An Efficient and Accurate Building Optimization Strategy Using Singular Value Decomposition

Optimizing the life cycle cost of a building typically involves a large number of variables due to the many options that exist at the time that a building is being designed. Such large-scale optimization problems are often prohibitive within the building industry because of the excessive computational time required by the building energy modeling software; therefore, any optimization studies that are performed during a building design are typically only completed using a small number of variables. To achieve the goal of performing a full life cycle building optimization in an acceptable time frame, this paper proposes an accurate and efficient method using singular value decomposition on the design variables. Through the use of singular value decomposition a large number of design variables can be reduced to a smaller subset of design variables that can be solved more quickly by the optimization algorithm. In this paper the authors apply the singular value decomposition method to a case study of a typical residential building in six separate locations across the U.S. and compare the results with those of the full optimization process over the entire design space

A Tool for Generating Reduced-Order Models from Building Energy Simulation Input Files to Enable Optimal Design and Control Analysis

Representing multi-zone building envelope systems with linear time invariant state-space forms provides a way of applying various advanced control methodologies for better design and control of buildings. For example, system properties such as time constant and frequency response of building envelopes can be easily investigated with the help of control toolkits such as Matlab/Simulink and a reduced-order model can be developed by applying a model order reduction technique, once a reliable LTI building representation is developed. However, in order to make the LTI representation approach useful for industry, an interfacing tool that automatically extracts building system information from input files of popular building energy simulation (BES) tools and constructs a physical thermal network from the data is needed. This paper presents a conceptual strategy to interpret object (class) of a building energy simulation software and a methodology to develop a high fidelity LTI thermal network model. A case study applying this approach is provided which utilizes a model-order reduction method that converts a BES building envelope model for a multi-zone building into a reduced-order LTI model (ROM). Comparisons of predicted building load profiles and computation times between the BES model and ROM are also provided

Cytosolic calcium regulates cytoplasmic accumulation of TDP-43 through Calpain-A and Importin alpha 3

Cytoplasmic accumulation of TDP-43 in motor neurons is the most prominent pathological feature in amyotrophic lateral sclerosis (ALS). A feedback cycle between nucleocytoplasmic transport (NCT) defect and TDP-43 aggregation was shown to contribute to accumulation of TDP-43 in the cytoplasm. However, little is known about cellular factors that can control the activity of NCT, thereby affecting TDP-43 accumulation in the cytoplasm. Here, we identified via FRAP and optogenetics cytosolic calcium as a key cellular factor controlling NCT of TDP-43. Dynamic and reversible changes in TDP-43 localization were observed in Drosophila sensory neurons during development. Genetic and immunohistochemical analyses identified the cytosolic calcium-Calpain-A-Importin α3 pathway as a regulatory mechanism underlying NCT of TDP-43. In C9orf72 ALS fly models, upregulation of the pathway activity by increasing cytosolic calcium reduced cytoplasmic accumulation of TDP-43 and mitigated behavioral defects. Together, these results suggest the calcium-Calpain-A-Importin α3 pathway as a potential therapeutic target of ALS. © Park et al.1

2D TMD Channel Transistors with ZnO Nanowire Gate for Extended Nonvolatile Memory Applications

© 2020 Wiley-VCH GmbH 2D transition metal dichalcogenides (TMDs) have been extensively studied due to their excellent physical properties. Mixed dimensional devices including 2D materials have also been studied, motivated by the possibility of any synergy effect from unique structures. However, only few such studies have been conducted. Here, semiconducting 1D ZnO nanowires are used as thin gate material to support 2D TMD field effect transistors (FETs) and 2D stack-based interface trap nonvolatile memory. For the trap memory, deep level electron traps formed at the first MoS2/second MoS(2)stack interface are exploited, since the first MoS(2)is treated in an atomic layer deposition chamber for a short while. On the one hand, a complementary inverter type memory device can also be achieved using a long single ZnO wire as a common gate to simultaneously support both n- and p-channel TMD FETs. In addition, it is found that the semiconducting ZnO nanowire itself operates as an n-type channel when the TMD materials can become a top-gate to charge the ZnO channel. It means that 2D (bottom gated) and 1D channel (top gated) FETs are respectively operational in a single device structure. The 1D-2D mixed devices seem deserving broad attention in both aspects of novelty and functionality11sciescopu

2D TMD Channel Transistors with ZnO Nanowire Gate for Extended Nonvolatile Memory Applications

© 2020 Wiley-VCH GmbH 2D transition metal dichalcogenides (TMDs) have been extensively studied due to their excellent physical properties. Mixed dimensional devices including 2D materials have also been studied, motivated by the possibility of any synergy effect from unique structures. However, only few such studies have been conducted. Here, semiconducting 1D ZnO nanowires are used as thin gate material to support 2D TMD field effect transistors (FETs) and 2D stack-based interface trap nonvolatile memory. For the trap memory, deep level electron traps formed at the first MoS2/second MoS(2)stack interface are exploited, since the first MoS(2)is treated in an atomic layer deposition chamber for a short while. On the one hand, a complementary inverter type memory device can also be achieved using a long single ZnO wire as a common gate to simultaneously support both n- and p-channel TMD FETs. In addition, it is found that the semiconducting ZnO nanowire itself operates as an n-type channel when the TMD materials can become a top-gate to charge the ZnO channel. It means that 2D (bottom gated) and 1D channel (top gated) FETs are respectively operational in a single device structure. The 1D-2D mixed devices seem deserving broad attention in both aspects of novelty and functionality11sciescopu

