Microorganisms baroinactivation of germinated mung bean (green gram) seeds

It is possible to describe the pressure degradation of microorganisms as being analogous to thermal inactivation. Equation for baroinactivation is derived from thermal death time (TDT) model D _p = D _pref 10^{(pref-p)/z _p} , where D _pref is decimal reduction time at the reference pressure (min), p _ref is the reference pressure (MPa), z _p is the pressure increase (MPa) required to reduce the D _p value by a factor of 10. This method was used for the calculation of baroinactivation model parameters of the total number of microorganisms of pressurized germinated mung bean (green gram) seeds (Vigna radiata (L.) Wilczek). Microbial contamination of germinated mung bean (green gram) seeds can be effectively decreased by treatment at a high pressure of 400 MPa, time of pressurization 5 min.     

Inorganic chemistry under high pressure

Abstract

In inorganic chemistry High Pressures can act as thermodynamic parameter and through the compression effect. Such effects can help the synthesis of new materials or induce specific properties. Such High Pressures studies are a great help for a better understanding of the chemical bonding and in field of resarches aimed at applications.     

Passive automatic exposure mechanism

In this paper, we will propose a passive automatic exposure mechanism. Different from general automatic exposure mechanism, the passive exposure mechanism directly searches suitable exposure images through the content of images. As exposure is one of the main factors to successfully take pictures, how to find an accurate exposure value is an important issue. Passive automatic exposure is the new trend and key issue of image processing. We will experiment and prove that the method we propose is effective.     

Development of superparamagnetic high-magnetization C18-functionalized magnetic silica nanoparticles as sorbents for enrichment and determination of methylprednisolone in rat plasma by high performance liquid chromatography

In this study, a novel extraction and enrichment technique based on superparamagnetic high-magnetization C₁₈-functionalized magnetic silica nanoparticles (C₁₈-MNPs) as sorbents was successfully developed for the determination of methylprednisolone (MP) in rat plasma by high performance liquid chromatography (HPLC). The synthesized silica-coated magnetite modified with chlorodimethyl-n-octadecylsilane was about 320 nm in diameter with strong magnetism and high surface area. It provided an efficient way for extraction and concentration of MP in the samples through hydrophobic interaction by the interior C₁₈ groups. Moreover, MP adsorbed with C₁₈-MNPs could be simply and rapidly isolated through placing a strong magnet on the bottom of container, and then easily eluted from C₁₈-MNPs by n-hexane solution. Extraction conditions such as amounts of C₁₈-MNPs added, adsorption time and desorption solvent, were investigated. Method validations including linear range, detection limit, precision, and recovery were also studied. The results showed that the proposed method based on C₁₈-MNPs was a simple, accurate and high efficient approach for the analysis of MP in the complex plasma samples.     

Development of novel backwash cleaning technique for reverse osmosis in reclamation of secondary effluent

The objective of the study was to further develop a novel cleaning technique for reverse osmosis in reclamation of municipal secondary effluent. This technique is a new backwash method via direct osmosis (DO) by intermittent injection of the high salinity (HS) solution without stopping of high pressure pump and it is environment and membrane friendly technique. In the study, DO-HS trials were carried out with a UF-RO pilot system which was operated on site with the secondary treated effluent as the raw feed. Different operating conditions for DO-HS treatment in the actual process were investigated. It was found that the operation for implementation of the DO-HS cleaning technique developed was easy. For the first time, the actual profiles of HS concentration, DO backwash flow rate, brine flow rate and permeate pressure during DO-HS treatment have been demonstrated. It was observed that turbidity of the brine stream during DO-HS treatment at 3 NTU was 5 times higher than that before DO-HS treatment. The results from this study have confirmed the previous hypothesis with DO-HS treatment that there would be a strong driving force for DO backwash to lift and sweep the foulants from the membrane surface which would be carried over to the brine. The optimal plant operating conditions in terms of RO feed flow rate, HS concentration and HS injection time are ready for the DO-HS method to be adopted and validated in a long-term continuous plant operation.     

