Building stock dynamics and its impacts on materials and energy demand in China

China hosts a large amount of building stocks, which is nearly 50 billion square meters. Moreover, annual new construction is growing fast, representing half of the world's total. The trend is expected to continue through the year 2050. Impressive demand for new residential and commercial construction, relative shorter average building lifetime, and higher material intensities have driven massive domestic production of energy intensive building materials such as cement and steel. This paper developed a bottom-up building stock turnover model to project the growths, retrofits and retirements of China's residential and commercial building floor space from 2010 to 2050. It also applied typical material intensities and energy intensities to estimate building materials demand and energy consumed to produce these building materials. By conducting scenario analyses of building lifetime, it identified significant potentials of building materials and energy demand conservation. This study underscored the importance of addressing building material efficiency, improving building lifetime and quality, and promoting compact urban development to reduce energy and environment consequences in China

The effect of substituted benzene dicarboxylic acid linkers on the optical band gap energy and magnetic coupling in manganese trimer metal organic frameworks

We have systematically studied a series of eight metal-organic frameworks (MOFs) in which the secondary building unit is a manganese trimer cluster, and the linkers are differently substituted benzene dicarboxylic acids (BDC). The optical band gap energy of the compounds vary from 2.62 eV to 3.57 eV, and theoretical studies find that different functional groups result in new states in the conduction band, which lie in the gap and lower the optical band gap energy. The optical absorption between the filled Mn 3d states and the ligands is weak due to minimal overlap of the states, and the measured optical band gap energy is due to transitions on the BDC linker. The Mn atoms in the MOFs have local moments of 5 mu B, and selected MOFs are found to be antiferromagnetic, with weak coupling between the cluster units, and paramagnetic above 10 K

Atomic and electronic structure of neutral and charged SinOm clusters

Using molecular orbital approach and the generalized gradient approximation in the density functional theory, we have calculated the equilibrium geometries, binding energies, ionization potentials, and vertical and adiabatic electron affinities of SinOm clusters (n⩽6,m⩽12). The calculations were carried out using both Gaussian and numerical form for the atomic basis functions. Both procedures yield very similar results. The bonding in SinOm clusters is characterized by a significant charge transfer between the Si and O atoms and is stronger than in conventional semiconductor clusters. The bond distances are much less sensitive to cluster size than seen for metallic clusters. Similarly, calculated energy gaps between the highest occupied and lowest unoccupied molecular orbital (HOMO-LUMO) of (SiO2)n clusters increase with size while the reverse is the norm in most clusters. The HOMO-LUMO gap decreases as the oxygen content of a SinOm cluster is lowered eventually approaching the visible range. The photoluminescence and strong size dependence of optical properties of small silica clusters could thus be attributed to oxygen defects

Structure and stability of Con(pyridine)m − clusters: Absence of metal inserted structures

A synergistic approach combining the experimental photoelectron spectroscopy and theoretical electronic structure studies is used to probe the geometrical structure and the spin magnetic moment of Con(pyridine)−m clusters. It is predicted that the ground state of Co(pyridine)− is a structure where the Co atom is inserted in a CH bond. However, the insertion is marked by a barrier of 0.33eV that is not overcome under the existing experimental conditions resulting in the formation of a structure where Co occupies a site above the pyridine plane. For Co2(pyridine)−, a ground-state structure is predicted in which the Co2 diametric moiety is inserted in one of the CH bonds, but again because of a barrier, the structure which matches the photoelectron spectrum is a higher-energy isomer in which the Co2 moiety is bonded directly to nitrogen on the pyridine ring. In all cases, the Co sites have finite magnetic moments suggesting that the complexes may provide ways of making cluster-based magnetic materials

Executive Information System Penjualan Bahan Kimia

Kebutuhan informasi sekarang ini menjadi kebutuhan mutlak bagi suatu organisasi atau Perusahaan untuk memenangkan sebuah persaingan. Dimana informasi digunakan sebagai penunjang pembuat keputusan, sehingga dibutuhkan penyampaian informasi yang akurat dan cepat dalam mendapatkannya agar tidak kalah dari pesaingnya. Informasi tersebut berisi kondisi yang terjadi di dalam maupun di luar Perusahaan yang selanjutnya akan digunakan sebagai dasar untuk perencanaan strategis dan program kerja. Seiring dengan berkembangnya kebutuhan informasi khususnya untuk para executive guna pengambilan keputusan dan untuk mengetahui kondisi kinerja Perusahaan, maka berkembanglah sebuah sistem informasi yang disebut Executive Information System (EIS). Dengan EIS informasi dapat ditampilkan dalam bentuk secara ringkas dan menampilkan data sesuai dengan kebutuhan sehingga mempermudah seorang eksekutif dalam pengontrolan setiap saat. Proses penjualan yang berjalan saat ini masih menggunakan sistem yang manual yaitu masih menggunakan proses pencatatan data sehingga membutuhkan waktu yang lama untuk pembuatan laporan dan laporan yang dihasilkan datanya belum tentu akurat. Dengan permasalahan diatas maka dibutuhkan suatu sistem yang dapat membantu pekerjaan pegawai sehingga laporan yang dihasilkan bisa tepat pada waktunya dan data yang dihasilkan lebih akurat