Ambipolar Nonvolatile Memory Behavior and Reversible Type-Conversion in MoSe2/MoSe2 Transistors with Modified Stack Interface

2D semiconductor devices have been studied due to their unique potential in architecture and properties. As one of the unique devices approaches, 2D hetero-stack channel field-effect transistors (FETs) have recently been reported, but homo-stack FETs are rare to find. Here, MoSe2/MoSe2 homo-stack transistors are rather fabricated for study. Unlike the equivalently-thick single MoSe2 FET, homo-stack FETs show n-type memory behavior that originates from stack interface-induced traps. Particularly, when their stack interfaces are engineered by surface oxidation of bottom MoSe2, more stable nonvolatile memory behavior turns out. Short-term ultraviolet ozone (UVO)-induced oxidation only results in n-type memory, but 15 min-long oxidation surprisingly enables both n- and p-type nonvolatile memory behavior due to nm-thin MoOx embedded between upper and lower MoSe2. Furthermore, by alternating gate voltage pulse to the 15 min-long UVO-treated FETs, channel polarity conversion appears reversible in a small gate voltage (V-GS) sweep range, which means that the channel type of a transistor can be reversibly modulated via stack interface engineering. It is believed that homo-stack interface engineering must be one of the approaches to maximize the potential of 2D devices.11Nsciescopu

Dramatic Reduction of Contact Resistance via Ultrathin LiF in Two-Dimensional MoS2 Field Effect Transistors

Molybdenum disulfide (MoS2) has been regarded as one of the most important n-type two-dimensional (2D) transition metal dichalcogenide semiconductors for nanoscale electron devices. Relatively high contact resistance (RC) remains as an issue in the 2D-devices yet to be resolved. Reliable technique is very compelling to practically produce low RC values in device electronics, although scientific approaches have been made to obtain a record-low RC. To resolve this practical issue, we here use thermal-evaporated ultrathin LiF between channel and source/drain metal to fabricate 2D-like MoS2 field effect transistors (FETs) with minimum RC. Under 4-bar FET method, RC less than similar to 600 Omega.mu m is achieved from the LiF/Au contact MoS2 FET. Our normal 2-bar FET with LiF thus shows the same mobility as that of 4-bar FET that should have no RC in principle. On the basis of these results, ultrathin LiF is also applied for transparent conducting oxide contact, successfully enabling transparent MoS2 FETs.11Nsciescopu

Comparison of the air change per hour measured over four seasons in the residential buildings of the urban, rural, and industrial areas of South Korea: K-IOP Study

Air infiltration, calcuated by air changes per hour (ACH) is a key factor in assessing the potential amount of air borne pollutants moving from outdoor into indoor spaces. We measured the natural ACH through fall, winter, spring, and summer (2 weeks/season), in 81 nonsmoking elderly houses located in urban (n = 29), industrial (n = 26) and rural (n = 26) areas from 2021 to 2022 consecutively. Indoor CO2 data measured at dawn (01:00 to 05:00 a.m.) over four season was used to estimate the ACH. Moreover, morning ACHs were also calculated from the CO2 level monitored in the morning, when the levels were dropped significantly with opening a window during fall, winter, and spring. The ACH at dawn over the four seasons ranged from 0.02 to 0.03,while that in the morning with opening a window was 0.2 to 0.3. Our multivariate regression models demonstrated that the difference in CO2 concentration during dawn was positively associated with the ACH change after adjusting for seasonality. In addition, after controlling for the study area, ACH was approximately 50 % higher during summer than during the other seasons (p < 0.05). This study elucidates the seasonal and regional distributions of ACH; a determination of these patterns may further contribute to future simulation or prediction studies assessing the associations among indoor air quality, activity patterns and ventilation practices among Korean elderly population

Origin of White Electroluminescence in Graphene Quantum Dots Embedded Host/Guest Polymer Light Emitting Diodes

Polymer light emitting diodes (PLEDs) using quantum dots (QDs) as emissive materials have received much attention as promising components for next-generation displays. Despite their outstanding properties, toxic and hazardous nature of QDs is a serious impediment to their use in future eco-friendly opto-electronic device applications. Owing to the desires to develop new types of nano-material without health and environmental effects but with strong opto-electrical properties similar to QDs, graphene quantum dots (GQDs) have attracted great interest as promising luminophores. However, the origin of electroluminescence from GQDs incorporated PLEDs is unclear. Herein, we synthesized graphene oxide quantum dots (GOQDs) using a modified hydrothermal deoxidization method and characterized the PLED performance using GOQDs blended poly(N-vinyl carbazole) (PVK) as emissive layer. Simple device structure was used to reveal the origin of EL by excluding the contribution of and contamination from other layers. The energy transfer and interaction between the PVK host and GOQDs guest were investigated using steady-state PL, time-correlated single photon counting (TCSPC) and density functional theory (DFT) calculations. Experiments revealed that white EL emission from the PLED originated from the hybridized GOQD-PVK complex emission with the contributions from the individual GOQDs and PVK emissions