_(d)(E_(D) refers to the damage energy) when the energy is comparable with E_(d).The effective energy E_(D,eff)proposed in the present work allows to describing the number of atomic displacements for most presently studied monatomic materials by the unique variable E_(D,eff)/E_(d).Nevertheless,it is noteworthy that the BCA simulation damage energy depends on E_(d),whereas the currently used analytical method is independent of E_(d).A more accurate analytical damage energy function should be determined by including the dependence on E_(d).

Comparison of Energy Consumption of the 12 Classroom Typical School Buildings in Selected 4 City in Turkey

School is a special place where students come together to become productive individuals of society,acquire basic skills and acquire citizenship knowledge.With the introduction of the new education system(4+4+4)in Turkey in 2012-2013,some difficulties occurred in the spatial structure of the schools.After the new system,increasing number of students and decreasing student requirements have been tried to be solved with temporary solutions.At the same time that millions of students studying in primary schools all over Turkey have the same architectural feature as one type of architectural school project,regardless of the geographical and social situation began to be implemented in all parts of the city.Therefore,the increase in consumption varies depending on the geographical reasons where the type projects are implemented.Selected regions of the four thermal zones in Turkey for this research are provided below:1^st Thermal district in Antalya;2^nd Thermal district in Bursa;3^rd Thermal district in Elaz??;4^th Thermal district in Kars.The calculation of the energy consumption created by the above cities by means of BEP-TR program and comparing classes.

Effect of Electron Correlation and Breit Interaction on Energies, Oscillator Strengths, and Transition Rates for Low-Lying States of Helium

The transition energies, E1 transitional oscillator strengths of the spin-allowed as well as the spin-forbidden and the corresponding transition rates, and complete M1, E2, M2 forbidden transition rates for 1s^(2), 1s2s, and 1s2p states of He I, are investigated using the multi-configuration Dirac–Hartree–Fock method. In the subsequent relativistic configuration interaction computations, the Breit interaction and the QED effect are considered as perturbation, separately. Our transition energies, oscillator strengths, and transition rates are in good agreement with the experimental and other theoretical results. As a result, the QED effect is not important for helium atoms, however, the effect of the Breit interaction plays a significant role in the transition energies, the oscillator strengths and transition rates.

Direct energy rebound effect for road transportation in China

The enhancement of energy efficiency stands as the principal avenue for attaining energy conservation and emissions reduction objectives within the realm of road transportation.Nevertheless,it is imperative to acknowledge that these objectives may,in part or in entirety,be offset by the phenomenon known as the energy rebound effect(ERE).To quantify the long-term EREs and short-term EREs specific to China’s road transportation,this study employed panel cointegration and panel error correction models,accounting for asymmetric price effects.The findings reveal the following:The long-term EREs observed in road passenger transportation and road freight transportation range from 13%to 25%and 14%to 48%,respectively;in contrast,the short-term EREs in road passenger transportation and road freight transportation span from 36%to 41%and 3.9%to 32%,respectively.It is noteworthy that the EREs associated with road passenger transportation and road freight transportation represent a partial rebound effect,falling short of reaching the magnitude of a counterproductive backfire effect.This leads to the inference that the upsurge in energy consumption within the road transportation sector cannot be solely attributed to advancements in energy efficiency.Instead,various factors,including income levels,the scale of commodity trade,and industrial structure,exert more substantial facilitating influences.Furthermore,the escalation of fuel prices fails to dampen the demand for energy services,whether in the domain of road passenger transportation or road freight transportation.In light of these conclusions,recommendations are proffered for the formulation of energy efficiency policies pertinent to road transportation.

Considerations on the Unification of Quantum Physics with the General Theory of Relativity

From a holistic perspective of a physical space of any given size1, it is invariably necessary to consider its energy content, since no physical means exists of making a physical space completely devoid of energy. Such a space would therefore only be a fictive “geometric space”—that can be intellectually conceived and treated according to the rules of the appropriate geometry—although not existing in reality in the cosmos. Cosmic space always contains energy in one form or another, limited by the space under consideration. Therefore, each space possesses an energy density—no matter how low, which never becomes zero. Because of the mass-energy equivalence relationship , cosmic space also possesses a mass equivalent and is therefore “materialistic” in nature. If this is considered in association with Einstein’s space-time, what is obtained instead is an “energy-time”, i.e. an energy effect, which is based on Planck’s action quantum h. Under this condition, a close relationship would appear to exist between the General Theory of Relativity and Quantum Physics. Furthermore, it will be shown that the physical conditions of space are such that a natural quantisation of space and time exists, thus obviating the need for any artificial or arbitrary quantisation.