On-line combination of single-drop liquid–liquid–liquid microextraction with capillary electrophoresis for sample cleanup and preconcentration: A simple and efficient approach to determining trace analyte in real matrices

In order to improve the sensitivity of capillary electrophoresis (CE) and overcome the deficiency of commercial CE instruments in handling complex matrices directly, we proposed a novel technique which combined single-drop liquid–liquid–liquid microextraction (SD-LLLME) with CE on-line. In this technique, SD-LLLME was realized using a commercial CE instrument and, to further concentrate the target analyte, large-volume sample stacking combined sweeping without polarity switching was utilized. Even though without agitating the donor phase in the extraction process, the model compound, adenine was enriched 550-fold in only 10 min. The enrichment factors were 760 and 1030 when the extraction time was extended to 30 and 60 min, respectively. The relative standard deviations (RSDs) of adenine were 5.24% and 2.29% for peak area and migration time, respectively, which indicated that this method was much more reproducible compared to the existing methods that combined sample-preparation strategies with CE. In addition, this approach was selective while cleaning up target analyte. These mentioned advantages allowed the developed method to be an attractive approach to determining trace target compounds in complex real samples.     

High‐Pressure Synthesis,Crystal Structure,and Properties of GdS2 with Thermodynamic Investigations in the Phase Diagram Gd–S

Gadolinium disulfide was prepared by high‐pressure synthesis at 8 GPa and 1173 K. It crystallizes in the monoclinic space group P12₁/a1 (No. 14) with lattice parameters a = 7.879(1) Å; b = 3.936(1) Å, c = 7.926(1) Å and β = 90.08(1)°. The crystal structure is a twofold superstructure of the aristotype ZrSSi and consists of puckered cationic [GdS]⁺ double slabs that are sandwiched by planar sulfur sheets containing S₂^2– dumbbells. The thermal decomposition of GdS₂ proceeds via the sulfur‐deficient polysulfides GdS_1.9, GdS_1.85 and GdS_1.77 and eventually results in the sesquisulfide Gd₂S₃. GdS₂ is a paramagnetic semiconductor which orders antiferromagnetically at T_N = 7.7(1) K. A metamagnetic transition is observed in the magnetically ordered state.     

Molecularly imprinted macroporous monolithic materials for protein recognition

Synthetic materials that can specifically recognize proteins will find wide application in many fields.In this report,bovine serum albumin was chosen as the template protein.Acrylamide and N,N’-methylenebisacrylamide were employed as the functional and cross-linker monomers,respectively.Molecularly imprinted macroporous monolithic materials that can preferentially bind the template protein in an aqueous environment were prepared by combination of molecular imprinting technique and freezing/thawing preparation method.The resulted imprinted macroporous monolithic columns were evaluated by utilizing as stationary phase in high performance liquid chromatography and solid-phase extraction materials.The experimental results indicated that the imprinted macroporous monolithic column exhibited good recognition for template protein,as compared with the control protein(hemoglobin),whereas the non-imprinted polymer(prepared under the same conditions except without addition template protein) had no selective properties.     

两个极限的注记

利用数值积分方法给出了波利亚的名著中两个极问题的证明,并给出了两个结论更强的结果.     

Pressure induced phase transformations and band structure of different high pressure phases in tellurium

We report here high-pressure x-ray diffraction (XRD) studies on tellurium (Te) at room temperature up to 40 GPa in the diamond anvil cell (DAC). The XRD measurements clearly indicate a sequence of pressure-induced phase transitions with increasing pressure. The data obtained in the pressure range 1 bar to 40 GPa fit five different crystalline phases out of Te: hexagonal Te (I) → monoclinic Te(II) → orthorhombic Te (III) → Β-Po-type Te(IV) → body-centered-cubic Te(V) at 4, 6.2, 11 and 27 GPa, respectively. The volume changes across these transitions are 10%, 1.5%, 0.3% and 0.5%, respectively. Self consistent electronic band structure calculations both for ambient and high pressure phases have been carried out using the tight binding linear muffin tin orbital (TB-LMTO) method within the atomic-sphere approximation (ASA). Reported here apart from the energy band calculations are the density of states (DOS), Fermi energy (E _f) at various high-pressure phases. Our calculations show that the ambient pressure hexagonal phase has a band gap of 0.42 eV whereas high-pressure phases are found to be metallic. We also found that the pressure induced semiconducting to metallic transition occurs at about 4 GPa which corresponds to the hexagonal phase to monoclinic phase transition. Equation of state and bulk modulus of different high-pressure phases have also been discussed.