Geometry, electronic structure, and energetics of copper-doped aluminum clusters

Using density functional theory and generalized gradient approximation for exchange-correlation potential, we have calculated the equilibrium geometries and energetics of neutral and negatively charged AlnCu (n=11,12,13,14) clusters. Unlike the alkali atom-doped aluminum clusters in the same size range, the copper atom resides inside the aluminum cluster cage. Furthermore, the 3d and 4s energy levels of Cu hybridize with the valence electrons of Al causing a redistribution of the molecular orbital energy levels of the Aln clusters. However, this redistribution does not affect the magic numbers of AlnCu clusters that could be derived by assuming that Cu donates one electron to the valence levels of Aln clusters. This behavior, brought about by the smaller size and large ionization potential of the copper atom, contributes to the anomalous properties of AlnCu− anions: Unlike AlnX− (X=alkali atom), the mass ion intensities of AlnCu− are similar to those of Al−n. The calculated adiabatic electron affinities are also in very good agreement with experiment

Electronic structure and chemical bonding of 3d-metal dimers ScX, X=Sc-Zn

The electronic and geometrical structures of the ground and excited states of the homonuclear Sc2, mixed ScTi, ScV, ScCr, ScMn, ScFe, ScCo, ScNi, ScCu, and ScZn 3d-metal dimers and their anions have been calculated using the density functional theory with generalized gradient approximation for the exchange-correlation potential. The ground states of the neutral dimers are found to be 5Σ−u (Sc2), 6Σ+ (ScTi), 7Σ+ (ScV), 4Σ+ (ScCr), 3Σ+ (ScMn), 2Δ(ScFe), 1Σ+ (ScCo), 2Σ+ (ScNi), 3Δ(ScCu), and 4Σ+ (ScZn). A natural bond analysis reveals an antiferrimagnetic spin coupling in the ground states of ScCr, ScMn, and ScFe. This is due to the electron transfer from Sc to the opposite atom and specific bond formations. While each dimer has a unique chemical bonding pattern, most curious is the localization of two 4s electrons at both atomic sites in the ground 5Σ−u state of Sc2, which leads to formation of two lone pairs and the bonding scheme: (3d+3d)3α(4s+4s)1β. No appreciable sd hybridization is found for the ground states of the ScX dimers except for ScNi. Even though the electron affinities of the ScX dimers are relatively low and do not exceed 1 eV, each ScX− (except ScCo−) possesses at least two states stable towards detachment of an extra electron

Optical constants of solid methane

Methane is the most abundant simple organic molecule in the outer solar system bodies. In addition to being a gaseous constituent of the atmospheres of the Jovian planets and Titan, it is present in the solid form as a constituent of icy surfaces such as those of Triton and Pluto, and as cloud condensate in the atmospheres of Titan, Uranus, and Neptune. It is expected in the liquid form as a constituent of the ocean of Titan. Cometary ices also contain solid methane. The optical constants for both solid and liquid phases of CH4 for a wide temperature range are needed for radiative transfer calculations, for studies of reflection from surfaces, and for modeling of emission in the far infrared and microwave regions. The astronomically important visual to near infrared measurements of solid methane optical constants are conspicuously absent from the literature. Preliminary results are presented on the optical constants of solid methane for the 0.4 to 2.6 micrometer region. Deposition onto a substrate at 10 K produces glassy (semi-amorphous) material. Annealing this material at approximately 33 K for approximately 1 hour results in a crystalline material as seen by sharper, more structured bands and negligible background extinction due to scattering. The constant k is reported for both the amorphous and the crystalline (annealed) states. Typical values (at absorption maxima) are in the .001 to .0001 range. Below lambda = 1.1 micrometers the bands are too weak to be detected by transmission through the films less than or equal to 215 micrometers in thickness, employed in the studies to date. Using previously measured values of the real part of the refractive index, n, of liquid methane at 110 K, n is computed for solid methane using the Lorentz-Lorenz relationship. Work is in progress to extend the measurements of optical constants n and k for liquid and solid to both shorter and longer wavelengths, eventually providing a complete optical constants database for condensed CH4