Effective Energy Density of Glass Rejuvenation

Glasses with rejuvenated structures usually exhibit improved room-temperature plasticity,which facilitates their applications.However,glass rejuvenation requires external energy injection to“shake up”the frozen-in disordered structure.In this work,we give the answer to how much the required energy is.According to the constitutive model of amorphous plasticity,we find that the applied stress higher than the steady-state flow value can effectively induce the structural disordering in terms of the generation of free volume.Therefore,the effective energy density(EED)of structural rejuvenation is defined as the integral of this effective stress on the corresponding strain.By tailoring the applied strain,strain rate,temperature and initial free volume,different degrees of structural rejuvenation are achieved,which show a generally linear correlation with the defined EED.This work deepens the understanding of glass rejuvenation from an energy perspective.

Energy rebound effect in China's manufacturing sector:Fresh evidence fromfirm-level data

The rebound effect refers to the phenomenon that individuals tend to consume more energy in the face of energy efficiency improvement,which reduces the expected energy-saving effect.Previous empirical studies on the rebound effect of regions and sectors do not provide microscopic evidence.To fill this gap,we use China's firmlevel data to estimate the rebound effect in China's manufacturing subsectors,providing a detailed picture of China's rebound effect across different sectors and different regions in 2001-2008.Results show that a partial rebound effect robustly appears in all industries,and the disparity between sectors is quite broad,ranging from 43.2%to 96.8%.As for the dynamic rebound effect of subsectors,most subsectors present an upward trend,whereas few subsectors show a clear downward trend.As a whole,the declined trend of the rebound effect is driven by the descent of minority sectors with high energy consumption and high energy-saving potential.In addition,we find that the disparity of the rebound effect across sectors is more significant than that across regions.

Surface and Nonlocal Effects on the Thermoelastic Damping in Axisymmetric Vibration of Circular Graphene Nanoresonators

In nanoresonators,thermoelastic damping(TED)is a primary energy dissipation mechanism.As a result,when designing nanoresonators,it is critical to limit this type of dissipation.This paper investigates the nonlocal TED of circular single-layered graphene sheet(SLGS)nanoresonators in axisymmetric out-of-plane vibration utilizing the generalized dual-phase-lag thermoelasticity theory.The nonlocal elasticity and Gurtin-Murdoch surface elasticity theories are employed to capture the small-scale and surface energy effects,respectively.By incorporating these effects into the model,the non-classical equations of the coupled thermoelastic problem are first obtained and then an analytical expression is introduced to predict TED in circular nanoplates.Moreover,the results obtained herein are validated by those of the classical continuum theory which can be found in the open literature.The influences of the aspect ratio,surface elastic modulus,surface residual stress and nonlocal parameter on TED of circular SLGS nanoresonators are investigated using numerical data.The calculated results show the significance of surface and nonlocal effects in nanoplate TED continuum modeling.

Achieving high thermoelectric performance through carrier concentration optimization and energy filtering in Cu_(3)SbSe_(4)-based materials

The previous works commonly adjust the carrier concentration through acceptor doping,but at the same time,the decrease of the Seebeck coefficient limits the further improvement of electrical properties in Cu_(3)SbSe_(4)-based materials.In this work,a microwave-assisted hydrothermal synthesis method was used to synthesize Cu_(3)SbSe_(4)/TiO_(2) hollow microspheres.Part of TiO_(2) participates in the reaction,replaces the Sb site of Cu_(3)SbSe_(4) to form holes,and the rest is dispersed in the matrix in the form of the second phase.The first-principles calculations reveal that the doping of Ti significantly changes the band structure and phonon spectrum,thereby regulating carrier concentration while increasing phonon scattering.In addition,experimental results show that the energy filtering effect generated by the extra-mixed TiO_(2) nano particles,which suppresses the decrease of Seebeck coefficient by acceptor doping.Consequently,the highest average power factor 897.5 mW m^(-1) K^(-2) and the zT peak value of 0.70 can be obtained in Cu_(3)SbSe_(4)/6%TiO_(2) sample at 298e623 K.This work provides a new sight to improve the thermoelectric properties in Cu_(3)SbSe_(4) through carrier concentration regulation and nano-phase composition.

A Stable and Energy-Efficient Routing Algorithm Based on Learning Automata Theory for MANET

The mobile Ad Hoc network(MANET)is a self-organizing and self-configuring wireless network,consisting of a set of mobile nodes.The design of efficient routing protocols for MANET has always been an active area of research.In existing routing algorithms,however,the current work does not scale well enough to ensure route stability when the mobility and distribution of nodes vary with time.In addition,each node in MANET has only limited initial energy,so energy conservation and balance must be taken into account.An efficient routing algorithm should not only be stable but also energy saving and balanced,within the dynamic network environment.To address the above problems,we propose a stable and energy-efficient routing algorithm,based on learning automata(LA)theory for MANET.First,we construct a new node stability measurement model and define an effective energy ratio function.On that basis,we give the node a weighted value,which is used as the iteration parameter for LA.Next,we construct an LA theory-based feedback mechanism for the MANET environment to optimize the selection of available routes and to prove the convergence of our algorithm.The experiments show that our proposed LA-based routing algorithm for MANET achieved the best performance in route survival time,energy consumption,energy balance,and acceptable per-formance in end-to-end delay and packet delivery ratio.

纳米结构和能带工程提高Bi-Sb-Te合金的热电性能

碲化铋由于其优异的性能,已成为商业上广泛使用的热电材料.然而,通过熔化方法获得的p型Bi-Sb-Te热电材料的性能仍有进一步改进的空间.在这项工作中,CsBr化合物被用来提高Bi_(0.42)Sb_(1.58)Te_(3)(BST)材料的热电性能.采用熔化法和放电等离子体烧结相结合的方法制备了BST+x wt%CsBr(x=0,0.10,0.20,0.30)的块状材料.Cs和Br共掺杂可以显著提高BST合金的电导率,同时降低其热导率,使其在323 K下的最大ZT值为1.2.对于x=0.20的样品,在400 K以下具有1.1的平均ZT.密度泛函理论和透射电子显微镜分析表明,Cs掺杂有效地减小了带隙,增加了费米能级附近的态密度,并使能带变平缓,从而使电输运特性得到了明显增强(最大功率因子接近3500μW mK^(-2)).此外,Cs掺杂可以使得Sb从晶格中脱离出来并与晶格中的游离氧结合形成纳米级Sb_(2)O_(3),使其能够有效地散射中频声子并降低热导率,同时保持相对较高的塞贝克系数.这项研究提出了一种新的方法,可以仅单独通过CsBr掺杂来解决热电材料中电导率和热导率之间的矛盾.

Low lattice thermal conductivity and enhanced thermoelectric performance of SnTe via chemical electroless plating of Ag

Interface engineering has been regarded as an effective strategy to manipulate the thermoelectric performance of materials.Here,we use a facile chemical electroless plating and a spark plasma sintering process to fabricate Ag-plated SnTe bulk.After sintering,a small amount of plated Ag can be doped into SnTe to suppress the Sn vacancies and the others form Ag precipitates with a size distribution from nanoscale to microscale,which introduces Ag/SnTe interfaces to enhance the Seebeck coefficient via energy filtering effect.Simultaneously,these structures result in strong scattering to reach a low lattice thermal conductivity of-0.62 W·m^(–1)·K^(–1).Consequently,a maximum figure of merit(zT)of-0.67 at 823 K is achieved in 2 wt%Ag-plated SnTe,which is-60%higher than that of pristine SnTe.Moreover,the microhardness indentation test results show that the mean microhardness of 2 wt%Ag-plated SnTe is HV 64.26,which is much higher than that of pristine SnTe,indicating that Ag electroless plating can improve the mechanical properties of SnTe.This work has provided a facile and eco-friendly method to realize the interface engineering for manipulating the thermoelectric and mechanical properties of SnTe.

High-power operation of double-pass pumped Nd:YVO4 thin disk laser

A simple,compact,double-pass pumped Nd:YVO4 thin disk laser is demonstrated.Its continuous-wave performance with different Nd doping concentrations and thicknesses is investigated experimentally.The maximum output power of 17.7 W is achieved by employing a 0.5 at.%doped sample,corresponding to an optical-to-optical efficiency of 46% with respect to the absorbed pump power.In addition,a numerical analysis and an experimental study of the temperature distribution,and thermal lens effect of the Nd:YVO4 thin disk,are presented considering the influence of the energy transfer upconversion effect and the temperature dependence of the thermal conductivity tensor.The simulated results are in good agreement with the experimental results.

Analysis of survival probability based on superasymmetric reaction systems

The survival probability of an excited compound nucleus was studied using two different approaches of the washing out of shell effects with excitation energy based on a superasymmetric reaction system.The estimated evaporation residue cross sections based on the two different methods are compared with the available experimental data.Both methods are in agreement with the experimental data to a certain extent for some specific reactions and emission channels.